JP2013174094A - Ground improvement construction machine suitable for construction in narrow place and ground improvement method - Google Patents

Abstract

An object of the present invention is to provide a small ground improvement construction machine suitable for ground improvement work to prevent liquefaction in a narrow residential area subject to various restrictions on the construction space, and a grid-like ground improvement wall using the construction machine at low cost. Providing ground improvement method for construction.
A rotary drive unit is driven while a rotary drive unit and rotary power devices are lifted by a fixed stroke by a lift drive unit and a rotary drive unit, and a drive shaft is fixed and supported by the rotary drive unit. 6 is moved downward, and the ground improvement process of mechanical agitation method by excavating the ground and injecting the solidified slurry is advanced downward. When the elevating drive unit 41 is lowered to the lower limit position, the rotation drive unit 6 fixes the drive shaft 5.・ Ground improvement process in which the support is released once, the rotation drive unit 6 is lifted by a fixed stroke, the drive shaft 5 is fixed and supported by the rotation drive unit 6 again in the ascending position, and the rotation drive unit 6 is lowered while being driven to rotate. Repeat steps to the target depth.
[Selection] Figure 1

Description

  The present invention is a ground improvement work for the purpose of preventing liquefaction, particularly in a narrow place that is near or close to an existing house (especially a detached house) or a residential area subject to various restrictions on the construction space. A grid-like ground in which a ground improvement body that is continuous in a wall shape is formed in a closed shape such as a rectangle in plan view, or the ground in the closed shape is further partitioned vertically and horizontally by a ground improvement wall The present invention belongs to the technical field of a small ground improvement construction machine suitable for construction for constructing an improved wall and a ground improvement construction method for constructing a grid-like ground improvement wall at low cost using the ground improvement construction machine.

Examining the damage caused by the Great East Japan Earthquake in March last year, the importance of implementing measures to prevent liquefaction of residential land or the foundation of houses was strongly recognized in order to prevent or reduce damage in detached houses as well. ing.
As a liquefaction prevention treatment for sandy ground with a high water content that is likely to cause liquefaction, for example, as proposed in the patent inventions according to the following Patent Documents 1 and 2, the ground improvement body has a wall shape in plan view. It is effective to construct a grid-like ground improvement wall that is constructed in a closed shape such as a rectangle that is continuous with the wall, or in which the internal ground surrounded by the wall of the closed shape is further divided vertically and horizontally by a ground improvement wall. It has been demonstrated and is highly reliable among those skilled in the art.
As conventional ground improvement construction machines, for example, various construction machines disclosed in Patent Documents 3 to 5 below are well known and well known.
Such ground improvement construction machines can be broadly classified into injection-stirring construction machines that implement the high-pressure spraying construction method and construction machines that implement the mechanical stirring construction method that injects cement-based solidification material (slurry) and stirs the excavated soil. Are known.
However, in the case of the high-pressure injection method using the above-mentioned jet-stirring construction machine, the minimum working space of the construction machine is relatively small with a width of 2m to 7m and a height of 3m to 7m, but the amount of mud generated during construction is improved. The amount is as large as 100% of the volume, and the treatment is difficult, and the construction cost is as high as 23,000 to 300,000 yen / m ³ . Moreover, construction speed is as slow as 48-100 m < ³ > / day.
On the other hand, in the case of a construction machine that implements a mechanical stirring method using a construction machine that injects and stirs the solidifying material slurry, the construction cost is 3000 to 40000 yen / m ³ and the amount of mud is small. However, the minimum working space of the construction machine is very large with a width of 2.5 m to 3.0 m and a height of 6 m to 50 m. Construction speed is as fast as 50 to 1200 m ³ / day.
Therefore, in the construction of ground improvement work for the purpose of preventing liquefaction in a confined area near the existing house (detached house) or in a residential area subject to various restrictions on the construction space, the jet agitation method is used. In many cases, the implementation of the high-pressure injection method using construction machines is considered.
However, the existing grid-like ground improvement work is designed to deepen the ground improvement wall until it penetrates the underground liquefied layer and reaches the non-liquefied layer below it. It extends to 10m. Therefore, in the construction machine of the jet stirring method, when the liquefied layer is thick, the construction cost becomes more expensive and the construction period is prolonged, so that it is difficult to adopt.

Japanese Examined Patent Publication No. 4-54004 Japanese Patent No. 2568115 (JP-A-2-132220) JP-A-56-153013 JP-A-7-150545 JP 2009-293359 A

In order to carry out ground improvement work for the purpose of preventing liquefaction of residential areas and residential foundations where the construction space is a confined place or a nearby place near the existing house (detached house) in the residential area, or the construction space is variously restricted. First, it must be possible to carry the ground improvement construction machine into the above-mentioned narrow place or residential land and to proceed with the installation.
Specifically, it is desired to develop a construction machine that is compact so that it can be constructed even under conditions where the boundary between adjacent houses is limited to 1.5 m and the height of the eaves is 3 m.
Therefore, it is desirable that the minimum working space of the construction machine is a small machine having a width of 1.5 m or less and a height of 2.5 m or less. As a model, it is desired to implement a mechanical stirring method using a slurry stirring type construction machine at a low construction cost and a high construction speed.
A ground improvement body that is continuous in the shape of a wall is formed into a closed shape wall such as a rectangle in plan view, or the internal ground surrounded by the closed shape wall is further partitioned into a lattice shape in the vertical and horizontal directions by the ground improvement wall. In order to efficiently construct the grid-like ground improvement wall, a multi-axis construction machine having two or more axes is desired.
And in order to improve the liquefaction prevention performance of the ground, it is possible to achieve excavation penetration accuracy that can ensure the lap size of the ground improvement body that is continuous in a wall shape sufficiently accurately, and the ground improvement wall that is created can be regarded as a single wall shape It must be possible to ensure water stopping performance.
Furthermore, the biaxial or multi-axis type ground improvement construction machine is required to exhibit the mobility that freely moves along the ground improvement wall to be created even in a narrow place that is spatially limited.

However, a ground improvement wall that has a closed shape such as a rectangle in a plan view in a narrow place is continuously formed into a single-wall structure, and the internal ground surrounded by the closed shape wall is latticed vertically and horizontally. The ground improvement construction machine that is suitable for constructing the ground improvement wall divided into shapes with good mobility should not exist at present, and it is extremely difficult to implement ground improvement work for narrow residential land or housing foundation It is.
Therefore, the object of the present invention is to construct a narrow residential land that is in the vicinity of or close to an existing house (detached house) in a residential area, or for ground improvement work for the purpose of preventing the liquefaction of a residential foundation, especially in plan view The ground improvement wall can be continuously formed into a single-wall structure, and it is also suitable for creating a ground improvement wall that partitions the internal ground surrounded by the closed shape wall into a lattice shape in the vertical and horizontal directions. It is to provide a ground improvement construction machine that is excellent in mobility, high in construction speed, low in construction cost, and easy to use.
The next object of the present invention is not to exclude the case of a single axis, but it is preferably a multi-axis type configuration having two or more axes with good construction efficiency, and suitable for carrying in and installing in a narrow residential land. It is the structure of this and is providing the ground improvement construction machine which has the function and structure suitable for the construction in the vicinity of an existing house (detached house), or the vicinity position, and can implement construction with few setup changes.
A further object of the present invention is that the vertical accuracy of the ground improvement body to be created is high, excellent in the accuracy of securing the lap dimension between adjacent ground improvement bodies, excellent in the integrity and water stop structure as the ground improvement wall, The purpose of the present invention is to provide a small ground improvement construction machine that can perform ground improvement work that is excellent in the effect of preventing liquefaction of the ground.

  The ultimate object of the present invention is to use a small ground improvement construction machine as described above to prevent liquefaction prevention in narrow residential areas or residential areas with limited spaces and residential foundations, and to improve ground in a closed shape in plan view. The ground can be constructed in a single-wall structure continuously, and the grid-shaped ground improvement wall that partitions the internal ground surrounded by the closed wall in the vertical and horizontal directions efficiently and in a short period of time and at low cost. It is to provide an improved construction method.

As a means for solving the above-described problems of the prior art, a ground improvement construction machine suitable for construction in a narrow place according to the invention described in claim 1,
An elevating guide frame 3 standing in a vertical direction is provided on a movable table 2 that is movable in the horizontal direction, elevating drive units 31 and 41 that move up and down along the elevating guide frame 3 are installed, and the elevating drive is performed. The part 41 is provided with a rotational drive unit 6 having a shaft hole 6a having a center hole structure that allows the drive shaft 5 to pass through in the vertical direction, and rotational power devices 7 and 8 that rotate the rotational drive unit 6.
At least a ground excavation blade 10 and a stirring blade 12 are attached to the lower end portion of the drive shaft 5 that is passed through the shaft hole 6a of the rotational drive portion 6,
The lift drive units 31 and 41 raise the rotation drive unit 6 and the rotary power devices 7 and 8 by a certain stroke, and the rotation drive unit 6 fixes and supports the drive shaft 5 to rotate and drive the rotation drive unit 6 down. Operate and proceed with the ground improvement process of mechanical agitation method by excavating the ground and injecting solidified material slurry, and when the elevating drive unit 41 is lowered to the lower limit position, the rotation drive unit 6 fixes and supports the drive shaft 5 The target is a ground improvement process step in which the rotary drive unit 6 is lifted by a fixed stroke, and once again released, the drive shaft 5 is fixed and supported by the rotary drive unit 6 again at the raised position, and the rotary drive unit 6 is moved downward while being rotated. It is the structure which advances repeatedly to the depth, It is characterized by the above-mentioned.

The ground improvement construction machine suitable for construction in a narrow place according to the invention described in claim 2,
An elevating guide frame 3 standing in the vertical direction is provided on a movable table 2 that can move in the horizontal direction, and elevating the elevating table 4 that moves up and down in the vertical direction along the elevating guide frame 3 to move up and down as a parallel movement in a horizontal posture. Drive units 31 and 41 are provided in the vertical direction along the lifting guide frame 3,
Rotation power units 7 and 8 for rotating the rotary drive unit 6 are installed in the vertical direction with a rotary drive unit 6 provided with a shaft hole 6a having a center hole structure through which the drive shaft 5 passes. Is also installed,
At least a ground improvement excavation blade 10 and a stirring blade 12 are attached to the lower end portion of the drive shaft 5 that is passed through the shaft hole 6a of the rotation drive unit 6 on the lifting platform 4,
The lift 4 is lifted by a certain stroke by the lift drives 31 and 41, the drive shaft 5 is fixed and supported by the rotary drive 6, and the lift 4 is lowered while being driven to rotate, thereby excavating the ground and slurry. When the ground improvement process of mechanical agitation method by injection is proceeded downward and the lifting platform (or lifting drive unit) is lowered to the lower limit position, the fixing / supporting of the drive shaft 5 by the rotary drive unit 6 is once released and the lifting platform 4 is released. Is lifted by a certain stroke by the lift drive units 31 and 41, and the drive shaft 5 is fixed and supported again by the rotary drive unit 6 at the lifted position, and the lift platform 4 is moved downward while rotating and driving the ground improvement process step to the target depth. It is the structure which advances repeatedly until.

The invention described in claim 3 is a ground improvement construction machine suitable for construction in a narrow place described in claim 1 or 2,
The movable table 2 that is movable in the horizontal direction is horizontally applied to at least two parallel rails 1 and 1 previously laid horizontally on the ground of the construction site along the construction position and construction direction of the ground improvement body. The movable table 2 is moved along the rail 1 to advance the construction of the ground improvement body, and the rail 1 is a pile driven into the ground, or into the ground. It is characterized by obtaining a reaction force at the time of excavation penetration of the ground improvement construction machine and a reaction force necessary for preventing overturning by a fixing tool such as a screw pile screwed in.

