JP2016204969A - External waterproof repair method of underground structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an external waterproof repair method of an underground structure capable of repairing water leakage by a few water cutoff agent.SOLUTION: An external waterproof repair method for repairing an external waterproof structure formed by adding a waterproof sheet 3 between an underground structure 1 and a natural ground side back face layer 2, comprises a hole drilling process of forming an injection hole 10 in the underground structure 1 and an injection process of dissipating by compressing a water passage 4 between the waterproof sheet 3 and the natural ground side back face layer 2 and the water passage 4 in the natural ground side back face layer 2, by pressing the waterproof sheet 3 to the natural ground side back face layer 2, by injecting a water cutoff agent 20 between the underground structure 1 and the waterproof sheet 3 from the injection hole 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an external waterproof repair method for an underground structure that repairs an external waterproof structure in which a waterproof sheet is provided between the underground structure and a ground-side back layer.

  For example, if water leakage occurs inside the lining in an outer waterproof structure such as a watertight tunnel, after cutting the injection hole from the inside of the lining, insert a nozzle into the injection hole and place the ground outside the waterproof sheet. A water-stopper was being injected into the water. That is, conventionally, the idea was to stop the water by directly filling the water gap of the natural mountain with the water-stopping agent.

  As the water stop agent, for example, the one shown in Patent Document 1 has been used. The water-stop agent of Patent Document 1 is a one-part water-stop agent that reacts with water to form a flexible and followable cured body and can exhibit a water-stop effect over a long period of time.

JP 2014-1381 A

  In the conventional repair method, when the flow rate of groundwater is high, the water-stopping agent flows out and is difficult to solidify, resulting in a problem that the injection amount becomes enormous.

  From such a viewpoint, an object of the present invention is to provide an external waterproof repair method for an underground structure that can repair water leakage with a small amount of water-stopping agent.

  The present invention for solving the above-described problems is directed to an outer waterproof repair method for repairing an outer waterproof structure in which a waterproof sheet is provided between the underground structure and the ground-side back layer, and an injection hole is formed in the underground structure. Drilling step to form, injecting a water-stopping agent between the underground structure and the waterproof sheet from the injection hole, pressing the waterproof sheet against the backside layer of the ground, and the waterproof sheet and the backside of the ground An outer waterproof repair method for an underground structure, comprising an injection step of compressing and eliminating a water channel between layers.

  According to such a method, the water-stopping agent is injected into a portion (between the underground structure and the waterproof sheet) separated from the ground mountain side rear surface layer by the waterproof sheet, and thus is not poured into the water channel. Therefore, it can be repaired with a small amount of water-stopping agent. In addition, since the water-stopping agent presses the waterproof sheet against the ground-side back layer and compresses the water channel between the waterproof sheet and the ground-side back layer, water can be avoided from the damaged portion of the waterproof sheet.

  In the outer waterproof repair method for an underground structure of the present invention, it is preferable that in the injection step, the water channel in the ground-side back layer is also compressed and disappeared by the injection of the water-stopping agent. According to such a method, the flow of water can be changed to a position away from the injected water-stopping agent by compressing and disappearing the water channel in the pressed area in the ground-side back layer. . Therefore, the waterproof effect can be further enhanced.

  In the outer waterproof repair method for an underground structure of the present invention, a protective layer is formed in advance between the underground structure and the waterproof sheet, and in the drilling step, a tip of a drilling machine is applied to the protective layer. It is preferable to stop the drilling machine when it reaches. According to such a method, the hole making process can be performed without damaging the waterproof sheet.

  In the outer waterproof repair method for an underground structure according to the present invention, in the injection step, a balloon is inserted between the underground structure and the waterproof sheet from the injection hole, and the water-stopping agent is injected into the balloon. It is preferable. According to such a method, it is possible to repair with the minimum water-stopping agent and to strongly press the ground-side back layer.

