JP2010053589A - Water-stopping method for ground having running water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of stopping welling up running water caused by the deterioration of post-processing materials, such as an old well and boring hole, and other reasons in an underground drilling work executed at a level lower than an underground water level, particularly a method for stopping running water on which ordinary chemical injection construction method is ineffective. <P>SOLUTION: The water-stopping method for a ground having running water is a method for stopping the running water welling up from a flooding hole of the ground. A granular material K having a material diameter and specific gravity large enough to be prevented from being carried away by the running water is supplied from flooding openings a, c, and d into flooding holes A, C, and D to fill them with the granular material K to suppress the energy, speed, and volume of running water. A chemical fluid is then injected into the area filled with the granular material K to cause the chemical fluid to gel or solidify in the space of the granular materials having a high specific gravity to close the flooding holes A, C, and D to stop running water. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  This invention does not make use of the water stop method, especially the usual chemical injection method, for stopping the flowing water that springs up due to deterioration of post-treatment materials such as old wells and boreholes in underground drilling work deeper than the groundwater level. It belongs to the technical field of methods for stopping running water.

In underground excavation work deeper than the groundwater level, groundwater may overflow to the excavation bottom due to deterioration of post-treatment materials such as old wells and boreholes. As a method for stopping such flowing water, conventionally, a chemical solution injection method mainly composed of water glass or foamed urethane is often performed. The water stopping mechanism using a chemical solution is based on a phenomenon in which the chemical solution gels or solidifies in the gaps between the soil particles, thereby closing the outlet holes.
For example, the following Patent Documents 1 to 3 disclose a chemical solution useful for water-stopping treatment of the ground as described above and a chemical solution injection method or a water-stop method using the chemical solution.
Moreover, the following patent document 4 discloses a water stopping method when groundwater leaks from an underground structure such as a tunnel or a sewer.

JP 7-324189 A JP 7-138564 A JP-A-8-3555 JP-A-8-158393

The chemical solution injection method or the water stop method disclosed in Patent Documents 1 to 4 are also useful construction methods. However, in the case of running water caused by deterioration of post-treatment materials such as old wells and boreholes, the gaps in the drainage holes are large, and when the speed and amount of running water are large, even if chemical injection is performed, There are many cases where the effect of the water stop treatment cannot be obtained because the chemical solution is poured into running water before gelation or solidification.
As a prior art in such a case, using a heavy machine, a casing pipe (stand pipe) with a diameter (inner diameter) much larger than the size of the water outlet and the water outlet hole (air gap dimension) that follows it. In the layout that surrounds the water outlet and the water outlet hole below it, it penetrates into the ground and rises higher than the groundwater level, fills the casing pipe with running water, and the running water gradient of the running water (water outlet hole) A value obtained by dividing the water level difference at the upper and lower ends by the distance between the upper and lower ends) and reducing the speed, flow rate, and momentum of the flowing water and then stopping the water by injecting the chemical solution has been implemented.

  However, if the speed, amount, and momentum of the flowing water are even greater and it is impossible to implement the water stop work using the above casing pipe, it is unavoidable that the underground excavation work area will be submerged with the flowing water flowing out, resulting in a hydrodynamic gradient. A method of stopping the water by injecting a chemical solution at a stage where the speed and amount of flowing water were suppressed was waited until it became smaller.

However, the water stop method that penetrates the casing pipe (stand pipe) into the ground and rises higher than the groundwater level requires large heavy machinery to be carried into the underground excavation work area in order to penetrate the casing pipe into the ground. In fact, if such heavy machinery cannot be prepared, it cannot be implemented.
In addition, the method of submerging the underground excavation work area with the flowing water flowing out is to wait for the submerged time until the flowing water is discharged and the speed and volume of the flowing water are suppressed, and then stop the water treatment. It is necessary to go through the process of draining all the water accumulated in the area and preparing an environment where the underground excavation work can be resumed, and it takes a lot of time during that time, and a considerable delay in the construction period is required. It is not possible to stop water.

