JP2000144708A - Improvement equipment of soft ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improvement equipment of soft ground without the lowering of suction caused by burying a suction hose and using a suction material having no capacity for lowering an absorption capacity even if a person treads thereon. SOLUTION: A ground improvement equipment is equipped with a large number of drain materials 1 penetrating into the ground E in an improving area, an absorbent mat 10 laid on the whole surface of the ground surface in the improving area, and a non-ventilative sheet 4 covering the upper surface of the absorbent mat 10, at the same time, burying the circumferential edge in the side of the improving area and sealing the surface in the improving area. It is equipped with a degassing joint 12 fixed to the circumference on the upper surface of an opening formed in a part of the non-ventilative sheet 4 and a suction hose 5 connecting one end thereof to the joint 12 and connecting the other end to a vaccuum suction pump 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a facility for improving soft ground using, for example, a vertical drain material.

[0002]

2. Description of the Related Art One of the methods for improving soft ground is an atmospheric pressure method using a drain material. In the atmospheric pressure method, a large number of drain materials made of PVC, plastic, or non-woven fabric, etc., which have formed many pores in the vertical direction, penetrate vertically into the ground at predetermined intervals, and the capillary phenomenon causes moisture in the ground to reach the surface. It pumps water to consolidate the ground.

FIG. 3 shows an example of equipment arrangement by the atmospheric pressure method, in which a large number of vertical drain members 1 penetrating into the ground E of the ground improvement area at predetermined intervals intersect a large number of horizontal drainage ends. A drain material 2 is laid on the ground surface, and a perforated pipe 3 is provided at an end of the horizontal drain material 2 so as to cross the end of the drain material 2.
Furthermore, after the above arrangement work, the ground surface is covered with the air-impermeable sheet 4 to shield the entire construction area. The end of the perforated pipe 3 is connected to one end of a suction hose 5, and the other end of the suction hose 5 is connected to a vacuum suction pump 6 arranged outside the improvement area. And the suction hose 5
Is embedded in the ground E together with the end of the sheet 4 and fixed, whereby the peripheral portion of the sheet 4 is hermetically sealed.

After the above preparatory work, the vacuum suction pump 6 is operated to generate a negative pressure between the surface of the ground and the sheet 4, and to suck the moisture in the ground using the atmospheric pressure as a load.
Water is drained out of the improved construction area through the perforated pipe 3 and the suction hose 5 to promote consolidation settlement and improve the density and strength of the ground.

[0005]

By the way, in this equipment, in order to secure the airtightness of the peripheral edge of the sheet, the suction hose 5 together with the air-impermeable sheet 4 is once drawn into the ground and exposed again to the ground surface. Work is required.
To this end, as shown by a broken line in the figure, the surrounding ground is dug down to a predetermined depth, the sheet 4 and the hose 5 are laid in a U-shape in the groove, and the excavated earth and sand is buried back.

However, there is a case where the compaction around the suction hose or the airtight sheet cannot be sufficiently performed. In this case, there is a problem that the degree of vacuum is not increased due to the cause of air leakage and the working efficiency is reduced. . In addition, there is another problem that, when the horizontal drain material 2 is laid, if the user accidentally steps on the material, the water absorption capacity is reduced by half.

The present invention solves the above-mentioned problems, and uses a water-absorbing material that does not cause a decrease in suction due to the burying of a suction hose and that does not have a lowering capacity even if the horizontal drain material is erroneously stepped on. It is an object of the present invention to provide improved facilities for soft ground.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a number of vertical drain materials penetrating into the ground of an improved area, and a water-absorbent mat laid on the surface of the improved area. And, while covering the upper surface of the water absorbent mat,
A non-breathable sheet whose periphery is embedded in the side of the improved area to seal the surface of the improved area; and a joint fixed around an upper surface of an opening formed in a part of the non-breathable sheet. And a suction hose having one end connected to the joint and the other end connected to a vacuum suction pump.

Therefore, according to the present invention, the entire surface surrounded by the air-impermeable sheet can be sucked without burying the suction hose in the ground. Further, as the water absorbing material on the ground surface side, a water absorbing mat laid on the entire surface is used instead of the horizontal drain material, so that it is possible to prevent a reduction in water absorbing ability due to a stepping pressure.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition,
The same parts as those in the related art are denoted by the same reference numerals, and only different parts or newly added parts will be described using different reference numerals.