The invention described in claim 4 is a ground improvement construction machine suitable for construction in a narrow place described in any one of claims 1 to 3,
A ground improvement excavation blade 10 and a stabilizer 11 and a stirring blade 12 positioned immediately above are attached to a lower end portion of the drive shaft 5 that is passed through the shaft hole 6a of the rotation drive unit 6, and the stabilizer 11 includes the excavation blade. The frame material 11a arranged in the diameter line direction of the excavation hole 14 excavated by 10 is attached to the drive shaft 5 so as not to rotate together and immovable in the axial direction.
A displacement restraining plate 11b having a circular arc shape equal to the curvature in the circumferential direction of the excavation hole is attached to a position at the tip portion of the frame member 11a and in contact with the inner wall surface of the excavation hole 14 excavated by the excavation blade 10. The corner portion 11c protruding from the outer surface of the displacement suppression plate 11b is configured to bite into the hole wall soil of the excavation hole 14.

The invention described in claim 5 is a ground improvement construction machine suitable for construction in a narrow place described in claim 1 or 4,
Rotation provided with at least two lifting guide frames 3 on the movable table 2 and having a shaft hole 6a through which the driving shaft 5 passes in the vertical direction to the lifting drive units 31 and 41 passing through the lifting guide frames 3 and 3. A drive unit 6 and rotational power devices 7 and 8 for rotating the rotation drive unit 6 are installed,
The at least two stabilizers 11 positioned immediately above the excavation blades 10 for ground improvement work attached to the lower end portions of at least two drive shafts 5 and 5 penetrated into the shaft holes 6a of the respective rotary drive units 6 are provided. The shaft member 18 of the inter-shaft fixing bracket 11d connecting the drive shafts 5 and 5 is arranged perpendicular to the inter-shaft fixing bracket 11d, and along the diameter line passing through the center of the drive shaft 5, respectively. Is provided,
Displacement restraining plate 11b having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole 14 at a position that is in contact with the inner wall of the excavation hole 14 excavated by the excavation blade 10 at the tip portion of each frame member 11a. Is attached, and the corner portion 11 c protruding from the outer surface of the displacement restraining plate 11 b is configured to bite into the hole wall soil of the excavation hole 14.

The invention described in claim 6 is a ground improvement construction machine suitable for construction in a narrow place described in claim 2 or 4,
At least two rotary drive units 6 having shaft holes 6a through which the drive shafts 5 pass in the vertical direction are installed on the lifting platform 4, and rotary power devices 7 and 8 that rotate the rotary drive units 6 are also installed. And
The at least two stabilizers 11 positioned immediately above the excavation blades 10 for ground improvement work attached to the lower end portions of at least two drive shafts 5 and 5 penetrated into the shaft holes 6a of the respective rotary drive units 6 are provided. The shaft member 18 of the inter-shaft fixing bracket 11d connecting the drive shafts 5 and 5 is arranged perpendicular to the inter-shaft fixing bracket 11d, and along the diameter line passing through the center of the drive shaft 5, respectively. Is provided,
A displacement restraining plate 11b having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole is located at the tip portion of each frame member 11a and in contact with the inner wall surface of the excavation hole 14 excavated by the excavation blade 10. It is attached, The corner | angular part 11c protruded from the outer surface of the said displacement suppression board 11b is set as the structure which bites into the hole wall soil of the excavation hole 14. It is characterized by the above-mentioned.

The invention described in claim 7 is a ground improvement construction machine suitable for construction in a narrow place described in claim 5 or 6,
A stabilizer 11 located immediately above the excavation blade 10 for ground improvement work attached to the lower end portions of at least two drive shafts 5, 5 penetrating through the shaft holes 6 a of at least two rotary drive portions 6, 6. The at least two drive shafts 5 and 5 are connected to each other by the shaft fixing bracket 11d and the frame member 11a arranged in the diameter line direction of the excavation hole 14 in at least two stages in the vertical direction of the drive shaft 5. And
Displacement forming an arc surface shape equal to the circumferential curvature of the excavation hole 14 at a position that is in contact with the inner surface of the excavation hole 14 excavated by the excavation blade 10 at the tip end of the upper and lower frame members 11a and 11a. The restraint plate 11b is attached to an arrangement in which the upper and lower two-stage frame members 11a and 11a are connected in the vertical direction, and the corner portion 11c protruding from the outer surface of the displacement restraint plate 11b is a hole of the excavation hole 14 It is characterized by being configured to bite into the wall soil.

The invention described in claim 8 is a ground improvement construction machine suitable for construction in a narrow place described in claim 7,
The stabilizer 11 attached to the lower end portion of the drive shaft 5 penetrated through the shaft hole 6a of the rotation drive unit 6 rotates together with the drive shaft 5 to an intermediate portion between the shaft cylinder 18 and the frame member 11b arranged in two upper and lower stages. A feature is that the stirring blades 12 are installed.

The invention described in claim 9 is a ground improvement construction method implemented using a ground improvement construction machine suitable for construction in a narrow place according to the invention described in claim 1 or 3-8,
A stage 2 on which a main part excluding the rail 1 is mounted in a ground improvement construction machine is suspended in a horizontal state by a small crane or supported in a horizontal state by a forklift and is carried into a construction site.
On the ground surface of the construction site, at least two rails 1 and 1 are laid in parallel along the construction position and construction direction of the ground improvement body, and the movable table 2 is placed on the rails 1 and 1 on the rail 1. Placing it in a movable state along the top,
The drive shaft 5 is passed through the shaft hole 6a of the rotation drive unit 6 installed in the elevation drive unit 41 that moves up and down in the vertical direction along the elevation guide frame 3 installed on the moving table 2, and the lower end of the drive shaft 5 Attaching at least the ground improvement excavation blade 10 and the stirring blade 12 to the section;
Moving the movable table 2 to a position where the center of the drive shaft 5 passed through the rotary drive unit 6 coincides with the construction position of the ground improvement body, and positioning and fixing the movable table 2;
While raising and lowering the lift drive units 31 and 41 by a certain stroke, the drive shaft 5 is fixed and supported by the rotary drive unit 6 at the raised position, and the rotary drive unit 6 is driven to rotate by the rotary power devices 7 and 8, A step of lowering the lifting drive unit 41 to excavate the ground, and injecting the solidified material slurry and stirring the ground downward,
When the elevating drive unit 41 is lowered to the lower limit position, the slurry injection is temporarily stopped, the fixing / supporting of the drive shaft 5 by the rotary drive unit 6 is released, the elevating drive unit 41 is lifted by a certain stroke, and the rotary drive unit is again at the raised position. 6, the drive shaft 5 is fixed and supported, and the lift drive unit 41 is moved downward while being driven to rotate, excavating the ground, and the ground improvement process step of injecting and stirring the slurry is repeated by a certain stroke to the target depth. The stage of creating ground improvement bodies,
When the creation of the ground improvement body is completed, the ascending / descending drive unit 41 is repeatedly raised and lowered while the drive shaft 5 is rotated in the reverse direction to bring the drive shaft 5 and the ground improvement excavation blade 10 and the stirring blade 12 to the ground. The stage of raising to
Thereafter, the moving platform 2 is moved horizontally on the rail 1 to the next-ranked ground improvement body construction position, and the construction of the next-ranked ground improvement body is advanced in the same procedure as described above.

The invention described in claim 10 is a ground improvement construction method implemented using a ground improvement construction machine suitable for construction in a narrow place according to the invention described in claims 2 to 8,
The stage 2 of the ground improvement construction machine carrying the main part excluding the rail 1 is suspended in a horizontal state by a small crane or is supported in a horizontal state by a forklift and is carried into the construction site;
At least two rails 1 and 1 are laid in parallel along the construction direction of the ground improvement body at the construction position on the ground surface of the construction site, and the movable table 2 is placed on the rails 1 and 1 on the rail 1. Placing it in a movable state along the top,
The drive shaft 5 is passed through the shaft hole 6a of the rotation drive unit 6 on the lifting platform 4 installed on the moving table 2, and at least the ground excavation blade 10 and the stirring blade 12 are attached to the lower end of the drive shaft 5. Stages,
Moving the movable table 2 to a position where the center of the drive shaft 5 passed through the rotary drive unit 6 coincides with the construction position of the ground improvement body, and positioning and fixing the movable table 2;
The elevator 4 is lifted by a certain stroke by the lift drive units 31 and 41, and the drive shaft 5 is fixed and supported by the rotary drive unit 6 at the lifted position, and the rotary drive unit 6 is rotated by the rotary power devices 7 and 8. While driving, the step of lowering the elevating platform 4 by the elevating drive units 31 and 41 excavating the ground and injecting the solidified material slurry and stirring the step of proceeding downward,
When the elevator 4 is lowered to the lower limit position, the slurry injection is temporarily stopped, the fixing / support of the drive shaft 5 by the rotary drive unit 6 is released, the elevator 4 is lifted by a certain stroke, and the rotary drive unit 6 again at the raised position. While the drive shaft 5 is fixed and supported, the lift 4 is moved downward while being driven to rotate, the ground is excavated, the slurry is injected and stirred, and the ground improvement process step is repeated for each predetermined stroke to reach the target depth. The stage of promoting the creation of
When the creation of the ground improvement body is completed, the drive shaft 5 and the ground improvement excavation blades 10 and the stirring blades 12 at the lower end thereof are moved to the ground by repeating the ascending and descending operations of the lifting platform 4 that reversely rotates the drive shaft 5 The stage of raising,
Thereafter, the moving platform 2 is moved horizontally on the rail 1 to the next-ranked ground improvement body construction position, and the construction of the next-ranked ground improvement body is advanced in the same procedure as described above.

The invention described in claim 11 is the ground improvement method according to the invention described in claim 9 or 10,
The drive shaft 5 uses unit material cut to a unit length that is not constrained in the construction space, and according to the progress of the ground improvement process, the unit material is sequentially added by the shaft joint to advance the ground improvement process and achieve the construction depth. To do,
Prior to the moving step of the moving table 2 in the ground improvement construction process, the rail 1 on which the moving table 2 is mounted and horizontally moved is made of a unit material cut to a unit length that is not restricted in the construction space. The unit material is preliminarily laid on the ground surface along the construction position and construction direction of the ground improvement body, and the construction of the ground improvement body is advanced.

The invention described in claim 12 is the ground improvement method according to the invention described in claim 9 or 10,
The operation of passing the drive shaft 5 through the shaft hole 6a of the rotation drive unit 6 and attaching at least the ground improvement excavation blade 10 and the stirring blade 12 to the lower end portion of the drive shaft 5 is performed by suspending the movable platform 2 with a small crane, Alternatively, prior to the step of placing on the rail 1 supported by a forklift, the moving table 2 is temporarily placed on a temporary placing stand prepared in the vicinity, or the moving table 2 is placed on the rail 1. After that, the preparation groove 13 is excavated in advance in the ground on which the ground improvement body is to be constructed.