The object of the present invention is to solve the above-mentioned problems of the prior art, especially in underground excavation work, the speed, amount, and momentum of the water overflowing from the ground outlet are large, and the implementation of the usual chemical injection method is used. It is to provide a water stop method that can be effectively implemented when not done.
A further object of the present invention is a water stopping method applying a chemical solution injection method, which does not require large heavy machinery, and does not require any special tools or mechanical devices other than the chemical solution injection device. It is to provide a water stop method for ground where there is running water, in order to create an environment where the effect of the chemical solution is fully demonstrated and to show the effectiveness of the water stop treatment.

As a means for solving the above-mentioned problem, the water stopping method for ground having flowing water according to the invention described in claim 1 is a particle size that is not allowed to flow into the flowing water in the method for stopping flowing water overflowing from the water discharge hole of the ground. The granular material with high specific gravity is supplied from the outlet to the outlet hole and filled to suppress the momentum, flow rate and flow rate of the flowing water, and then the chemical solution is injected into the granular material filling region, and the granular material with the high specific gravity is injected. It is characterized in that it is gelled or solidified in the gaps to block the inside of the outlet holes and stop the water.

The invention described in claim 2 is the water stop method for the ground with the flowing water according to claim 1,
As a granular material with a particle size that does not flow into the flowing water and a high specific gravity, the selection of the granular material with a specific gravity that is greater than the force that the granular material receives from the flowing water, if the shape of the granular material is spherical, the following formula,
D ≧ [3 / {2 · (γ−1)}] · i
Where γ is the specific gravity of the granular material, D is the particle size of the granular material, and i is the hydrodynamic gradient of the flowing water overflowing from the outlet hole.
The invention described in claim 3 is the water stop method of the ground with the flowing water according to claim 1,
As a granular material that does not flow into running water and has good fillability in the drainage holes, iron balls with a particle size smaller than the gaps in the drainage holes are supplied to the drainage holes from the outlet, and the momentum, flow rate, and flow rate of the flowing water decrease. It is characterized by filling until.
According to a fourth aspect of the present invention, there is provided a water stopping method for a ground having flowing water according to the first aspect,
As a granular material that does not flow into running water and has good fillability in the drainage holes, iron balls with a particle size smaller than the gaps in the drainage holes are supplied to the drainage holes from the outlet, and the momentum, flow rate, and flow rate of the flowing water decrease. Continue to supply until filling, and after visually confirming that the momentum, flow rate, and flow rate of running water have decreased, inject the chemical into the iron ball filling area including the depth where the surrounding ground is an impermeable layer. , And the gelled or solidified in the gap between the iron ball and the soil particles to block the inside of the water outlet and stop the water.

The method for stopping the ground with flowing water according to the present invention is when underground water overflows from the ground outlet due to deterioration of post-treatment materials of old wells and boreholes in underground excavation work deeper than the groundwater level. In addition, the water stopping method is effective when the speed, flow rate, and momentum of the flowing water are so large that the chemical solution is poured into the flowing water to stop the flowing water and the water stopping effect cannot be obtained.
The water stop mechanism of the present invention does not suppress the flow of water by reducing the gradient of water flow as in the prior art, but does not flow into the flow of water. Supply from the water port to fill the outlet hole with the required amount, and control the momentum, flow rate, and flow rate of the flowing water to such an extent that no chemicals are allowed to flow. The inhibitory effect is confirmed by visual observation of the momentum, flow velocity, and flow rate of the flowing water from the water outlet at the bottom of the excavation, and then the chemical solution is injected into the granular material filling region, and gelled in the gap between the granular material and the soil particles. Or it is the method of making it solidify and obstruct | occluding the inside of a water outlet hole, and stopping water. Therefore, in order to carry out the present invention, there is no need for special tools or mechanical devices other than the existing chemical liquid injector. Moreover, without requiring special technical skill, anyone can easily and quickly carry out on-site water discharge, and a water stop effect can be obtained. Moreover, since the injected chemical solution is fully effective and the water outlet is fundamentally blocked to stop the water, a permanent water stop effect can be obtained, enabling rapid progress of underground excavation work, reducing construction costs, and the construction period. It can greatly contribute to the shortening.

