Hinged expansion joints between structural units of tunnels traversing active fractures and their construction procedures
By employing curtain grouting, steel mesh sprayed with steel fiber concrete initial support, W-shaped waterstop, steel pipe polyurethane support, and steel foam concrete sealing structure in active fracture tunnels, the leakage risk and deformation adaptation problem of hinged expansion joints in active fracture tunnels were solved, waterproofing performance and construction safety were improved, and controllable discharge of leaking water was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGJIANG SURVEY PLANNING DESIGN & RES CO LTD
- Filing Date
- 2026-05-26
- Publication Date
- 2026-07-31
AI Technical Summary
Existing technologies, when traversing active fracture tunnels, present challenges such as high risk of leakage during the construction period of articulated expansion joints, insufficient deformation adaptability, easy failure of waterproofing systems, and poor compressibility of filling materials. These issues make it difficult to meet the comprehensive requirements of adapting to large deformations, waterproofing under high water head, and controllable construction safety.
The surrounding rock is pre-reinforced by curtain grouting and radial grouting, combined with steel mesh sprayed steel fiber concrete initial support, and equipped with W-shaped waterstop, steel pipe polyurethane support structure and steel foam concrete closed structure, and with drainage embedded Ω waterstop, forming a multi-layer waterproof and support system that can adapt to large deformation and achieve active control of water leakage.
It improved construction safety and waterproofing reliability, enhanced the deformation adaptability and durability of expansion joints, reduced the risk of water leakage, enabled controllable drainage during operation, and extended the service life of the tunnel.
Smart Images
Figure CN122280619B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of tunnel engineering, specifically to a hinged deformation joint between structural units of a tunnel traversing an active fault zone and its construction procedure, which is particularly suitable for tunnel drainage and deformation adaptation structures in active fault zones of water-rich surrounding rock areas. Background Technology
[0002] The construction of mountain tunnels often requires traversing active fault zones. These active fault zones may shift during geological history and into the future, exerting adverse effects on the tunnel structure such as shearing, tension, or compression. To ensure the safety of the tunnel structure, hinged expansion joints are typically installed between tunnel structural units to accommodate the relative displacement caused by fault zone shifting.
[0003] Currently, conventional hinged expansion joints are mainly treated in the same way as ordinary expansion joints, using a waterproofing scheme of embedded waterstops combined with back-adhesive waterstops. This approach has the following drawbacks:
[0004] High risk of leakage during construction: Conventional expansion joints are not reinforced in advance, which can easily lead to significant water leakage during construction, affecting construction safety and progress.
[0005] Insufficient deformation adaptability: The width of conventional expansion joints is usually only 2-3cm, which cannot adapt to the large deformation requirements under active fracture and displacement, and is prone to structural cracking and damage.
[0006] Waterproofing systems are prone to failure: Embedded and back-adhesive waterstops have limited deformation capacity and are easily broken when stretched at the hinge joint, leading to complete failure of the waterproofing system.
[0007] Poor compressibility of filling materials: Conventional expansion joint filling materials do not have a large compressibility and cannot gain enough space for displacement under active fracture compression, which aggravates structural damage.
[0008] Later-stage water leakage is difficult to control: After water leakage occurs in conventional expansion joints during the operation period, it is impossible to achieve regular drainage. Long-term water leakage will erode the structure and reduce the durability of the tunnel.
[0009] In summary, existing technologies are insufficient to meet the comprehensive requirements of articulated expansion joints for tunnels traversing active fractures in terms of "adaptability to large deformations, waterproofing under high water head, and controllable construction safety." Summary of the Invention
[0010] This invention addresses the shortcomings of existing technologies by providing a hinged expansion joint and its construction procedure for tunnel structural units traversing active fractures. This improves the expansion joint's adaptability to large deformations (especially tension and compression) under active fracture slippage; enhances the waterproof reliability and durability of the expansion joint under high water head conditions; improves the stability of the surrounding rock during construction and reduces the risk of leakage; and enables controllable and drainable leakage water during operation.
