A railway box girder support system adjacent to an existing high-speed railway is installed and dismantled

Abstract

The present application belongs to the technical field of box girder support, and particularly relates to a railway box girder support system installation and disassembly method adjacent to an existing high-speed railway. In the installation and disassembly method, the support system is arranged between two adjacent pier columns and away from the high-speed railway line, so that the support system does not affect the operation of the existing high-speed railway line. A disc-type support is erected on the side of the two adjacent pier columns away from the existing high-speed railway line, a box girder cast-in-place formwork is erected on the disc-type support, the pouring of the concrete box girder is completed, after the cast-in-place box girder is completed, the box girder cast-in-place formwork on the cast-in-place support system is removed, the cast-in-place box girder is driven by the slide shoe to slide from the top of the disc-type support to the top of the pier column, then the lifting mechanism falls, and the cast-in-place box girder falls on the top of the pier column. The construction of erecting the box girder on the pier column adjacent to the existing high-speed railway line is completed, and the erection of the box girder and the operation of the existing high-speed railway line do not affect each other, which not only improves the construction efficiency, but also has less impact on the existing high-speed railway line.

Description

Technical Field

[0001] This invention belongs to the field of box girder support technology, specifically relating to a method for installing and dismantling a railway box girder support system adjacent to an existing high-speed railway. Background Technology

[0002] Most of my country's high-speed railways are based on bridges, with high-speed rail lines laid on viaducts. However, during the construction of viaducts, there are situations where existing high-speed rail lines intersect or are very close to them. In such cases, the construction of the viaduct can cause mutual interference between the bridge construction and the operation of the existing high-speed rail lines. In current technology, the operation of the high-speed rail line is usually suspended, and the viaduct is constructed quickly. However, suspending the operation of the existing high-speed rail line will seriously affect the normal operation of the existing high-speed rail line, resulting in poor economic benefits and negatively impacting the travel of people in that section.

[0003] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0004] The purpose of this invention is to provide a method for installing and dismantling a railway box girder support system adjacent to an existing high-speed railway, so as to at least solve the above-mentioned problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for installing and dismantling a railway box girder support system adjacent to an existing high-speed railway. The high-speed railway box girder support system includes a cast-in-place support system and a transverse support system. The cast-in-place support system is located on the side of two adjacent piers away from the existing high-speed railway line, and the cast-in-place support system and the transverse support system have overlapping parts.

[0007] The cast-in-place support system includes a cast-in-place foundation and a disc-lock scaffold. The disc-lock scaffold is used to support the cast-in-place formwork of the box girder. The cast-in-place formwork of the box girder is located on the side of two adjacent piers away from the existing high-speed railway line.

[0008] The transverse support system includes a transverse foundation and steel pipe supports. Two rows of steel pipe supports are set between two adjacent piers, with each row of steel pipe supports set close to the pier.

[0009] Each row of steel pipe supports is equipped with a sliding lifting system, which includes a load-bearing beam and a slide rail. Multiple lifting mechanisms are set between the load-bearing beam and the slide rail, and sliding shoes are slidably installed on the slide rail.

[0010] The installation and removal method includes the following steps:

[0011] Step 1: Construct the cast-in-place foundation and the laterally moved foundation;

[0012] Step 2: Build a steel pipe support on the transverse foundation and a disc-lock scaffold on the cast-in-place foundation;

[0013] Step 3: Erect the box girder casting formwork above the disc-lock scaffold and carry out the box girder casting operation;

[0014] Step 4: After the box girder construction is completed, remove the cast-in-place formwork and disc-lock scaffolding for the box girder.

[0015] Step 5: Move the box girder along the slide rail by using the sliding shoe so that the crossbeam moves from the side of the pier away from the existing high-speed railway line to the top of the pier.

[0016] Step 6: The lifting mechanism descends to allow the box girder to land on the two piers. Then, the lifting mechanism continues to descend to disengage the box girder from the sliding shoe.

[0017] Step 7: Dismantle the sliding lifting system and the steel pipe support.

[0018] As described above, the method for installing and dismantling the railway box girder support system adjacent to the existing high-speed railway is preferably carried out in step 1, where a first cement-soil replacement layer is first constructed on the side of the two piers away from the existing high-speed railway line, and then a first concrete cushion layer is constructed on the first cement-soil replacement layer to complete the construction of the cast-in-place foundation.