The ground improvement construction machine according to the present invention has a construction in which the main equipment of the construction machine is assembled (stacked) on a movable table 2 that is movable in the horizontal direction. The movable table 2 is a tire wheel or endless running on the ground. It is not equipped with a rail belt (so-called Caterpillar = registered trademark) or the like, and is configured to move on the rail 1 separately laid on the ground, and the existing vertical penetration structure as a support and push-in penetration mechanism for the drive shaft 5 Without adopting, the rotary drive unit of the drive shaft 5 directly to the lift drive unit 41 that moves up and down along the lift guide frame 3 standing vertically on the movable table 2 or to the lift table 4 attached to the lift drive unit 41 6 is configured to advance the ground improvement process by mechanical stirring by excavating the ground and injecting solidified material slurry by the lifting operation of the lifting drive unit 41 and the rotational drive of the drive shaft 5 by the rotational drive unit 6. Behind the construction machine Of the conditions within the height 2.5m is the minimum working space of the target can be easily achieved.
Similarly, regarding the width dimension which is the condition of the minimum work space, since the tire wheel or the endless rail is not equipped, the target width dimension of 1.5 m or less can be easily achieved. Therefore, it is possible to provide a small machine suitable for ground improvement construction in a narrow place (residential area or the like) that is in the vicinity or near the existing detached house.

  Since the ground improvement construction machine according to the present invention is configured such that the moving base 2 moves horizontally on the rail 1 previously laid along the construction position and construction direction of the ground improvement body on the ground of the construction site, even in a narrow place It exhibits good maneuverability that enables efficient and efficient construction of ground improvement bodies arranged in parallel in the vertical direction. Therefore, it contributes to carrying out ground improvement work with excellent construction speed and good construction efficiency at a low cost in a short construction period.

Since the ground improvement construction machine according to the inventions described in claims 5 to 7 is based on a multi-axial configuration of at least two axes or three axes or more, two or two or more ground improvement bodies (hereinafter simply referred to as a simple structure) It may be abbreviated as an improved body.) It is suitable for construction to create a wall shape that continues in parallel in the ground. And the lap dimension between adjacent improvement bodies can be ensured and integrated accurately, and the ground improvement wall excellent in water stop performance can be constructed efficiently.
That is, according to the ground improvement construction machine of the present invention, the stabilizer 11 positioned immediately above the ground improvement excavation blade 10 attached to the lower end portion of the drive shaft 5 is the excavation blade as in the inventions described in claims 4 to 8. 10 is attached to the tip of the frame member 11a disposed in the diameter line direction of the excavation hole 14 excavated at 10 and touches the inner surface of the hole wall of the excavation hole 14, and protrudes from the outer surface of the displacement suppression plate 11b. Since the corner portion 11c is configured to bite into the hole wall soil of the excavation hole 14, the resistance that the excavation blade 10 receives when excavating the ground, or the hard part of the improved body that has been created in advance, or conversely the soft part. It is difficult to cause displacement and core blur due to the difference in force.
This is because the corner portions 11c located at both ends of the frame member 11a arranged in the diameter line direction of the excavation hole 14 dig into the hole wall soil and receive strong support from the ground. Prevents displacement and core blurring in the same direction (same direction as the wall body created = in-plane direction).
Rather, according to the configuration of the biaxial type or the multiaxial type of two or more axes shown in FIG. 4, the inter-axis fixing bracket 11d is compared with the single-axis type that does not use the inter-axis fixing bracket 11d. Since the effect and the effect of preventing displacement in the same direction as the wall (= in-plane direction) and core blurring are exhibited, the configuration is such that displacement and core blurring are unlikely to occur.
Also, as shown in FIG. 4, according to the configuration provided with the arc-shaped displacement restraining plates 11b located at both ends of the frame member 11a and in contact with the hole wall inner surface of the excavation hole 14, the contact pressure (surface Pressure) and the displacement restraining plate 11b strongly prevents the displacement and core blurring in the same diameter line direction as the frame member 11a (direction perpendicular to the formed wall = out-of-plane direction) within the range of the arc angle. Play.
Therefore, each of the driving shaft 5 and the excavating blade 10 attached to the tip thereof has an action and an effect of preventing the displacement and the core blurring when viewed in the horizontal two-dimensional direction (360 degrees in all directions) by the stabilizer 11. It can be expected and can achieve construction with high vertical penetration accuracy.
As a result, it is possible to accurately secure and integrate the lap dimensions between the ground improvement bodies to be created, and to reliably implement the construction of the ground improvement wall in a single wall state having excellent water stop performance. As a result, construction of a ground improvement wall closed in a rectangular shape with a large liquefaction prevention effect, and a grid-like ground improvement wall obtained by partitioning the ground in the rectangular wall with vertical and horizontal ground improvement walls, It is possible to construct a single wall with excellent performance, and it is possible to implement ground improvement construction with a large liquefaction prevention effect.

Next, according to the ground improvement construction method according to claims 9 to 12, which uses the ground improvement construction machine according to the invention described in claims 1 to 8, the main improvement except the rail 1 among the ground improvement construction machines. The structural part can be carried to the site by hanging it with a small crane or by supporting it horizontally with a forklift etc., so even if the road width to be used is narrow, if there is a road width of about 2 m at least, It is easy to carry into a construction site such as a small residential area surrounded by buildings (detached houses, etc.), and it is possible to perform ground improvement work in a narrow place.
On the other hand, on the ground surface of the construction site, at least two rails 1 and 1 are laid in parallel along the construction position and construction direction of the ground improvement body, and the moving table 2 is mounted on the rail 1. The ground improvement construction machine is ready for construction (use) by placing it on the rail 1 so as to be movable.
In this case, as a step before placing the movable table 2 on the rail 1 or as a step after placing, the drive shaft 5 is passed through the shaft hole 6a of the rotary drive unit 6, and the drive shaft 5 At least a ground excavation blade 10 and a stirring blade 12 are attached to the lower end of the ground.
And the upper part of the drive shaft 5 is grabbed and fixed and supported by the rotation drive unit 6, while the rotation drive unit 6 is driven to rotate by the rotary power devices 7 and 8, and is moved downward by the elevating drive unit 41. The ground improvement body can be created up to the target depth by repeating the ground improvement step of excavating and injecting cement-based solidified material (slurry) and stirring with the excavated soil by a certain downward stroke.
Further, when the formation of the ground improvement body is achieved to a predetermined depth, the rotary drive unit 6 is raised while the drive shaft 5 is rotated in the reverse direction, and the ground improvement excavation blade 10 and the stirring blade 12 or the stabilizer 11 at the lower end of the drive shaft are provided. Pull up to the ground position. Then, the moving platform 2 is moved forward on the rail 1 by a distance of one construction section, positioned and fixed to the construction position of the next-stage ground improvement body, and the construction procedure of the ground improvement body is again advanced in the same procedure as described above. Thus, ground improvement bodies can be created in parallel in the ground. In addition, the ground improvement wall that is continuous in the shape of a single wall is closed to a closed shape such as a rectangle in plan view, or the ground in the closed shape is further partitioned by vertical and horizontal ground improvement walls to move the ground. It can be constructed inexpensively in a short construction period.
In particular, as shown in FIG. 6A, the ground improvement wall can be easily constructed even at a position close to a neighboring house 50 in a narrow residential area.
Incidentally, according to the calculation of the ground improvement method, the construction cost can achieve the target of 20000 yen / m ³ or less.

In addition, even if the work site is subject to space restrictions due to the height of the eaves of existing houses, overhead wires, trees, etc., the ground improvement construction machine can have a ground height of within 2.5 m and a width of about 1.5 m. Construction in a narrow or space-constrained place can be carried out without hindrance. Moreover, although the usual excavation construction depth is designed to be around 10 m, if the length of the drive shaft 5 is 10 m, the construction can be carried out at once. When the space is subject to spatial restrictions, the above-mentioned space restriction can be avoided by using a unit material with a drive shaft 5 having a unit length of, for example, about 5 m, and adding two to it. It is possible to carry out construction of ground improvement bodies that extend in depth.
Similarly, the length of the rail 1 on which the movable table 2 is placed and travels horizontally is also prepared by unit length material cut to a length that is not restricted in the construction space. Prior to laying the unit material along the construction direction of the ground improvement body on the ground surface at the construction position in advance, the ground improvement work in a narrow place or a place subject to spatial constraints is carried out efficiently and inexpensively. it can.

It is the perspective view which showed conceptually Example 1 of the ground improvement construction machine by this invention. It is a top view of the ground improvement construction machine shown in the said FIG. It is a front view of the ground improvement construction machine shown in the said FIG. It is a side view of the ground improvement construction machine shown in the said FIG. Fig. A is an elevational view showing an embodiment of excavation blades, stabilizers and stirring blades attached to the drive shaft of the ground improvement construction machine, and Fig. B is a view in the direction of arrow b indicated in Fig. A. It is the top view which showed the planar structure of the stabilizer in case the drive shaft of FIG. 3 is a structure of 2 axes | shafts. FIG. A is an elevation view showing a second embodiment of the excavation blade, the stabilizer, and the stirring blade attached to the drive shaft of the ground improvement construction machine, and FIG. B is a cross-sectional view taken in the direction indicated by the arrow b in FIG. . AC is operation | movement explanatory drawing which showed the progress step of the ground improvement construction by the said ground improvement construction machine in order. It is the side view which showed Example 2 of the ground improvement construction machine by this invention from the same viewpoint as the said FIG. 2B.

The ground improvement construction machine suitable for construction in a narrow place according to the present invention is provided with a lifting guide frame 3 standing in a vertical direction on a movable table 2 movable in a horizontal direction.
A shaft hole through which the drive shaft 5 penetrates in the vertical direction directly on the moving table 2 to the lifting drive unit 41 that moves up and down along the lifting guide frame 3 or to the lifting table 4 attached to the lifting drive unit 41. The rotational drive unit 6 provided with 6a is installed, and the rotational power devices 7 and 8 of the rotational drive unit 6 are also installed.
The drive shaft 5 is passed through the shaft hole 6 a of the rotational drive unit 6, and at least the ground improvement excavation blade 10 and the stirring blade 12 are attached to the lower end portion of the drive shaft 5.
The drive shaft 5 is grabbed and fixed and supported by the rotary drive unit 6 and the lift drive units 31 and 41 are moved down by a certain stroke while being driven to rotate, and the ground is excavated, and solidified slurry is injected to machine. Advance the ground improvement process of the type stirring method downward.
When the elevating drive unit 41 is lowered to the lower limit position, the fixing and supporting of the drive shaft 5 by the rotation drive unit 6 is once released, the elevating drive unit 41 is raised by a certain stroke, and the drive shaft 5 is again driven by the rotation drive unit 6 at the raised position. The ground improvement process step of lowering the lifting and lowering drive unit 41 while rotating and driving is repeated, and the ground improvement construction to the target depth is advanced.

The ground improvement construction method implemented using the ground improvement construction machine according to the present invention is that the main structural portion of the ground improvement construction machine excluding the rail 1 is hung the movable platform 2 by a small crane or by a forklift or the like. Bring it to the construction site with a horizontal support.
On the other hand, on the ground surface at the construction site, at least two rails 1 and 1 are laid in parallel along the construction position and construction direction of the ground improvement body, and the above-mentioned movable table 2 is placed on the rail 1. It is placed in a movable state along the rail 1.
The drive shaft 5 is passed through the shaft hole 6 a of the rotation drive unit 6 on the moving table 2, and at least the ground excavation blade 10 and the stirring blade 12 are attached to the lower end portion of the drive shaft 5. And the center of the rotational drive part 6 and the drive shaft 5 is made to correspond with the construction position of a ground improvement body, and the positioning of the movable stand 2 is performed to the position.