[0011] To achieve the above objectives, the present invention provides a hinged expansion joint between structural units of an active fracture tunnel, comprising: a pre-reinforcement and initial support structure, including a curtain grouting layer and a radial grouting layer disposed within the surrounding rock of the expansion joint section for reinforcing the surrounding rock of the expansion joint section before construction; and a steel mesh sprayed with steel fiber reinforced concrete initial support layer disposed on the inner wall of the tunnel for providing initial support; a W-shaped waterstop disposed circumferentially along the expansion joint, with its two ends embedded in the tunnel lining structure on both sides of the expansion joint and firmly welded to the waterproofing membranes on both sides, for adapting to changes in the width of the expansion joint and providing core waterproofing function; and a steel pipe polyurethane... The supporting structure, located inside the W-shaped waterstop, comprises multiple hollow steel pipes arranged in a ring. The hollow steel pipes are filled with polyurethane to provide radial support for the W-shaped waterstop and accommodate compression deformation. A steel-reinforced foamed concrete enclosed structure, located inside the steel-reinforced polyurethane supporting structure, comprises a steel frame and foamed concrete poured outside the steel frame to enhance the overall rigidity and durability of the expansion joint structure. A drainable, embedded Ω-shaped waterstop, located inside the expansion joint, is fixedly connected to the lining on both sides via embedded steel plates at the ends, and is used to guide leaked water into a drainage ditch, enabling proactive control of leaks during operation.
[0012] Furthermore, the W-shaped waterstop has a deformation adaptability width of 2cm to 50cm, and its deformation capacity is more than 3 times that of the expansion joint width.
[0013] Furthermore, the hollow steel pipe is provided with grouting holes, through which the polyurethane is filled into the interior of the steel pipe; the hollow steel pipe is independently formed into rings, and multiple rings are arranged along the width direction of the deformation joint.
[0014] Furthermore, the steel frame is made of I16 I-beams with a spacing of 50cm, and the bottom is raised to the design elevation by foam concrete; the drainable embedded Ω-shaped waterstop has pre-reserved foam concrete backfill holes.
[0015] A construction procedure for a hinged expansion joint between structural units of an active fracture tunnel includes the following steps: Step 1: Pre-reinforcement construction, implementing curtain grouting and radial grouting in the section where the expansion joint is located to pre-reinforce the surrounding rock; Step 2: Initial support construction, constructing a steel mesh sprayed steel fiber concrete initial support structure on the pre-reinforced tunnel inner wall; Step 3: Installation of embedded parts and waterstops, installing auxiliary fixing steel bars in the lining on both sides of the expansion joint, installing end steel plate embedded parts, and embedding both ends of the W-shaped waterstop into the lining, welding it firmly to the waterproofing membrane on both sides; Step 4: Waterstop The construction of the supporting structure involves laying multiple hollow steel pipes in a ring inside the W-shaped waterstop, and filling the inside of the steel pipes with polyurethane through grouting holes to form a steel pipe polyurethane support structure; Step 5: Construction of the steel profile and drainage waterstop involves setting a steel frame inside the steel pipe polyurethane support structure, and installing a drainage-compatible embedded Ω-shaped waterstop through pre-embedded parts in the end steel plates; Step 6: Foamed concrete backfilling involves backfilling foamed concrete into the expansion joint through the pre-reserved backfilling holes on the drainage-compatible embedded Ω-shaped waterstop, making it densely fill the outside of the steel frame and the space of the expansion joint.
[0016] Furthermore, in step one, the curtain grouting is set up with a ring along the deformation joint, with a circumferential depth of not less than 5m and an extension of not less than 10m on each side; the radial grouting is set up with a ring before construction, with a grouting length of not less than 5m and a circumferential spacing of not more than 1m.
[0017] Furthermore, in step three, the spacing of the embedded parts of the end steel plate is 50-80cm, and the width of the W-shaped waterstop is selected from 2cm to 50cm according to the design width of the expansion joint.
[0018] Furthermore, in step four, the hollow steel pipe is independently formed into rings, and multiple rings are set along the width direction of the deformation joint. The polyurethane filling inside the steel pipe is used to improve the bending stiffness of the steel pipe and adapt to compression deformation.
[0019] Furthermore, in step five, the steel frame is an I16 I-beam with a spacing of 50cm, and the bottom is raised to the design elevation by foam concrete; the drainable embedded Ω-shaped waterstop is welded to the end steel plate pre-embedded part.
