An underground space floor deformation joint leakage treatment method

Abstract

The present application relates to the field of building maintenance and repair, and particularly relates to a method for treating leakage of a deformation joint of a bottom plate of an underground space, which comprises the following steps: pouring first filling material to the rear of a concrete cushion through a grouting hole formed on one side of the deformation joint; retreating the grouting nozzle to the thickness range of the structure bottom plate to pour second filling material; injecting third filling material to the lower part of a buried water stop belt through a needle tube; brushing sealing non-solidified rubber waterproof paint on the deformation joint above the buried water stop belt; embedding a drainage pipe extending along the deformation joint in the longitudinal direction in the non-solidified rubber waterproof paint through sand and gravel; and setting an external water stop belt and a protective steel plate on the top of the deformation joint to replace the structure, so as to form a treatment mode of external cutting, middle blocking and internal prevention and internal drainage, which can avoid water seepage and leakage as much as possible, ensure the long-term effectiveness of the treatment of the deformation joint leakage, and reduce the maintenance cost and difficulty of the treatment of the deformation joint leakage in the later period by backfilling waterproof liquid to the drainage pipe for self-repairing under complex and extreme conditions in the later period.

Description

Technical Field

[0001] This invention relates to the field of building maintenance and repair, and in particular to a method for treating leakage at expansion joints in the foundation slab of an underground space. Background Technology

[0002] Water seepage in underground spaces such as basements and underground utility tunnels has always been a problem that plagues the civil engineering industry. Although there are many waterproofing technologies available, various leakage phenomena still occur from time to time due to the high permeability of groundwater and the inherent characteristics of underground space structures. Among these, leakage at expansion joints is the most common.

[0003] like Figure 1 The diagram shows a structural schematic of an expansion joint in a reinforced concrete structure in an underground space. Typically, during construction, a concrete pad 1, a waterproof membrane 2, and a protective layer 3 are sequentially installed on the foundation to form a waterproofing measure on the outside of the expansion joint. During the forming of the reinforced concrete base slab 4, an embedded waterstop 6 is installed inside the expansion joint 5, forming two layers of waterstop measures. However, if the outer waterproofing measure fails, underground seepage will directly or indirectly converge at the expansion joint 5 through other water channels, pushing upwards against the waterstop above it. When the seepage reaches a certain pressure value, the seepage will bypass the waterstop or enter the underground usable space through the aging and damaged gaps in the waterstop itself, affecting the normal use of the underground space.

[0004] Current methods for treating leakage at expansion joints in underground space floor slabs often involve directly sealing the expansion joints. However, the sealing effect is not lasting and leakage often recurs, failing to permanently eliminate the risk of leakage. Furthermore, repairs after leakage recurs are difficult, resulting in high maintenance costs after sealing the expansion joints.

[0005] Therefore, there is an urgent need for a technical solution to address the problems of repeated water seepage and high maintenance costs associated with the treatment of leakage at the expansion joints of existing underground space floor slabs. Summary of the Invention

[0006] The purpose of this invention is to provide a method for treating leakage at expansion joints in underground space floor slabs, addressing the technical problems of recurring water seepage and high maintenance costs associated with existing methods for treating leakage at these joints.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for treating leakage at expansion joints in the foundation slab of an underground space includes the following steps: S1: Forming a grouting hole on one side of the expansion joint, the grouting hole penetrating the concrete cushion layer below the foundation slab; S2: Injecting a first sealant into the concrete cushion layer through a grouting nozzle located within the thickness range of the concrete cushion layer to cut off or drain water accumulating near the expansion joint; S3: Retracting the grouting nozzle to within the thickness range of the foundation slab, injecting a second sealant, the second sealant having a greater penetrating power than the first sealant; S4: Injecting water into the expansion joint through an injection needle inserted through an embedded waterstop strip within the expansion joint. S5: The expansion joint below the embedded waterstop is fully filled with a third sealant, which includes chemical grouting material; S6: The expansion joint above the embedded waterstop is coated and sealed with a non-curing rubber waterproof coating, in which a gravel layer is set, and a drainage pipe extending longitudinally along the expansion joint is buried in the gravel layer, which is connected to a sump; S7: The surface layer at the expansion joint is excavated to form an excavation trench, and an external waterstop and a protective steel plate are installed in the excavation trench for structural replacement, with the protective steel plate placed above the external waterstop.

