JP2006057405A - Water cutoff method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water cutoff method for stopping water outflow from a water leak section at a low cost. <P>SOLUTION: The ground G is excavated to form an excavated hole V using a casing pipe 2 fitted to a boring machine 1 so that the excavated hole V may reach a space X formed in the ground G near the water leak section Z due to the outflow of the water from the water leak section of an earth retaining wall W constructed in the ground G. An injection pipe 7 having a long bag body 8, which is shrunk to have pleats and fitted to the outer peripheral surface of the injection pipe 7, is inserted into the excavated hole V through the casing pipe 2, and the front ends of the injection pipe 7 and the bag body 8 are protruded into the space X. By injecting a hardening agent into the bag body 8 from the injection pipe 7, the bag body 8 is sent into the space X while being expanded, is separated from the outer peripheral surface of the injection pipe 7, and is left in the space X. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water stop construction method for stopping outflow of water from a water leakage portion of an object installed in the ground.

  As an installation object provided in the ground, there is a retaining wall made of steel sheet pile or soil cement, for example. The retaining wall is installed in the ground so as to surround the construction site before constructing an underground structure or the like, and prevents the ground from collapsing during construction work. FIG. 2 is a diagram showing a state in which the inside of the retaining wall is excavated to construct an underground structure after the retaining wall is installed. In FIG. 2, W is a retaining wall installed in the ground G, H is an excavation shaft for constructing an underground structure formed by excavating the retaining wall W, and K is a bottom in the retaining wall W. The retaining wall W prevents the ground G from collapsing into the open shaft H, but the groundwater in the ground G from the gap between the sheet piles constituting the retaining wall W and cracked portions of soil cement into the open shaft H May leak out. In addition, earth and sand may be mixed with groundwater. Z is a water leakage portion of the retaining wall W including the above-described defect portion, and X is a gap generated in the ground G by groundwater and earth and sand flowing out from the water leakage portion Z. In addition, since the space | gap X becomes a flow path of groundwater etc., if the outflow of groundwater etc. continues, the space | gap X will be expanded further from the magnitude | size shown in figure. If groundwater or the like flows into the open shaft H as described above, the work cannot be performed safely in the open shaft H, and measures to stop this outflow are necessary.

  Therefore, conventionally, after the ground G is excavated from the surface Ga to the gap X near the water leakage portion Z by the casing pipe attached to the boring machine, the excavation hole is formed as shown by the broken line, and then the hollow in the casing pipe is formed. It has been practiced to stop the outflow of groundwater from the water leakage part Z into the open shaft H by injecting a hardening material into the gap X through the part and hardening the injected hardening material. However, in this method, since the hardened material injected into the gap X flows into the open shaft H from the water leakage part Z together with the groundwater before hardening, the hardened material is hard to be hardened in the gap X and the groundwater flows out. It is very difficult to stop. There is also a problem that the amount of the hardener injected increases and the cost of the hardener increases.

  On the other hand, in Patent Document 1 below, a bag is housed in a rod of an excavator, a drill hole is formed deeper than the water leakage portion of the water blocking wall with the rod, and then the rod is pulled out from the drill hole. Leakage by leaving the bag body in the hole, watertightly connecting the inlet of the pump for injecting the hardener to the opening near the ground surface of the bag body, injecting the hardener into the bag body and expanding the bag body It is described that the outflow of groundwater from the water leakage part is stopped by pressure bonding to the part.

JP-A-5-132962

  In order to stop the outflow of groundwater from the water leakage portion Z as shown in FIG. 2 into the open shaft H by the method as described in Patent Document 1 described above, after leaving the bag body in the excavation hole, Since the inlet of the pump for injecting the curing material must be connected to the opening, a long bag body corresponding to the depth of the water leakage portion Z extending from the water leakage portion Z to the ground surface is required. Further, in order to inflate the bag body by injecting the curing material and press-fit it to the water leakage portion Z, a wide bag body that can expand in the lateral width direction more than the width of the gap X is required. When such a large bag is used, the cost required for the bag increases, and a very large amount of curing material is required to inflate the bag, resulting in a high cost for the curing material. There is a problem of becoming.

  This invention solves the said problem, and the place made into the subject is providing the water stop construction method which can stop the outflow of the water from a water leak part at low cost.

  The present invention is a water stop construction method that stops the outflow of water from the water leakage part of the installed object in the ground, and excavates by excavating the ground until it reaches the void generated in the ground due to the water outflow from the water leakage part After forming the hole, the bag body is expanded by shrinking the long bag body into a pleated shape, inserting an injection tube attached to the outer peripheral surface into the excavation hole, and injecting a curing material into the bag body from the injection tube Then, it is fed into the gap, separated from the outer peripheral surface of the injection tube, and left in the gap.

