Anti-permeation combined deformation joint structure and construction method

Abstract

The present application relates to the technical field of thermal power plant, and particularly relates to a kind of anti-permeation combined deformation joint structure and construction method. The deformation joint structure includes a water retaining system, a drainage system and a covering system. The water retaining system includes a water retaining edge of a transfer station and a water retaining edge of a trestle. A gap is provided between the transfer station and the trestle. The water retaining edge of the transfer station is arranged on the edge of the transfer station close to the trestle. The water retaining edge of the trestle is arranged on the edge of the trestle close to the transfer station. The drainage system includes a drainage pipe. The drainage pipe passes through the water retaining edge of the trestle, the gap and the water retaining edge of the transfer station. The inlet end of the drainage pipe is located on the trestle deck. The covering system is arranged on the water retaining edge of the transfer station and the water retaining edge of the trestle and covers the gap. The present application solves the technical problem of coal water leakage and wall pollution caused by aging failure of flexible sealing material in the existing deformation joint structure, and improves the long-term waterproof reliability of the deformation joint.

Description

Technical Field

[0001] This invention relates to the field of thermal power plant technology, and in particular to a seepage-resistant combined expansion joint structure and construction method. Background Technology

[0002] Coal trestle bridges and transfer stations are critical nodes in material conveying lines of thermal power plants, port terminals, and coal storage and transportation systems. Trestle bridges are typically elevated corridor structures with independent foundations, housing conveyors and flushing systems; transfer stations, on the other hand, are enclosed buildings used for material transfer and distribution. Because trestle bridges have a large length along the conveying direction, resulting in high longitudinal stiffness but relatively weak lateral stiffness, while transfer stations are regular frame structures with significant vertical loads, their structural forms are completely different. Therefore, expansion joints must be installed at the connection between the trestle bridge and the transfer station to accommodate structural displacements caused by temperature changes, settlement differences, and seismic forces.

[0003] Currently, the standard practice for expansion joints at the interface between the trestle bridge and the transfer station is to construct them according to architectural drawings. Specifically, this involves installing a rubber waterstop at the joint between the trestle bridge deck and the transfer station floor, and then sealing it with sealant.

[0004] However, coal conveyor bridges require regular water flushing to remove accumulated coal during daily operation. The flushing water is large in volume and contains a significant amount of coal dust. In actual operation, it has been found that flexible sealing materials such as rubber waterstops, constantly exposed to moisture and coal-water erosion, are prone to aging, detachment, or gradually losing their sealing effect due to minor structural deformation. Once the waterstops fail or the sealant cracks, coal-containing wastewater leaks along the expansion joints to the outer walls of the transfer station, creating a phenomenon known as "urine wall." Once the coal-water seeps into the structural layer, it is difficult to clean, not only polluting the building facade and affecting its aesthetics but also accelerating steel corrosion and concrete deterioration, threatening the building's durability. Furthermore, because the expansion joints are located at the bridge deck elevation, the flushing water flows directly through this area, increasing the waterproofing pressure on the sealing structure and making it difficult for conventional flexible sealing methods to remain effective in the long term. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a seepage-resistant combined expansion joint structure for the interface between a trestle bridge and a transfer station, thereby solving the technical problem of coal and water leakage and wall contamination caused by the aging and failure of flexible sealing materials in existing expansion joint structures, and thus improving the long-term waterproof reliability of the expansion joint.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: In a first aspect, embodiments of the present invention provide a seepage-resistant combined expansion joint structure for use at the interface between a trestle and a transfer station, comprising: a water-blocking system, a drainage system, and a covering system; the water-blocking system includes a water-blocking edge of the transfer station and a water-blocking edge of the trestle, with a gap between the transfer station and the trestle, the water-blocking edge of the transfer station being disposed on the edge of the transfer station near the edge of the trestle, and the water-blocking edge of the trestle being disposed on the edge of the trestle near the edge of the transfer station; the drainage system includes a drainage pipe, which passes through the water-blocking edge of the trestle, the gap, and the water-blocking edge of the transfer station, with the inlet end of the drainage pipe located on the trestle surface; the covering system is disposed on the water-blocking edge of the transfer station and the water-blocking edge of the trestle, and covers the gap.