A granular material having a particle size and high specific gravity that is not flowed into running water is supplied from the outlet to the outlet hole and filled to reduce the momentum, flow rate, and flow rate of the flowing water. After confirming the fact of the suppression, a chemical solution is injected into the granular material filling region and gelled or solidified in the gap between the high specific gravity granular material and soil particles to block the inside of the water discharge hole and stop. Water.
Selection of a granular material having a particle size that does not flow into the flowing water and a high specific gravity, that is, selection of a granular material having a specific gravity greater than the force that the granular material receives from the flowing water, when the shape of the granular material is spherical, The following formula is used.
D ≧ [3 / {2 · (γ−1)}] · i
Where γ is the specific gravity of the granular material, D is the particle size of the granular material, and i is the hydrodynamic gradient of the flowing water overflowing from the outlet hole. The hydraulic gradient γ is a value obtained by dividing the water level difference at the upper and lower ends of the water outlet hole by the distance between the upper and lower ends as described above.
As a granular material that does not flow into running water and has good fillability to the water outlet, supply the required amount of iron balls having a particle size smaller than the gap of the water outlet from the outlet to the outlet. Fill until low. Thus, at the stage where it was visually confirmed that the momentum, flow velocity, and flow rate of the flowing water were reduced to such an extent that gelation or solidification could occur in the gaps between the granular material and the soil particles without flowing even when the chemical solution was injected. The chemical solution is injected into the iron ball filling area including the depth where the surrounding ground is an impermeable layer, and gelled or solidified in the gap between the iron balls (and soil particles, etc.) to block the inside of the water outlet and stop the water To do.

Next, the present invention will be described based on the illustrated embodiment.
First, FIG. 1 conceptually illustrates an example of a phenomenon (or cause) of flowing water in which groundwater springs up to the ground or the like in underground excavation work deeper than the groundwater level W. A symbol A in the figure indicates a water outlet generated due to deterioration of the post-treatment material of the old well B, and a indicates a water outlet. C indicates a water outlet generated due to poor post-treatment of the bore hole, and c indicates the water outlet. D indicates a water discharge hole by the water supply generated on the back surface of the impermeable wall (mountain wall) E, and d indicates the water outlet. In addition, it has been empirically known that water holes are actually generated due to various causes and phenomena, and groundwater flows out.

FIG. 2 conceptually shows the actually measured environment and construction conditions when water stoppage treatment is performed by the method of the present invention for the water outlet A generated due to deterioration of the post-treatment material of the old well B, etc. ing.
The old well B shown in the embodiment of FIG. 2 is installed at a depth that penetrates the underground impermeable layer G and reaches the aquifer F existing thereunder (43 m in the illustrated example). On the other hand, the groundwater level W was 18 meters underground in the example of FIG. The underground excavation work in the example shown in the figure has already progressed to 23 meters underground, and a large amount of groundwater overflows from the water outlet A along the old well B with a large flow velocity and flow rate. Therefore, it is in a condition where gelation or solidification cannot be expected.

The procedure for carrying out the water stop method according to the present invention for the generation of the above-mentioned flowing water began by first measuring and grasping the flow velocity and flow rate of the flowing water and the gap size of the outlet port a.
As described above, the depth of the groundwater level W is 18 meters underground, and the current depth of the bottom of excavation is 23 meters underground is known as an actual measurement value related to construction. Therefore, based on these known conditions, the water level difference (pressure level) h (5 m in the illustrated example) at the upper and lower ends of the water outlet A, and the distance H (in the illustrated example) between the upper and lower ends of the outlet hole A. 20m) was easily grasped by calculation.
As a result, the running water gradient i of the running water was determined as follows from the equation i = h / H. That is, i = 5/20 = 0.25 based on the above measured values.
Moreover, since the gap | interval size of the water outlet a was able to be acquired by actually measuring, as a result, the dimension (outside diameter etc.) of the granular material which can be thrown in from the water outlet a was roughly grasped.