Then, the rotary drive unit 31, 41 raises the rotational drive unit 6 by a certain stroke, and the rotary drive unit 6 grips and fixes and supports the drive shaft 5 at the raised position. Then, the rotary drive unit 6 is rotated by the rotary power devices 7 and 8 and is moved downward by the elevating drive units 31 and 41, thereby excavating the ground with the excavating blade 10 and injecting the solidified slurry. Proceed downward in the ground improvement process that agitates the excavated soil.
When the elevating drive unit 41 is lowered to the lower limit position, the slurry injection is temporarily stopped, the fixing / supporting of the drive shaft 5 by the rotary drive unit 6 is released, and the elevating drive unit 41 is raised by a certain stroke. The drive shaft 5 is fixed and supported by the rotational drive unit 6 again at the ascending position, and the rotational drive unit 6 is moved downward while excavating the ground by injecting the solidified material slurry and stirring with the excavated soil. Repeat the improvement process steps to advance the ground improvement body to the target depth.
When the formation of the ground improvement body is achieved to a predetermined depth, the operation of raising or lowering the rotational drive unit 6 while rotating the drive shaft 5 in reverse is repeated, and the ground improvement excavation blade 10 and the stirring blade at the lower end of the drive shaft are repeated. Raise 12 to the ground position.
After that, the moving platform 2 is horizontally moved to the next-ranked ground improvement body construction position, and the ground improvement construction is advanced again in the same procedure as described above at the next-ranked ground improvement body construction position.

Hereinafter, the present invention will be described based on illustrated embodiments.
First, Example 1 of the ground improvement construction machine shown in FIG. 1 and FIG. 2 is a short planographic movement that can be moved in the horizontal direction for the purpose of a compact configuration suitable for construction in a narrow place. The base 2 is adopted as the machine base. This movable table 2 has a width (vertical / horizontal dimensions) that can assemble each component of the construction machine described below, and is configured to have strength and rigidity that can withstand such loading loads. Yes. However, the form of the movable table 2 is not limited to the illustrated example.
On the other hand, the moving table 2 is placed on two (but not limited to) two rails 1 and 1 laid along the construction position and direction of the ground improvement body wall on the ground surface of the construction site. It is configured to be movable along the rails 1 and 1. For the rail 1, for example, I-shaped steel or H-shaped steel is used.
In other words, the present invention avoids the use of tire wheels and endless rails (so-called Caterpillar (registered trademark)) that occupy a large proportion of the height and width in order to reduce the height and width of the construction machine as small as possible. It is a configuration.
Of course, when there are few spatial constraints on the construction site and the height and width are not limited, or the degree is small, tire wheels and endless rails are used to support the moving platform 2. I would like to remind you that it is not an idea to eliminate the implementation of the ground improvement construction machine with the above configuration.

There are various and various means and mechanisms for mounting the movable table 2 on the rails 1 and 1 and configured to be movable along the rails 1 and 1. In the case of the illustrated example, small-diameter flanged wheels 2 a (tracking wheels) that roll on the rail 1 are installed at the four corner positions of the moving table 2. However, the present invention can also be similarly implemented by a sliding mechanism that uses a bearing roller that does not use the wheel and that has a low rolling resistance, or a sliding mechanism that uses a low-resistance sliding material.
At the four corner positions of the moving table 2, for example, a vertical jack 2b such as a hydraulic type, and a mechanical type (screw type or the like) for determining the horizontal level obtained by the vertical jack 2b are used for leveling the moving table 2. Jacks 2d are installed as a pair. Further, the movable base 2 moved on the rail 1 is positioned and fixed exactly at the construction position, and the upper flange of the rail 1 is grasped as a positioning means for obtaining the reaction force against the lifting at the time of excavation through the rail 1 to the ground. A jack-shaped fixture 2 c (clamp tool) is also installed on the movable table 2. The fixture 2c (clamp) is implemented by a manual type or a hydraulic type.

Elevating guide frames 3 and 3 having a flat plate structure that are symmetrically arranged and juxtaposed in the vertical direction are provided at both side positions of the upper surface central portion of the moving table 2 described above. The upper ends of the two lifting guide frames 3 and 3 are integrally joined by a horizontal connecting beam 30 to ensure the rigidity and vertical accuracy of the lifting guide frames 3 and 3.
However, only one lifting guide frame 3 is installed on one side of the movable table 2 depending on the spatial restriction conditions or the construction mode received by the ground improvement construction machine, and the lifting table 4 described later is cantilevered. It can also be implemented in a configuration that is supported in a form or a configuration in which a total of four lifting guide frames 3 are installed on four sides along two other different sides.
In the case of the first embodiment, a rectangular parallelepiped shape is formed as a lightweight and high-rigidity hollow frame frame structure at a position between the elevating guide frames 3 and 3 arranged side by side on the movable table 2 as described above. The lifting platform 4 configured as described above is placed in a stacked state. However, the form and structure of the lifting platform 4 are not limited to the illustrated example. The lifting platform 4 is configured to be moved up and down by lifting drive units 31 and 41 installed in the vertical direction along a rail-shaped lifting guide (not easily visible in the drawing) formed on the lifting guide frame 3.
In the illustrated embodiment, a configuration example in which a hydraulic cylinder mechanism is employed for the lift drive units 31 and 41 is shown. That is, the upper end of the rod 31 is fixed to the lifting guide frame 3, the lifting platform 4 is attached to the cylinder body 41, and the lifting platform 4 moves up and down together with the cylinder body 41 that moves up and down along the lifting guide formed on the lifting guide frame 3. A working configuration is shown. However, the lifting drive unit is not limited to the above configuration. A mechanism in which the lifting platform 4 is raised and lowered together with a chain that circulates in the vertical direction using the lifting guide frame 3, or a rack is formed on the lifting guide frame 3, a pinion is installed on the lifting platform, and the lift is driven by rotating the pinion. The structure etc. which raise / lower the raising / lowering stand 4 by applying the mechanism etc. which make it possible can also be implemented.
In addition, although it is difficult to see in the description of the drawings, the moving table 2 having the above-described configuration is in a position directly below the stacking position of the lifting table 4 and is smaller than the outer dimension of the moving table 2 in plan view. The cavity 20 having a shape and size that does not hinder the vertical axis is provided so as to penetrate in the vertical direction, and a drive shaft, which will be described later, can be penetrated in the vertical direction.

On the other hand, the lifting platform 4 configured in the above-described hollow frame structure is provided with a shaft hole 6a having a center hole structure that allows the drive shaft 5 to pass through in the vertical direction at a central portion as viewed in plan as shown in FIG. In the example shown in the figure, the two rotary drive units 6 and 6 are arranged side by side in the same direction as the longitudinal direction of the rail 1, and the lower part penetrates the lifting platform 4 and is opened directly below. It is installed so as to face the empty space 20 of the table 2.
However, the rotational drive unit 6 may be implemented as a single-axis type in which only one unit is installed, or may be similarly implemented as a multi-axis type in which three or more units are provided. In the hollow portion of the shaft hole 6a provided in the center hole type structure of the rotation drive unit 6, the drive shaft 5 penetrated is grasped and rotated integrally, or the drive shaft 5 is released and the drive shaft 5 is released. It is configured to have a built-in gripping tool such as a clamp-type structure that forms a gap that does not hinder the operation of moving up and down in the vertical direction, and is configured to allow the drive shaft 5 to penetrate and to be rotated. Has been.
Incidentally, in consideration of the structure in which the drive shaft 5 is grasped and rotated integrally, and the ease of the means, the planar shape of the shaft hole 6a of the rotation drive unit 6 is configured as a hexagon in the embodiment shown in FIG. 2A. doing. However, the horizontal cross-sectional shape (plan view) of the shaft hole 6a and the drive shaft 5 can also be implemented as a quadrangle or a polygon. The drive shaft 5 has a hollow structure in which a slurry injection pipe is incorporated in order to supply and inject a cement-based solidified material (slurry).

Next, rotational power devices 7 and 8 for synchronously rotating the two rotational drive units 6 and 6 in the opposite rotational directions at the same speed are also installed on the lifting platform 4.
Although the detailed illustration of the configuration of the rotary power devices 7 and 8 is omitted, a synchronous rotation mechanism in which the same number of synchronous gears are attached to and engaged with the rotation driving units 6 and 6 is adopted. The above-mentioned synchronizing gears are individually driven to rotate by the rotary power devices 7 and 8. Incidentally, the rotational power devices 7 and 8 are configured by a hydraulic motor as an example, and are configured to switch a rotational torque and a rotational speed by combining two-speed hydraulic motors having different capacities. However, an electric motor can be similarly employed as a power source.
Although not shown, the hydraulic pressure generating unit for supplying the hydraulic pressure as a power source to the rotary power devices 7 and 8 is installed at a position near the construction site as a separate structure from the ground improvement construction machine. The rotational power units 7 and 8 are connected by hydraulic hoses. And the operation | movement of the ground improvement construction by the said construction machine is controlled through the wired or wireless controller which the driver | operator which is not shown in figure has. Of course, when using an electric motor as a power source, a receiving / transforming facility will be installed.

By the way, an important concern in the ground improvement work by this kind of ground improvement construction machine is the excavation mechanism portion attached to the lower end portion of the drive shaft 5, that is, the ground improvement excavation blade 10 and the stabilizer 11 (however, the single shaft type (In case of non-rotating blade) and agitating blade 12, excavation penetration accuracy when excavating the ground with the agitating blade 12 and injecting solidified material slurry to mechanically agitate the excavated soil and slurry to advance the ground improvement body downward How to secure or enhance. If drilling penetration accuracy is poor and the accuracy of the lap dimension between the ground improvement bodies created is poor, the continuity of the ground improvement body walls, that is, the water stop performance will be poor, and the plan view is closed with a rectangular shape. This is because even if it is applied to a continuous wall structure having a shape, it results in poor liquefaction prevention performance.
Therefore, as means for increasing the excavation penetration accuracy, the present invention has been made to improve the excavation penetration accuracy by improving the stabilizer 11 (or the non-rotating blade) to the configuration illustrated in FIG. 3 or FIG.

First, in the embodiment of the excavation stirring mechanism shown in FIGS. 3A and 3B, the shafts 17 of the stirring blades 12 and 12 arranged in two stages on the lower end of the drive shaft 5 are concentric by fitting shaft couplings. Connected to the state. A stabilizer 11 (with a structure that is rotatable with respect to the stirring blade shaft 17 is provided below the stirring blade shaft 17 via a rotating shaft cylinder 18 that is supported vertically by thrust receiving plates 15 and 15 in the axial direction. Or a non-rotating blade).
FIG. 4 shows a configuration example of a stabilizer 11 in which the drive shaft 5 is applied to a two-shaft type with two more specifically. The stabilizer 11 located immediately above the excavation blade 10 for ground improvement work attached to the lower ends of the two drive shafts 5 and 5 includes a rotary shaft cylinder 18 that rotatably supports the two drive shafts 5 and 5. The drive shaft 5 is constrained by being connected by the inter-shaft fixing bracket 11d. The two left and right rotating shaft cylinders 18, 18 pass through the center of the drive shaft 5 and are oriented at right angles to the inter-axis fixing bracket 11 d and to the diameter line of the excavation hole 14 excavated by the excavating blade 10. Frame members 11a are respectively installed along the arrangement.
Next, an arc surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is formed at a position that is in contact with the inner surface of the hole wall of the excavation hole 14 excavated by the excavation blade 10 at the tip of each frame member 11a, 11a. A displacement suppression plate 11b is attached. And the corner | angular part 11c protruded from the outer surface of the said displacement suppression board 11b is set as the structure which bites into the hole wall soil of the excavation hole 14, for example about 10 cm. As shown in FIG. 3B, the corner portion 11c is formed in a plate shape that is elongated in the vertical direction of the excavation hole 14 (see FIG. 3B), and bites into the hole wall soil of the excavation hole 14 to prevent displacement and core shake described later. Therefore, it is configured to generate sufficient earth pressure resistance.