[0019] As described above, the method for installing and dismantling the railway box girder support system adjacent to an existing high-speed railway preferably includes the lateral foundation comprising the existing pier cap and the enlarged foundation. The steel pipe support closer to the pier is erected on the existing pier cap, and the steel pipe support farther from the pier is erected on the enlarged foundation.

[0020] The method for installing and dismantling the railway box girder support system adjacent to the existing high-speed railway, as described above, preferably involves constructing a second cement-soil replacement layer on the side of the existing pier cap away from the existing high-speed railway line during the construction of the enlarged foundation, and then constructing a second concrete cushion layer on top of the second cement-soil replacement layer to complete the construction of the enlarged foundation.

[0021] As described above, the method for installing and dismantling the railway box girder support system adjacent to an existing high-speed railway preferably involves, in step 2, constructing multiple steel pipe groups on the transverse foundation, setting a distribution beam above each steel pipe group, installing load-bearing crossbeams on the multiple distribution beams, and ensuring that each distribution beam is perpendicular to the load-bearing crossbeam.

[0022] The method for installing and dismantling the railway box girder support system adjacent to the existing high-speed railway, as described above, preferably involves installing multiple transverse connecting rods between adjacent steel pipes in the steel pipe group; and installing multiple Z-shaped connecting systems between adjacent steel pipe groups.

[0023] As described above, the method for installing and dismantling the railway box girder support system adjacent to an existing high-speed railway preferably involves setting multiple pier body embedded parts on the pier column, and installing a support arm between the steel pipe group near the pier column and the pier body embedded parts on the pier column so that the steel pipe support and the pier column are connected to each other.

[0024] As described above, the method for installing and dismantling the railway box girder support system adjacent to an existing high-speed railway is preferably implemented in step 3. After the cast-in-place formwork of the box girder is erected, the cast-in-place formwork of the box girder is preloaded and monitored. The preload is applied in stages according to 60%-110% of the total construction load, and the formwork is left to stand for a set time after each loading stage to observe the settlement of the cast-in-place support system.

[0025] As described above, the method for installing and dismantling the railway box girder support system adjacent to the existing high-speed railway is preferably as follows: in step 5, the sliding shoe is part of the bottom formwork in the cast-in-place formwork of the box girder, and the sliding shoe directly presses against the bottom of the cast-in-place box girder; a reaction seat is set on the side of the slide close to the existing high-speed railway line, and the reaction seat is connected to steel strands.

[0026] The sliding shoe is equipped with a clearance hole, through which the steel strand passes. A continuous jack is installed on the side of the sliding shoe away from the existing high-speed railway line, and the continuous jack is connected to the steel strand.

[0027] In the above-described method for installing and dismantling the railway box girder support system adjacent to an existing high-speed railway, preferably, in step 6, multiple guide rods are also provided on the load-bearing crossbeam, and guide holes are provided on the slide rail. The guide rods extend into the guide holes on the slide rail. When the slide rail drives the adjacent section to descend, the slide rail moves along the guide rods for guidance. A spring is also sleeved around the guide rods.

[0028] Beneficial effects:

[0029] The support system is positioned between two adjacent piers, away from the high-speed rail line, ensuring that it does not affect the operation of the existing high-speed rail line. A disc-lock scaffold is erected on the side of the two adjacent piers away from the existing high-speed rail line. The cast-in-place formwork for the box girder is then installed on the disc-lock scaffold, and the concrete box girder is poured. After the cast-in-place box girder is completed, the formwork on the cast-in-place scaffold system is removed. A sliding shoe then moves the cast-in-place box girder from the top of the disc-lock scaffold to the top of the pier. A lifting mechanism then lowers the cast-in-place box girder onto the top of the pier. This completes the construction of the box girder on piers adjacent to the existing high-speed rail line, ensuring that the box girder erection operation does not interfere with the operation of the existing high-speed rail line. This not only improves construction efficiency but also minimizes the impact on the existing high-speed rail line, guaranteeing both the safety of the existing high-speed rail line and the efficiency and quality of construction.

[0030] During the descent of the slide, the slide moves along the guide rod, enabling it to descend stably. At the same time, springs are fitted around the guide rods, which can evenly bear the pressure between the slide and the load-bearing crossbeam, ensuring the stability of the slide during descent and thus greatly improving the safety of the cast-in-place box girder descent process. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0032] Figure 1 This is a schematic diagram of the support system in the vertical bridge direction according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the lateral movement of a cast-in-place box girder according to an embodiment of the present invention.