Next, based on the hydrodynamic gradient i determined as described above, the magnitude of the force that the granular material to be input receives from the flowing water was determined by the following calculation method.
As illustrated in FIG. 3, when the granular material K is spherical (or the same for a water droplet-shaped granular material), the magnitude of the force P that the granular material K receives from flowing water can be grasped as follows. Incidentally, if the shape of the granular material is spherical, there is no unnecessary catch, so it is selected as an effective material for improving the filling rate of the granular material in the water outlet.
When the weight of the spherical granular material K in water is Q and the force received by the granular material K by running water is P, the following “Expression 1” is established. In this case, however, the relationship between the weight Q of the granular material K in the water and the force P received by the granular material K by flowing water is a precondition that Q ≧ P as a condition for preventing the granular material K from flowing by flowing water. It becomes.
[Formula 1]
(Γ−γ _W ) · V ≧ f {V (i)} · S
Where γ is the density of the granular material (g / cm ³ ), γ _W is the density of the water flow in the outlet hole (g / cm ³ ), V is the volume of the granular material (cm ³ ), and V (i) is The speed (cm / min) that the granular material receives, f {V (i)} is the pressure (g / cm ² ) that the granular material K receives by flowing water, S is the projected area of the granular material, and the relationship with the particle size D Is S = π · (1 / 2D) ² .

When the magnitude of the force P applied to the granular material K by the flowing water is found from the above “Expression 1”, the selection of the granular material having a particle size and high specific gravity that is not flowed into the flowing water can be grasped by “Expression 2”.
[Formula 2]
D ≧ 3 · i / {2 (γ−1)}
However, D is the particle size of the granular material, γ is the density of the granular material (g / cm ³ ), and i is the hydrodynamic gradient as described above.

FIG. 4 is a graph showing the relationship between the hydrodynamic gradient i, the specific gravity of the granular material, and the particle size D, based on the above “Formula 2”. FIG. 5 is a graph showing the minimum particle diameter of the granular material to be input.
According to FIG. 4, since the pressure P which flowing water gives to a granular material can be considered as continuous, it turns out that the particle size D of the granular material which is not flowed into flowing water can be evaluated with the dynamic water gradient i and the density of a granular material. That is, according to FIG. 4, as a general theory with respect to the hydraulic gradient i = 0.25 calculated from the actually measured value of the paragraph number [0014], the minimum particle diameter of the substance X having a specific gravity x is grasped as Dx. Similarly, the minimum particle diameter of the substance Y having a specific gravity y was determined to be Dy.
Further, FIG. 5 is a graph in which the characteristic line Z1 is a graph obtained by obtaining the minimum particle diameter regarding the iron material having a specific gravity γ of 7.85, and the characteristic line Z2 is the minimum particle diameter regarding soil particles having the specific gravity γ of 2.65. It is the graph which calculated | required.
Accordingly, the silica sand having a particle diameter of 1.9 mm marked with a ▲ mark in FIG. 5 is less than the characteristic line Z2, and thus is washed away with running water having a dynamic gradient i = 0.25, and the granular material filled in the running water is shown in FIG. It is clear that it is not suitable as a material.
On the other hand, an iron ball having a particle diameter of 11 mm, known as an intercostal pachinko sphere, is also positioned far above the characteristic line Z1 as indicated by the ● mark in FIG. It can be clearly evaluated that it is sufficiently suitable as a granular material not filled with running water and filled into the running water.