With the above-described configuration, the stabilizer 11 is installed in a state where it does not rotate together with the excavation blade 10 and the stirring blade 12.
Then, the shaft 16 of the excavating blade 10 is concentrically connected to the lower end portion of the agitating blade shaft 17 by a fitting-type shaft coupling, thereby forming the excavating and agitating mechanism portion of FIG. 3A).
According to the stabilizer 11 configured as described above, the drive shaft is caused by the difference in excavation resistance force that the excavation blade 10 receives when excavating the hard portion or the soft portion of the ground as the drive shaft 5 rotates. 5 and the excavating blade 10 are kept in a restrained state in which the inter-shaft fixing bracket 11d connects the two drive shafts 5 and 5 via the rotating shaft cylinder 18 even under conditions that are likely to cause displacement or core blurring. Therefore, basically, displacement and core blurring of the drive shaft 5 hardly occur.
Moreover, in the embodiment shown in FIGS. 3 and 4, the displacement restraining plate 11b having an arc surface shape equal to the curvature of the circumferential direction of the excavation hole 14 is provided. Resist by surface pressure (earth pressure) (stabilizer function). Accordingly, at least in the range of the arc angle of the displacement suppression plate 11b, misalignment and displacement in the longitudinal direction of the frame member 11a (the out-of-plane direction of the formed wall body) are reliably prevented.
On the other hand, with respect to displacement in the direction orthogonal to the longitudinal direction of the frame member 11a (same direction as the inter-axis fixing bracket 11d) and core blurring, the corner portion 11c protruding from the outer surface of the displacement restraining plate 11b is an excavation hole. 14 is blocked by the action of digging deeply into the pore wall soil and resisting by receiving earth pressure.
As described above, the stabilizer 11 having the configuration shown in FIG. 3 is effective when the drive shaft 5 is implemented as a “non-rotating blade” having only one drive shaft 5 and no inter-shaft fixing bracket 11d. As a result, core blurring and displacement in the orthogonal two-dimensional direction when the excavating blade 10 and the drive shaft 5 are viewed in the plane direction are effectively prevented, and ground improvement construction with high vertical accuracy can be realized.

As described above, according to the ground improvement construction machine of the present invention, it is possible to proceed with high-accuracy ground improvement construction in which the lap dimension between adjacent ground improvement bodies is well ensured according to the design conditions. Therefore, the ground improvement body wall of the single wall structure excellent in water stop performance can be constructed, and it contributes to creation of the ground improvement body with a large liquefaction prevention effect.
Incidentally, in the case of the present embodiment, the length of the line connecting the center of the drive shaft 5 and the stirring blade shaft 17 to the outer surface of the left and right displacement suppression plates 11b is substantially equal to the diameter D ₀ of the rotating circle of the excavating blade 10. Equal to the diameter of the borehole 14. On the other hand, also through the center of the stirring blade axis 16, the right and left displacement suppression plate 11b corner portion 11c protruding from the outer surface of the length D ₂ of the line connecting the tips of 11c is rotated circle diameter D of the drilling blades 10 Greater than _zero . Incidentally, an example of the protruding amount of the corner 11c is about 10 cm.

Next, an embodiment of the stabilizer 11 (or the non-rotating blade in the case of a single shaft) constituting the excavation and stirring mechanism shown in FIGS. 5A and 5B will be described.
The basic structure of this embodiment is largely in common with the embodiment of FIG. That is, the shaft 17 of the stirring blade 12 is connected to the lower end portion of the drive shaft 5 in a concentric state by a fitting-type shaft coupling. The stirring blade shaft 17 is positioned directly below the stirring blade 12 with respect to the stirring blade shaft 17 via a rotating shaft cylinder 18 which is supported by the thrust receiving plates 15 and 15 in an axially stationary state. The stabilizer 11 is attached in a rotatable state, that is, in a structure that does not rotate together with the excavation blade 10 and the stirring blade 12.
In the case of the present embodiment, the shaft fixing bracket 11d (see FIG. 4) for connecting the rotating shaft cylinder 18 constituting the stabilizer 11 and the rotating shaft cylinders 18 and 18 supporting the two drive shafts 5 and 5 is respectively provided. It is arranged in two upper and lower stages with a configuration in which another stirring blade 12 is sandwiched at an intermediate position in the vertical direction. Of course, the stirring blade 12 is installed in a structure that rotates integrally with the stirring blade shaft 17.
Furthermore, the shaft 16 of the excavating blade 10 is concentrically connected to the lower end portion of the stirring blade shaft 17 by a fitting-type shaft coupling.
Therefore, also in the embodiment shown in FIG. 5, the frame members 11 a and 11 a arranged in two upper and lower stages constituting the stabilizer 11 are respectively excavated by the excavating blades 10 through the centers of the drive shafts 5. It is arranged along the diameter line direction of the hole 14 and in a direction perpendicular to the inter-axis fixing bracket 11d (see FIG. 4). And the arc surface shape equal to the curvature of the circumferential direction of the excavation hole 14 is formed at the tip of each frame member 11a, 11a at a position inscribed in the hole wall inner surface of the excavation hole 14 excavated by the excavation blade 10. A displacement restraining plate 11b is attached.
The characteristic configuration in the embodiment of FIG. 5 is configured as a double type in which frame members 11a and 11a arranged in two upper and lower stages are integrally joined by the above-described arc-shaped displacement restraining plate 11b. That is.
Therefore, the corner portion 11c protruding from the outer surface of the displacement restraining plate 11b is also configured to be vertically long along the displacement restraining plate 11b that is long in the vertical direction as described above, and bites into the hole wall soil of the excavation hole 14 by, for example, about 10 cm. Thus, the non-rotation state is maintained.

Therefore, according to the above configuration of the embodiment of FIG. 5, the configuration of the single type stabilizer 11 shown in FIG. 3 does not provide a necessary and sufficient earth pressure reaction force due to the softness of the ground soil and the like. In ground improvement construction under conditions where the effect of suppressing displacement and displacement is poor. It works effectively to increase vertical penetration accuracy. That is, since the upper and lower double-stage stabilizer 11 is configured, the pressure receiving areas of the displacement suppression plate 11b and the corner portion 11c can be configured to be sufficiently large.
Further, in this embodiment, since the stirring blade 12 is installed at the intermediate portion between the upper and lower stabilizers 11, 11, the stirring effect between the excavated soil and the solidified material slurry is also high.

As described above, according to the embodiment of FIG. 5, the drive shaft 5 and the excavation blade 10 are caused by the magnitude difference (unbalance) of excavation resistance force that the excavation blade 10 receives when excavating a hard part or a soft part of the ground. Even in the construction conditions where the rotation of the excavation blade 10 is likely to cause a displacement or a core blur, the double type stabilizer 11 has a displacement restraining plate 11b having an arc surface shape equal to the curvature in the circumferential direction of the excavation hole 14. 14 is strongly in contact with the inner surface of the hole wall to generate a large surface pressure (earth pressure) to resist, and displacement or misalignment (bending) in a direction perpendicular to the inter-axis fixing bracket 11d (out-of-plane direction of the formed wall). Surely stops.
Further, regarding the displacement in the longitudinal direction (in-plane direction of the formed wall body) and the core blur of the inter-axis fixing bracket 11d, the corners 11c and 11c on both sides protruding from the outer surface of the displacement suppression plate 11b are formed in the excavation hole 14. It resists and blocks by the earth pressure that penetrates deeply into the pore wall soil of the earth.
Thus, displacement in the two-dimensional direction orthogonal to the excavation blade 10 and the drive shaft 5 in plan view and core blurring are effectively prevented, and ground improvement construction with high vertical accuracy can be realized. Therefore, it is particularly effective when performing construction using a single-axis construction machine.
In other words, it is possible to secure the lap dimension between adjacent ground improvement bodies as per the design conditions, and it is possible to create a ground improvement wall with a single wall structure with excellent water stopping performance, which is effective for preventing liquefaction. Construction of large ground improvement bodies can be carried out.
Incidentally, in the case of the embodiment of FIG. 5, the displacement suppression plate 11b of the left and right through the center of the stirring blade axis 16, the length of a line connecting the outer surface of the 11b, the diameter D ₀ of the rotational circle of the drilling blades 10 substantially Equal, which is equal to the diameter of the borehole 14. On the other hand, also the two corners 11c protruding from the outer surface of the displacement suppression plate 11b of the left and right through the center of the stirring blade axis 16, the length D ₃ of the line connecting the tips of 11c, the rotation circle of the drilling blades 10 It is larger than the diameter D _0, that is _{, the} diameter of the excavation hole 14. An example of the protruding length of the corner 11c is about 10 cm.

Next, the ground improvement construction method constructed in a narrow place using the ground improvement construction machine configured as described above will be described below based on FIGS.
At the time of construction, first, the above-described moving table 2 is suspended by a small crane or horizontally supported by a forklift or the like and carried into the construction site. And it mounts on the two rails 1 and 1 previously laid along the construction position and construction direction of a ground improvement body on the ground surface of a construction site, and the wheel with a hook which shows on the rail 1 in FIG. 2a is installed in a movable state.
In addition, as illustrated in FIGS. 6A to 6C at the stage before and after the above-described equipment process, the drive shaft 5 is passed through the shaft hole 6a of the rotation drive unit 6 of the ground improvement construction machine and is below the moving table 2. The excavating blade 10 constituting the excavating mechanism shown in FIG. 3 or FIG. A stirring blade 12 is attached.
As the method, as a step before placing the movable stand 2 suspended or supported on the rail 1 as described above, the movable stand 2 is placed on a temporary stand prepared in advance in the vicinity of the construction site. Place in a horizontal position. Then, the excavating blade 10, the stabilizer 11, and the stirring blade 12 are passed through the shaft hole 6 a of the rotation driving unit 6 and the lower end portion of the driving shaft 5 protruding downward from the movable table 2, for example, FIG. Or it attaches to the structure shown in FIG. Thereafter, the movable table 2 is again mounted on the rail 1 by hanging it with a small crane.
Alternatively, as a process after the movable table 2 is directly placed on the rail 1, as shown in FIGS. 6A and 6B, by using the depth of the preparation groove 13 excavated in the construction target ground in advance, the rotation drive unit A method of attaching the excavating blade 10 for improving the ground, the stabilizer 11 and the stirring blade 12 to the lower end of the drive shaft 5 that has been passed through the six shaft holes 6a is also possible.

When the preparation for construction is completed as described above, the movable table 2 is moved along the rail, and the center of the rotary drive unit 6 and the drive shaft 5 installed on the movable table 2 is installed at the construction position of the ground improvement body. The movable base 2 is positioned and fixed.
As a procedure and means for positioning and fixing the movable table 2, for example, as shown in FIG. 1, by operating hydraulic vertical jacks 2 b provided at the four corner positions of the movable table 2, Do. Then, the determined horizontal state is fixed by operating the screw jack 2d.
Next, the jack-type fixture 2c (clamp) provided on the moving base 2 is operated to grip the upper flange of the rail 1 to firmly fix the moving base 2 in the above state, and thus the excavation blade for ground improvement The reaction force against the lifting due to the excavation operation of the ground by 10 is also secured.
As preparation for that premise, the rails 1 and 1 to be laid on the ground surface of the construction site are not shown in the figure, but a process of firmly placing the piles or screwed piles into the ground and fixing them to the ground is performed. .