  According to a second aspect of the present invention, there is provided an outer waterproof repair method for repairing an outer waterproof structure in which a waterproof sheet is attached between the underground structure and the ground-side back layer, and the injection hole formed in the underground structure A waterproofing agent is injected between the underground structure and the waterproof sheet, the waterproof sheet is pressed against the ground-side back layer, and the water channel between the waterproof sheet and the ground-side back layer is compressed and disappears. An external waterproof repair method for an underground structure characterized by comprising an injecting step.

  According to the present invention, water leakage can be repaired with a small water-stopping agent.

It is a figure for demonstrating the external waterproof repair method of the underground structure which concerns on 1st embodiment of this invention, Comprising: (a) is sectional drawing which showed the state before repair, (b) is the state after drilling (C) is sectional drawing which showed the state after water-stopper injection | pouring. It is a figure for demonstrating the external waterproof repair method of the underground structure which concerns on 2nd embodiment of this invention, Comprising: (a) is sectional drawing which showed the state before water-stopper injection | pouring, (b) is water stop It is sectional drawing which showed the state after agent injection | pouring. It is a figure for demonstrating the outer waterproof repair method of the underground structure which concerns on 3rd embodiment of this invention, Comprising: (a) is sectional drawing which showed the state before repair, (b) is the state after drilling (C) is sectional drawing which showed the state after water-stopper injection | pouring.

  Hereinafter, an outer waterproof repair method for an underground structure according to the first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1A, the outer waterproof structure includes, for example, an underground structure 1 such as a watertight tunnel, a ground-side back layer 2 outside the underground structure 1, and an underground structure 1 and a ground-side back surface. A waterproof sheet 3 laid between the layers 2 is provided. The natural ground side back layer 2 is composed of a back natural ground or a back structure (in this embodiment, it is a back natural ground). Generally, the natural ground side back surface layer 2 is rarely a steel structure or a concrete structure, and is often in the form of irregularities such as natural ground or shotcrete. For this reason, a fine gap often exists between the underground structure 1 and the waterproof sheet 3.

  A large number of water channels 4 exist in the gap between the natural ground side back layer 2 and the waterproof sheet 3 and in the natural ground side back layer (back ground mountain) 2. If the waterproof sheet 3 has a hole 5 and the water channel 4 is connected to the hole 5, water flows into the gap between the underground structure 1 and the waterproof sheet 3 from the hole 5. If a crack 6 from the inner surface 1 a of the underground structure 1 to the back surface (outer surface) 1 b occurs in the portion where the water flows, water leaks inside the underground structure 1 through the crack 6. The outer waterproof repair method according to the first embodiment for repairing at such a location where water leakage occurs includes a drilling step and an injection step.

The drilling step is a step of forming the injection hole 10 in the underground structure 1 as shown in FIG. The injection hole 10 is a hole for injecting the water blocking agent 20, and is a linear through hole extending from the inner surface 1a to the back surface 1b. The injection hole 10 is formed from the inside of the underground structure 1 by a drilling machine such as a drill. The injection hole 10 is formed by inserting a drill in the normal direction of the inner surface 1a from the vicinity of the end of the crack 6 on the inner surface 1a (where water leakage occurs). The drill is inserted by the thickness of the underground structure 1. The thickness dimension is grasped by a design drawing, nondestructive inspection, or the like. At the start of drilling, the drill is pushed in at a normal drilling speed, and when the desired insertion depth approaches, the drilling speed is reduced and drilled carefully. Immediately before the penetration, it is preferable that the hole drilling machine is replaced and the hole drilling is performed slowly while measuring the pushing torque. By drilling in this way, the injection hole 10 can be formed without making a hole in the waterproof sheet 3.
In addition, a drilling process can be skipped when the injection hole is previously formed in the tunnel lining which is an underground structure.

  The injection step is a step of injecting the water-stopping agent 20 between the underground structure 1 and the waterproof sheet 3 from the injection hole 10. The water-stopping agent 20 is determined by the size of the gap between the underground structure 1 and the natural ground side back layer 2. The water-stopping agent 20 may be a cement-based material or a urethane-based material, and is a non-foamed or low-foamed material having a foaming ratio of about 1.0 to 1.2. Note that a material that causes volume shrinkage cannot be used as the water-stopping agent 20. Moreover, in order to improve waterproof performance, it is preferable to use the water-stopping agent 20 as a material having low water permeability.

