JP3881961B2 - Pile embedding method and excavator used for the method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pile burying method and an excavator used in the method. Specifically, the present invention relates to a pile burying method by a non-exhaust earth method and an earth and sand excavating apparatus used for the non-exhaust earth method. More specifically, using a steel pipe, and using an outer pipe (casing) and an inner pipe, a foundation pile embedding method that should also be referred to as “a non-exhaust earth construction method with an earth and sand container in the ground” and the foundation pile The present invention relates to earth and sand excavation equipment used in the burying method. The present invention can be applied not only to burying off-the-shelf piles, but also to construction of steel pipe piles and site-built piles.
[0002]
[Prior art]
[Patent Document 1]
JP 2002155553 A
[0003]
An auger is usually used to bury prefabricated piles (concrete piles). In this case, earth and sand (including gravel) generated by excavation is discharged through a earth and sand discharging mechanism such as a spiral screw provided on the rod. Then, after excavating to the planned depth, the pile is built to a predetermined depth while rotating. Therefore, when an auger is used, discharge of a considerable amount of earth and sand cannot be avoided.
[0004]
Recently, with the increase in size and height of structures, foundation piles are shifting to large diameters. For this reason, the amount of earth and sand discharged by burying piles is also large, and the treatment of earth and sand (residual soil) as industrial waste has become a major social problem.
In addition, the labor and cost for disposal of earth and sand is increasing. For example, when building a large building, the amount of earth and sand discharged during foundation work is about 5,000 to 10,000 cubic meters, and in this case the earth and sand disposal cost is 70 to 100 million yen. Also reach. Considering this on a nationwide scale, approximately 100 billion yen is spent annually for soil disposal.
[0005]
Under such circumstances, many studies have been made on pile burying methods that do not discharge soil, that is, non-exhaust soil, and patent applications are occasionally found. However, the construction method called the conventional soil-free construction method is mainly a construction method in which a metal fitting for excavation is attached to the tip of the pile and excavated by this, or using a device with a slightly improved degree of this, Both are still under development, and it is hard to say that they have been completed. For example, if the ground is soft, the pile to be buried is short, the pile diameter is small, etc., construction is possible, but construction is difficult in the case of hard ground, long pile, large pile diameter, etc. There are many cases. Moreover, in order to excavate earth and sand, a drilling blade is attached to the tip of the auger. However, since these drilling blades are all consumables, the economic burden for this is extremely large.
[0006]
Currently, most of the construction of ready-made piles is the “cement milk rooting expansion method” (certified method). Problems common to all certified methods include drilling with an auger, then injecting a hardener such as cement milk to fix the surrounding area, and bentonite to prevent the drilled hole wall from collapsing. The solidification material is injected, and then the pile is rotated while being built and buried. In this method, hardened or solidified materials such as cement milk and bentonite are mixed with the excavated earth and sand to form mud, which fills the borehole and overflows from the pile head. There is a problem with things. In such a state, it becomes difficult to confirm the pile position after construction, but especially in the ground with a gravel layer, a drainage layer, or a severe layer of drainage, it was filled with cement milk at the end of construction. The subsidence phenomenon occurred in the borehole over time, so the construction was completed without confirming whether or not sufficient peripheral fixation was maintained for the pile head, which is the most important part of the horizontal force of the pile. The current situation is. Since the horizontal force of the pile is the maximum in the vicinity of the head, there is a concern that problems may arise in an emergency if the periphery of the pile head is insufficiently fixed.
[0007]
In light of the current state of the above-mentioned foundation pile laying method, the present inventor has continued research for many years to develop a pile burying method using non-draining soil, uses a steel pipe, and uses both an outer pipe (casing) and an inner pipe. Invented a burying method that can realize complete soil-free soiling by a construction method that is completely different from the conventional idea, filed a patent application as Japanese Patent Application No. 2000-354183, and disclosed as Japanese Patent Application Laid-Open No. 2002-155331 Has been. The present invention is a further improvement of the invention of the prior application, and realizes a more complete soil-free construction method by providing an excavated earth and sand container in the ground.