[0034] In the diagram: 10. Cast-in-place support system; 11. Disc-lock scaffold; 12. Cast-in-place foundation;

[0035] 20. Lateral shift support system; 21. Steel pipe support; 22. Lateral shift foundation; 23. Distribution beam; 24. Z-shaped connection system;

[0036] 30. Sliding lifting system; 31. Load-bearing crossbeam; 32. Slide rail; 33. Slipper; 34. Lifting mechanism; 35. Guide rod; 36. Spring; 37. Steel strand; 38. Continuous jack;

[0037] 100. Pier column; 200. Existing high-speed railway line. Detailed Implementation

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0039] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0040] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0041] According to specific embodiments of the present invention, such as Figure 1-2 As shown, the present invention provides a method for installing and dismantling a railway box girder support system adjacent to an existing high-speed railway. The high-speed railway box girder support system includes a cast-in-place support system 10 and a transverse support system 20. The cast-in-place support system 10 is located on the side of two adjacent piers 100 away from the existing high-speed railway line 200, and the cast-in-place support system 10 and the transverse support system 20 have overlapping parts.

[0042] The cast-in-place support system 10 includes a cast-in-place foundation 12 and a disc-locked support 11. The disc-locked support 11 is used to support the cast-in-place formwork of the box girder. The cast-in-place formwork of the box girder is located on the side of the two adjacent piers 100 away from the existing high-speed railway line 200.

[0043] The transverse support system 20 includes a transverse foundation 22 and a steel pipe support 21. Two rows of steel pipe supports 21 are set between two adjacent piers 100, and each row of steel pipe supports 21 is set close to the pier 100.

[0044] Each row of steel pipe supports 21 is supported by a sliding lifting system 30. The sliding lifting system 30 includes a load-bearing beam 31 and a slide rail 32. Multiple lifting mechanisms 34 are set between the load-bearing beam 31 and the slide rail 32. Sliding shoes 33 are slidably set on the slide rail 32.

[0045] The installation and removal method includes the following steps:

[0046] Step 1: Construct the cast-in-place foundation 12 and the transversely moved foundation 22;

[0047] Step 2: Build a steel pipe support 21 on the transverse foundation 22 and a disc-lock support 11 on the cast-in-place foundation 12;

[0048] Step 3: Erect the box girder casting formwork above the disc-lock scaffold 11 and carry out the box girder casting operation;

[0049] Step 4: After the box girder construction is completed, remove the cast-in-place formwork and the disc-lock scaffold 11 for the box girder.

[0050] Step 5: The box girder is moved along the slide rail 32 by the sliding shoe 33 so that the crossbeam moves from the side of the pier 100 away from the existing high-speed railway line 200 to the top of the pier 100.

[0051] Step 6: The lifting mechanism 34 descends to allow the box girder to land on the two piers 100. Then the lifting mechanism 34 continues to descend to disengage the box girder from the sliding shoe 33.

[0052] Step 7: Remove the sliding lifting system 30 and the steel pipe support 21.

[0053] In the installation and dismantling method of the railway box girder support system, a disc-lock scaffold 11 is erected on the side of two adjacent piers 100 away from the existing high-speed railway line 200. The box girder cast-in-place formwork is erected on the disc-lock scaffold 11, steel bars are tied in the cast-in-place formwork, and the concrete box girder is poured. After the cast-in-place box girder is completed, the cast-in-place formwork of the box girder on the cast-in-place scaffold system 10 is removed. The cast-in-place box girder is slid from the top of the disc-lock scaffold 11 to the top of the pier 100 by the sliding shoe 33. Then the lifting mechanism 34 falls, so that the cast-in-place box girder lands on the top of the pier 100. The construction of the box girder erection on the pier 100 adjacent to the existing high-speed railway line 200 is completed, and the box girder erection operation does not affect the operation of the existing high-speed railway line 200. This not only improves the construction efficiency, but also has little impact on the existing high-speed railway line 200.

[0054] In this embodiment, the number of lifting mechanisms 34 is increased or decreased according to the span (i.e., length) of the slide 32. When the span of the slide 32 is large, the number of lifting mechanisms 34 is increased so that the slide 32 is better supported.

[0055] In step 1, a first cement-soil replacement layer is first constructed on the side of the two piers 100 away from the existing high-speed railway line 200, and then a first concrete cushion layer is constructed on the first cement-soil replacement layer to complete the construction of the cast-in-place foundation 12.