[0020] Furthermore, in step six, after the foamed concrete backfill is compacted, the drainable embedded Ω-shaped waterstop is used to introduce the leaking water in the expansion joint into the drainage ditch in real time, and water can be actively diverted through drilling during operation.
[0021] Compared with the prior art, the present invention has the following beneficial effects.
[0022] 1. Significantly improved construction safety and environmental friendliness: The use of radial grouting small pipes and curtain grouting pre-reinforcement, combined with steel mesh sprayed steel fiber concrete initial support, effectively improves construction safety and feasibility, while reducing early deformation of surrounding rock and reducing drainage volume, which is in line with the concept of environmentally friendly construction.
[0023] 2. Significantly enhanced waterproofing performance and structural durability: The W-type waterstop can flexibly adapt to expansion joint widths from 2cm to 50cm, and its deformation capacity can reach more than three times the width of the expansion joint, effectively preventing tensile fracture; the steel pipe concrete structure provides stable support for the W-type waterstop; the steel-reinforced foam concrete closed structure further enhances the overall rigidity of the expansion joint. Tests have verified that this invention still maintains a waterproof head of over 60m after active fracture.
[0024] 3. Significantly improved deformation adaptability: Through the synergistic effect of the W-type waterstop and the polyurethane support structure of the steel pipe, it can effectively adapt to the large hinge deformation under active fracture slip, solving the pain point of insufficient deformation capacity of conventional expansion joints.
[0025] 4. Improved leakage control during operation: The drainage-embedded Ω-shaped waterstop can guide leakage water into the drainage ditch in real time, reducing the waterproofing pressure on the hinged expansion joint; during operation, water can be actively drilled to further optimize the waterproofing effect, prevent leakage water from eroding the structure in the later stage, and extend the service life of the tunnel. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the overall structure of the hinged deformation joint between structural units traversing the active fracture tunnel in an embodiment of the present invention.
[0027] Figure 2 This is a schematic diagram of the construction layout of the curtain grouting layer in the pre-reinforcement construction of an embodiment of the present invention.
[0028] Figure 3 This is a schematic diagram of the construction layout of the radial grouting layer in the pre-reinforcement construction of an embodiment of the present invention.
[0029] Figure 4 This is a schematic diagram of the structure of the initial support layer of steel mesh sprayed with steel fiber concrete in the initial support construction of an embodiment of the present invention. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0031] Example 1: Structural Composition of Hinged Expansion Joint
[0032] like Figure 1 As shown, this embodiment provides a hinged expansion joint between tunnel structural units that traverse active fractures. The expansion joint is set between adjacent tunnel structural units, and its width can be designed to be 2cm~50cm according to the expected displacement of the active fracture. It mainly includes the following components: 1. Pre-reinforcement and initial support structure, 2. W-shaped waterstop, 3. Steel pipe polyurethane support structure, 4. Steel foam concrete sealing structure, and 5. Drainable embedded Ω waterstop.
[0033] like Figures 1-4 As shown, the pre-reinforcement and initial support structure 1 includes a curtain grouting layer 11 and a radial grouting layer 12 set in the surrounding rock of the section where the deformation joint is located, for reinforcing the surrounding rock of the section where the deformation joint is located before construction, and a steel mesh sprayed steel fiber concrete initial support layer 13 set in the inner wall of the tunnel, for providing initial support.
[0034] A ring of curtain grouting layer is set along the 11 deformation joint, with a circumferential depth of not less than 5m and an extension of not less than 10m on each side; a ring of radial grouting layer 12 is set before construction, with a grouting length of not less than 5m and a circumferential spacing of not more than 1m.
[0035] The steel mesh sprayed steel fiber concrete initial support layer 13 is set on the inner wall of the tunnel, including a steel mesh 131 and a sprayed steel fiber concrete layer 132. The steel mesh is laid on the surface of the inner wall of the tunnel, and the sprayed steel fiber concrete layer 132 covers the outside of the steel mesh 131, forming an initial support system.