When the preparation is completed, the operator first raises the rotary drive unit 6 to the ascending limit position by the operation of the elevating drive unit 41 by a method such as operating a controller (not shown). At the raised position, a clamp-type gripping tool (not shown) provided in the shaft hole 6a of the rotary drive unit 6 is driven and controlled so that the drive shaft 5 is gripped and firmly fixed and supported.
In addition, the rotary drive unit 6 is driven to rotate by the rotary power devices 7 and 8, and the elevator table 3 is moved downward along the lift guide 31 of the lift guide frame 3 by the lift drive units 31 and 41 to push the force. By adding (penetration input), the ground is excavated by the excavating blade 10 at the lower end of the drive shaft 5 and simultaneously injected with slurry, and the ground is obtained by mechanical agitation to agitate the cement solidified slurry and excavated soil. Advance the improvement process downward.
When the elevating drive unit 41 is lowered to the lower limit position in this way, the slurry injection is once stopped and the fixing / support of the drive shaft 5 by the rotary drive unit 6 is released. And the raising / lowering drive part 41 is raised to a raise limit position. In the ascending position, the drive shaft 5 is fixed and supported by the rotation drive unit 6 again, and the lift drive unit 41 is moved downward while the drive shaft 41 is driven to rotate, so that the ground is excavated and the slurry is injected and excavated. Continue the ground improvement process with stirring with the soil.
By repeating the ascending / descending stroke of the ascending / descending drive unit 41, the ground improvement construction step up to the target depth is advanced. When the formation of the ground improvement body is achieved to the planned depth in the ground, the operation for raising or lowering the raising / lowering drive unit 41 is repeated while the drive shaft 5 is reversely rotated by the rotation drive unit 6. Then, the drive shaft 5 is pulled up, and the ground improvement excavating blade 10, the stabilizer 11, and the stirring blade 12 at the lower end of the drive shaft are pulled up to the ground position.

After that, the fixed state of the moving platform 2 is released, and it is horizontally moved along the rail 1 to the construction position of the next-level ground improvement body, and is positioned and fixed again at the position of the next-level ground improvement body construction. Repeat the procedure and proceed with ground improvement work.
Therefore, as shown in FIG. 6A, even in the ground improvement construction in a place that approaches the eaves of the neighboring house 50, by laying the rail 1 exactly at a certain distance from the house 50, The ground improvement construction can be carried out in a peaceful and reliable manner without causing any trouble in the existence of the house 50 and without causing physical damage to the house 50.

Finally, Example 2 of the ground improvement construction machine shown in FIG. 7 will be described.
The second embodiment is based on the same technical idea as the construction machine of the first embodiment shown in FIG. 1 and FIG. 2, but is greatly different in that it does not include the lifting platform shown in FIG.
That is, the construction machine according to the second embodiment is premised on a two-axis type and is arranged so as to be symmetrically opposed to both sides of the movable table 2 that is movable in the horizontal direction and back and forth in the moving direction. Two lifting guide frames 3 and 3 are provided. And the raising / lowering drive parts 31 and 41 which raise / lower in the perpendicular direction along the said raising / lowering guide frame 3 are provided.
Also in the case of the second embodiment, the lifting drive units 31 and 41 are common to the first embodiment in that they are installed along the rail-shaped lifting guide of the lifting guide frame 3. The second embodiment also shows a configuration example in which the lifting drive units 31 and 41 employ a hydraulic cylinder mechanism. That is, the upper end of the rod 31 is fixed to the lifting guide frame 3, and the cylinder body 41 moves up and down along the lifting guide formed on the lifting guide frame 3. The structure which the raising / lowering stand 4 raises / lowers with the cylinder main body 41 is shown. Originally, a mechanism in which the lifting platform 4 moves up and down together with a chain that circulates in the vertical direction using the lifting guide frame 3, or a mechanism in which a rack is formed on the lifting guide frame 3 and a pinion is installed on the lifting platform is used. Thus, a configuration for moving the lifting platform 4 up and down can also be implemented.
A feature of the second embodiment is that the rotary drive unit 6 including the shaft hole 6a having a center hole structure and the rotary drive unit 6 directly to the lift drive unit 41 without using the lift platform of the first embodiment. A pair of rotational power units 7 and 8 that rotate the unit are structurally integrated units, and are installed in a back-to-back arrangement on the left and right lifting guide frames 3 and 3, respectively. Therefore, the construction is effective for further reducing the height of the construction machine by the amount not using the lifting platform.
The left and right units formed by integrating the rotation drive unit 6 and the rotation power units 7 and 8 are integrally joined by a high-rigidity connecting member 60, and the left and right rotation drive units 6 and 6 are respectively lifted and lowered drive units 41. It is configured to move up and down synchronously in an integrated relationship by the action of.

Next, at a position close to the upper surface of the moving table 2, the drive shaft 5 penetrating the shaft hole 6 a of the rotary drive unit 6 is temporarily grasped and supported, or is released by a hydraulic method or the like when penetrating. A shaft clamp 70 is provided with a cylindrical structure that penetrates the drive shaft 5. In the case of FIG. 7, the shaft clamp 70 is installed on a mounting table 71 installed on the upper surface of the movable table 2 via a universal joint 72 that allows a slight displacement in the horizontal direction.
The function of the shaft clamp 70 is to penetrate the rotary drive unit 6 while the rotary drive unit 6 grasps and rotates the drive shaft 5 and works by the lift drive unit 41. When excavating the ground with the excavating blade 10 at the tip, the drive shaft 5 is released to allow the penetration and excavation process. However, when the elevating drive unit 41 is lowered to the lower limit position and then moves to the ascending stroke, the drive shaft 5 is held and supported in order to hold the position and height of the drive shaft 5 firmly at the current position. To do. In other words, it operates in an alternating relationship with the shaft clamp installed in the shaft hole 6a of the rotary drive unit 6 to reliably push in the drive shaft 5 necessary for excavating the ground or lift the drive shaft 5 after excavation. The control system to perform is assembled.

Incidentally, in FIG. 1 and FIG. 2 showing the construction machine of the first embodiment, the shaft clamp of FIG. 7 is not clearly shown, but this is for the convenience of illustration, and on the moving table of the first embodiment. I would like to remind you that a shaft clamp is installed in the same way.
Since the content of the ground improvement construction method by the ground improvement construction machine of the present Example 2 and the construction operation are substantially the same as the construction method by the construction machine of Example 1 described above, redundant description is omitted.

  Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to the configuration of the illustrated embodiment. I would like to remind you that it includes the scope of design changes, applications, and uses that will be made by those skilled in the art.

DESCRIPTION OF SYMBOLS 1 Rail 2 Moving stand 3 Lift guide frame 4 Lift stand 5 Drive shaft 6 Rotation drive part 7, 8 Rotation power part 31 Lift guide 41 Lift drive part
DESCRIPTION OF SYMBOLS 10 Excavation blade 11 Stabilizer 12 Stirring blade 11a Frame material 11b Displacement suppression board 11c Corner | angular part 11d Centering bracket 14 Excavation hole 70 Axis clamp

As a means for solving the above-described problems of the prior art, a ground improvement construction machine suitable for construction in a narrow place according to the invention described in claim 1,
An elevating guide frame 3 standing in the vertical direction is provided on a movable table 2 that is movable in the horizontal direction, elevating drive units 31 and 41 that elevate in the vertical direction along the elevating guide frame 3 are installed, and the elevating drive unit 41 is provided with a rotation drive unit 6 having a shaft hole 6a having a center hole structure that allows the drive shaft 5 to pass through in the vertical direction, and rotation power devices 7 and 8 for rotating the rotation drive unit 6.
The lower end of the drive shaft 5 through the shaft hole 6a of the rotary drive unit 6, at least ground improvement drilling blades 10 and agitating blades 12 are attached, et al is, a cement solidifying material through slurry injection tube of the drive shaft 5 It is configured to supply,
The lifting drive unit 31 and 41 a rotation driving unit 6 and the rotary power device 7, 8 is constant stroke increases, the rotational drive unit while rotatably driven so on which is fixed and supported to the drive shaft 5 by the rotational driving unit 6 6 , The ground improvement excavation blades 10 and the stirring blades 12 of the drive shaft 5 are advanced downward by the mechanical agitation method ground improvement process by excavating the ground and injecting solidified slurry, and the lifting drive unit 41 is set to the lower limit. When the position is lowered to the position, the fixing and supporting of the drive shaft 5 by the rotation drive unit 6 is once released, the rotation drive unit 6 is lifted by a fixed stroke by the lift drive units 31 and 41, and the drive shaft is again driven by the rotation drive unit 6 at the raised position. The ground improvement process step in which the rotary drive unit 6 is moved downward while the rotary drive unit 6 is fixed and supported and rotated is repeatedly advanced to the target depth.

The ground improvement construction machine suitable for construction in a narrow place according to the invention described in claim 2,
Is elevation guide frame 3 standing vertically on movable mobile base 2 to the horizontal direction is provided, wherein the lifting guide frame 3 and the temperature descending drive unit 31 you lift vertically along the 41 is installed, the lifting The drive units 31 and 41 are provided with a lifting platform 4 that translates in the vertical direction while maintaining a horizontal posture.
Rotation power units 7 and 8 for rotating the rotary drive unit 6 are installed in the vertical direction with a rotary drive unit 6 provided with a shaft hole 6a having a center hole structure through which the drive shaft 5 passes. Is also installed,
At least a ground excavation blade 10 and a stirring blade 12 are attached to the lower end portion of the drive shaft 5 that is passed through the shaft hole 6 a of the rotary drive unit 6 on the elevator 4, and passes through the slurry injection tube of the drive shaft 5. It is configured to supply cement-based solidifying material,
The lifting by the drive unit 31 and 41 allowed the elevation frame 4 is fixed stroke increases, and the elevation frame 4 while rotated is lowered work on was fixed and supporting the drive shaft 5 by the rotational driving unit 6, the drive shaft 5 When the ground improvement excavation blade 10 and the stirring blade 12 are used to advance the ground improvement process of the mechanical agitation method by excavating the ground and slurry injection, and the elevator 4 (or the elevator drive unit) is lowered to the lower limit position, it rotates. temporarily release the fixing and supporting the drive shaft 5 by the driving unit 6 by a predetermined stroke increases the lifting platform 4 by means of a raising and lowering drive unit 31 and 41, by fixing and supporting the drive shaft 5 by the rotational driving unit 6 again raised position characterized in that the ground improvement process steps the elevation table 4 Ru is lowered operation while rotationally driving a repetition advancing structure to the target depth.

The invention described in claim 3 is a ground improvement construction machine suitable for construction in a narrow place described in claim 1 or 2,
The movable table 2 that is movable in the horizontal direction is horizontally applied to at least two parallel rails 1 and 1 previously laid horizontally on the ground of the construction site along the construction position and construction direction of the ground improvement body. is moved rests freely, the mobile base 2 is configured to move along the rails 1 advances the construction of the soil improvement material, before Symbol rail 1 piles that are driven into the ground, or into the ground It is characterized by obtaining a reaction force at the time of excavation penetration of the ground improvement construction machine and a reaction force necessary for preventing overturning by a fixing tool such as a screw pile screwed in.