[0008]
[Problems to be solved by the invention]
In other words, the present invention is a soil-free state (no sediment or gravel remains on the ground surface) regardless of the type or size of the pile, such as ready-made pile, steel pipe pile, and site-built pile. The first problem is to provide a new method that can be embedded in a state). The present invention also provides a pile burying method that does not require a solidifying material such as bentonite, does not use a hardening material such as cement milk, or can reduce the amount used, thereby avoiding environmental pollution. The second issue Furthermore, this invention makes it a 3rd subject to provide the pile embedding method which can confirm a pile head reliably after completion | finish of construction, and can ensure the horizontal force of a pile. Furthermore, this invention makes it the 4th subject to provide the novel excavation apparatus which can be used conveniently for solving each said subject from 1st to 3rd.
[0009]
  The invention described in claim 1 among the present inventions developed to solve the above-mentioned problems is that a steel pipe outer pipe and a steel pipe inner pipe provided with a plurality of earth discharge ports are arranged on a concentric circle. An excavation head is attached to the tip of the outer pipe, and a space for accommodating excavated earth and sand is provided in the gap between the inner pipe and the outer pipe, and the lower part of the outer pipe is reduced in diameter to the upper part of the outer pipe. The upper and lower parts of the outer pipe are connected by a connecting pipe having a tapered portion with a constriction.Bottom edge ofIs placed on the connecting pipe without fixing,Fix the top of the outer tube and the inner tube,Drilling is started by inserting an auger into the inner pipe, and the excavation is carried out while accommodating most of the soil from the discharge port to the receiving part. After drilling to the specified depth, the auger is lifted to move the inner part of the inner pipe. Built a pile inUnfix the inner and outer pipes,Pull up the inner pipe and fill the periphery of the pile with earth and sand in the housing, then the outer pipeAnd all the parts connected to itThis is a method of burying piles that will lift up the soil and leave no unnecessary earth and sand or gravel on the surface.
[0010]
In the invention according to claim 2 of the present invention, the excavation head is mounted at the lower end and the lower diameter is reduced by reducing the upper diameter relative to the upper diameter so that the gap between the upper and lower parts is reduced. A steel pipe outer pipe connected by a connecting pipe having a tapered portion and a steel pipe inner pipe provided with a plurality of earth discharge ports are arranged concentrically, and a gap between the inner pipe and the outer pipe is arranged. Is provided with a storage section for storing the excavated earth and sand, the lower end of the inner pipe is placed on the connecting pipe without being fixed, the upper part of the outer pipe and the inner pipe are secured, and the auger is placed inside the inner pipe. And start up excavation while rotating the inner and outer pipes and the auger in opposite directions, carrying the excavated earth and sand upward with the auger screw. The excavation is carried out while being accommodated in the accommodating part from the earth discharge port, and after excavating to a predetermined depth, The pile is built inside the inner pipe, the lashing of the inner pipe and the outer pipe is released, the inner pipe is lifted to the ground, and the surroundings of the pile are filled with earth and sand in the housing, and then the outer pipe and the pipe are connected to it. It is a pile burying method that pulls up all the parts that have been continued so as not to leave unnecessary earth and sand or gravel on the ground.
[0011]
According to a third aspect of the present invention, an invention includes an outer ring plate that fixes the lower end of the upper portion of the outer tube and an inner ring plate that is fitted to the lower end of the inner tube, and a gap is provided between the outer ring plate and the inner ring plate. The pile embedding method according to claim 1 or 2, wherein a connecting plate is attached to the upper end of the connecting plates connected by a plurality of reinforcing bars.
[0012]
Further, according to the invention described in claim 4 of the present invention, the excavation head is mounted at the lower end, and the lower diameter is reduced by narrowing the upper diameter relative to the upper diameter, and the gap between the upper and lower portions is reduced. An outer pipe made of steel pipe connected by a connecting pipe having a tapered portion and an inner pipe made of steel pipe provided with a plurality of drainage openings are arranged concentrically, and the earth and sand from the drainage outlet is removed. In the excavator, an accommodating portion to be accommodated is formed in the gap between the inner tube and the outer tube, and the lower end of the inner tube is placed on the connecting tube without being fixed.
[0013]
Furthermore, the invention described in claim 5 of the present invention has an outer ring plate for fixing the lower end of the upper part of the outer tube and an inner ring plate fitted to the lower end of the inner tube, and a gap is provided between the outer ring plate and the inner ring plate. The excavator according to claim 4, wherein a connecting plate connected by a plurality of reinforcing bars is attached to an upper end of the connecting pipe.