  An example of the water stopping agent 20 that satisfies such conditions will be described below. The water-stop agent 20 is made of, for example, a one-component water-stop agent. As a one-pack type water-stopping agent, for example, “High Cell OS-248” manufactured by Toho Chemical Industry Co., Ltd. is available. This one-part water-stopper contains a urethane prepolymer having a terminal isocyanate group and a silicone-based antifoaming agent. The terminal isocyanate group is obtained by reacting a polyol with an organic polyisocyanate. The polyol contains a castor oil-based polyol and polytetramethylene glycol and a tetrahydrofuran-neopentyl glycol copolymer as essential components, or a castor oil-based polyol and a polytetramethylene glycol or a tetrahydrofuran-neopentyl glycol copolymer. Is contained as an essential component.

  The polyol preferably further contains a polyether polyol having an oxypropylene group in the polyoxyalkylene chain of 70% by mass or more based on the total mass of the polyoxyalkylene chain. Furthermore, as for the water stop agent 20, what contains a diluent is still more preferable.

  The cured product formed by the water-stopping agent 20 having such a structure reacting with water usually has a foaming ratio of 1.0 to 1.2 (that is, no foaming or low foaming). Due to these characteristics, the water-stopping agent 20 is particularly effective in water-stopping under high water pressure.

  Moreover, resin can be used together other than the water stop agent 20 according to the construction situation. Examples of such resins that can be used in combination include epoxy resins, acrylic resins (such as methyl methacrylate), and styrene resins. When using other resin together, 1-50 mass% can be mix | blended with respect to the mass of the urethane prepolymer used for the water stop agent 20. FIG.

  The water-stopping agent 20 configured as described above has a hardened product as compared with a urethane-based water-stopping agent that is generally used in the past, and has high followability to displacement such as vibration and displacement at the injection site. Therefore, it can be expected that the waterproof performance will be demonstrated over a long period of time. “Followability” is a concept that indicates the flexibility that a cured product can conform to the behavior of deformation when the filling portion of the hardening is deformed by an earthquake vibration or the like. “High” means that even when the cured product is deformed by vibration or the like, the cured product is less likely to crack or peel from the adherend surface.

  Further, since the water-stopping agent 20 is a one-pack type, it is very good in terms of workability in an actual construction site as compared with a two-pack type foam-type injection.

  The water-stop agent 20 is not limited to the above-described configuration, and may be a one-component water-stop agent having another configuration or a two-component water-stop agent.

  When injecting such a water-stopping agent 20, an injection tube 21 is inserted into the injection hole 10 and the water-stopping agent 20 is injected between the underground structure 1 and the waterproof sheet 3. The injection of the water blocking agent 20 is performed under pressure management. The injection pressure is set as follows. First, the pressure obtained by adding the peripheral pressure (water pressure) and the waterproof sheet pressing pressure and the pressure related to the filling of the waterproofing agent 20 are calculated, and the injection pressure is set according to the calculated pressure.

  This pressure setting is set by bringing a generally known Kaiser effect into a waterproof structure. The Kaiser effect means that when plastic deformation continues in the same direction, once the stress is unloaded and reloaded, AE (acoustic emission) does not occur until the stress value at the unloaded point is reached. This is a phenomenon that cracks do not occur. Conventionally, when a waterproof sheet is installed on the back of an underground structure to construct the underground structure, the underground structure has often been cast on-site. In the case of placing on-site concrete on the wall of an underground structure with a 3 m lift, the pressure is about 0.075 MPa even when placed in the lower part where the most pressure is applied. For this reason, when a water pressure equal to or less than 0.075 MPa (water depth of about 7.5 m) or less is applied, adhesion is maintained, but when a water pressure higher than that is applied, the waterproof sheet and the ground-side back surface are maintained. Water begins to permeate between the layers, and the water becomes stagnant between the waterproof sheet and the ground-side back layer. In a shallow underground structure of about 2m underground, the waterproof sheet and the ground-side back layer can be intimately contacted even with the pressure of concrete pouring alone, but this is a problem in the case of deep underground structures.