  By doing as described above, the long bag body in an expanded state fed into the gap is curved and bent until the hardened material is cured, and is freely changed in shape and superimposed. Since the water flow path is blocked by filling the water, it is possible to stop water from flowing through the gap and stop the outflow of water from the water leakage portion. For this reason, it is not necessary to use a large bag body that can be expanded in the width direction according to the depth of the water leaking portion and more than the width of the gap as in Patent Document 1, and the cost for the bag body and the curing material is reduced. Can be suppressed. Also, by injecting the hardener into the bag, the hardener will not flow out of the water leaking part or diffuse into the ground, so the amount of hardener injected will increase as before, and the hardener will be applied. There is no cost increase. Furthermore, by shrinking the long bag body into a pleat and attaching it to the outer peripheral surface of the injection tube, when the bag body is expanded and left in the gap, the volume of the bag body increases, The filling rate of the gap by the bag body per one construction of the water stop method (the ratio of the volume of one bag body in the gap to the volume of the gap) can be increased, and the inside of the gap is filled from the water leakage part. It is possible to shorten the construction period until the water outflow is stopped.

  Moreover, in embodiment of this invention, a bag body is made to detach | leave from the outer peripheral surface of an injection tube with the injection | pouring pressure which inject | pours a hardening material into a bag body from an injection tube. In this case, it is not necessary to provide a means and a process for separating the bag body from the outer peripheral surface of the injection tube, so the cost for the apparatus for constructing the water stop method can be kept low, and the construction period can be reduced. It becomes possible to shorten.

  According to the present invention, the long bag body in an expanded state left in the gap fills the gap and closes the flow path of the water, and prevents water from flowing through the gap. It is not necessary to use a large bag body that can be inflated according to the depth of the part and larger than the width of the gap, and the outflow of water from the water leakage part can be stopped while keeping the cost for the bag body and the curing material low It becomes possible.

  1A and 1B are views for explaining a water stop method according to the present invention. In each figure, W is a retaining wall installed in the ground G as an installation in the ground, H is an excavation shaft for constructing an underground structure formed by excavating the retaining wall W, K is in the retaining wall W It is the bottom board. Z is a water leakage part of the retaining wall W including gaps between sheet piles constituting the retaining wall W and missing portions such as cracks in soil cement. The groundwater in the ground G and the earth and sand are mixed with the groundwater G from the water leakage portion Z and flow into the open shaft H. X is a gap generated in the ground G in the vicinity of the water leakage portion Z when groundwater and earth and sand flow out from the water leakage portion Z. In addition, since the space | gap X becomes a flow path, such as groundwater, it expands further from the magnitude | size shown in the figure.

  First, a plurality of sandbags D filled with earth and sand or the like are stacked on the side of the excavated vertical shaft H of the water leakage part Z to suppress outflow of groundwater or the like to the side of the open vertical shaft H. Next, as shown in FIG. 1A (a), the boring machine 1 is installed on the ground surface Ga, and the casing pipe 2 with the bit 3 attached to the tip is rotated by the boring machine 1 to reach the gap X. The ground G is excavated until the excavation hole V is formed. A cone-shaped rubber check valve 4 is attached to the inside of the casing pipe 2 at the front end side to prevent inflow of groundwater and earth and sand into the casing pipe 2.

  When the excavation hole V is formed as described above, as shown in FIG. 1A (b), the casing pipe 2 is fixed so as to be positioned in the excavation hole V by the fixing base 5 installed on the ground surface, and the boring machine 1 is removed. To do. Next, the injection pipe 7 penetrating the cap 6 is inserted into the casing pipe 2, the check valve 4 is pushed open, and the tip of the injection pipe 7 is protruded from the tip of the casing pipe 2 into the gap X. Then, the cap 6 is fitted to the rear end of the casing pipe 2 to fix the injection pipe 7 so as not to move, and the rear end of the casing pipe 2 is sealed.