[0014]
[Action]
The pile embedding method according to the present invention and the excavation apparatus used in the method have the above-described configuration, and since the earth and sand accommodating portion is formed in the gap between the outer pipe and the inner pipe, most of the excavated earth and sand is Then, it is transported upward along the auger rod, and is accommodated in the accommodating portion from each earth discharge port. Therefore, most of the excavated earth and sand is accommodated in a so-called “underground accommodation part”, so that the amount of earth and sand and gravel discharged to the ground surface can be extremely small.
[0015]
In addition, since the pile embedding method according to the present invention and the excavator used in the method are placed on the connecting pipe without fixing the lower end of the inner pipe, It is possible to easily expand the capacity of the earth and sand container by pulling up the ground. Therefore, even if it seems that there is a shortage of earth and sand at first glance, the entire volume of excavated earth and sand and gravel, including the earth and sand discharged on the surface, can be accommodated inside the excavation hole. It is possible to bury the piles with complete soil-free soiling.
[0016]
Hereinafter, the pile embedding method according to the present invention and the earth and sand excavation device used in the method will be described in more detail based on examples and drawings.
FIG. 1 is a side sectional view of an earth and sand excavation device used in one embodiment (Example 1) of a pile embedding method according to the present invention, and FIG. 2 shows a state in which the device is disassembled into three parts. FIG. FIG. 3 is a plan view of the connecting plate P used in the first embodiment. Furthermore, FIG. 4 is explanatory drawing which shows the construction process of the method of burying the pile a using the earth and sand excavation apparatus of Example 1. FIG.
[0017]
[Example 1]
<Description of earth and sand excavator>
In this embodiment, depending on the pile diameter and pile length, the auger capacity used for the outer pipe (casing) is 100 HP to 200 HP, and the auger capacity mounted on the auger machine is 80 HP to 160 HP. The capacity is about ~ 360HP. Corresponding pile drivers are 70 to 120 tons.
In addition, the construction capacity of the earth and sand excavating apparatus of this example is such that when viewed from the ground, the N value is about 200 and the gravel diameter is 400 mm, and when viewed from the pile, the pile diameter is 1000 mm and the pile length is 50 m. Up to can be constructed.
[0018]
  When the earth and sand excavating apparatus of this embodiment is not used, as shown in FIG. 2, a double pipe portion A composed of an outer pipe upper portion 11 and an inner pipe 2, a connecting pipe B to which a connecting plate P is attached, an outer pipe. beneath12And the excavation head 10 (shown in FIG. 1) can be disassembled into three parts of the excavation pipe section C. When used for excavation, all these parts are connected together and configured as shown in FIG. The auger 5 is inserted inward of the inner pipe 2 and the earth and sand are excavated in a so-called double auger state.
[0019]
1 and 2, reference numeral 1 denotes an outer tube made of a steel pipe having an outer diameter corresponding to the diameter of the excavation hole, and is composed of an outer tube upper portion 11 and an outer tube lower portion 12. Is equipped with a drilling head 10. Further, the diameter of the outer pipe lower portion 12 is reduced to be reduced with respect to the diameter of the outer pipe upper portion 11, and the tapered connecting pipe B (steel pipe) is formed between the outer pipe upper portion 11 and the outer tube lower portion 12. Connected).
Reference numeral 2 denotes an inner pipe made of a steel pipe having a plurality of earth discharge openings H2, H3, H4,... Formed on a side wall and arranged on a concentric circle of the outer pipe 1. In the gap between the outer pipe 1 and the inner pipe 2, there is provided a receiving portion 3 for receiving the earth and sand sent from the discharging port H1 of the connecting pipe B and the discharging ports H2, H3, H4. is there. The lower end of the inner tube 2 is placed on the connecting plate P attached to the connecting tube B without being fixed.
[0020]
The connecting plate P is attached to the upper end of the connecting tube B, and as shown in FIG. 3, the outer ring plate 1 ′ connected and fixed to the lower end of the upper portion of the outer tube 11 and the inner ring plate fitted to the lower end of the inner tube 2. 2 ′, and the outer ring plate 1 ′ and the inner ring plate 2 ′ are connected and fixed by a plurality of reinforcing bars R, R,.
