JPH0442495B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a construction method for an underground continuous impermeable wall.

[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, it is necessary to construct an underground continuous wall, or to pour sheet piles 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.

(b) Underground walls are usually constructed with a wall thickness greater than necessary, making the construction unnecessarily large-scale and requiring a large amount of excess concrete, resulting in high construction costs.

(b) The construction method of driving sheet piles and pouring into the joints also requires extensive construction and is expensive in material cost.

(c) It is possible to build thinner underground continuous walls to reduce construction costs, but there are no machines that can excavate narrow trenches, and even if a narrow trench could be dug, the wall thickness would be reduced. A homogeneous underground wall cannot be completed due to the loss of fluidity.

(d) Also, from the point of view of water stoppage certainty and reliability,
Cracks during earthquakes impair the water-stopping properties of concrete walls, and construction methods using precast concrete panels or sheet piles were unable to obtain sufficient water-stopping performance due to contaminants, bentonite, etc. being trapped in the joints.

An object of the present invention is to provide an underground continuous water-blocking construction method that is easy to construct, has low construction costs, and can construct a water-blocking wall that is highly reliable and reliable.

[Means for solving problems]

The method of constructing an underground continuous impermeable wall according to this invention is as follows:
Adjacent water-shielding sheets on the left and right are connected by a connecting sheet, and the grooves are partitioned into left and right sides in the width direction.

Dig a trench in the ground. Water-shielding sheets, each having an adhesive portion continuously provided in the vertical direction on at least one of the right and left ends, are suspended into the groove so as to be adjacent to each other. A connecting sheet is provided between the adjacent water-shielding sheets, with adhesive portions provided continuously in the vertical direction at both ends. The inside of the groove is partitioned into right and left sides in the width direction by the connected water-shielding sheets by inflating a pack car arranged in the groove and pressing the adhesive parts of the water-shielding sheet and the connecting sheet. A water-shielding wall incorporating this water-shielding sheet will be constructed inside the trench.

〔Example〕

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

(1) Trench excavation A trench 1 is excavated in the ground up to the impermeable layer. 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 is a polyethylene sheet,
Rubber asphalt waterproof sheets, etc. can be used. 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 arranged one after another in the above-mentioned 1, and adhesive parts 4 that are continuous in the vertical direction are provided at both left and right end portions of one surface of the water-shielding sheet 2 that is arranged in advance. It is being

The adhesive constituting the adhesive part 4 is modified asphalt, which is a compound containing at least asphalt and a rubber substance, and has a softening temperature of 60°C or higher and a penetration of 60 to 400, preferably 150 to 300. suitable.

(3) Arranging the water-shielding sheet The water-shielding sheet 2 is rolled out from the roll 5 placed on the ground and sinks into the groove 1. A plurality of water shielding sheets 2 are arranged next to each other in the longitudinal (depth) direction of the groove 1.

(4) Arrangement of connecting sheet The connecting sheet 6 can also be made of polyethylene sheet, rubber asphalt waterproof sheet, etc. The connecting sheet 6 is a sheet similar to the width water-shielding sheet 2, and has a weight member 3 attached to its lower end. Adhesive portions 4, 4 that are continuous in the vertical direction are also provided at both left and right ends of one surface of the connecting sheet 6.

This connecting sheet 6 is pulled out from a roll 7 which is also placed on the ground and is lowered into the groove 1. The connecting sheet 6 is disposed to face the gap between the water-blocking sheets 2, 2 adjacent to each other in the horizontal direction, and the bonded portions 4, 4 at the ends between the water-blocking sheets 2, 2 and both left and right ends of the connecting sheet 6 are connected to each other. The adhesive parts 4, 4 of the two are faced to each other.

(5) Patsucar sinking Patsucar 8 is lowered into trench 1. The packer 8 is formed into a long bag shape from polyethylene sheet or the like, and is placed along the long reinforcing material 9.
This reinforcing material 9 is sunk into the groove 1. The packers 8, 8 are arranged at positions corresponding to both left and right ends of the connecting sheet 6.

(6) Connecting the water-shielding sheets In the above state, water and air are injected into the pack cars 8, 8 to inflate them. The packers 8, 8 expand and connect the adhesive parts 6, 6 of the left and right ends of the connecting sheet 6 to the adhesive parts 6, 6 of the water-blocking sheets 2, 2,
6 and adhere. In this way, the water-blocking sheets 2, 2 are connected by the connecting sheet 6, and the inside of the groove 1 is partitioned into left and right sides in the width direction.

(7) Filling Inject hardening materials such as mortar and concrete into the muddy water in trench 1 to solidify the muddy water and construct an impermeable wall.

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 configuration and can obtain the following effects.

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

(b) Since the completed water-shielding wall has a water-shielding sheet sandwiched inside, its water-stopping properties will not be impaired even if cracks occur due to earthquakes, etc., making it more reliable and reliable.

(c) Because it is constructed by solidifying muddy water or filling it 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.

(d) Adhesive parts were provided at the ends of the water-shielding sheets, and connecting sheets with adhesive parts at both left and right ends were placed in correspondence with the gaps between adjacent water-shielding sheets, and the sheets were placed in the grooves. The packer is inflated and the adhesive portion is pressed and placed continuously in the groove. Therefore,
The water-blocking sheet can be easily placed in the groove, and construction is easy.

[Brief explanation of drawings]

Figures 1 to 5 are plan views of the construction sequence of this invention;
6 to 9 are sectional views showing the construction sequence of the present invention. 1...Groove, 2...Waterproof sheet, 3...Weight material,
4... Adhesive part, 5... Roll, 6... Connecting sheet, 7... Roll, 8... Packer, 9... Reinforcement material.

Claims (1)

[Claims] 1. A trench is excavated in the ground, and water-shielding sheets with continuous adhesive parts provided in the vertical direction on at least one of the left and right ends are suspended into the groove next to each other, and the adjacent water-shielding sheets are A connecting sheet with a continuous adhesive section in the vertical direction on both ends is placed in between, and a patch car placed in the groove is inflated to connect the waterproof sheet and the adhesive section of the connecting sheet by pressing and bonding. A construction method for an underground continuous impermeable wall characterized by partitioning the inside of the trench from side to side in the width direction with a sheet, and constructing an impermeable wall containing the impermeable sheet inside the trench.