[0008] This invention discloses a method for treating leakage at expansion joints in underground space foundation slabs. The method involves using a first sealant to cut off or drain water accumulating outside the expansion joint, converting pressurized water into slightly pressurized interstitial water. A second sealant then blocks the expansion joint, transforming the interstitial water into unpressurized seepage, which is then discharged through a drainage pipe within the expansion joint. Finally, an external waterstop and protective steel plate are installed at the top of the expansion joint for structural replacement, forming a treatment method of external interception, central blocking, and internal prevention and drainage. The treatment process is clear, easy to operate, and effectively implements the "adapting to local conditions, combining prevention and drainage, and comprehensive treatment" concept proposed in waterproofing engineering specifications. This method minimizes repeated seepage at the expansion joint, ensuring the long-term effectiveness and long-term sustainability of the leakage treatment. It completely eliminates the vicious cycle of "repairing leaks, then repairing them again" that plagues the engineering industry. Furthermore, under complex and extreme conditions in the later stages, self-repair can be achieved by reinjecting waterproofing liquid into the drainage pipe, reducing the later maintenance costs and difficulty of the expansion joint leakage treatment.

[0009] In a preferred embodiment of the present invention, in S1, the grouting hole is a circular hole with a diameter of 14-20 mm, and the vertical distance between the grouting hole opening and the expansion joint is 250-350 mm. This appropriate distance between the grouting hole opening and the expansion joint effectively intercepts water accumulation behind the structural base plate near the expansion joint and avoids the grouting hole affecting the embedded waterstop.

[0010] As a preferred embodiment of the present invention, in S2, the timing for stopping the grouting of the first sealant satisfies the condition that the grouting pressure is close to and less than 0.8 times the characteristic value of the foundation bearing capacity. Based on the actual construction situation, attention is paid to the grouting pressure and grout discharge during the grouting process. After reaching the specified grouting pressure value, the pressure is maintained for 10-30 seconds, and appropriate grout replenishment is performed to ensure the grouting effect.

[0011] In a preferred embodiment of the present invention, in step S3, the grouting nozzle is positioned within a range of 100mm to 1 / 2 the thickness of the structural base slab below the surface during the grouting process, and the second sealant and the first sealant are stopped at the same time. This positions the grouting nozzle above the 1 / 2 thickness line of the structural base slab, more than 100mm from the slab surface, reducing the later sealing range of the grouting hole.

[0012] As a preferred embodiment of the present invention, in S3, the remaining space at the top of the grouting hole is sealed and blocked with a cement-based penetrating crystalline waterproof coating, a polyvinyl chloride waterproof coating, or a non-curing rubber waterproof coating.

[0013] As a preferred embodiment of the present invention, the first sealant includes anti-dispersion cement-based filler, the second sealant includes acrylate grout, modified epoxy grout, or foamed polyurethane grout, and the third sealant includes acrylate grout, modified epoxy grout, or foamed polyurethane grout.

[0014] In a preferred embodiment of the present invention, in S5, the non-curing rubber waterproof coating includes molten asphalt waterproof material.

[0015] As a preferred embodiment of the present invention, S5 specifically includes the following steps: S5.1: Apply non-curing rubber waterproof coating to the deformation joint within the height range h above the embedded waterstop to form an interface layer, and then pour in non-curing rubber waterproof coating to seal it, where h < 1 / 2 of the thickness H of the structural base plate above the embedded waterstop; S5.2: After the non-curing rubber waterproof coating to be sealed loses its fluidity, fill the deformation joint with a first gravel layer of 5-6cm thickness; S5.3: Install a drainage pipe on the first gravel layer, wherein the drainage pipe is provided with several drainage outlets and wrapped with filter cloth; S5.4: Fill the deformation joint with a second gravel layer of 5-6cm thickness; S5.5: Apply non-curing rubber waterproof coating to the deformation joint above the second gravel layer (13) to form an interface layer, and then pour in non-curing rubber waterproof coating to seal it.

[0016] In a preferred embodiment of the present invention, the drainage pipe is located in the middle of the thickness range of the structural base plate above the embedded waterstop. A sufficiently thick layer of non-curing rubber waterproof coating is used to seal the area above the drainage pipe.