[0021]
The connecting pipe B is a tapered steel pipe with a constriction, and as shown in FIG. 2, supports the outer ring plate 1 ′ of the connecting plate P, and supports the inner ring plate 2 ′ which also serves as the side wall of the connecting pipe B. And a support tube B2 having a slightly constricted taper shape. Further, the support pipe B2 is provided with a discharge port H1. The lower surface of the connecting plate P and the upper end of the connecting tube B are fixed by connecting the outer ring plate 1 'and the support tube B1, and the inner ring plate 2' and the support tube B2 by an appropriate method such as welding. Furthermore, the upper surface of the inner ring plate 2 ′ of the connecting plate P is provided with a cut portion that fits into the lower end of the inner tube 2.
That is, the support shaft of the connecting pipe B is the outer pipe 1, and therefore no problem occurs even if the inner pipe 2 is pulled out. Further, the lower end of the connecting pipe B is integrated with the support pipes B1 and B2, and is connected and fixed to the upper end of the lower part 12 of the outer pipe.
[0022]
In addition, although the connection pipe B of the present embodiment has a shape of the entire side wall (that is, the shape of the support pipe B1) having a “conical taper”, the connection pipe used in the present invention is not limited to this shape. Alternatively, a part of the side wall may be formed in a “squeezed tapered shape”. In short, the connecting pipe of the present invention has a “squeezed tapered part” and an upper portion of the outer pipe having a large diameter. Any shape can be used as long as the outer tube lower portion having a small diameter can be integrally connected and fixed.
[0023]
The diameter of the discharge port HI of the connecting pipe B is about 300 mm, and the discharge ports H2, H3, H4, etc. of the inner pipe 2 are about 200 mm in diameter, and 20 mm rebars are spaced at intervals of about 50 mm at each discharge port. It is attached so that gravels and soil blocks of 50 mm or more are not mixed into the housing part 3.
[0024]
  When the excavator having the above-described configuration is used in a state of being disassembled into three parts, the inner tube 2 is placed on the connecting plate P of the connecting tube B, and the inner tube 2 is inserted into the cut portion. While fitting the lower end, the outer tube upper portion 11, the connecting tube B (the connecting plate P is attached to the upper end), and the outer tube lower portion 12 are integrally connected and fixed by welding or other methods. Then, since the lower end of the inner tube 2 is only placed and fitted in a notch provided in the connection plate P of the connection tube B, the connection with the connection plate P is automatically performed when the inner tube 2 is lifted. The inner tube 2 is easily separated from the connecting tube B. However, the outer pipe upper part 11, the connecting plate P, the connecting pipe B, the outer pipe lower part 12, and the excavation headTsuSince the outer tube upper part 11 is lifted up, all the parts connected to the outer pipe 11 are pulled up while being connected together. Therefore, when the outer pipe upper part 11 is rotated while being rotated, the connecting plate P, the connecting pipe B, the outer pipe lower part 12 and the excavation head 10 are respectively connected to the support pipe B2 of the connecting pipe B. While discharging the earth and sand downward from the provided discharge port H1, it is pulled up to the ground while rotating simultaneously with the outer pipe upper part 11.
[0025]
The outer pipe upper portion 11 and the inner pipe 2 are each provided with a plurality of small holes in the upper portions of both pipes, and through the horizontal vibration preventing rebar 4 through the small holes, the horizontal vibration caused by the rotation, the vibration generated during excavation, and the floating of the pipe It is firmly secured to suppress such things.
In addition, the surface of the outer surface of the entire excavator (the outer pipe upper part 11, the connecting pipe B, the outer pipe lower part 12) is a friction-cut reinforcing bar in order to reduce the frictional resistance of the earth and sand accompanying the excavation and the frictional resistance during the lifting. 9 is wound spirally.
[0026]
As shown in FIG. 1, the spiral screw 7 is attached to the rod 6 of the auger 5 used in the present embodiment up to 5 m from the tip, and thereafter, the portion where the spiral screw 7 is not attached ( The spiral screw 7 is attached to some places of the rod 6 by alternately combining the portion where only the auger rod 6 is 2 m and the portion where the spiral screw 7 is attached is 3 m. However, the combination of the wearing positions may be arbitrarily changed depending on circumstances such as the ground.