[0007] As a further technical solution, the water-retaining edge of the transfer station is a reinforced concrete structure vertically arranged on the edge of the main body of the transfer station, and the water-retaining edge of the trestle bridge is a reinforced concrete structure vertically arranged on the edge of the main body of the trestle bridge. Both the water-retaining edge of the transfer station and the water-retaining edge of the trestle bridge are integrally cast with the corresponding main structure.

[0008] As a further technical solution, the drainage pipe is arranged at an angle, wherein one end located inside the trestle is higher than the other end located inside the transfer station, and the trestle deck is provided with a drainage slope that slopes towards the inlet end of the drainage pipe.

[0009] As a further technical solution, the inlet end of the dredging pipe is located at the root of the water-retaining edge of the trestle on the bridge deck.

[0010] As a further technical solution, the outlet end of the dredging pipe extends to one side of the transfer station and is connected to the drainage system of the transfer station; an open ditch or floor drain is provided on the floor of the transfer station corresponding to the location of the outlet of the dredging pipe, and the open ditch or floor drain is connected to the coal-containing sewage collection system of the transfer station.

[0011] As a further technical solution, a water-stop ring is fitted on the dredging guide pipe, the water-stop ring is located inside the concrete of the water-retaining edge of the trestle bridge, and elastic waterproof adhesive is provided around the water-retaining edge of the transfer station on the dredging guide pipe.

[0012] As a further technical solution, a removable filter screen is provided at the inlet of the dredging conduit.

[0013] As a further technical solution, the dredging guide has multiple guides, which are arranged at intervals along the transverse direction of the bridge deck.

[0014] As a further technical solution, the covering system includes a sealant, a waterstop, and a metal cover plate. The sealant is filled between the covering system and the water-blocking edge of the transfer station or the water-blocking edge of the trestle. The waterstop and the metal cover plate cover the top of the water-blocking edge of the transfer station or the water-blocking edge of the trestle.

[0015] Secondly, embodiments of the present invention also provide a construction method for the aforementioned impermeable composite expansion joint structure, comprising: Before pouring the water-retaining edge of the trestle, the drainage pipe is pre-embedded and positioned so that the drainage pipe is set at an angle and the inlet end is level with or lower than the elevation of the trestle surface, and the outlet end passes through the water-retaining edge of the trestle. When pouring the main body of the trestle bridge, concrete is poured upwards from the edge of the trestle bridge to form a water-retaining edge. When pouring the main body of the transfer station, concrete is poured upwards from the edge of the transfer station floor slab to form a water-retaining edge. An expansion joint is reserved between the two water-retaining edges. A covering system was constructed on top of the water barriers of the trestle bridge and the transfer station to seal the expansion joints.

[0016] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: In the expansion joint structure of this invention, the water-blocking system physically intercepts the flushing water on one side of the trestle bridge deck, preventing it from directly contacting the expansion joint, thus forming the first line of defense. The drainage system, through the sloping bridge deck and inclined drainage pipes, systematically guides the water collected at the base of the water-blocking edge to the transfer station drainage system, forming the second line of defense. The covering system, located at the top of the water-blocking edge, serves as a conventional sealing structure for the expansion joint, providing the third layer of waterproofing. Since most of the flushing water has been treated by the first two lines of defense, the covering system only bears a very small amount of splashing water or rainwater, greatly reducing the waterproofing pressure. The combination of these three elements achieves a waterproofing effect of first blocking and then draining, combining prevention and drainage, and multi-layered protection, thereby solving the problem in traditional structures where a single flexible waterstop bears all the water pressure and, once aged, leads to leakage into the wall.

[0017] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, the dimensions or spacing between the components are exaggerated to show the position of each component, and the schematic diagrams are for illustrative purposes only.

[0019] Figure 1 This is a schematic diagram of the layout of the trestle bridge and transfer station provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the drainage pipe and water-stopping ring provided in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the expansion joint structure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the zero-meter layer provided in an embodiment of the present invention; In the diagram: 1. Main body of the trestle bridge; 2. Main body of the transfer station; 3. Gap; 4. Water-retaining edge of the trestle bridge; 5. Water-retaining edge of the transfer station; 6. Drainage pipe; 7. Water-stop ring; 8. Covering system; 81. Metal cover plate; 82. Aluminum alloy base and support; 83. Water-stop strip; 84. C15 concrete block coping; 85. @400 expansion bolts; 86. Additional waterproof membrane; 87. Building sealant; 9. Floor drain; 10. Filter screen; 11. Drainage ditch; Detailed Implementation To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the linguistic context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0020] Generally speaking, the terms "include" and "contain" only indicate that steps and elements are explicitly identified, and these steps and elements do not constitute an exclusive list, as the method or apparatus may also include other steps or elements.