[0017] As a preferred embodiment of the present invention, the first gravel layer is made of washed medium sand, the second gravel layer is made of washed coarse sand, and satisfies the following condition: the volume fraction of particles with a diameter greater than 0.5 mm in the gravel used exceeds 80%.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. By using the first sealant to cut off or drain the water outside the expansion joint, the pressurized water is converted into slightly pressurized gap water. Then, the second sealant is used to seal the expansion joint, converting the gap water into unpressurized seepage water, which is then discharged through the drainage pipe inside the expansion joint. Finally, an external waterstop and protective steel plate are installed at the top of the expansion joint for structural replacement, forming a treatment method of external interception, middle blocking, and internal prevention and drainage. The treatment process is clear, easy to operate, and effectively implements the treatment concept of "adapting to local conditions, combining prevention and drainage, and comprehensive treatment" in waterproofing projects. 2. To the greatest extent possible, repeated water seepage at the expansion joints can be avoided, ensuring the long-term effectiveness of the expansion joint leakage treatment; 3. Under complex and extreme conditions in the later stages, waterproofing liquid can be injected back into the drainage pipe for self-repair, reducing the later maintenance costs and difficulty of the expansion joint leakage treatment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the deformation joint of a reinforced concrete structure in an underground space, based on existing technology. Figure 2 This is a schematic diagram of the expansion joint structure under S2 conditions; Figure 3 This is a schematic diagram of the expansion joint structure under S3 conditions; Figure 4 This is a schematic diagram of the expansion joint structure under S4 conditions; Figure 5 This is a schematic diagram of the expansion joint structure under S5 conditions; Figure 6 yes Figure 5 A magnified structural diagram of part A in the middle; Figure 7 This is a schematic diagram of the structure of the drain pipe described in this invention. Figure 1 ; Figure 8 This is a schematic diagram of the structure of the drain pipe described in this invention. Figure 2 ; Figure 9 This is a schematic diagram of the structure of the expansion joint after treatment by the method for treating leakage at the expansion joint of the foundation slab of an underground space according to the present invention.

[0020] icon: 1-Concrete cushion layer, 2-Waterproof membrane, 3-Waterproof membrane protective layer, 4-Structural base plate, 5-Expansion joint, 6-Embedded waterstop, 7-Grouting hole, 8-First joint filler, 9-Second joint filler, 10-Third joint filler, 11-Non-curing rubber waterproof coating, 12-First gravel layer, 13-Second gravel layer, 14-Drainage pipe, 141-Water inlet hole, 142-Strip groove, 15-Surface layer, 16-External waterstop, 17-Protective steel plate. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings.

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] Example 1 like Figures 1-9 As shown, a method for treating leakage at expansion joints in underground space foundation slabs includes steps S1-S6 performed sequentially. First, a first sealant 8 cuts off external water accumulation at the expansion joint 5, converting pressurized water into slightly pressurized interstitial water. Then, a second sealant 9 seals the expansion joint, converting the interstitial water into unpressurized seepage, which is then discharged through a drainage pipe 14 within the expansion joint 5. Finally, an external waterstop 16 and a protective steel plate 17 are installed at the top of the expansion joint 5 for structural replacement, forming a treatment method of external interception, central blocking, and internal prevention and drainage. This method minimizes repeated seepage at the expansion joint 5, ensuring the long-term effectiveness and sustainability of the leakage treatment. Furthermore, under complex and extreme conditions in the later stages, waterproofing liquid can be reinjected into the drainage pipe 14 for self-repair, reducing the later maintenance costs and difficulties of the leakage treatment. The treatment process is clear, easy to operate, and fully embodies the waterproofing engineering concept of "adapting to local conditions, combining prevention and drainage, and comprehensive treatment."

[0024] Specifically, it includes the following: S1: Using the drilling method, a hole is drilled on one side of the expansion joint 5 to form a grouting hole 7, which penetrates the concrete cushion layer 1 below the structural base plate 4.

[0025] Specifically, in this embodiment, the grouting hole 7 is preferably a round hole with a diameter of 20mm. The grouting hole 7 can be a vertical hole or an oblique hole relative to the structural base plate 4, but it cannot pass through the embedded waterstop 6. The vertical distance between the opening of the grouting hole 7 and the expansion joint 5 is 250-350mm to avoid the embedded waterstop 6. At the same time, if the grouting hole 7 is too far from the expansion joint 5, the amount of injected material will increase, and it will be impossible to cut off or drain the water below the expansion joint 5. If the grouting hole 7 is too close to the expansion joint 5, the amount of injected material may be insufficient, resulting in a weakened water-cutting effect. In this embodiment, the grouting hole 7 formed by vertical drilling is kept within a distance of about 30cm from the expansion joint 5, so that the distance between the grouting hole 7 and the expansion joint 5 is appropriate, which can effectively cut off or drain the water behind the structural base plate 4 near the expansion joint 5, and can form a cut-off and sealing area with a suitable coverage surface below the expansion joint 5.