[0027]
<Description of pile burying method>
A pile embedding method according to this embodiment will be described with reference to FIGS. 1, 2, and 4.
As shown in FIG. 2, each part (double pipe part A, connecting pipe B to which connecting plate P is attached, excavating pipe part C) that is disassembled into three parts is assembled as shown in FIG. Excavation is made after confirming whether or not the upper pipe 11 and the inner pipe 2 are secured so that the outer pipe 11 and the inner pipe 2 rotate in the same direction and can withstand lateral vibration and vibration accompanying rotation. Launch on the surface of the point. Before and after this, the auger 5 is inserted into the hole of the inner pipe 2, and as shown in FIG. 4 (a), the auger head 8 is pushed to the burial point of the pile a together with the excavator. This completes the preparation for construction.
[0028]
The excavator placed at the construction position is set by a pile driver (not shown), starts excavating earth and sand while being rotated by an auger machine equipped on the pile driver, and starts the auger 5 With the “double auger” construction method, excavation of earth and sand is started while rotating the auger head 8 in the direction opposite to that of the excavation device (inner tube / outer tube tying body), and the generated torques are offset each other. As shown in (b), the excavation proceeds deep into the soil.
[0029]
The excavated earth and sand b is pushed upward by a spiral screw 7 provided on the rod 6, and a part of the earth and sand is, as shown in FIG. It is accommodated in the earth and sand accommodating portion 3 formed in the gap between the outer tube 1 and the inner tube 2. The remaining earth and sand and gravel are further pushed up by the auger screw 7 and are accommodated in the accommodating portion 3 from the earth discharge ports H2, H3, H4,. Therefore, most of the excavated earth and sand b is accommodated in the accommodating part 3, but part of the earth and sand, large gravel, etc. are discharged to the ground via the auger rod 6. However, as will be described later, this phenomenon is not a problem. Sediment and gravel discharged to the surface can be finally returned to the excavation hole, except for large gravel that is judged to be unsuitable for backfilling.
[0030]
After excavation to the planned depth, cement milk c is ejected from the tip of the auger head 8 as shown in FIG. Subsequently, the auger 5 is pulled up, and the pile a is built in the hole of the inner pipe 2 as shown in FIG. The tip of the pile a is an open type, but the tip of the built-in pile a is closed by the cement milk c injected from the auger head 8 to solidify the tip. Therefore, the cement milk c does not enter the hole of the pile a, and the usage amount of the cement milk c can be greatly reduced. Moreover, since the muddy material d formed by mixing the earth and sand b and the cement milk c does not enter the hole of the pile a, the muddy material d does not overflow from the pile head to the ground surface. After the completion of construction, the pile head can be confirmed reliably, and the pile horizontal force required for earthquake resistance can be sufficiently inspected and confirmed.
[0031]
Next, the reinforcing bars 4 that secure the upper portion 11 of the outer tube and the inner tube 2 are removed.
After confirming the built-in state of the pile a, the inner pipe 2 is lifted to the ground. As described above, the inner pipe 2 is only placed on the notch portion of the connecting plate P attached to the connecting pipe B. Therefore, when the inner pipe 2 is gradually lifted, the inner pipe 2 and the connecting pipe B are automatically separated.
[0032]
When the inner pipe 2 is pulled up, as shown in FIG. 4 (e), the earth and sand b filled in the accommodating portion 3 provided in the gap between the outer pipe 1 and the inner pipe 2 is removed by pulling out the inner pipe 2. Since the earth and sand accommodating part expands to the outer diameter of the pile a including the thickness of the pipe 2, the earth and sand b filled in the accommodating part 3 falls to the periphery of the pile a, and a part moves downward. This state will be described in more detail as follows.
[0033]
Most of the earth and sand b excavated by the auger 5 passes through any one of the discharge ports H1, H2, H3, H4,... Provided in the excavator, and the accommodating portion 3 provided in the gap between the outer pipe 1 and the inner pipe 2. This state is the primary containment of earth and sand.
Next, after the construction of the pile a is completed, the inner pipe 2 is lifted up. However, since the inner pipe 2 is pulled out to the outer diameter of the pile a including the thickness of the inner pipe 2, The state is secondary containment of earth and sand.