The invention described in claim 4 is a ground improvement construction machine suitable for construction in a narrow place described in any one of claims 1 to 3,
A ground improvement excavation blade 10 and a stabilizer 11 and a stirring blade 12 positioned immediately above are attached to a lower end portion of the drive shaft 5 that is passed through the shaft hole 6a of the rotation drive unit 6, and the stabilizer 11 includes the excavation blade. The frame material 11a arranged in the diameter line direction of the excavation hole 14 excavated by 10 is attached to the drive shaft 5 so as not to rotate together and immovable in the axial direction.
A displacement restraining plate 11b having a circular arc shape equal to the curvature in the circumferential direction of the excavation hole is attached to a position at the tip portion of the frame member 11a and in contact with the inner wall surface of the excavation hole 14 excavated by the excavation blade 10. The corner portion 11c protruding outward in the radial direction from the outer surface of the displacement suppression plate 11b has both vertical side surfaces and is configured to bite into the hole wall soil of the excavation hole 14.

The invention described in claim 5 is a ground improvement construction machine suitable for construction in a narrow place described in claim 1 or 4,
Rotation provided with at least two lifting guide frames 3 on the movable table 2 and having a shaft hole 6a through which the driving shaft 5 passes in the vertical direction to the lifting drive units 31 and 41 passing through the lifting guide frames 3 and 3. A drive unit 6 and rotational power devices 7 and 8 for rotating the rotation drive unit 6 are installed,
The at least two stabilizers 11 positioned immediately above the excavation blades 10 for ground improvement work attached to the lower end portions of at least two drive shafts 5 and 5 penetrated into the shaft holes 6a of the respective rotary drive units 6 are provided. The shaft member 18 of the inter-shaft fixing bracket 11d connecting the drive shafts 5 and 5 is arranged perpendicular to the inter-shaft fixing bracket 11d, and along the diameter line passing through the center of the drive shaft 5, respectively. Is provided,
Displacement restraining plate 11b having an arcuate surface shape equal to the curvature in the circumferential direction of excavation hole 14 at a position in contact with the inner wall of the excavation hole 14 excavated by excavation blade 10 at the tip portion of each frame member 11a. The corner portion 11c protruding outward in the radial direction from the outer surface of the displacement restraining plate 11b has vertical side surfaces and is configured to bite into the hole wall soil of the excavation hole 14. To do.

The invention described in claim 6 is a ground improvement construction machine suitable for construction in a narrow place described in claim 2 or 4,
At least two rotary drive units 6 having shaft holes 6a through which the drive shafts 5 pass in the vertical direction are installed on the lifting platform 4, and rotary power devices 7 and 8 that rotate the rotary drive units 6 are also installed. And
The at least two stabilizers 11 positioned immediately above the excavation blades 10 for ground improvement work attached to the lower end portions of at least two drive shafts 5 and 5 penetrated into the shaft holes 6a of the respective rotary drive units 6 are provided. The shaft member 18 of the inter-shaft fixing bracket 11d connecting the drive shafts 5 and 5 is arranged perpendicular to the inter-shaft fixing bracket 11d, and along the diameter line passing through the center of the drive shaft 5, respectively. Is provided,
A displacement restraining plate 11b having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole is located at the tip portion of each frame member 11a and in contact with the inner wall surface of the excavation hole 14 excavated by the excavation blade 10. The corner portion 11c, which is attached and protrudes radially outward from the outer surface of the displacement restraining plate 11b, has both vertical sides and is configured to bite into the hole wall soil of the excavation hole 14. .

The invention described in claim 7 is the ground improvement construction machine suitable for construction in narrow places according to claim 5 or 6,
A stabilizer 11 located immediately above the excavation blade 10 for ground improvement work attached to the lower end portions of at least two drive shafts 5, 5 penetrating through the shaft holes 6 a of at least two rotary drive portions 6, 6. The at least two drive shafts 5 and 5 are connected to each other by the shaft fixing bracket 11d and the frame member 11a arranged in the diameter line direction of the excavation hole 14 in at least two stages in the vertical direction of the drive shaft 5. And
Displacement forming an arc surface shape equal to the circumferential curvature of the excavation hole 14 at a position that is in contact with the inner surface of the excavation hole 14 excavated by the excavation blade 10 at the tip end of the upper and lower frame members 11a and 11a. The restraint plate 11b is attached to an arrangement in which the upper and lower two-stage frame members 11a and 11a are connected in the vertical direction, and the corner portion 11c protruding radially outward from the outer surface of the displacement restraint plate 11b is vertical. It is characterized by having both side surfaces and biting into the hole wall soil of the excavation hole 14.

The invention described in claim 9 is a ground improvement construction method implemented using a ground improvement construction machine suitable for construction in a narrow place according to the invention described in claim 1 or 3-8,
A method for carrying hanging in a horizontal position, or supported in a horizontal state to the construction site by truck by mobile base 2 is smaller cranes equipped with a main portion excluding the rail 1 out of the ground improvement construction machine,
On the ground surface of the construction site, at least two rails 1 and 1 are laid in parallel along the construction position and construction direction of the ground improvement body, and the movable table 2 is placed on the rails 1 and 1 on the rail 1. Placing it in a movable state along the top,
The drive shaft 5 is passed through the shaft hole 6a of the rotary drive unit 6 installed in the lift drive unit 41 that moves up and down in the vertical direction along the lift guide frame 3 installed on the movable table 2, and the lower end of the drive shaft 5 Attaching at least the ground improvement excavation blade 10 and the stirring blade 12 to the section;
Moving the movable table 2 to a position where the center of the drive shaft 5 passed through the rotary drive unit 6 coincides with the construction position of the ground improvement body, and positioning and fixing the movable table 2;
While raising and lowering the lift drive units 31 and 41 by a certain stroke, the drive shaft 5 is fixed and supported by the rotary drive unit 6 at the raised position, and the rotary drive unit 6 is driven to rotate by the rotary power devices 7 and 8, A step of lowering the lifting drive unit 41 to excavate the ground, and injecting the solidified material slurry and stirring the ground downward,
When the elevating drive unit 41 is lowered to the lower limit position, the slurry injection is temporarily stopped, the fixing / supporting of the drive shaft 5 by the rotary drive unit 6 is released, the elevating drive unit 41 is lifted by a certain stroke, and the rotary drive unit is again at the raised position. 6, the drive shaft 5 is fixed and supported, and the lift drive unit 41 is moved downward while being driven to rotate, excavating the ground, and the ground improvement process step of injecting and stirring the slurry is repeated by a certain stroke to the target depth. The stage of creating ground improvement bodies,
When the creation of the ground improvement body is completed, the ascending / descending drive unit 41 is repeatedly raised and lowered while the drive shaft 5 is rotated in the reverse direction to bring the drive shaft 5 and the ground improvement excavation blade 10 and the stirring blade 12 to the ground. The stage of raising to
Thereafter, the moving platform 2 is moved horizontally on the rail 1 to the next-ranked ground improvement body construction position, and the construction of the next-ranked ground improvement body is advanced in the same procedure as described above.

The invention described in claim 10 is a ground improvement method implemented using a ground improvement construction machine suitable for construction in a narrow place according to the invention described in claims 2-8,
The stage 2 for carrying the main part excluding the rail 1 of the ground improvement construction machine is suspended in a horizontal state by a small crane, or is supported in a horizontal state by a forklift and is carried into the construction site;
At least two rails 1 and 1 are laid in parallel along the construction direction of the ground improvement body at the construction position on the ground surface of the construction site, and the movable table 2 is placed on the rails 1 and 1 on the rail 1. Placing it in a movable state along the top,
The drive shaft 5 is passed through the shaft hole 6a of the rotation drive unit 6 on the lifting platform 4 installed on the moving table 2, and at least the ground excavation blade 10 and the stirring blade 12 are attached to the lower end of the drive shaft 5. Stages,
Moving the movable table 2 to a position where the center of the drive shaft 5 passed through the rotary drive unit 6 coincides with the construction position of the ground improvement body, and positioning and fixing the movable table 2;
The elevator 4 is lifted by a certain stroke by the lift drive units 31 and 41, and the drive shaft 5 is fixed and supported by the rotary drive unit 6 at the lifted position, and the rotary drive unit 6 is rotated by the rotary power devices 7 and 8. While driving, the step of lowering the elevating platform 4 by the elevating drive units 31 and 41 excavating the ground and injecting the solidified material slurry and stirring the step of proceeding downward,
When the elevator 4 is lowered to the lower limit position, the slurry injection is temporarily stopped, the fixing / support of the drive shaft 5 by the rotary drive unit 6 is released, the elevator 4 is lifted by a certain stroke, and the rotary drive unit 6 again at the raised position. While the drive shaft 5 is fixed and supported, the lift 4 is moved downward while being driven to rotate, the ground is excavated, the slurry is injected and stirred, and the ground improvement process step is repeated for each predetermined stroke to reach the target depth. The stage of promoting the creation of
When the creation of the ground improvement body is completed, the drive shaft 5 and the ground improvement excavation blades 10 and the stirring blades 12 at the lower end thereof are moved to the ground by repeating the ascending and descending operations of the lifting platform 4 that reversely rotates the drive shaft 5 The stage of raising,
After that, the ground improvement construction method is characterized in that the moving platform 2 is horizontally moved on the rail 1 to the next-grade ground improvement body construction position, and the construction of the next-order ground improvement body is advanced in the same procedure as described above.

First, in the embodiment of the excavation stirring mechanism shown in FIGS. 3A and 3B, the shafts 17 of the stirring blades 12 and 12 arranged in two stages on the lower end of the drive shaft 5 are concentric by fitting shaft couplings. Connected to the state. A stabilizer 11 (with a structure that is rotatable with respect to the stirring blade shaft 17 is provided below the stirring blade shaft 17 via a rotating shaft cylinder 18 that is supported vertically by thrust receiving plates 15 and 15 in the axial direction. Or a co-rotating stop blade) is attached.
FIG. 4 shows a configuration example of a stabilizer 11 in which the drive shaft 5 is applied to a two-shaft type with two more specifically. The stabilizer 11 located immediately above the excavation blade 10 for ground improvement work attached to the lower ends of the two drive shafts 5 and 5 includes a rotary shaft cylinder 18 that rotatably supports the two drive shafts 5 and 5. The drive shaft 5 is constrained by being connected by the inter-shaft fixing bracket 11d. The two left and right rotating shaft cylinders 18, 18 pass through the center of the drive shaft 5 and are oriented at right angles to the inter-axis fixing bracket 11 d and to the diameter line of the excavation hole 14 excavated by the excavating blade 10. Frame members 11a are respectively installed along the arrangement.
Next, an arc surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is formed at a position that is in contact with the inner surface of the hole wall of the excavation hole 14 excavated by the excavation blade 10 at the tip of each frame member 11a, 11a. A displacement suppression plate 11b is attached. And the corner | angular part 11c protruded radially outward from the outer surface of the said displacement suppression board 11b is set as the structure which bites into the hole wall soil of the excavation hole 14 about 10 cm. As shown in FIG. 3B, the corner portion 11c is formed in a long and narrow plate shape having both side surfaces perpendicular to the vertical direction of the excavation hole 14 (see FIG. 3B), and bites into the hole wall soil of the excavation hole 14 to be described later. It is configured to generate necessary and sufficient earth pressure resistance against displacement and core blur to prevent displacement and core blur and to secure necessary and sufficient vertical accuracy .