  In the present embodiment, the injection pressure of the water blocking agent 20 is set in consideration of the above phenomenon. Specifically, the pressure (water pressure) which added peripheral water pressure (water pressure of the ground mountain side back surface layer 2 anticipated in a filling location) and waterproof sheet pressing pressure (pressure which presses the waterproof sheet 3 against the ground mountain side back surface layer 2). The pressure P1 that pushes the waterproof sheet 3 outward against the pressure) and the pressure P2 that relates to the filling of the water-stopping agent 20 (pressure for causing the water-stopping agent 20 to flow) P2 are calculated. And the pressure which is lost in connection with construction to the larger one of these calculated pressures P1 and P2 (pressure loss in piping of water-stopping agent 20, pressure loss due to elbow, etc., or related to pump and injection device) P3 is added. Set as injection pressure. If the injection pressure is set in this way, the waterproof sheet 3 can always be brought into close contact with the natural ground side back layer 2.

  By the way, in order for the waterproof sheet 3 to adhere to the ground mountain side back surface layer 2, the waterproofing agent 10 needs to sufficiently penetrate into the gap between the underground structure 1 and the waterproof sheet 3. Therefore, pressure related to infiltration (a phenomenon in which the water blocking agent 20 spreads in the gap between the underground structure 1 and the waterproof sheet 3) is calculated from the positional relationship between the underground structure 1, the waterproof sheet 3, and the ground mountain side rear layer 2. There is a need.

The first case 1 is a case where there is a sufficient gap (a gap of about 5 mm or more) between the underground structure 1 and the waterproof sheet 3. In this case 1, since it is considered that there are no obstacles related to penetration, only the pressure loss P4 generated when the waterproofing agent 20 is filled between the underground structure 1 and the waterproof sheet 3 may be considered. That is, the injection pressure is P1 (or P2) + P3 + P4. In this case, when the permeability (fluidity) of the water blocking agent 20 is high, the loss pressure is considered to be almost zero. In addition, in this embodiment, although the injection hole 10 is one place, when several injection holes are formed closely, the filling pressure of the water-stopper injected from the adjacent injection hole is considered.

  The second case 2 is a case where there is no sufficient gap between the underground structure 1 and the waterproof sheet 3 (when the gap thickness is approximately 0 to 5 mm). Case 2 corresponds to the shape of the present embodiment shown in FIG. In this case 2, since there is a portion where the waterproof sheet 3 and the underground structure 1 are in contact with the unevenness of the ground back side layer 2, the contact portion inhibits the flow of the water-stopping agent 20 and penetrates. Is disturbed. For this reason, in addition to the above-described loss pressure P4, a pressure P5 for expanding the contact portion and passing through is applied. That is, the injection pressure is P1 (or P2) + P3 + P4 + P5.

  When the water-stopping agent 20 is injected at the pressure set as described above (case 2 pressure), the water-stopping agent 20 is placed between the underground structure 1 and the waterproof sheet 3 as shown in FIG. Filled. The water-stopping agent 20 expands the volume of the region between the underground structure 1 and the waterproof sheet 3, thereby bringing the waterproof sheet 3 into close contact with the surface of the ground mountain side back layer 2 and the waterproof sheet 3 with a predetermined pressure. Press against the ground mountain side back layer 2. Thereby, the clearance gap between the waterproof sheet 3 and the natural ground side back layer 2 disappears, and the water channel 4 of the portion disappears. Furthermore, since the natural ground side back surface layer 2 around the water-stopping agent 20 is compressed and the water channel 4 inside thereof is also compressed, the water channel 4 is crushed and disappears. In addition, in the damaged part of the waterproof sheet 3, the water-stopping agent 20 is filled also in the natural ground side back layer 2 side, and the gap of the water channel 4 may be directly filled.