FIG. 1 shows an example of the overall configuration of a facility arrangement according to the present invention. In the figure, a number of vertical drain members 1 penetrate at predetermined intervals in the ground E of the ground improvement area.
On the ground surface, a water-absorbing mat 10 (horizontal drainage material) is laid over the entire surface (or a part) of the improvement area. The water-absorbent mat 10 is made of a resin having a labyrinth structure which is self-supporting and does not cause early clogging.

The upper surface of the water-absorbent mat 10 is covered with the same air-impermeable sheet 4 as described above, and the outer edge of the sheet 4 is buried in the ground at the side of the improved area, thereby forming the sheet 4.
The ground surface enclosed by is sealed airtight. Sheet 4
It is made of a fiber-reinforced PVC-based sheet or rubber sheet used for a water-impervious sheet or the like, and a hole is formed in a part of the sheet. Connected to the suction end of suction hose 5.

Then, by driving the vacuum suction pump 6, a negative pressure is generated between the ground surface and the sheet 4,
Groundwater is pumped up through the vertical drain material 1 and absorbed by the water-absorbent mat 10, and water in the ground is sucked to the pump 6 side through the suction hose 5 and discharged out of the improvement work area.

In the above configuration, the suction hose 5
Are airtightly connected by the joint 12 and the edges of the sheet 4 are securely embedded, so that the airtightness of the inside of the sheet 4 is sufficiently ensured and the inside of the sheet 4 can be sucked with a high vacuum.

FIG. 2 shows a specific example of the construction of the joint 12. The joint 12 has a large-diameter flange 14a for sheet welding at one end and a connecting flange 14b at the other end. Union joint 15 provided with a hose union 15a provided with an end of the hose 5 at one end and a flange 15b connected to the elbow 14 at the other end, and both flanges 14b, 1
Rubber packing 16 and both flanges 14 interposed in 5b
b, 15b.

An example of a method of attaching the elbow 14 to the seat 4 is as follows. First, a hole 4a is opened at an appropriate position of the seat 4, a large-diameter flange 14a of the elbow 14 is seated on an upper peripheral edge thereof, and an ultrasonic horn or the like is placed thereon. By pressing
The parts shown by the broken lines in the figure are welded to each other and can be fixed airtight.

After this processing, if the elbow 14 and the union joint 15 are flange-coupled with the bolt nut 17, the two can be air-tightly connected, and the other end side is pumped while the hose 5 is wound on the seat 4. When the connection is made to 6, the connection work is completed.

The joint 12 is not limited to the flange connection type shown in the figure, but may be of a union type using a screw connection, or a nipple may be formed by projecting a nipple at the end of an elbow. Various connection forms such as those having a simple structure that is fixed by the above method can be adopted.

In the drawing, only one vacuum suction pump 6 is used. However, if the improvement area is a wide area, a plurality of vacuum suction pumps 6 are provided in accordance with the capacity of the improvement area, and the sealing treatment of the joint end between the sheets 4 is performed. Sufficient drainage can of course be achieved by sufficiently performing drainage even if the improvement area is wide.

[0020]

As is apparent from the above description, according to the improved facility for soft ground according to the present invention,
It is possible to eliminate the danger of a decrease in suction caused by burying a hose. Further, since the water-absorbing material is a self-supporting water-absorbing mat laid over the entire area of the improvement area, there is no decrease in water-absorbing capacity due to stepping pressure as in the prior art, and stable rapid construction can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing an example of the overall configuration of a facility arrangement according to the present invention.

FIG. 2 is an exploded view showing details of a joint tool in a portion viewed from an arrow of FIG. 1A.

FIG. 3 is an explanatory cross-sectional view showing an example of the overall configuration of equipment arrangement in a conventional ground improvement method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical drain material 4 Non-breathable sheet 5 Suction hose 6 Vacuum suction pump 10 Water absorbing mat 12 Joint

Claims (1)

[Claims] A plurality of vertical drain members penetrating into the ground of the improvement area, a water-absorbing mat laid on the surface of the improvement area, and a top surface of the water-absorbing mat;
A non-breathable sheet whose periphery is embedded in the side of the improved area to seal the surface of the improved area; and a joint fixed around an upper surface of an opening formed in a part of the non-breathable sheet. And a suction hose having one end connected to the joint and the other end connected to a vacuum suction pump.