[0036] The W-shaped waterstop 2 is installed along the circumferential length of the expansion joint, with its two ends embedded in the tunnel lining structure 6 on both sides of the expansion joint. The W-shaped waterstop 2 is firmly welded to the waterproofing membrane 7 on both sides, forming the first waterproof barrier. The W-shaped waterstop 2 is made of highly elastic rubber material, and its cross-section has a W-shaped folded structure. The appropriate specifications can be selected according to the width of the expansion joint, and the deformation capacity can reach more than 3 times the width of the expansion joint.
[0037] 3. Steel pipe polyurethane support structure
[0038] The steel pipe polyurethane support structure 3 is installed inside the W-shaped waterstop 2. This structure comprises multiple hollow steel pipes 31 arranged in rings, each forming an independent ring, with multiple rings arranged along the width of the expansion joint. Grouting holes are provided on the hollow steel pipes 31, and polyurethane material 32 is filled through these holes to form a steel pipe polyurethane composite structure. This support structure provides radial support to the W-shaped waterstop 2, preventing excessive deformation under water pressure, and also adapts to compressive displacement during active fracture through the compressive deformation of the hollow steel pipes 31 and the elastic deformation of the polyurethane material 32.
[0039] The steel-reinforced foamed concrete enclosed structure 4 is installed inside the steel pipe polyurethane support structure 3. This structure includes a steel frame 41 and foamed concrete 42. The steel frame 41 uses I16 I-beams spaced 50cm apart, with its bottom raised to the design elevation by foamed concrete. The foamed concrete 42 is poured outside the steel frame 41 and within the expansion joint space, with a porosity greater than 50%, further accommodating compressive deformation during active fracture. This structure enhances the overall stiffness of the expansion joint area and improves durability during operation.
[0040] The drainable embedded Ω-shaped waterstop 5 is installed on the innermost side of the expansion joint, located on the inner surface of the steel-reinforced foam concrete closed structure 5. The drainable embedded Ω-shaped waterstop 5 is fixedly connected to the lining on both sides via end steel plate embedded parts 9 and is securely welded. This waterstop has an Ω-shaped cross-section, with pre-drilled holes for foam concrete backfilling. The drainable embedded Ω-shaped waterstop 5 is used to guide leaked water into the drainage ditch in real time, reducing the waterproofing pressure on the hinged expansion joint.
[0041] Example 2: Construction procedures for hinged expansion joints
[0042] This embodiment provides the construction procedure for the hinged expansion joint between structural units traversing the above-mentioned active fracture tunnel, combined with... Figures 1 to 4 Specifically, it includes the following steps.
[0043] Step 1: Pre-reinforcement construction
[0044] like Figure 2 and Figure 3 As shown, pre-reinforcement measures are first implemented in the section where the expansion joint is located. A curtain grouting layer 11 is installed along the tunnel circumference at the expansion joint location, with a grouting depth of not less than 5m and extending at least 10m on each side. Simultaneously, a radial grouting layer 12 is installed before construction, with a grouting length of not less than 5m and a circumferential spacing of not more than 1m. Pre-reinforcement of the surrounding rock through curtain grouting and radial grouting improves construction safety and surrounding rock stability.
[0045] Step 2: Initial Support Construction
[0046] After pre-reinforcement is completed, the tunnel is excavated according to the design outline. For example... Figure 4 As shown, an initial support structure was immediately constructed on the inner wall of the tunnel: first, steel mesh 131 was laid, and then a layer of steel fiber concrete 132 was sprayed to form an initial support system, which further controlled the deformation of the surrounding rock.
[0047] Step 3: Installation of embedded parts and W-type waterstop
[0048] Before constructing the lining on both sides of the expansion joint, lay a waterproof membrane 7 and geotextile to ensure the waterproof base layer is flat and firm. Then, install auxiliary fixing steel bars 8 within the lining 6 on both sides of the expansion joint, and install end steel plate embedded parts 9, with each end steel plate embedded part 9 spaced 50-80cm apart. Figure 4 As shown, the two ends of the W-shaped waterstop 2 are embedded in the lining 6, and then welded firmly to the waterproofing plates 7 on both sides. The width of the W-shaped waterstop 2 is selected according to the design expansion joint width, and can be adapted to expansion joints of 2cm to 50cm.