As described above, the primary containment alone is filled with excavated earth and sand b, and at first glance, it seems that the accommodation is insufficient. This lack of accommodation is discharged to the ground surface along with the auger rod 6 together with gravel etc. exceeding 50 mm, but as described above, after the pile a is built and the inner pipe 2 is lifted, Along with the expansion, a gap is formed around the upper part of the excavation hole, so that the entire amount of earth and sand b once discharged to the surface (removing gravel and the like determined to be inappropriate for backfilling) is backfilled into the excavation hole. be able to. In this case, (1) the accommodating portion 3 provided in the gap between the outer tube 1 and the inner tube 2 and (2) the accommodating portion in the gap between the inner wall including the thickness of the inner tube 2 and the outer diameter of the pile a are Is roughly equal. Therefore, the amount of excavation that has been filled in the primary accommodation is about half the height of the sediment around the pile a due to the accommodation portion expanded by the lifting of the inner pipe 2, that is, the secondary accommodation. This half cuts about half of the upper part of the storage space, allowing the earth and sand discharged on the surface to be stored in this space, and achieving a soil-free construction method that maintains a balance between excavation and storage. This state is shown in FIG.
[0034]
Following the inner pipe 2, the outer pipe upper part 11 and all the parts connected and fixed thereto, that is, the connecting plate P, the connecting pipe B, the outer pipe lower part 12 and the excavation head 10 are rotated and connected to the ground. Pull it up. Then, since a void is formed in the excavation hole, earth and sand or gravel discharged to the ground surface is backfilled in the excavation hole as necessary. By this backfilling, as shown in FIG. 4 (f), the pile a is buried without leaving earth and sand or gravel on the ground surface, and the pile embedding work of this embodiment is completed. In this step, the outer pipe upper part 11 may be lifted after the earth and sand discharged on the surface of the earth are buried in the excavation hole. In short, the entire amount of excavated sediment and gravel should be finally backfilled in the excavation hole.
[0035]
In this example, the burying of a pile having a pile diameter of 600 mm and a pile length of 30 m was examined. In this case, although the installation position of the connection pipe B is set to a portion 2 m from the tip of the pile with respect to a 30 m pile length, the connection pipe B may be installed at an arbitrary position according to the ground or the pile diameter. . It is also possible to appropriately increase (or decrease) the amount of earth and sand accommodated by further expanding the outer diameter of the excavator or lengthening the accommodating portion.
[0036]
In this embodiment, as shown in FIGS. 1 and 4, the support tube B2 of the connecting tube B is formed in a slightly tapered shape, but if the support tube B2 is tapered, the outer tube The volume of the earth and sand container 3 surrounded by 1 and the inner pipe 2 can be increased, and the volume of earth and sand can be increased.
[0037]
In the above embodiment, the three parts of the double pipe part A (the outer pipe upper part 11 and the inner pipe 2), the connection pipe B to which the connection plate P is attached, and the excavation pipe part C (the outer pipe lower part 12 and the excavation head 10). However, the excavator used in the present invention is not limited to the one that can be disassembled in this way, and the combination of the outer pipe and the inner pipe provided with a plurality of discharge ports on the side wall It is only necessary to have a structure in which the housing portion can be provided in the ground and the inner tube can be easily pulled out, and is not necessarily a device that is composed of the above three parts or can be disassembled into three parts. It's okay. However, since the excavating apparatus according to the present invention often has a considerable weight and scale, after excavation is finished and it is pulled up to the ground surface, about 3 to 4 are provided to facilitate transportation and storage. It is desirable for the structure to be disassembled into appropriate parts.
[0038]
Further, in the above embodiment, a plurality of small holes are formed in the upper portions of both pipes as means for securing the outer pipe upper portion 11 and the inner pipe 2 and the small holes are secured through the reinforcing bars 4. Securing the upper and inner pipes of the outer pipe is not necessarily limited to such means, but to prevent lateral vibration of the outer and inner pipes caused by rotation, and to suppress vibrations caused by excavation. Any means may be used as long as it can be fixed.
[0039]
In the present invention, the amount of earth and sand generated by excavation and the amount thereof are calculated as follows.
That is, the amount of earth and sand generated is calculated by “excavation area (inner pipe inner diameter) × inner pipe length”, while the amount of earth and sand contained is “outer pipe inner diameter × length and pile inner diameter × length. It is calculated by “total of”.