Based on the above examination results, in the embodiment shown in FIG. 2, a water stopping method using an iron ball having a particle diameter of 11 mm, which has been found not to be poured into flowing water having the above-described dynamic water gradient i = 0.25, as a granular material. Examples of this will be described below.
As described above, the measured value of the size of the gap at the outlet a and the distance from the bottom of the ground to the aquifer F through the impermeable layer G directly below (20 m in the example shown) An iron ball having a particle diameter of 11 mm was prepared in an approximate amount obtained by integrating the values. And the iron ball was supplied from the water outlet a and filled in the water outlet A as required. The filling operation of the iron ball is provided with a shape and size spout that can be applied to the gap obtained by actually measuring the size of the gap of the water outlet a, and with an appropriately large iron ball capacity, for example, Using a supply container with a funnel, the iron ball was supplied to the outlet a as quickly and surely as possible to shorten the filling work time. As a result, the iron balls gradually descended into the water discharge holes without being swept away by the force of the flowing water, and as the filling amount of the iron balls increased, the water flow, flow velocity, flow rate, etc. gradually decreased. However, when the momentum, flow rate, and flow rate of the flowing water are reduced, silica sand with a particle size of 1.9 mm is supplied together with the iron ball to proceed with filling, and the gap between the iron balls is filled with silica sand to close the gap. Efforts were made to increase the effectiveness and quickly control the momentum of running water.

  As described above, the iron ball is supplied from the water outlet a, and the momentum, the flow velocity, and the flow rate of the flowing water are visible at the stage where the equivalent amount of the iron ball is filled in the water outlet A. Declined. In short, the iron ball descends in the gap of the water outlet A in FIG. 2 without losing water and reaches the bottom (lower end A ′) reaching the aquifer F below the impermeable layer G. Thus, the filling effect that the iron balls completely fill the gap from the lower end A ′ of the water discharge hole A up to a certain height is obtained.

The above-mentioned filling effect can be confirmed and grasped as a drop in the momentum, flow rate, and flow rate of the flowing water that the operator sees at the outlet a. Therefore, as a rule of thumb for those skilled in the art, there is an effect of implementing a normal chemical injection method. A well-known chemical solution injection method was carried out at the stage where the momentum of running water was reduced until it was empirically determined by a contractor. That is, a mechanical device M necessary for carrying out the chemical solution injection method is prepared in advance, and the tip nozzle N of the chemical solution injection tube is positioned near the lower end A ′ of the water outlet A, in other words, in the present invention. “Particle filling area” (Claim 1), more specifically, “Iron ball filling area including the depth where the surrounding ground is an impermeable layer” (Claim 4) can be estimated, For example, a necessary amount of a chemical solution mainly containing existing water glass or urethane foam was injected.
The chemical injection method and method, the chemical injection amount, the chemical material type, and the like are performed as well known in the existing chemical injection method.
Incidentally, the chemical solution used in this example is a water glass-based entite-5S manufactured by Ryohin Co., Ltd. (solution type ultra-instantaneous type, gel time 3 seconds (actual measured value), 7-day compressive strength 5 kgf / cm ² ) was used first, followed by the company's water glass-based enutite-GS (suspension type instantaneous setting type, gel time 25 seconds (actual measurement value), 7-day compressive strength 70 kgf / cm ² ).

As a result of the above steps, the chemical solution gelled or solidified U in the gap between the filled iron ball K and the silica sand, and the gap of the outlet hole A was totally blocked, and the running water could be stopped almost completely.
The actual situation of the water stop treatment is shown in FIG. FIG. 6 is a photograph of the site where the applicant excavated the ground where the water stop method of the present invention was implemented after excavation work was completed. According to FIG. 6, the iron balls K supplied as described above fill the gaps in the outlet holes A, and the injected chemical U is gelled or solidified in the gaps between the filled iron balls K and soil particles. The fact that the inside of the water outlet was blocked, the situation could be confirmed. That is, the chemical U deeply injected into the filled region of the iron ball K, which is a granular material, moves along the gentle flowing water of the water whose flow is suppressed and moves in the height direction of the outlet hole A in the height direction of the outlet ball A and the silica sand. It was confirmed that the water stoppage effect was made permanent by exhibiting a phenomenon in which the gaps of the water discharge holes A were effectively closed by gelling or solidifying in the gaps.