[0026] S2: The first sealant 8 is injected into the back of the concrete pad 1 through the grouting nozzle located within the thickness range of the concrete pad 1. The first sealant 8 is used to cut off or drain water near the deformation joint 5.

[0027] Specifically, in this embodiment, the first joint filler 8 is an anti-dispersion cement-based filler used to cut off or drain a large amount of accumulated water near the deformation joint 5, and to convert pressurized water into micro-pressure gap water. The timing for stopping the injection of the first joint filler 8 satisfies the following condition: the grouting pressure is close to and less than 0.8 times the characteristic value of the foundation bearing capacity.

[0028] Specifically, in actual operation, under the above-mentioned size and position of the grouting hole 7, and using the above-mentioned grouting termination conditions, the grouting nozzle is extended from the grouting hole 7 into the thickness range of the concrete cushion layer 1. During the grouting process, attention is paid to the grouting pressure and grout discharge. After reaching the specified grouting pressure value, the pressure is maintained for 10-30 seconds, and grout is added appropriately to ensure the grouting effect of the first sealant 8.

[0029] S3: Retract the grouting nozzle to within the thickness range of the structural base plate 4, and inject the second sealant 9. The penetration power of the second sealant 9 is greater than that of the first sealant 8.

[0030] Specifically, the second sealant 9 includes acrylate grout, modified epoxy grout, or foamed polyurethane grout. In this embodiment, acrylate grout is preferred. During the grouting process, the grouting nozzle is located within 100mm to 1 / 2 the thickness of the structural base plate below the surface 4, that is, the grouting nozzle is located above the 1 / 2 thickness line of the structural base plate and more than 100mm away from the plate surface.

[0031] Specifically, the second sealant 9 is injected at the same time as the first sealant 8. The second sealant 9 is used to seal the tiny gaps left after the first sealant 8 is injected, as well as the tiny gaps between the structural base plate 4 and the waterproof membrane 2, so as to convert the gap water into unpressurized seepage.

[0032] Specifically, during actual operation, attention should be paid to the grouting pressure and grout discharge during the grouting process. After the grouting pressure reaches the point where it stops, the pressure should be maintained for 10-30 seconds and grout should be added as needed to ensure the grouting effect of the second sealant 9.

[0033] Specifically, the remaining space at the top of the grouting hole 7 is sealed and plugged with cement-based penetrating crystalline waterproof coating, polyvinyl chloride waterproof coating or non-curing rubber waterproof coating 11, which can meet the waterproofing and usage requirements of the underground space surface layer and further improve the sealing effect.

[0034] S4: Using the needle method, the injection needle passes through the embedded waterstop 6 in the deformation joint 5 and injects the third sealant 10 into the deformation joint 5 below the embedded waterstop 6. The third sealant 10 includes chemical grouting material.

[0035] Specifically, in this embodiment, the third sealant 20 is an acrylic resin grout or a similar flexible chemical grout, used to seal the remaining fine gaps below the embedded waterstop 6 and further prevent the seepage path of groundwater.

[0036] S5: The deformation joint 5 above the embedded waterstop 6 is sealed by applying non-curing rubber waterproof coating 11. A gravel layer is set in the non-curing rubber waterproof coating 11. A drainage pipe 14 extending longitudinally along the deformation joint 5 is buried in the gravel layer. The drainage pipe 14 is connected to the water collection well.

[0037] Specifically, in this embodiment, the non-curing rubber waterproof coating 11 uses molten asphalt waterproof material, which can be applied to the side wall of the deformation joint 5 after melting to form an interface layer. It has flexible characteristics, can maintain the function of the deformation joint 5, and can achieve the sealing effect under vibration, cracks and other conditions through its flexible bonding characteristics during later use, and has good environmental adaptability.