[0021] Example 1 Coal transport trestle bridges and transfer stations are two different types of structures on material conveying lines. Trestle bridges are elevated walkways with independent foundations, while transfer stations are frame buildings with significant vertical loads. Expansion joints must be installed at their connection points to accommodate temperature changes and settlement differences. However, the large amount of coal-containing wastewater generated during the daily washing of trestle bridges easily leaks along the expansion joints, causing wall contamination and structural corrosion. To address this problem, in a typical embodiment of this disclosure, a seepage-resistant combined expansion joint structure consisting of three parts: a water-blocking system, a drainage system, and a covering system is provided. Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the system includes: a water-blocking system, a drainage system, and a covering system 8; the water-blocking system includes a water-blocking edge 5 at the transfer station and a water-blocking edge 4 at the trestle bridge, with a gap 3 between the transfer station and the trestle bridge; the water-blocking edge 5 at the transfer station is located on the edge of the transfer station near the edge of the trestle bridge, and the water-blocking edge 4 at the trestle bridge is located on the edge of the trestle bridge near the edge of the transfer station; the drainage system includes a drainage pipe 6, which passes through the water-blocking edge 4 at the trestle bridge, the gap 3, and the water-blocking edge 5 at the transfer station, with the inlet end of the drainage pipe 6 located on the trestle bridge surface; the covering system 8 is installed on the water-blocking edge 5 at the transfer station and the water-blocking edge 4 at the trestle bridge, and covers the gap 3.

[0022] The water-blocking system comprises two water-blocking edges, located at the edges of the trestle bridge deck and the transfer station floor slab, respectively. Taking the trestle bridge water-blocking edge 4 as an example, this edge, situated at the trestle bridge edge, physically confines the bridge deck flushing water to one side of the trestle bridge, preventing black coal water from directly contacting the expansion joint. The drainage system includes a drainage pipe 6 that passes through the trestle bridge deck, water-blocking edge 4, and transfer station water-blocking edge 5, with its inlet end located on the bridge deck. This pipe guides the water intercepted by the water-blocking edges to the outside. The covering system 8 is located on top of the two water-blocking edges, covering the gap 3, serving as a standard sealing structure for the expansion joint. These three systems form a tiered waterproofing system: a first layer of interception, a second layer of drainage, and a third layer of sealing. The water-blocking system isolates water from the expansion joint at its source, the drainage system systematically drains the intercepted water, and the covering system 8 acts as a final waterproofing supplement. The combined effect of these three systems solves the problem of flexible sealing materials in traditional structures easily failing when bearing waterproofing pressure alone.

[0023] The water-retaining edge 5 of the transfer station is a reinforced concrete structure that is vertically set upward on the edge of the main body 2 of the transfer station; the water-retaining edge 4 of the trestle bridge is a reinforced concrete structure that is vertically set upward on the edge of the main body 1 of the trestle bridge; both the water-retaining edge 5 of the transfer station and the water-retaining edge 4 of the trestle bridge are integrally cast with the corresponding main structure.

[0024] The height of the water-retaining edge should not be less than 200mm. Integrated casting refers to the process of simultaneously casting the water-retaining edge while erecting formwork at the edge of the trestle bridge deck or transfer station floor slab, rather than a subsequent secondary construction and installation. Integrated cast concrete structures have no construction joints, and there are no joints between the water-retaining edge and the main structure, avoiding the seepage channels that can occur at the base of prefabricated structures. Furthermore, reinforced concrete is a rigid material with the same lifespan as the main structure, eliminating the need for replacement due to the aging of rubber materials.

[0025] The drainage pipe 6 is arranged at an angle, with one end located inside the trestle bridge being higher than the other end located inside the transfer station; the trestle bridge deck is provided with a drainage slope that slopes towards the inlet end of the drainage pipe 6.