[0049] Step 4: Construction of the waterstop support structure
[0050] A DN100 hollow steel pipe 31 is installed inside the W-type waterstop 2. Each hollow steel pipe 31 forms an independent ring, with multiple rings arranged along the width of the expansion joint. Grouting holes are pre-drilled on the hollow steel pipe 31. Polyurethane material 32 is filled into the steel pipe through these holes, with the grouting pressure controlled at 0.5~1.0 MPa, until the steel pipe is completely filled, forming a polyurethane support structure 3. This structure provides stable support for the W-type waterstop 2 and also has compressive deformation capability.
[0051] Step 5: Construction of steel profiles and drainage waterstops
[0052] A steel frame 41 is installed inside the polyurethane support structure 3. The steel frame 41 is made of I16 I-beams with a spacing of 50cm, and the bottom is raised to the design elevation by foam concrete. A drainage embedded Ω-shaped waterstop 5 is installed through the end steel plate embedded part 9, and welded firmly, with a foam concrete backfill hole reserved.
[0053] Step Six: Foamed Concrete Backfilling
[0054] Foamed concrete 42 is backfilled into the expansion joint through the pre-reserved foamed concrete backfill holes on the drainable embedded Ω-shaped waterstop 5. Layered backfilling and layer-by-layer vibration are used to ensure that the foamed concrete 42 densely fills the exterior of the steel frame 41 and the expansion joint space. The backfill holes are then sealed after backfilling. The high porosity of the foamed concrete 42 provides deformation space for compressive slippage during active fracture.
[0055] Application effect verification: The articulated expansion joint and its construction procedures described in this embodiment were applied and verified in a tunnel project crossing an active fracture. The design displacement of the active fracture was: tensile 20cm, compression 15cm, and shear 10cm. The application results are as follows.
[0056] Deformation adaptability: In the simulated active fracture slip test, the W-type waterstop 2 deformed accordingly with the change of the expansion joint width without breaking or falling off; the hollow steel pipe 31 and polyurethane material 32 in the steel pipe polyurethane support structure 3 effectively absorbed deformation under compression conditions, and the steel frame 41 maintained the overall stability of the structure.
[0057] Waterproofing capability: Under a water head pressure of 80m, the W-type waterstop 2 and the drainable embedded Ω-type waterstop 5 work together without any leakage in the expansion joint area. The drainable embedded Ω-type waterstop 5 promptly directs any small amount of seepage water into the drainage ditch, effectively reducing the water pressure burden on the waterproofing system.
[0058] Construction feasibility: The pre-reinforced structure effectively controlled the deformation of the surrounding rock and the amount of water inflow during the construction period. After the initial support structure was constructed, the surrounding rock stabilized, creating safe working conditions for subsequent procedures.
[0059] Leakage control during operation: During operation, water can be actively drained through the pre-reserved backfill holes of the drainage embedded Ω waterstop 5, so that leakage can be managed and controlled, reducing the leakage by more than 90% compared with conventional expansion joints.
[0060] Verification results show that the hinged expansion joint and its construction process described in this invention are significantly superior to existing technologies in terms of deformation adaptability, waterproof reliability, construction safety, and maintainability during operation.
[0061] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A hinged deformation joint between tunnel structure units crossing an active fault, characterized in that, include: The pre-reinforcement and initial support structure includes a curtain grouting layer and a radial grouting layer set in the surrounding rock of the expansion joint section to reinforce the surrounding rock of the expansion joint section before construction, and a steel mesh sprayed steel fiber concrete initial support layer set in the inner wall of the tunnel to provide initial support. W-shaped waterstop is installed circumferentially along the expansion joint. Its two ends are embedded in the tunnel lining structure on both sides of the expansion joint and are firmly welded to the waterproofing membrane on both sides. It is used to adapt to the changes in the width of the expansion joint and provide the core waterproofing function. A steel pipe polyurethane support structure is set inside the W-shaped waterstop and includes multiple hollow steel pipes arranged in a ring. The hollow steel pipes are filled with polyurethane to provide radial support for the W-shaped waterstop and to accommodate compression deformation. A steel-reinforced foamed concrete enclosed structure is provided inside the steel pipe polyurethane support structure. It includes a steel frame and foamed concrete poured outside the steel frame to enhance the overall stiffness and durability of the expansion joint structure. The drainage-inlaid Ω-shaped waterstop is installed inside the expansion joint and is fixedly connected to the lining on both sides through the pre-embedded steel plate at the end. It is used to introduce the leakage water into the drainage ditch and realize the active control of leakage water during operation.