  The rear end of the injection tube 7 is connected to a curing material supply source 10 including a tank that stores the curing material and a pump that supplies the curing material at a predetermined pressure. As the curing material, for example, a cement-based curing material such as cement milk is used. In addition to this, for example, a curing material having a fast curing property (a two-material mixing type curing material having a relatively short gel time) that is cured by mixing two materials of a cement-based main material and a curing accelerator may be used. Good. In this case, a double pipe composed of an outer pipe and an inner pipe is used as the injection pipe 7 and the main material is passed through one of the outer pipe or the inner pipe, and the curing accelerator is passed through the other. If the two materials are injected and mixed at the injection destination, they will be cured. On the outer peripheral surface below the cap 6 of the injection tube 7 (the ground G side), a long bag body 8 is fitted in a pleated shape. Specifically, after covering the long bag body 8 from the distal end side of the injection tube 7 and shrinking it into a pleated shape, a plurality of rubber bands 9 are attached on the bag body 8 at predetermined intervals. The bag body 8 is temporarily fixed to the outer peripheral surface of the injection pipe 7 with a weak tightening force so that the bag body 8 does not slip off due to its own weight. The tip of the injection tube 7 is opened so that a hardening material can be injected into the bag body 8. The bag body 8 is formed of a knitted fabric made of synthetic fibers, and has a water permeability that allows the cement-based hardener injected therein to permeate until the cement particles are clogged. In addition to this, for example, even if the bag body 8 is formed of a woven fabric or a nonwoven fabric made of synthetic fibers, or a knitted fabric made of natural fibers, a woven fabric or a nonwoven fabric, etc., it can have the same water permeability as above. it can. Further, the bag body 8 may be formed of a stretchable and impermeable material such as rubber or synthetic resin.

  As shown in FIG. 1A (b), the injection tube 7 and the end of the bag 8 are projected into the gap X, and the injection tube 7 is fixed. The hardening material is supplied from the hardening material supply source 10 to the injection tube 7 at a predetermined pressure. It is supplied and injected into the bag body 8 from the tip of the injection tube 7. Thereby, as shown to FIG. 1A (c), the bag body 8 is sent out from the inside of the casing pipe 2 into the space | gap X, expanding. Further, when the hardener is continuously injected, the bag body 8 and the band 9 above the check valve 4 (cap 6 side) are pulled downward by the injection pressure of the hardener, and gradually the injection pipe 7 shifts to the tip side. The injection pressure of the curing material is observed by a pressure gauge (not shown) installed in the curing material supply source 10.

  When the inside of the bag body 8 is filled with the hardener, the bag body 8 and the band 9 are separated from the outer peripheral surface of the injection pipe 7 by the injection pressure of the hardener as shown in FIG. It falls inside and is left. When the bag body 8 is detached from the outer peripheral surface of the injection tube 7, the injection pressure of the curing material is reduced. For this reason, when the drop of the injection pressure is confirmed by the above-described pressure gauge, the supply of the curing material from the curing material supply source 10 is stopped. The inflated bag body 8 that has entered the gap X is bent or flexed until it is cured until the internal hardened material is cured, and the shape is freely changed and superimposed. Go fill up. Moreover, since the bag body 8 has water permeability as described above, the cured material oozes out from the bag body 8 and overlaps the gap between the bag body 8 and the gap between the bag body 8 and the retaining wall W. And the gap between the bag body 8 and the gap X, respectively. In addition, since the upper end part of the bag body 8 is not closed, the hardening material flows out from the upper end part. However, since the hardening material previously injected into the bag body 8 has already started to harden, the outflow amount of the hardening material. Is a small amount.

  When the bag body 8 is left in the gap X, the cap 6 is removed from the rear end of the casing pipe 2, and the injection pipe 7 is pulled up and extracted from the casing pipe 2. Next, after attaching another bag body 8 to the drawn out injection tube 7, the injection tube 7 is inserted into the casing pipe 2, and the tip of the injection tube 7 is inserted into the gap X as shown in FIG. 1B (e). To protrude. Alternatively, another injection pipe 7 that is previously attached with the bag body 8 is passed through the cap 6 and connected to the curing material supply source 10, and then the injection pipe 7 is inserted into the casing pipe 2. As shown in 1B (e), the tip of the injection tube 7 is projected into the gap X. As described above, the cap 6 is fitted to the rear end of the casing pipe 2 to fix the injection tube 7.

  When the injection tube 7 is fixed, the hardening material is supplied from the hardening material supply source 10 at a predetermined pressure, and is injected into the bag body 8 from the tip of the injection tube 7. Thereby, as shown in FIG. 1B (f), the bag body 8 is sent out from the casing pipe 2 into the gap X while expanding. When the inside of the bag body 8 is filled with the curing material as described above, the bag body 8 is detached from the outer peripheral surface of the injection tube 7 as shown in FIG. Left inside.