  According to such an external waterproof repair method, the waterproofing agent 20 is injected into a portion (between the underground structure 1 and the waterproof sheet 3) separated from the natural mountain side back layer 2 by the waterproof sheet 3. It does not flow into the back layer 2. Therefore, the water-stopping agent 20 is not flowed to the water channel 4 and can be repaired with a small amount of the water-stopping agent 20.

  Moreover, since the water-stopping agent 20 presses the ground mountain side back surface layer 2 through the waterproof sheet 3 and compresses and disappears the water channel 4 in the pressed area, the water flow is moved away from the waterproof sheet 3. Can be changed. Thereby, water can be avoided from the damaged portion (hole 5) of the waterproof sheet 3. Furthermore, since the inside of the hole 5 (underground structure 1 side) is filled with the water blocking agent 20, the hole 5 is blocked from the inside. Therefore, it becomes difficult for water to flow from the hole 5 to the underground structure 1 side.

  Next, an outer waterproof repair method for an underground structure according to a second embodiment of the present invention will be described with reference to FIG. In the outer waterproof repair method according to the second embodiment, the waterproofing agent 20 is filled through the balloon 22. In addition, the drilling step is equivalent to the first embodiment. The balloon 22 is made of a rubber bag and is inflated by being filled with the water blocking agent 20. The balloon 22 has a pressure resistance greater than the injection pressure of the water-stopping agent 20.

  In the injection step, the balloon 22 is inserted into the injection hole 10 as shown in FIG. The tip of the balloon 22 is made to reach between the underground structure 1 and the waterproof sheet 3. The injection tube 23 is connected to the balloon 22.

  Thereafter, as shown in FIG. 2 (b), the water stopping agent 20 is injected into the balloon 22. The water stopping agent 20 is supplied from the injection tube 23 into the balloon 22 at a predetermined pressure. The injection pressure of the water-stopping agent 20 is set to a numerical value obtained by adding the pressure for inflating the balloon 22 to the injection pressure of the first embodiment. As the injection of the water-stopping agent 20 proceeds, the tip of the balloon 22 swells in the gap between the underground structure 1 and the waterproof sheet 3, and presses the waterproof sheet 3 against the surface of the ground mountain side back layer 2. That is, in the present embodiment, the water-stopping agent 20 presses the waterproof sheet 3 against the surface of the natural ground side back layer 2 via the balloon 22. As a result, the ground-side back layer 2 around the water-stopping agent 20 is compressed and the water channel 4 inside thereof is also compressed, so that the water channel 4 is crushed and disappears.

  According to the outer waterproof repair method of the present embodiment, the following operational effects can be obtained in addition to the operational effects equivalent to those of the first embodiment. In this embodiment, since the water-stopping agent 20 is injected into the balloon 22, the water-stopping agent 20 is partitioned from the natural ground side back layer 2 by the two members of the balloon 22 and the waterproof sheet 3. Even if the damaged portion of the waterproof sheet 3 is large, the water-stopping agent 20 is partitioned from the natural ground side back layer 2 by the balloon 22. Therefore, it can prevent reliably that the water-stopping agent 20 flows out to the natural ground side back surface layer 2. FIG.

  In addition, even in the case of a waterproof structure that does not have a waterproof sheet, if a balloon is placed between the underground structure and the ground-side back layer, the underground structure will not flow out to the ground-side back layer. It can be filled between the object and the natural ground side back layer. As a result, the ground layer-side back surface layer can be compressed to eliminate the water channel near the balloon.

  Next, an outer waterproof repair method for an underground structure according to a third embodiment of the present invention will be described with reference to FIG. The outer waterproof structure of the third embodiment includes a protective layer 7 as shown in FIG. The protective layer 7 is disposed between the underground structure 1 and the waterproof sheet 3. The protective layer 7 serves as a spacer for securing a space between the underground structure 1 and the waterproof sheet 3. By providing the protective layer 7, the tip of the drill for drilling the underground structure 1 does not come into contact with the waterproof sheet 3 even when it protrudes to the natural ground side. The protective layer 7 is a sheet-like member made of, for example, a nonwoven fabric or a bubble cushioning material. The protective layer 7 is thicker than the waterproof sheet 3. The protective layer 7 is laid so as to cover the outer peripheral surface of the underground structure 1.