2. A hinged deformation joint between tunnel structure units crossing an active fault according to claim 1, characterized in that, The W-type waterstop has a deformation adaptability width of 2cm to 50cm, and its deformation capacity is more than 3 times that of the expansion joint width.
3. A hinged deformation joint between tunnel structure units crossing an active fault according to claim 1, characterized in that, The hollow steel pipe is provided with grouting holes, and the polyurethane is filled into the inside of the steel pipe through the grouting holes; the hollow steel pipe is independently formed into rings, and multiple rings are arranged along the width direction of the deformation joint.
4. A hinged deformation joint between tunnel structure units crossing an active fault according to claim 1, characterized in that, The steel frame is made of I16 I-beams with a spacing of 50cm, and the bottom is raised to the design elevation by foam concrete; the drainable embedded Ω-shaped waterstop has pre-reserved foam concrete backfill holes.
5. A construction procedure for a hinge deformation joint between tunnel structure units crossing an active fault, characterized in that, Includes the following steps: Step 1: Pre-reinforcement construction, implementing curtain grouting and radial grouting in the section where the deformation joint is located to pre-reinforce the surrounding rock; Step 2: Initial support construction, constructing a steel mesh sprayed steel fiber concrete initial support structure on the pre-reinforced tunnel inner wall; Step 3: Setting up embedded parts and waterstops. Auxiliary fixing steel bars are set in the lining on both sides of the expansion joint, the end steel plate embedded parts are installed, and the two ends of the W-shaped waterstop are embedded in the lining and welded firmly to the waterproofing plates on both sides. Step 4: Construction of the waterstop support structure. Multiple hollow steel pipes forming a ring are laid inside the W-shaped waterstop, and polyurethane is filled into the steel pipes through the grouting holes to form a steel pipe polyurethane support structure. Step 5: Construction of steel profiles and drainage waterstops. A steel frame is set inside the polyurethane support structure of the steel pipe, and a drainage embedded Ω-type waterstop is installed through the end steel plate pre-embedded parts. Step Six: Foamed Concrete Backfilling. Foamed concrete is backfilled into the expansion joint through the pre-reserved backfill holes on the drainable embedded Ω-shaped waterstop, so that it densely fills the outside of the steel frame and the space of the expansion joint.
6. The construction procedure of crossing the hinged deformation joint between the tunnel structure units of the active fault according to claim 5, characterized in that, In step one, the curtain grouting is set up with a ring along the deformation joint, with a circumferential depth of not less than 5m and an extension of not less than 10m on each side; the radial grouting is set up with a ring before construction, with a grouting length of not less than 5m and a circumferential spacing of not more than 1m.
7. The construction procedure for the articulated expansion joint between structural units traversing an active fracture tunnel according to claim 5, characterized in that, In step three, the spacing of the embedded parts of the end steel plate is 50-80cm, and the width of the W-shaped waterstop is selected from 2cm to 50cm according to the design width of the expansion joint.
8. The construction procedure of crossing the hinged deformation joint between the tunnel structure units of the active fault according to claim 5, characterized in that, In step four, the hollow steel pipe is independently formed into rings, and multiple rings are set along the width direction of the expansion joint. The polyurethane filling inside the steel pipe is used to improve the bending stiffness of the steel pipe and adapt to compression deformation.
9. The construction procedure of crossing the hinged deformation joint between the tunnel structure units of the active fault according to claim 5, characterized in that, In step five, the steel frame is an I16 I-beam with a spacing of 50cm, and the bottom is raised to the design elevation by foam concrete; the drainable embedded Ω-shaped waterstop is welded to the end steel plate pre-embedded part.
10. The method of claim 5, wherein the method further comprises: In step six, after the foamed concrete backfill is compacted, the drainable embedded Ω-shaped waterstop is used to introduce the leaking water in the expansion joint into the drainage ditch in real time. During operation, water can be actively diverted through drilling.