[0056] In one embodiment of this application, the concrete cushion layer is made of 20cm thick C20 concrete, and a 50cm cement-soil replacement layer is placed beneath it. The cement-soil bearing capacity is not less than 220kPa, and the bearing capacity of the original soil foundation beneath the replacement layer is not less than 110kPa. The cement-soil replacement layer is laid and compacted in layers, with each layer not exceeding 30cm in thickness. After each layer is compacted, the bearing capacity of the replacement layer foundation and the subgrade is tested using a light cone penetration test.

[0057] The transverse foundation 22 includes the existing pile cap and the enlarged foundation of the pier 100. The steel pipe support 21 close to the pier 100 is erected on the existing pile cap, and the steel pipe support 21 far from the pier 100 is erected on the enlarged foundation.

[0058] During the construction of the enlarged foundation, a second cement-soil replacement layer is constructed on the side of the existing pier cap of pier 100 away from the existing high-speed railway line 200. Then, a second concrete cushion layer is constructed on top of the second cement-soil replacement layer to complete the construction of the enlarged foundation.

[0059] In one embodiment of this application, the second concrete layer has dimensions of 5m (width) × 7.35m (length) × 0.9m (height). Below the concrete layer, a 0.8m cement-soil replacement layer is used to ensure that the bearing capacity of the replacement layer is not less than 220kPa and the bearing capacity of the original soil foundation below the replacement layer is not less than 110kPa.

[0060] In step 2, multiple steel pipe groups are first constructed on the transverse foundation 22. A distribution beam 23 is set above each steel pipe group, and load-bearing crossbeams 31 are installed on the multiple distribution beams 23, with each distribution beam 23 being perpendicular to the load-bearing crossbeams 31.

[0061] In one embodiment of this application, each steel pipe group includes at least two steel pipes, the bottom of which is connected to the transverse foundation 22 via an embedded part. The bottom of the steel pipe is welded to the embedded part. The existing foundation embedded part is installed using inverted conical adhesive anchor bolts.

[0062] In the steel pipe assembly, multiple transverse connecting rods are installed between adjacent steel pipes; multiple Z-shaped connecting systems 24 are installed between adjacent steel pipe assemblies.

[0063] In one embodiment of this application, the transverse connecting rod between the steel pipes is made of [20a channel steel and welded to the steel pipe column by means of brackets. Each steel pipe in the steel pipe group is connected together by the transverse connecting rod. Each adjacent steel pipe group is connected by a Z-shaped connecting system 24. Each Z-shaped connecting system 24 and the steel pipe form two triangular reinforcing structures, which not only connects multiple steel pipe groups into a whole, but also greatly improves the structural strength of the overall steel pipe group, giving it better support capacity.

[0064] Multiple pier body embedded parts are installed on the pier column 100. A support arm is installed between the steel pipe group near the pier column 100 and the pier body embedded parts on the pier column 100 so that the steel pipe support 21 is connected to the pier column 100.

[0065] In one embodiment of this application, the support arm is made of 20a channel steel and is welded to the steel pipe column and the pier body embedded parts via brackets. Connecting the steel pipe assembly to the pier column 100 via the support arm enables the steel pipe assembly and the pier column 100 to be connected as a whole, improving the stability of the steel pipe assembly and thus improving the support capacity of the transverse support system 20.

[0066] In step 3, after the box girder cast-in-place formwork is erected, the pre-loading monitoring of the box girder cast-in-place formwork is carried out. The pre-loading is carried out in stages according to 60%-110% of the total construction load, and the static time is set after each loading stage to observe the settlement of the cast-in-place support system 10.

[0067] In one embodiment of this application, after each stage of preloading, a set static rest period is observed, and vertical deformation is measured at multiple support observation points in the cast-in-place support system 10. After all loads are applied, deformation values ​​are measured every 6 hours. The preloading unloading time is determined based on the principle of stable settlement deformation of the cast-in-place foundation 12. Preloading unloading is terminated when the difference between the average values ​​of the last two settlement measurements is no greater than 2 mm. During unloading, unloading is performed stage by stage according to the loading sequence, and the elastic deformation values ​​are observed.

[0068] After unloading, the observation points of the support structure are re-measured and the data is compiled, thus completing the pre-stressing construction of the support structure. The observation data is then handed over to the alignment monitoring personnel for analysis to determine the formwork elevation.