The water stoppage method for the ground with running water according to the present invention is not limited to water discharge due to deterioration of the post-treatment material of the old well as shown in FIG. 2, but the deterioration of the post-treatment material of the borehole C shown in FIG. As for the water stoppage method such as water stoppage treatment by water discharge or water discharge by the tap water generated on the back of the impermeable wall E (mountain wall), if the filling material can be supplied from the water outlet and can be filled, it is exactly the same Can be implemented.
Moreover, even if it is the material and particle size of the granular material to be used, if it is the specific gravity and particle size which are not calculated | required by the method demonstrated based on FIG. 4, FIG. , Other granular materials that can be supplied and filled from the water outlet, for example, old and new, iron bolts and nuts (especially cap nuts are preferred), screws, and even rebar and other pieces of iron Or crushed stone and gravel can be used in a wide variety.

  As mentioned above, although this invention was demonstrated based on the Example shown in figure, this invention is not limited to the Example mentioned above. A so-called person skilled in the art can carry out various modifications within the scope of design changes and applications that are necessary, and includes them.

It is sectional drawing which showed notionally the example which a flowing water generate | occur | produces in the ground etc. in underground excavation construction. It is sectional drawing which showed notionally the Example of the water stop method regarding the water outlet generated by the deterioration of the post-treatment material of an old well, etc. It is explanatory drawing which shows the relationship of the force which a spherical granular material receives with flowing water. It is a graph which shows the relationship between the specific gravity of the flowing water gradient, the granular material with which it fills, and a particle size. It is a graph which shows the relationship between the hydrodynamic gradient and the minimum particle diameter of flowing water regarding the material (iron and earth particle) of a granular material. It is explanatory drawing which showed the water stop mechanism of this invention with the ground excavation photograph.

Explanation of symbols

A, C, D Water outlet K Granular material (Iron ball)
a, c, d Water outlet U Gelled or solidified chemical solution

Claims (4)

In the method of stopping running water that overflows from the ground outlet, the granular material with a particle size that does not flow into the running water is supplied from the outlet to the outlet and filled to reduce the momentum, flow rate, and flow rate of the flowing water, After that, a chemical solution is injected into the granular material filling region and gelled or solidified in the gap of the high specific gravity granular material to block the inside of the outlet hole and stop the water. Water stop method. As a granular material with a particle size that does not flow into the flowing water and a high specific gravity, the selection of the granular material with a specific gravity that is greater than the force that the granular material receives from the flowing water, if the shape of the granular material is spherical, the following formula,
D ≧ [3 / {2 · (γ−1)}] · i
Wherein γ is the specific gravity of the granular material, D is the particle size of the granular material, and i is the hydrodynamic gradient of the flowing water overflowing from the outlet hole. Water way.   As a granular material that does not flow into running water and has good fillability in the drainage holes, iron balls with a particle size smaller than the gaps in the drainage holes are supplied from the outlet to the drainage holes, and the momentum, flow rate, and flow rate of the flowing water decrease. It fills until it does, The water stop method of the ground with the flowing water of Claim 1 characterized by the above-mentioned.   As a granular material that does not flow into running water and has good filling properties in the water outlet, an iron ball having a particle size smaller than that of the water outlet is supplied from the outlet to the outlet, and the momentum, flow rate, and particle size of the flowing water are reduced. Continue to supply until the pressure decreases, and after visually confirming that the momentum, flow rate, and flow rate of the flowing water have decreased, inject the chemical into the iron ball filling area including the depth where the surrounding ground is an impermeable layer. The water stopping method for ground with running water according to claim 1, wherein gelling or solidifying is performed in the gap between the iron balls and soil particles to block the inside of the water outlet hole and stop the water.

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