JPS63308112A - Construction of underground continuous cut-off wall - Google Patents

Abstract

PURPOSE:To easily and economically construct a cut-off wall by a method in which a sheet having a weight on its lower end is hung down into a trench, the adjacent sheets are connected, and soil cement is packed into the trench or mud water in the trench is solidified. CONSTITUTION:Water-stop sheets 2 having weights 3 on their lower ends are hung down into a trench 1 excavated in the ground and the adjacent sheets 2 are connected with each other by receiving hook 4 and coupling hook 5 attached to the sheets 2. Soil cement is packed into the trench 1 partitioned by a locking pipe 7, or a hardener, e.g., cement mortar or concrete is poured into the mud water of the trench 1 to solidify the mud water to construct a cut-off wall. The cut-off wall can thus be constructed easily and economically and a damage to the water-stop property can also be prevented even when cracks occur in the cut-off wall on earthquake, etc., because the water-stop sheets are inserted inside.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an underground continuous impermeable wall, method (2).

[Problems to be solved by this invention]

To prevent groundwater from springing up during construction of underground structures, or to stop groundwater during dam construction, construct underground continuous walls, or install sheet piles and inject into joints. construction method has been adopted.

When these conventional construction methods are used for construction purposes only to stop water, the following problems arise.

■ Underground continuous walls are usually built with a wall thickness greater than necessary, making the construction unnecessarily large-scale and using a large amount of excess concrete, resulting in high construction costs.

＠ The construction method of driving sheet piles and injecting into the joints also requires extensive construction work and is expensive in material cost.

θ It is possible to make the wall thickness thinner in order to reduce the construction cost for underground continuous walls, but there is no machine that can excavate narrow trenches, and even if a narrow trench could be dug, the flow of concrete would be difficult. A homogeneous underground wall cannot be completed due to the loss of properties.

○ Also, from the point of view of water-stopping reliability and reliability, cracks in concrete walls during earthquakes impair the water-stopping performance, and construction methods that use precast concrete panels or sheet piles can cause contaminants, bentonite, etc. to build up in the joints. It was not possible to obtain sufficient water-stopping performance.

This invention is easy to construct and has low construction costs.
It is an object of the present invention to provide an underground continuous impermeable wall construction method that is capable of constructing an impermeable wall that is highly reliable and ensures water stoppage.

[Means for solving problems]

The continuous underground impermeable wall construction method according to the present invention connects horizontally adjacent impermeable sheets using hooks, and divides the groove into left and right sides in the width direction.

Attach heavy timber to the bottom edge of the water-shielding sheet. A receiving hook having a hook-shaped cross section that is continuous in the vertical direction is fixed to the end of the water-shielding sheet that is placed first among the water-shielding sheets that are adjacent to each other on the left and right. A plurality of retaining hooks having a hook-shaped cross section are also provided at the end of the water-blocking sheet disposed later. While engaging the engagement hook with the receiving hook of the preceding water-shielding sheet, the trailing water-shielding sheet is suspended and continuous, and the groove is divided into left and right sides in the width direction. Fill the groove with soil mortar or solidify the muddy water in the groove to construct an impermeable wall.

〔Example〕

Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

(1) Trench excavation Excavate trench 1 in the ground. The groove 1 does not have to be wide, which makes construction easier. Trench 1 is excavated while being filled with muddy water, which is a stabilizing liquid. If the ground is good and the possibility of collapse is low, excavation will be carried out without water.

(2) Water-shielding sheet The water-shielding sheet 2 may be a polyethylene sheet, a rubber asphalt waterproof sheet, or the like.

A bar-shaped weight member 3 is attached to the lower end of the water-shielding sheet 2 along its entire length. A plurality of water-shielding sheets 2 are sequentially arranged in the groove 1, and a receiving hook having a hook-shaped cross section that continues in the vertical direction is provided at the trailing end of the water-shielding sheet 2 that is arranged in advance. 4 is fixed.

Further, an engagement hook 5 having a hook-shaped cross section is fixed to the leading end of the water-blocking sheet 2. Although a plurality of single engagement hooks 5 are attached in the embodiment, a single engagement hook 5 may be formed so as to be continuous in the vertical direction and attached.

(3) Water-shielding sheet arrangement The water-shielding sheet 2 is suspended from a rod-shaped hanging member 6 and lowered into the groove 1 by a crane or the like. When disposing the trailing water-shielding sheet 2 in the groove 1 following the leading water-shielding sheet 2, the engaging hook 5 of the trailing water-shielding sheet 2 is connected to the receiving hook 4 of the preceding water-shielding sheet 2. engage and descend.

A plurality of water-blocking sheets 2 as described above are arranged continuously,
The groove 1 is divided into left and right sides in the width direction.

(4) When solidifying the muddy water built into the locking pipe, until the next sheet is engaged, the engaging hook 4 or 5 part is set so that the solidifying range remains at the approved position so that the muddy water does not solidify. A locking pipe 7 is installed to partition the groove 1.

(5) Solidification of muddy water A hardening material such as mortar or concrete is injected into the muddy water in the groove 1 partitioned by the rocking pipe 7 to solidify the muddy water and construct an impermeable wall. After the muddy water has solidified, the locking pipe 7 is pulled out.

If the ground is vertical and hard, excavation is performed without water, but in this case, soil mortar is poured into the trench 1 and hardened.

Since the purpose is to block water, in either case, a low-strength material with strong properties can be used as a filler to hold down the water-blocking sheet.

〔Effect of the invention〕

The present invention has the above-described configuration, and can achieve the following effects.

■ Construction is easy because it only involves digging a trench, placing a water-blocking sheet, and solidifying muddy water, and there is no need for laborious construction, making the construction cost low.

@ The completed water-shielding wall will have a water-shielding sheet sandwiched inside, so even if cracks occur due to earthquakes, water-stopping properties will not be impaired, and reliability and reliability will be high.

Since it is constructed by solidifying O mud or filling with soil mortar, the entire underground wall can be made into a uniform underground wall. Furthermore, even if there is a portion where the strength is reduced, water-stopping properties are ensured by the water-blocking sheet as described above.

■ Since a plurality of water-shielding sheets are continuously placed in the groove using hooks, it is easy to arrange the water-shielding sheets in the groove, and construction is easy.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is a front view of a water-blocking sheet. 1. Groove, 2. Waterproof sheet, 3. Heavy timber, 4. Receiving hook, 5. Engagement hook, 6. Hanging material, 7. Locking pipe.

Claims (1)

[Claims] A weight is attached to the lower end of the water-shielding sheet that is suspended into a groove formed in the ground, and a weight is attached to the trailing edge of the water-shielding sheet that is placed first among the water-shielding sheets adjacent to the left and right in the vertical direction. A receiving hook with a hook-shaped cross section continuous to the front side is fixed, and an engagement hook with a hook-shaped cross section is also provided at the leading end of the water-blocking sheet to be placed later, and a hook with a hook-shaped cross section is fixed to the receiving hook of the preceding water-blocking sheet. While engaging the engagement hook, the trailing water-shielding sheet is suspended and continuous to partition the groove to the left and right in the width direction, and the groove is filled with soil mortar or the muddy water in the groove is solidified. An underground continuous impermeable wall construction method that is characterized by constructing an impermeable wall.