Claims (12)

An elevating guide frame that stands in the vertical direction is provided on a movable table that is movable in the horizontal direction, and an elevating drive unit that elevates vertically along the elevating guide frame is installed. The elevating drive unit is driven in the vertical direction. A rotation drive unit having a shaft hole of a center hole type structure that penetrates the shaft and a rotation power device of the rotation drive unit are installed,
At least the excavation blade for ground improvement and the stirring blade are attached to the lower end portion of the drive shaft that is passed through the shaft hole of the rotational drive portion,
The rotary drive unit and the rotary power device are lifted by a certain stroke by the elevating drive unit, and the rotary drive unit is lowered and driven while the drive shaft is fixed and supported by the rotary drive unit, thereby excavating the ground and solidifying material slurry. When the ground improvement process of mechanical agitation method by injection is proceeded downward, and when the elevating drive unit is lowered to the lower limit position, the fixing and supporting of the drive shaft by the rotary drive unit is once released, and the rotary drive unit is raised by a certain stroke, In a narrow place, the structure is such that the ground improvement process step in which the drive shaft is fixed and supported again by the rotary drive unit in the ascending position and the rotary drive unit is lowered while being rotated is repeatedly advanced to the target depth. Ground improvement construction machine suitable for construction. An elevating guide frame standing in a vertical direction is provided on a movable table that is movable in the horizontal direction, and an elevating drive unit that elevates the elevating table that moves up and down in the vertical direction along the elevating guide frame as a parallel movement while maintaining a horizontal posture. It is provided in the vertical direction along the lifting guide frame,
A rotary drive unit having a shaft hole of a center hole type structure that penetrates the drive shaft is installed in the vertical direction, and a rotary power device of the rotary drive unit is also installed.
At least a ground improvement excavation blade and a stirring blade are attached to the lower end portion of the drive shaft that is passed through the shaft hole of the rotation drive unit on the lifting platform,
The lifting and lowering drive unit raises the lifting platform by a fixed stroke, the drive shaft is fixed and supported by the rotation driving unit, and the lifting and lowering table is lowered while being driven to rotate. Proceed with the ground improvement process downward, and when the lifting platform is lowered to the lower limit position, the drive shaft is fixed and supported by the rotary drive unit, and the lift platform is lifted by a fixed stroke. A ground improvement construction machine suitable for construction in confined spaces, characterized in that it is configured to repeatedly move the ground improvement process steps to the target depth by moving the lifting platform while being fixed and supported and rotating.   A movable platform that can move in the horizontal direction can be moved in the horizontal direction on at least two parallel rails that have been laid in the horizontal state in advance along the construction position and construction direction of the ground improvement body on the ground of the construction site. The moving platform is moved along the rail and the construction of the ground improvement body is advanced, and the rail is a pile driven into the ground or a screw pile screwed into the ground. Construction in a narrow place according to claim 1 or 2, characterized in that it is configured to obtain a reaction force at the time of excavation and penetration of the ground improvement construction machine and a reaction force necessary to prevent falling by a fixing tool. Suitable ground improvement construction machine. A ground improvement excavation blade and a stabilizer and a stirring blade positioned immediately above are attached to the lower end portion of the drive shaft that is passed through the shaft hole of the rotation drive unit, and the stabilizer has a diameter of the excavation hole excavated by the excavation blade. The frame material arranged in the linear direction is attached to the drive shaft in a state where it does not co-rotate and is stationary in the axial direction.
A displacement restraining plate having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole is attached to a position at the tip portion of the frame member and in contact with the hole wall inner surface of the excavation hole excavated by the excavating blade. The ground suitable for construction in a narrow place according to any one of claims 1 to 3, wherein corners protruding from the outer surface of the plate are configured to bite into the hole wall soil of the excavation hole. Improved construction machine. A rotary drive unit having at least two lift guide frames installed on the moving table, and having a shaft hole through which the drive shaft passes in the vertical direction to the lift drive unit that passes through each lift guide frame, and the rotational power of the rotary drive unit Equipment is installed,
The stabilizer located immediately above the excavation blade for ground improvement construction attached to the lower end portion of at least two drive shafts penetrating into the shaft holes of the respective rotation drive portions connects between the at least two drive shafts. A frame member is provided on the shaft cylinder of the shaft fixing bracket along a diameter line passing through the center of the drive shaft in an arrangement orthogonal to the shaft fixing bracket.
A displacement restraining plate having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole is attached to a position that is in contact with the inner surface of the hole wall of the excavation hole excavated by the excavation blade at the tip portion of each frame member. 5. The ground suitable for construction in a narrow place according to claim 1 or 4, characterized in that corners protruding from the outer surface of the displacement restraining plate are configured to bite into the hole wall soil of the excavation hole. Improved construction machine. At least two rotary drive units having shaft holes through which the drive shaft passes in the vertical direction are installed on the lifting platform, and rotational power devices for each rotary drive unit are also installed.
The stabilizer located immediately above the excavation blade for ground improvement construction attached to the lower end portion of at least two drive shafts penetrating into the shaft holes of the respective rotation drive portions connects between the at least two drive shafts. A frame member is provided on the shaft cylinder of the shaft fixing bracket along a diameter line passing through the center of the drive shaft in an arrangement orthogonal to the shaft fixing bracket.
A displacement restraining plate having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole is attached to a position that is in contact with the inner surface of the hole wall of the excavation hole excavated by the excavation blade at the tip portion of each frame member. 5. The ground suitable for construction in a narrow place according to claim 2 or 4, characterized in that a corner protruding from the outer surface of the displacement restraining plate bites into the hole wall soil of the excavation hole. Improved construction machine. The stabilizer located immediately above the excavation blade for ground improvement construction attached to the lower end of at least two drive shafts that penetrated through the respective shaft holes of at least two rotary drive units is provided with at least two drive shafts. The inter-axis fixing bracket to be connected and the frame material arranged in the diameter line direction of the excavation hole are each arranged in at least two stages in the vertical direction of the drive shaft,
Displacement restraining plates having a circular arc shape equal to the curvature in the circumferential direction of the excavation hole are arranged at the tip of the upper and lower two-stage frame material and in contact with the inner wall surface of the excavation hole excavated by the excavating blade. It is attached to the arrangement in which the frame members of the steps are connected in the vertical direction, and the corner portion protruding from the outer surface of the displacement suppression plate is configured to bite into the hole wall soil of the excavation hole. The ground improvement construction machine suitable for construction in a narrow place according to claim 5 or 6.   The stabilizer attached to the lower end of the drive shaft that is passed through the shaft hole of the rotation drive unit is configured such that a stirring blade that rotates together with the drive shaft is installed in the middle part of the shaft cylinder and the frame material arranged in two stages above and below The ground improvement construction machine suitable for construction in a narrow place according to claim 7, wherein the construction machine is suitable for construction. The stage where the main part excluding the rail is mounted in the ground improvement construction machine is suspended in a horizontal state by a small crane, or is supported in a horizontal state by a forklift and is carried into the construction site,
On the ground surface of the construction site, at least two rails are laid in parallel along the construction position and direction of the ground improvement body, and the movable table can be moved on the rails along the rails. The stage of mounting on,
Excavation blades for ground improvement at least to the lower end of the drive shaft through the shaft hole of the rotary drive unit installed in the lift drive unit that moves up and down in the vertical direction along the lift guide frame installed on the moving table And attaching a stirring blade,
Moving the movable table to a position where the center of the drive shaft passed through the rotation drive unit coincides with the construction position of the ground improvement body, and positioning and fixing the movable table;
The lift drive unit is lifted by a certain stroke, the drive shaft is fixed and supported by the rotary drive unit at the lifted position, and the rotary drive unit is rotationally driven by the rotary power device, while the lift drive unit is moved downward and the ground And proceeding downward the ground improvement process of injecting and stirring the solidified material slurry,
When the elevating drive unit is lowered to the lower limit position, the slurry injection is temporarily stopped, the drive shaft is fixed and supported by the rotary drive unit, the elevating drive unit is lifted by a certain stroke, and the drive shaft is moved again by the rotary drive unit at the raised position. A stage where the ground improvement process step, which is fixed and supported, is further driven to rotate, and the lift drive unit is lowered to excavate the ground, and slurry is injected and agitated, is repeated for each stroke, and the ground improvement body is advanced to the target depth. When,
When the creation of the ground improvement body is completed, the step of raising and lowering the drive shaft and the ground improvement excavation blade and the stirring blade at the lower end of the drive shaft and the lowering operation portion are repeated while rotating the drive shaft in the reverse direction,
After that, the moving platform is moved horizontally on the rail to the next-ranked ground improvement body construction position, and the construction of the next-ranked ground improvement body is advanced in the same procedure as described above, A ground improvement method implemented using a ground improvement construction machine suitable for construction in a narrow place according to the described invention. The stage where the main part excluding the rail of the ground improvement construction machine is mounted in a horizontal state by a small crane or supported in a horizontal state by a forklift and carried to the construction site,
A state where at least two rails are laid in parallel along the construction direction of the ground improvement body to the construction position on the ground surface of the construction site, and the movable table can be moved on the rails along the rail. The stage of mounting on,
Passing the drive shaft through the shaft hole of the rotary drive unit on the lifting platform installed in the moving table, and attaching at least the ground improvement excavating blade and the stirring blade to the lower end of the drive shaft;
Moving the movable table to a position where the center of the drive shaft passed through the rotation drive unit coincides with the construction position of the ground improvement body, and positioning and fixing the movable table;
The lifting platform is lifted by a certain stroke by the lifting drive unit, and the drive shaft is fixed and supported by the rotary drive unit at the raised position, and the rotary drive unit is rotationally driven by the rotary power device, while the lifting drive unit lifts the lift platform Digging the ground by moving down, and advancing the ground improvement process of pouring and stirring the solidified material slurry,
Once the platform is lowered to the lower limit position, the slurry injection is temporarily stopped, the drive shaft is fixed and supported by the rotary drive unit, and the platform is raised by a certain stroke, and the drive shaft is fixed again by the rotary drive unit at the raised position. Supporting, further rotating and moving the lifting platform while excavating the ground, excavating the ground, injecting slurry and agitating the ground improvement process step, repeating the creation of the ground improvement body to the target depth by repeating each stroke, and
When the creation of the ground improvement body is completed, the lifting operation of the lifting platform that reversely rotates the drive shaft and the lowering operation are repeated to raise the drive shaft and the ground improvement excavation blade and the stirring blade to the ground,
After that, the moving platform is horizontally moved on the rail to the next-ranked ground improvement body construction position, and the construction of the next-ranked ground improvement body is advanced by the same procedure as described above, A ground improvement construction method implemented using a ground improvement construction machine suitable for construction in a narrow place according to the invention. The drive shaft uses unit material cut to a unit length that is not constrained in the construction space, and according to the progress of the ground improvement process, the unit material is sequentially added by shaft joints to advance the ground improvement process and achieve the construction depth. about,
As for the rail for moving horizontally by placing the moving table, the unit material is cut before the moving step of the moving table 2 in the ground improvement construction process using a unit material cut to a unit length which is not restricted in the construction space. The ground improvement construction method according to the invention according to claim 9 or 10, wherein the ground improvement body is laid in advance along the construction position and the construction direction of the ground improvement body on the ground surface to proceed with the construction of the ground improvement body.   The operation of attaching the excavating blade and the agitating blade for ground improvement to the lower end of the drive shaft through the shaft hole of the rotary drive unit is performed by hanging the moving platform with a small crane or supporting it with a forklift rail. Prior to the process of placing it on the ground, temporarily place the moving base on a temporary stand prepared in the vicinity, or place the moving base on the rail, and then place the ground improvement body on the ground The ground improvement method according to claim 9 or 10, wherein the ground improvement method is performed using a pre-excavated preparation groove.

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