However, as a factor that increases the excavation capacity, the gravel crushed by the auger becomes a small piece of gravel, and the volume increases compared to the original shape before excavation. The water content varies greatly depending on the ground. Furthermore, the volume changes depending on the mixing state of clay, sand, gravel, etc. that form the ground. For this reason, it is extremely difficult to predict an increase in volume by excavation. At the same time, some excavated earth and sand are considered to be unsuitable for storage in the ground. Therefore, in the present invention, it is assumed that the volume is increased by 20% by excavation, and 10% of the volume is accommodated in the ground, but the remaining 10% is considered unsuitable for storage in the ground. A separate processing method is adopted.
As described above, the estimated amount is assumed to increase by 10% with respect to the excavation amount.
[0040]
For example, when considering the case of a pile diameter of 600 mm (thickness of 90 mm) and a pile length of 30 m, the outer tube (casing) used for making no soil has an inner diameter of 940 mm and the inner tube has an inner diameter of 740 mm. Then
Drilling side (inner pipe hole diameter 740mm)
Sediment generation 3.14 × 0.37 × 0.37 × 30 m = 12.89 m^Three
Increase (10%) 12.89 × 10% = 1.28 m^Three
That is, total 14.17 m^Three Is the amount of earth and sand generated. In contrast,
Accommodation side (outer tube 940mm and tip 740mm)
Sediment capacity 3.14 × 0.47 × 0.47 × 28 m = 19.42 m^Three
Sediment capacity 3.14 × 0.37 × 0.37 × 2 m = 0.85 m^Three
That is, total 20.27 m^ThreeIs the capacity of earth and sand.
Based on the above calculation, excavation amount is 14.17m^ThreeCapacity is 20.27m^ThreeThe accommodation side is 6.10m^ThreeThe volume of piles to be buried is 4.32m.^Three1.78m even if you subtract^Three Since the storage side is large, it is clear that the soil-free construction method can be achieved by the present invention even when considering the relationship between excavation and storage.
[0041]
【The invention's effect】
As described above in detail, according to the pile embedding method of the present invention and the excavation apparatus used for the method, any pile can be embedded by a complete soil-free construction method. Therefore, the social and economic significance of the present invention is extremely great.
That is, since the pile burying method of the present invention does not produce residual soil and mud, it can solve the social concern of reducing industrial waste and eliminates the cost of residual soil treatment. The effect is extremely large. Furthermore, in the method of the present invention, the wall of the excavation hole is suppressed by the outer pipe, so there is no need to use a solidifying material such as bentonite used in the conventional construction method, and there is no hardening material such as cement milk. Since it is not used or its usage can be greatly reduced, the economic effect on this aspect is also great. Moreover, it does not pollute the environment such as the construction site, its surroundings and its groundwater. Furthermore, since the pile burying method of the present invention can surely check the pile head after completion of construction, the pile horizontal force can be reliably checked. As described above, the pile embedding method of the present invention is a construction method that can achieve extremely great effects in terms of economy, environment, and safety.
[0042]
Furthermore, since the excavator used in the present invention adopts a “double auger” method in which an outer tube (casing) equipped with an excavation head at the tip and an auger is used, the construction accuracy is lower than that of a conventional excavator. Improve dramatically.
Moreover, according to the pile embedding method of the present invention, a wide range of construction is possible from a small-diameter pile to a large-diameter pile. In the present invention, construction of a pile having a diameter of 1000 mm is possible. Therefore, the present invention can be applied not only to the laying of ready-made piles, but also to the construction of steel pipe piles and site-built piles.
Thus, the pile embedding method according to the present invention is an epoch-making method capable of correcting various drawbacks of the conventional method. The excavator according to the present invention is also epoch-making.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an earth and sand excavating apparatus used in Example 1 of the present invention.
FIG. 2 is a side sectional view showing a state in which the earth and sand excavation device used in Example 1 of the present invention is disassembled into three parts.
3 is a plan view of a connecting plate used in Example 1. FIG.