[0026] The drainage pipe 6 is arranged at an angle. This elevation difference allows the water to flow naturally within the pipe due to gravity, without the need for external power. The trestle bridge deck has a drainage slope, meaning the bridge deck is not horizontal, but rather the inlet of the drainage pipe 6 is the lowest point. The flushing water can naturally converge to the inlet of the drainage pipe 6 along the slope. The bridge deck slope guides the water to the inlet, while the pipe's inclination ensures the smooth drainage of the water entering the pipe. Together, they achieve active drainage of accumulated water.

[0027] The inlet of the drainage pipe 6 is located at the root of the water-retaining edge 4 on the trestle bridge deck. The root refers to the point where the water-retaining edge 4 intersects with the bridge deck, specifically the connection between the bottom of the water-retaining edge and the bridge deck. By placing the inlet of the drainage pipe 6 at the root, water on the bridge surface will naturally collect at this lowest point after encountering the water-retaining edge, maximizing water collection and preventing water accumulation on the bridge. During construction, the drainage pipe 6 is pre-embedded at the bottom of the water-retaining edge, with the inlet flush with or slightly below the bridge deck elevation, facilitating water flow without affecting the normal use of the bridge deck.

[0028] The outlet end of the drainage pipe 6 extends to one side of the transfer station and is connected to the drainage system of the transfer station; an open ditch or floor drain 9 is provided on the floor of the transfer station corresponding to the outlet of the drainage pipe 6, and the open ditch or floor drain 9 is connected to the coal-containing sewage collection system of the transfer station.

[0029] After passing through the water-retaining edge 5 of the transfer station, the outlet of the drainage pipe 6 is located on one side of the transfer station floor, directly connecting to the existing drainage system of the transfer station. In the coal conveying system of a thermal power plant, the transfer station usually has a coal-containing wastewater collection network, and the water discharged from the drainage pipe 6 can directly flow into this system. An open ditch or floor drain 9 is installed on the transfer station floor at the location corresponding to the outlet of the drainage pipe 6, forming a transition between the outlet of the drainage pipe 6 and the drainage system, and the water is collected through the open ditch or floor drain 9. Both the open ditch and the floor drain 9 are connected to the coal-containing wastewater collection system of the transfer station to ensure the integrity of the entire drainage path.

[0030] A water-stop ring 7 is fitted onto the drainage pipe 6, and the water-stop ring 7 is located inside the concrete of the water-blocking edge 4 of the trestle bridge; the drainage pipe 6 is provided with elastic waterproof adhesive around the water-blocking edge 5 of the transfer station.

[0031] The water-stop ring 7 is a ring-shaped metal piece fitted onto the outer wall of the drainage pipe 6. Depending on the shape of the drainage pipe 6, it can be circular or square, and is embedded in the concrete of the trestle's retaining edge 4. When water seeps in along the tiny gap between the outer wall of the drainage pipe 6 and the concrete, the presence of the water-stop ring 7 prolongs the seepage path, and the ring-shaped piece is tightly bonded to the concrete, thus intercepting the water. On one side of the transfer station's retaining edge 5, a 30mm thick elastic waterproof sealant is installed around the drainage pipe 6. This sealant fills the gap 3 between the steel pipe and the concrete, providing a sealing effect. The water-stop ring 7 and the elastic waterproof sealant are located at different crossing points of the drainage pipe 6; the former is inside the concrete of the trestle's retaining edge 4, and the latter is at the transfer station's retaining edge 5. Together, they block the seepage path around the drainage pipe 6 from both ends.

[0032] A removable filter screen 10 is installed at the inlet of the dredging pipe 6. The flushing water of the trestle contains a large amount of coal dust and coal lumps of varying sizes. If these coal lumps directly enter the dredging pipe 6, they may cause blockage. Installing the filter screen 10 at the inlet can intercept large coal particles, causing them to remain on the bridge surface for periodic manual cleaning. The filter screen 10 is removable, making it easy to remove and clean when blocked or requiring cleaning, thus facilitating maintenance.

[0033] The dredging pipe 6 has multiple pipes, which are arranged at intervals along the transverse direction of the bridge deck.