[0038] Specifically, in this embodiment, S5 includes the following steps performed sequentially: S5.1: Apply non-curing rubber waterproof coating 11 to the deformation joint 5 within the height range h above the embedded waterstop 6 to form an interface layer, and then pour in non-curing rubber waterproof coating 11 to seal it; S5.2: After the sealed non-curing rubber waterproof coating 11 loses its fluidity, fill the deformation joint 3 with a first gravel layer 12 with a thickness of 5-6 cm; S5.3: Install a drainage pipe 14 on the first gravel layer 12, the drainage pipe 14 is provided with several drainage outlets and wrapped with filter cloth; S5.4: Fill the deformation joint 5 with a second gravel layer 13 with a thickness of 5-6 cm; S5.5: Apply non-curing rubber waterproof coating 11 to the deformation joint 5 above the second gravel layer 13 to form an interface layer, and then pour in non-curing rubber waterproof coating 11 to seal it. The installation of the drainage pipe 14 and the non-curing rubber waterproof coating 11 can further prevent water seepage into the expansion joint 5, reduce the amount of water seepage to a minimum, and discharge the small amount of seepage into the collection well through the drainage pipe 14. The seepage is discharged manually, and a channel is established between the collection well and the expansion joint 5, which can facilitate the later maintenance and treatment. After the leakage recurs, the waterproof coating can be applied through the drainage pipe 14 to achieve further leakage sealing treatment according to the actual situation.

[0039] Preferably, the overall thickness of the gravel layer, composed of the first gravel layer 12 and the second gravel layer 13, is 10-12 cm. The thickness of the non-cured rubber waterproof coating 11 below and above the first gravel layer 12 is h, satisfying h = (H-10) / 2 ~ (H-12) / 2 cm, meaning that the drainage pipe 14 is located in the middle of the thickness range of the structural base plate 4 above the embedded waterstop 6. Sufficient thickness of non-cured rubber waterproof coating 11 is provided above and below the gravel layer, encasing the gravel layer within it. This constraint by the non-cured rubber waterproof coating 11 ensures the stability of the drainage pipe 14 and provides a certain degree of flexibility. In complex usage environments, such as vibration environments, the flexibility of the non-cured rubber waterproof coating 11 can ensure the long-term normal operation of the drainage pipe 14.

[0040] Specifically, the coating process includes applying a non-curing rubber waterproof coating 11 to the inner wall of the expansion joint 5 using a wool brush.

[0041] Specifically, the first gravel layer 12 uses ordinary river sand washed medium sand, and the second gravel layer 13 uses washed coarse sand. Manufactured sand is not recommended. The gravel layer must meet the following requirements: the volume fraction of particles larger than 0.5 mm in the gravel must exceed 80% to make the gravel particles slightly larger, which can fully meet the filtration effect. In addition, the river sand has a low mud content and high particle size, and there will be no cracks in the particle crystals. It will not break later and cause the particles to become smaller and fail to achieve the filtration effect, and will not cause pore blockage.

[0042] Specifically, the diameter of the drainage pipe 14 is determined based on the size of the expansion joint 5 and the amount of water seepage, such as... Figures 7-8 As shown, this embodiment preferably uses a porous PVC pipe with an inner diameter of 20mm. Several water inlet holes 141 or strip grooves 142 are arranged longitudinally and staggered in the drain pipe 14, and a filter cloth is wrapped around it to prevent sand and gravel from entering the drain pipe 14, so that the seepage water can smoothly enter the drain pipe 14 for drainage. Preferably, the water inlet holes 141 or strip grooves 142 are only set at the bottom of the drain pipe 14 and in the area below the middle partition, so that the seepage water can be smoothly transported to the collection well along the drain pipe 14 after entering the drain pipe 14 from bottom to top, and will not be output from the top of the drain pipe 14.

[0043] S6: The surface layer at the top opening of the expansion joint 5 is enlarged to form an enlarged trench. An external waterstop 16 and a protective steel plate 17 are installed in the enlarged trench for structural replacement. The protective steel plate 17 is positioned above the external waterstop 16. The expansion joint is further sealed to ensure that no water seepage occurs at the expansion joint under extreme conditions.

[0044] Specifically, the excavation is carried out before the expansion joint is sealed. After the expansion joint is sealed, an external waterstop and a protective steel plate are installed. Preferably, the coverage area of ​​the protective steel plate 17 is larger than that of the external waterstop 16. Bolts or other blocking components are installed on the protective steel plate 17 corresponding to the outer edge of the external waterstop 16 and inserted into the structural base plate 4 to limit the relative displacement between the protective steel plate 17 and the external waterstop 16, thereby achieving simultaneous fixation of the protective steel plate 17 and the external waterstop 16.