FIG. 4 is an explanatory view showing a construction process of a pile burying method using the excavator of Example 1;
[Explanation of symbols]
1. Outer pipe
11 ... Upper part of outer pipe
12 ... Lower part of outer pipe
2 ... Inner pipe
3 ··· Earth and sand container
4 .... Reverse reinforcing bars
5 ... Auger
6 .... Auger rod
7 ... Spiral screw
8 .... Auger head
9. Friction cut reinforcing bar
10 ... Drilling head
1 '... outer ring plate of connecting plate
2 '... inner ring plate of connecting plate
A ... Double pipe
B ... Connection pipe
B1, B2 ... Support pipe for connecting pipe
C ... Drilling pipe
H1 ... Soil outlet provided in the connecting pipe
H2 / H3 / H4 ... Drainage port provided in the inner pipe
P ・ ・ ・ ・ Connecting plate
a ... Pile
b ... Sediment
c ... Cement milk
d ・ ・ ・ ・ Muddy material mixed with earth and cement milk

Claims (5)

The outer pipe made of steel pipe and the inner pipe made of steel pipe provided with a plurality of discharge ports are arranged concentrically, a drilling head is attached to the tip of the outer pipe, and the gap between the inner pipe and the outer pipe is drilled A storage section is provided to store earth and sand, and the lower part of the outer pipe is reduced by reducing the diameter with respect to the upper part of the outer pipe, and the upper and lower parts of the outer pipe are connected by a connecting pipe having a tapered portion with a constriction. The lower end of the inner pipe is placed on the connecting pipe without being fixed, the upper part of the outer pipe and the inner pipe are fixed , the auger is inserted into the inner pipe, and excavation is started. The excavation is carried out while being housed in the housing part from the soil discharge port, and after excavating to a predetermined depth, the auger is lifted and a pile is built inward of the inner pipe, and the inner pipe and the outer pipe are unfixed, and the inner pipe is released. fill around the piles in sediment in the storage unit salvaged, then useless soil or gravel to withdraw all part Yuizoku and therewith outer tube to the surface Burying method piles to avoid the. A steel pipe with an excavation head attached to the lower end and reduced in diameter by lowering the lower caliber relative to the upper caliber, and connected between the upper and lower parts by a connecting pipe having a tapered tapered portion. An outer pipe made of steel and an inner pipe made of steel pipe provided with a plurality of earth discharge ports are concentrically arranged, and an accommodation portion for accommodating excavated earth and sand is provided in the gap between the inner pipe and the outer pipe. The lower end of the pipe is placed on the connecting pipe without being fixed, the upper part of the outer pipe and the inner pipe are secured, the auger is inserted inward of the inner pipe, and it is raised to the excavation point. The excavation was started while rotating the fixed body and the auger in opposite directions, carrying the excavated earth and sand with the spiral screw of the auger, and proceeding with the excavation while accommodating most of the earth and sand from the discharge port to the accommodation part, After excavating to the prescribed depth, the auger is pulled up and a pile is built inside the inner pipe Unlock the inner and outer pipes, lift the inner pipe to the ground, fill the periphery of the pile with the earth and sand in the housing, then lift the outer pipe and all the parts connected to it, A method of burying piles so that gravel does not remain on the surface. A connecting plate having an outer ring plate for fixing the lower end of the upper portion of the outer tube and an inner ring plate fitted to the lower end of the inner tube and connected by a plurality of reinforcing bars arranged at intervals between the outer ring plate and the inner ring plate. The pile embedding method according to claim 1 or 2, wherein a connecting pipe attached to the upper end is used. A steel pipe with an excavation head attached to the lower end and reduced in diameter by lowering the lower caliber relative to the upper caliber, and connected between the upper and lower parts by a connecting pipe having a tapered tapered portion. The outer pipe made of steel and the inner pipe made of steel pipe provided with a plurality of drainage openings are concentrically arranged, and an accommodating portion for accommodating the earth and sand from the drainage outlet is formed in the gap between the inner pipe and the outer pipe. The excavator is mounted on the connecting pipe without fixing the lower end of the inner pipe. A connecting plate having an outer ring plate for fixing the lower end of the upper portion of the outer tube and an inner ring plate fitted to the lower end of the inner tube and connected by a plurality of reinforcing bars arranged at intervals between the outer ring plate and the inner ring plate. The excavator according to claim 4, wherein the excavator is attached to an upper end of the connecting pipe.

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