[0034] The bridge deck has a certain width, and a single drainage pipe 6 cannot effectively collect water accumulated at various locations on the bridge deck. By arranging multiple drainage pipes 6 at designed intervals along the transverse direction of the bridge deck, water accumulated at different width locations on the bridge deck can be discharged into the corresponding drainage pipes 6 nearby, forming a multi-point collection and segmented discharge drainage pattern, which improves the drainage capacity of the drainage system.

[0035] The covering system 8 is a conventional expansion joint sealing structure, including joint filler material, a waterstop, and a metal cover plate. The joint filler material is placed between the covering system 8 and the water-retaining edge 5 of the transfer station or the water-retaining edge 4 of the trestle. The waterstop and metal cover plate cover the top of the water-retaining edge 5 of the transfer station and the water-retaining edge 4 of the trestle. Specifically, as shown... Figure 3 As shown, the covering system 8 includes a C15 concrete block capping 84, @400 expansion bolts 85, additional waterproof membrane 86, cement-based waterproof coating and building sealant 87 applied internally, and installed around the galvanized buried pipe, between the cover plate and the retaining edge, as well as a metal cover plate 81, an aluminum alloy base and support 82, and a waterstop 83. The cement-based waterproof coating has a thickness of not less than 1mm, and is applied evenly at corners to ensure coating quality.

[0036] It should be noted that the covering system 8 is located at the top of the water-retaining edge, away from the main area of ​​bridge deck wash water. Therefore, it mainly bears a small amount of splashing water, rainwater, or a small amount of seepage that may overflow from the top of the water-retaining edge, and the waterproofing pressure is relatively small. This structural arrangement makes the covering system 8 act as a third line of defense, forming a three-dimensional waterproofing layout with the lower water-retaining system and drainage system.

[0037] In summary, this expansion joint structure has the following advantages: Eliminating the problem of urine-stained walls: A 200mm high water-blocking edge physically intercepts the flushing water on one side of the trestle, preventing black coal water from directly contacting the side wall and fundamentally solving the problem of external wall pollution.

[0038] Active drainage: The pre-embedded drainage pipe 6 with water-stopping ring 7 drains the accumulated water into the sewage system in an organized manner, realizing the combination of prevention and drainage.

[0039] Double protection: The lower drainage and top sealing form a three-dimensional waterproof system. Even if the drainage pipe 6 is blocked or the top cover fails, there is still a line of defense, making it extremely reliable.

[0040] Long service life: The water-blocking edge is made of reinforced concrete and has the same service life as the main body; the drainage pipe 6 and the water-stop ring 7 are made of rigid metal materials, avoiding the maintenance and replacement problems caused by the aging of traditional rubber materials.

[0041] Example 2 This embodiment provides a construction method for the aforementioned impermeable composite expansion joint structure, including: Before pouring the water-retaining edge 4 of the trestle bridge, the drainage pipe 6 is pre-embedded and positioned so that the drainage pipe 6 is set at an angle and the inlet end is level with or lower than the elevation of the trestle bridge surface, and the outlet end passes through the water-retaining edge 4 of the trestle bridge. When pouring the main body 1 of the trestle bridge, concrete is poured upwards from the edge of the trestle bridge to form the trestle bridge water-blocking edge 4. When pouring the main body 2 of the transfer station, concrete is poured upwards from the edge of the transfer station floor slab to form the transfer station water-blocking edge 5. Expansion joint spacing is reserved between the two water-blocking edges. Construction of a covering system 8 on top of the water-retaining edge 4 of the trestle bridge and the water-retaining edge 5 of the transfer station to seal the expansion joints.

[0042] During the construction phase, when pouring the main body 1 of the trestle bridge, concrete is poured directly at a height of 200mm or more at its edge to form the trestle bridge water-retaining edge 4; similarly, the water-retaining edge 5 of the transfer station is poured at the edge of the floor slab of the main body 2 of the transfer station. The two water-retaining edges are set in parallel, with a gap 3 of the designed width reserved in the middle.

[0043] Before pouring the water-retaining edge 4 of the trestle bridge, multiple drainage pipes 6 are pre-embedded and positioned according to the design spacing. The drainage pipes 6 are set at an angle, with their inlets flush with or slightly lower than the bridge deck elevation, and their outlets passing through the water-retaining edge. A water-stop ring 7 is welded to the middle of the drainage pipe 6. After the concrete is poured, the water-stop ring 7 is tightly bonded to the concrete, extending the water seepage path and effectively preventing water from seeping along the outer wall of the steel pipe.