  When the gap X is almost filled with the inflated bag 8 as shown in FIG. 1B (g), the injection pressure rises during the injection of the hardener into the bag 8. For this reason, when an increase in the injection pressure is confirmed by the aforementioned pressure gauge during the injection of the curing material, the bag body 8 is subsequently detached from the outer peripheral surface of the injection tube 7 and a decrease in the injection pressure is confirmed. Immediately without stopping the supply of the curing material from the curing material supply source 10, the supply of the curing material is continued for a while and then the supply is stopped. As a result, a predetermined amount of the hardening material is poured onto the bag body 8 left in the gap X from the injection tube 7, and the overlapping gap between the bag body 8, the gap between the bag body 8 and the retaining wall W, and the bag body 8. And the gap X.

  Thereafter, the cap 6 is removed from the rear end of the casing pipe 2, the injection pipe 7 is pulled out from the casing pipe 2, and then the casing pipe 2 is pulled out from the excavation hole V to remove the fixed base 5 from the ground surface. . Then, as shown in FIG. 1B (h), the excavation hole V is filled, and the cured material in the bag body 8 and the cured material that has been poured onto the bag body 8 are cured.

  By doing as described above, the elongated bag body 8 in an expanded state fed into the gap X is bent and bent until the curing material is cured, and is freely changed in shape and superimposed. Since the gap X is filled and the flow path of the water is blocked, it is possible to stop water from flowing through the gap X and stop the outflow of water from the water leakage portion Z. For this reason, it is not necessary to use a large bag body that can be expanded in the width direction in accordance with the depth of the water leakage portion Z and larger than the width of the gap X as in Patent Document 1, and the bag body 8 and the curing material are applied. Cost can be kept low.

  In addition, by injecting the hardener into the bag 8, the hardener does not flow out from the water leakage part Z or diffuses into the ground G. The cost for the hardener does not increase. Further, when the bag body 8 is inflated and left in the gap X by shrinking the long bag body 8 into a pleat and attaching it to the outer peripheral surface of the injection tube 7, the volume of the bag body 8 is increased. Therefore, the filling rate of the gap X by the bag body 8 per one-time construction of a series of processes until the bag body 8 is left in the gap X (one bag body 8 with respect to the volume of the gap X is in the gap X) The ratio of the volume occupied by (3) can be increased, and it is possible to shorten the construction period until the gap X is filled and the outflow of water from the water leakage portion Z is stopped.

  Furthermore, since the bag body 8 is detached from the outer peripheral surface of the injection pipe 7 by the injection pressure of the curing material, it is not necessary to provide means and a process for removing the bag body 8, so the above-described water stopping method is used. It is possible to reduce the construction period by keeping the cost for the apparatus for construction low.

  In the embodiment described above, an example is given in which two bags 8 are left in the gap X generated in the ground G in the vicinity of the water leakage portion Z and the gap X is filled. The number of bags left in the gap may be one, or three or more. That is, the number of bags left in the gap may be determined in accordance with the size of the gap generated in the ground near the leaked portion and the stoppage state of water from the leaked portion.

  In the embodiment described above, the water stop method according to the present invention is applied in order to stop the outflow of groundwater from the leakage portion of the retaining wall W into the open shaft H. It is not limited to this. In addition to this, for example, the wall of an underground building such as a basement or a subway station, or the wall of a civil engineering structure such as a tunnel or a mountain retaining wall is cracked, etc. It can also be applied to stop groundwater runoff. Moreover, it can also be applied to stop the outflow of water into the ground from a water leaking part such as a joint part of a water pipe installed in the ground or a missing part such as a crack.

It is a figure for demonstrating the water stop construction method concerning this invention. It is a figure for demonstrating the water stop construction method concerning this invention. It is a figure for demonstrating the conventional problem.

Explanation of symbols

7 Injection pipe 8 Bag body G Ground W Retaining wall V Drilling hole X Cavity Z Water leakage part

Claims (2)

It is a water stop construction method that stops the outflow of water from the water leakage part of the installed objects in the ground,
After excavating the ground until it reaches the gap generated in the ground due to water flowing out from the water leakage part, forming a drilling hole,
Inserting an injection tube attached to the outer peripheral surface by shrinking a long bag into a pleat shape into the excavation hole,
By injecting a hardening material from the injection tube into the bag body, the bag body is sent into the gap while being expanded, separated from the outer peripheral surface of the injection pipe, and left in the gap. Water stop method. In the water stop construction method according to claim 1,
A waterproofing method characterized in that the bag body is detached from the outer peripheral surface of the injection pipe by an injection pressure for injecting a curing material into the bag body from the injection pipe.

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