JP7042687B2 - Weight balance water immersion method - Google Patents

Description

The present invention relates to a weight balance water immersion method applied to underground construction.

Conventionally, a method of using a deep well (deep well) for lowering the groundwater level in underground construction has been known (see, for example, Patent Document 1). In the deep well where the pump is operating, the pump operation is stopped and the well is closed after satisfying the condition of "body weight> buoyancy due to groundwater" in order to prevent the newly installed underground skeleton from rising due to buoyancy.

FIG. 2 shows an example of the procedure for closing / removing the drainage facility (deep well) in the conventional underground construction. In this procedure, first, as shown in FIG. 2 (1), a water blocking wall 2 is constructed in the ground G around the area A where the underground skeleton 1 is newly installed, and deep wells 3 (deep wells 3 inside and outside the water blocking wall 2) are constructed. A pumping well) and a recharge well 4 (water injection well) will be provided. Then, by connecting these with a pipe 5, a drainage facility for pumping (draining) water from the ground G directly under the area A to the outside of the water blocking wall 2 is constructed, and the pumps in the wells 3 and 4 are operated to cut the roots.・ Install the floor. Subsequently, as shown in FIG. 2 (2), the underground skeleton 1 is placed in the area A, and after confirming that the condition of "body weight> buoyancy due to groundwater (lifting pressure)" is satisfied, it is directly under the area A. Stop pumping from ground G. Finally, as shown in FIG. 2 (3), the deep well 3 and the recharge well 4 are closed and the pipe 5 is removed.

Japanese Unexamined Patent Publication No. 2016-079567

However, it usually takes several months to meet the above conditions, and during this period, (1) temporary equipment such as deep wells, recharge wells, and pipes cannot be removed and closed, and (2) pumped groundwater is discharged into sewage. If this is the case, there are problems such as enormous discharge costs, which may lead to an increase in on-site costs and a longer construction period.

It is preferable if the pumping of groundwater can be stopped as soon as possible after the new underground skeleton is placed, because it will be advantageous for the site cost and construction period. For this reason, there has been a demand for a technology that can stop the pumping of groundwater at an early stage after constructing a new underground skeleton.

The present invention has been made in view of the above, and an object of the present invention is to provide a weight-balanced water immersion method capable of stopping the pumping of groundwater at an early stage after constructing an underground skeleton.

In order to solve the above-mentioned problems and achieve the object, the weight balance water immersion method according to the present invention is a water immersion method for preventing the underground skeleton from rising due to the buoyancy of the groundwater when constructing the underground skeleton. , The step of installing a drainage facility in the ground to drain the groundwater below the area where the underground skeleton is to be constructed, and then the buoyancy of the groundwater while constructing the underground skeleton while operating the drainage facility. It includes a step of adding weight water for balance to the underground skeleton for countering, and then a step of stopping the function of the drainage facility when the weight of the underground skeleton to which the weight water is added exceeds the buoyancy of the groundwater. It is characterized by that.

Further, in the other weight balance water immersion method according to the present invention, in the above-mentioned invention, as the weight of the underground skeleton increases due to the progress of the construction of the underground skeleton, the weight water added to the underground skeleton is drained to the outside. It is characterized by further providing steps.

Further, another weight balance water immersion method according to the present invention is characterized in that, in the above-mentioned invention, water containing a chemical having a disinfecting or bactericidal action is used as the weight water.

According to the weight balance water immersion method according to the present invention, when constructing an underground skeleton, it is a water immersion method that prevents the underground skeleton from rising due to the buoyancy of the groundwater, and is the groundwater below the area where the underground skeleton is constructed. The step of installing a drainage facility in the ground to drain the water to the outside, and then, while constructing the underground skeleton while operating the drainage facility, the weight water for balance to counter the buoyancy of the groundwater is used as the underground skeleton. Since the step of adding to the groundwater and the step of stopping the function of the drainage facility when the weight of the groundwater to which the weight water is added exceeds the buoyancy of the groundwater, the weight of the groundwater should be increased by the weight water. This has the effect of stopping the drainage (pumping) of groundwater earlier than the conventional method.

Further, according to another weight balance water immersion method according to the present invention, as the weight of the underground skeleton increases due to the progress of the construction of the underground skeleton, the step of draining the weight water added to the underground skeleton to the outside is further increased. Since it is prepared, it has the effect of improving the construction efficiency of underground construction.

Further, according to another weight balance water immersion method according to the present invention, water containing a chemical having a disinfecting or bactericidal action is used as the weight water, so that the hygienic environment of the underground skeleton after construction can be improved. It has the effect of being able to do it.

FIG. 1 is a construction procedure diagram showing an embodiment of the weight balance water immersion method according to the present invention, in which (1) is root cutting / flooring, and (2) is underground skeleton placement, weight water injection, and pumping stop. , (3) is the blockage / removal of the drainage facility, and (4) is the skeleton start-up and weight water control. FIG. 2 is a diagram showing the procedure for closing / removing the conventional drainage facility. (1) is root cutting / flooring, (2) is underground skeleton placement and pumping stop, and (3) is blockage / removal of the drainage facility. This is an example of removal.

Hereinafter, embodiments of the weight balance water immersion method according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

This embodiment is an underground construction method for early removal of the drainage facility used to prevent the underground skeleton from rising due to the buoyancy of the groundwater when constructing the underground skeleton.