[0044] When the trestle is washed, a large amount of black coal water is first blocked by the 200mm high trestle water retaining edge 4, preventing it from directly spreading to the expansion joint. The water flows along the slope of the bridge into the inlet of the drainage pipe 6, is filtered by the filter screen 10, and then discharged into the drainage ditch 11 of the main body 2 of the transfer station through the drainage pipe 6, and finally flows into the zero-meter layer water collection pit.

[0045] A small amount of water that may splash or seep into the top of the water-retaining edge is waterproofed a second time by the covering system 8 installed on top of the water-retaining edge. Since the main water flow has been diverted, the top structure only withstands a small amount of seepage or rainwater, greatly reducing the probability of leakage.

[0046] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A seepage-resistant composite expansion joint structure for use at the interface between a trestle bridge and a transfer station, characterized in that, include: Water-blocking system, drainage system, and covering system; The water-blocking system includes a water-blocking edge for the transfer station and a water-blocking edge for the trestle bridge. There is a gap between the transfer station and the trestle bridge. The water-blocking edge for the transfer station is located on the edge of the transfer station near the edge of the trestle bridge, and the water-blocking edge for the trestle bridge is located on the edge of the trestle bridge near the edge of the transfer station. The drainage system includes a drainage pipe that passes through the water-retaining edge of the trestle, the gaps, and the water-retaining edge of the transfer station, with the inlet end of the drainage pipe located on the trestle surface. The covering system is installed on the water-retaining edge of the transfer station and the water-retaining edge of the trestle, and covers the gap.

2. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, The water-retaining edge of the transfer station is a reinforced concrete structure that is vertically set upward on the edge of the main body of the transfer station, and the water-retaining edge of the trestle bridge is a reinforced concrete structure that is vertically set upward on the edge of the main body of the trestle bridge. Both the water-retaining edge of the transfer station and the water-retaining edge of the trestle bridge are integrally cast with the corresponding main structure.

3. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, The drainage pipe is arranged at an angle, with one end inside the trestle being higher than the other end inside the transfer station. The trestle deck is provided with a drainage slope that slopes towards the inlet end of the drainage pipe.

4. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, The inlet end of the dredging pipe is located at the root of the water-retaining edge of the trestle bridge on the bridge deck.

5. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, The outlet end of the dredging pipe extends to one side of the transfer station and connects to the drainage system of the transfer station; an open ditch or floor drain is provided on the floor of the transfer station corresponding to the location of the outlet of the dredging pipe, and the open ditch or floor drain is connected to the coal-containing sewage collection system of the transfer station.

6. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, A water-stop ring is fitted onto the dredging guide pipe, and the water-stop ring is located inside the concrete of the water-retaining edge of the trestle. Elastic waterproof adhesive is provided around the water-retaining edge of the transfer station on the dredging guide pipe.

7. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, A removable filter screen is provided at the inlet of the dredging conduit.

8. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, The dredging guide has multiple guides, which are arranged at intervals along the transverse direction of the bridge deck.

9. The anti-seepage combined expansion joint structure as described in claim 1, characterized in that, The covering system includes a sealant, a waterstop, and a metal cover plate. The sealant is filled between the covering system and the water-retaining edge of the transfer station or the water-retaining edge of the trestle. The waterstop and the metal cover plate cover the top of the water-retaining edge of the transfer station or the water-retaining edge of the trestle.

10. A construction method for a waterproof composite expansion joint structure as described in any one of claims 1-9, characterized in that, include: Before pouring the water-retaining edge of the trestle, the drainage pipe is pre-embedded and positioned so that the drainage pipe is set at an angle with the inlet end level with or lower than the elevation of the trestle surface and the outlet end passing through the water-retaining edge of the trestle. When pouring the main body of the trestle bridge, concrete is poured upwards from the edge of the trestle bridge to form a water-retaining edge. When pouring the main body of the transfer station, concrete is poured upwards from the edge of the transfer station floor slab to form a water-retaining edge. An expansion joint is reserved between the two water-retaining edges. A covering system was constructed on top of the water barriers of the trestle bridge and the transfer station to seal the expansion joints.

Images