[0045] Preferably, in this embodiment, the external waterstop 16 is made of Sika 2mm thick external waterstop tape, which is composed of two materials: modified polyolefin (FPO) waterproof tape and two-component thixotropic epoxy adhesive. In the width direction of the expansion joint 5, the external waterstop 16 is 300mm wide, the protective steel plate 17 is 400mm wide, and the protective steel plate 17 is 2mm thick.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for treating leakage at expansion joints in the floor slab of an underground space, characterized in that, Includes the following steps: S1: A grouting hole (7) is formed on one side of the expansion joint (5). The grouting hole (7) penetrates the concrete cushion layer (1) below the structural base plate (4). The grouting hole (7) does not pass through the embedded waterstop (6). S2: The first sealant (8) is injected into the concrete pad (1) through the grouting nozzle located within the thickness range of the concrete pad (1) to cut off or drain the water near the deformation joint (5) and convert the pressurized water into micro-pressure gap water. S3: Retract the grouting nozzle to the thickness range of the structural base plate (4), and inject the second sealant (9). The penetration power of the second sealant (9) is greater than that of the first sealant (8), which will turn the gap water into pressureless seepage. S4: Through the injection needle, pass through the embedded waterstop (6) in the deformation joint (5) and inject the third sealant (10) into the deformation joint (5) below the embedded waterstop (6). The third sealant (10) includes chemical grouting material to block the seepage path of groundwater. S5: The deformation joint (5) above the embedded waterstop (6) is sealed by applying non-curing rubber waterproof coating (11). A gravel layer is set in the non-curing rubber waterproof coating (11). A drainage pipe (14) extending longitudinally along the deformation joint (5) is buried in the gravel layer. The drainage pipe (14) is connected to the water collection well. S6: The surface layer at the expansion joint (5) is enlarged to form an enlarged trench. An external waterstop (16) and a protective steel plate (17) are installed in the enlarged trench for structural replacement. The protective steel plate (17) is installed above the external waterstop (16). S5 specifically includes the following steps: S5.1: Apply non-curing rubber waterproof coating (11) to the deformation joint (5) within the height range h above the embedded waterstop (6) to form an interface layer, and then pour in non-curing rubber waterproof coating (11) to seal it. h < 1 / 2 of the thickness H of the structural base plate (4) above the embedded waterstop (6). S5.2: After the non-cured rubber waterproof coating (11) to be sealed loses its fluidity, fill the expansion joint (5) with a first gravel layer (12) with a thickness of 5-6cm. S5.3: Install a drain pipe (14) on the first gravel layer (12), the drain pipe (14) being provided with several drain outlets and wrapped with filter cloth; S5.4: Fill the expansion joint (5) with a second gravel layer (13) with a thickness of 5-6cm. S5.5: Apply non-curing rubber waterproof coating (11) to the expansion joint (5) above the second gravel layer (13) to form an interface layer, and then pour in non-curing rubber waterproof coating (11) to seal it.

2. The method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 1, characterized in that, In S1, the grouting hole (7) is a round hole with a diameter of 14-20mm, and the vertical distance between the opening of the grouting hole (7) and the deformation joint (5) is 250-350mm.

3. The method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 1, characterized in that, In S2, the timing for stopping the grouting of the first sealant (8) satisfies the condition that the grouting pressure is close to and less than 0.8 times the characteristic value of the foundation bearing capacity.

4. The method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 2, characterized in that, In S3, the grouting nozzle is located within 100mm-1 / 2 of the thickness of the structural base plate (4) below the surface of the structural base plate during the grouting process, and the second sealant (9) and the first sealant (8) stop grouting at the same time.

5. The method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 4, characterized in that, In S3, the remaining space at the top of the grouting hole (7) is sealed and blocked with cement-based penetrating crystalline waterproof coating, polyvinyl chloride waterproof coating or non-curing rubber waterproof coating (11).

6. The method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 1, characterized in that, The first sealant (8) includes anti-dispersion cement-based filler, the second sealant (9) includes acrylate grout, modified epoxy grout or foamed polyurethane grout, and the third sealant (10) includes acrylate grout, modified epoxy grout or foamed polyurethane grout.

7. The method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 1, characterized in that, In S5, the non-curing rubber waterproof coating (11) includes molten asphalt waterproof material.

8. The method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 1, characterized in that, The drainage pipe (14) is located in the middle of the thickness range of the structural base plate (4) above the embedded waterstop (6).

9. A method for treating leakage at expansion joints in the floor slab of an underground space as described in claim 1, characterized in that, The first gravel layer (12) is made of washed medium sand, and the second gravel layer (13) is made of washed coarse sand, and the following conditions are met: the volume fraction of particles with a diameter greater than 0.5 mm in the gravel used exceeds 80%.

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