  In the drilling step, the drilling machine is stopped when the tip of the drill (drilling machine) reaches the protective layer 7. Specifically, in the drilling process of this embodiment, as in the first embodiment, the drill is pushed in at a normal drilling speed at the start of drilling, and when the desired insertion depth approaches, the drilling process is performed. Slowly drill holes at a slower speed. At this time, it is preferable to perform drilling while measuring the indentation torque by exchanging the drilling machine immediately before penetration.

  In the injection process, the water-stopping agent 20 is injected between the underground structure 1 and the protective layer 7. The water stopping agent 20 is supplied through the injection hole 10 at a predetermined pressure. In addition, the supply pressure of the water stopping agent 20 is set to a numerical value obtained by adding a pressure for expanding the protective layer 7 to the supply pressure of the first embodiment. As the injection of the water-stopping agent 20 proceeds, the protective layer 7 is spread together with the waterproof sheet 3 and is pressed against the surface of the natural ground side back layer 2. As a result, the ground-side back layer 2 around the water-stopping agent 20 is compressed, and the water channel 4 inside the ground-side back layer 2 around the water-stopping agent 20 is crushed and disappears.

  According to the outer waterproof repair method of this embodiment, in addition to obtaining the same effects as the first embodiment, even if the drill slightly protrudes from the back surface of the underground structure 1 in the drilling step, the protective layer 7 Since it exists, the effect that the waterproof sheet 3 can be reliably prevented from being damaged can be obtained. In this embodiment, the water-stopping agent 20 may be injected through the balloon 22 as in the second embodiment.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not the meaning limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention. For example, in the embodiment, the case where the underground structure 1 is a lining of a watertight tunnel has been described as an example, but the underground structure 1 is not limited to the lining of a watertight tunnel. For example, the present invention can be applied to a structural frame in an underground part of a building.

  Moreover, in the said embodiment, although the injection hole 10 is formed in one place of the vicinity of the water leak part of the crack 6, it is not limited to one place, You may provide multiple.

DESCRIPTION OF SYMBOLS 1 Underground structure 2 Ground-side back layer 3 Waterproof sheet 4 Water path 7 Protective layer 10 Injection hole 20 Water stop agent 22 Balloon

Claims (5)

In the outer waterproof repair method of repairing the outer waterproof structure formed by attaching a waterproof sheet between the underground structure and the ground-side back layer,
Drilling step of forming an injection hole in the underground structure;
A water-stopping agent is injected between the underground structure and the waterproof sheet from the injection hole, the waterproof sheet is pressed against the ground-side back layer, and a water channel between the waterproof sheet and the ground-side back layer. And a waterproofing repair method for an underground structure characterized by comprising an injection process for compressing and disappearing. In the said injection | pouring process, the water waterproof in the said natural ground side back surface layer is compressed and lose | disappeared by injection | pouring of the said water stop agent. The external waterproof repair method of the underground structure of Claim 1 characterized by the above-mentioned. A protective layer is formed in advance between the underground structure and the waterproof sheet,
The method for repairing an external waterproofing of an underground structure according to claim 1 or 2, wherein, in the drilling step, the drilling machine is stopped when a tip of the drilling machine reaches the protective layer. . The said injection | pouring process inserts a balloon between the said underground structure and the said waterproof sheet from the said injection hole, and inject | pours the said water stop agent into the said balloon. The Claims 1 thru | or 3 characterized by the above-mentioned. The external waterproof repair method for an underground structure according to any one of the above items. In the outer waterproof repair method of repairing the outer waterproof structure formed by attaching a waterproof sheet between the underground structure and the ground-side back layer,
A water-stopping agent is injected between the underground structure and the waterproof sheet from the injection hole formed in the underground structure, and the waterproof sheet is pressed against the ground-side back layer, and the waterproof sheet and the ground-side back surface An outer waterproof repair method for an underground structure, comprising: an injection process for compressing and eliminating a water channel between layers.

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