As shown in FIG. 1 (1), first, as in the conventional method, a water blocking wall 10 is constructed in advance on the ground G around the region A, and a deep well 12 is formed inside the water blocking wall 10. A (pumping well) is provided, and a recharge well 14 (water injection well) is provided on the outside of the water blocking wall 10. Then, the drainage facility 18 is constructed by connecting the deep well 12 and the recharge well 14 with the pipe 16. After that, the pumps in the wells 12 and 14 are operated to operate the drainage facility 18, and the groundwater W is pumped (drained) from the ground G directly under the area A toward the outside of the water blocking wall 10 to raise the groundwater level WL. While controlling, root cutting and flooring are performed for area A.

Next, as shown in FIG. 1 (2), while operating the drainage facility 18, concrete is poured into the area A to construct the underground skeleton 20. As a result, the drainage pit 22 is formed inside the underground skeleton 20, and the space 26 is formed inside the outer wall 24. Weight water 28 for balance is injected into the drainage pit 22 and the internal space 26.

For the weight water 28, for example, tap water or groundwater can be used. Further, if necessary, water mixed with a chemical such as an oxidizing agent having a disinfecting and bactericidal action such as hypochlorous acid may be used as weight water. By doing so, the sanitary environment such as the internal space 26 of the underground skeleton 20 after draining the weight water 28 in the post-process can be maintained in a good state.

The weight of the underground skeleton 20 increases by the amount of the weight water 28 injected, and the force against the buoyancy of the groundwater increases. After that, when it is confirmed that the weight of the underground skeleton 20 including the weight water 28 exceeds the buoyancy (lifting pressure) of the groundwater, the operation of the drainage facility 18 is stopped and the pumping is stopped.

Next, as shown in FIG. 1 (3), the deep well 12 and the recharge well 14 are closed, and the drainage facility 18 such as the pipe 16 is removed. As described above, according to the present embodiment, since the weight of the underground skeleton 20 can be increased by injecting the weight water 28, the drainage facility 18 can be removed at an earlier stage than the conventional method.

Next, as shown in FIG. 1 (4), as the underground skeleton 20 rises and the weight of the underground skeleton 20 increases due to the progress of the construction, the weight water 28 is pumped by the pump P while balancing with the buoyancy of the groundwater. Drain to the outside and carry out cleaning and other skeleton work. As a result, the construction efficiency of underground construction can be improved.

As described above, according to the present embodiment, the pumping of groundwater can be stopped earlier than the conventional method. As a result, the drainage facility 18 can be removed at an early stage, so that the site cost can be reduced as compared with the conventional method and the construction period can be shortened.

In the above embodiment, the case where the groundwater pumped from the deep well 12 is restored to the recharge well 14 has been described as an example, but the present invention is not limited to this, and the present invention is not limited to this. It can be applied to any underground work as long as it is a work that lowers the groundwater of the direct ground board. For example, it may be applied to the construction of draining the groundwater pumped from the deep well to the outside without condensing it. As described above, the present invention can also be applied to construction work that does not use a recharge well.

As described above, according to the weight balance water immersion method according to the present invention, when constructing the groundwater, it is a water immersion method that prevents the groundwater from rising due to the buoyancy of the groundwater, and constructs the groundwater. For the step of installing a drainage facility in the ground to drain the groundwater under the area to the outside, and then for the balance to counter the buoyancy of the groundwater while constructing the underground skeleton while operating the drainage facility. Since the step of adding the weight water to the groundwater and then the step of stopping the function of the drainage facility when the weight of the groundwater to which the weight water is added exceeds the buoyancy of the groundwater, the weight water is used underground. The weight of the skeleton can be increased, and the drainage (pumping) of groundwater can be stopped earlier than the conventional method.

Further, according to another weight balance water immersion method according to the present invention, as the weight of the underground skeleton increases due to the progress of the construction of the underground skeleton, the step of draining the weight water added to the underground skeleton to the outside is further increased. Therefore, it is possible to improve the construction efficiency of underground construction.

Further, according to another weight balance water immersion method according to the present invention, water containing a chemical having a disinfecting or bactericidal action is used as the weight water, so that the hygienic environment of the underground skeleton after construction can be improved. can.

As described above, the weight balance water immersion method according to the present invention is useful for underground construction using a drainage facility such as a deep well for lowering the groundwater level, and is particularly suitable for removing the drainage facility at an early stage. ing.

10 Water stop wall 12 Deep well 14 Recharge well 16 Piping 18 Drainage facility 20 Underground frame 22 Drainage pit 24 Outer wall 26 Internal space 28 Weight water A area G Ground P Pump W Groundwater WL Groundwater level

Claims (3)

It is a water immersion method that prevents the underground skeleton from rising due to the buoyancy of the groundwater when constructing the underground skeleton.
A step to install a drainage facility in the ground to drain the groundwater below the area where the underground skeleton is to be constructed, and then to build the underground skeleton while operating the drainage facility while countering the buoyancy of the groundwater. It is provided with a step of adding weight water for balance to the underground skeleton for making the weight water, and then a step of stopping the function of the drainage facility when the weight of the underground skeleton to which the weight water is added exceeds the buoyancy of the groundwater. Weight balance water immersion method featuring. The weight balance water immersion method according to claim 1, further comprising a step of draining the weight water added to the underground skeleton to the outside as the weight of the underground skeleton increases due to the progress of the construction of the underground skeleton. .. The weight balance water immersion method according to claim 1 or 2, wherein as the weight water, water containing a chemical having a disinfecting or bactericidal action is used.

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