[0069] In step 5, the sliding shoe 33 serves as part of the bottom formwork in the cast-in-place box girder formwork, and the sliding shoe 33 directly presses against the bottom of the cast-in-place box girder; a reaction seat is provided on the side of the slide 32 near the existing high-speed railway line 200, and the reaction seat is connected to the steel strand 37; a clearance hole is provided on the sliding shoe 33, and the steel strand 37 passes through the clearance hole on the sliding shoe 33; a continuous jack 38 is provided on the side of the sliding shoe 33 away from the existing high-speed railway line 200, and the continuous jack 38 is connected to the steel strand 37.

[0070] In one embodiment of this application, after the cast-in-place box girder is poured and the construction is completed, the cast-in-place formwork of the box girder is removed, so that two slippers 33 are supported on both sides of the cast-in-place box girder respectively. Two continuous jacks 38 are controlled to operate synchronously. The continuous jacks 38 push the slippers 33 toward the reaction seat, so that the slippers 33 drive the cast-in-place box girder to move above the pier 100.

[0071] In step 6, the load-bearing crossbeam 31 is also provided with a plurality of guide rods 35, and the slide rail 32 is provided with guide holes. The guide rods 35 extend into the guide holes on the slide rail 32. When the slide rail 32 drives the adjacent slide rail to descend, the slide rail 32 moves along the guide rods 35. A spring 36 is sleeved around the guide rods 35.

[0072] In one embodiment of this application, during the descent of the slide rail 32, the slide rail 32 moves along the guide rod 35 to ensure stable descent; at the same time, a spring 36 is sleeved around the guide rod 35, which can evenly bear the pressure between the slide rail 32 and the load-bearing crossbeam 31, ensuring the stability of the slide rail 32 during descent, thereby greatly improving the safety of the cast-in-place box girder descent process.

[0073] It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.

Claims

1. A railway box girder support system installation and dismantling method adjacent to an existing high-speed railway, characterized by, The high-speed rail box girder support system comprises a cast-in-place support system and a transverse support system, the cast-in-place support system is located on the side of two adjacent pier columns away from the existing high-speed rail line, and the cast-in-place support system and the transverse support system have a mutual overlapping part; The cast-in-place support system comprises a cast-in-place foundation and a disc buckle support, the disc buckle support is used for supporting a box girder cast-in-place formwork, and the box girder cast-in-place formwork is located on the side of two adjacent pier columns away from the existing high-speed rail line; The transverse support system comprises a transverse foundation and a steel pipe support, two rows of steel pipe supports are arranged between two adjacent pier columns, and each row of steel pipe supports is arranged close to the pier column; Each row of steel pipe supports is supported by a sliding lifting system, the sliding lifting system comprises a bearing crossbeam and a slide, a plurality of lifting mechanisms are arranged between the bearing crossbeam and the slide, and a sliding shoe is slidingly arranged on the slide; A plurality of guide rods are further arranged on the bearing crossbeam, guide holes are arranged on the slide, the guide rods extend into the guide holes on the slide, and the slide moves along the guide rods in a guided manner when the slide drives an adjacent pier column to descend; and a spring is arranged around the guide rod; The dismounting method comprises the following steps: Step 1, constructing a cast-in-place foundation and a transverse foundation; Step 2, erecting a steel pipe support on the transverse foundation and erecting a disc buckle support on the cast-in-place foundation; Step 3, erecting a box girder cast-in-place formwork above the disc buckle support and performing a box girder pouring operation; Step 4, after the box girder construction is completed, removing the box girder cast-in-place formwork and the disc buckle support; Step 5, moving the box girder along the slide by means of the sliding shoe, so that the crossbeam moves from the side of the pier column away from the existing high-speed rail line to the top of the pier column; Step 6, lowering the lifting mechanism, so that the box girder falls on the two pier columns, and then the lifting mechanism continues to descend, so that the box girder and the sliding shoe are separated from each other; Step 7, removing the sliding lifting system and the steel pipe support.

2. The method according to claim 1, wherein the method is characterized by, In step 1, a first cement soil replacement layer is first constructed on the side of the two pier columns away from the existing high-speed rail line, and then a first concrete cushion layer is constructed on the first cement soil replacement layer, so as to complete the construction of the cast-in-place foundation.

3. The method for installing and dismantling a railway box girder support system adjacent to an existing high-speed railway as described in claim 2, characterized in that, The transverse foundation comprises an existing pile cap of the pier column and an enlarged foundation, the steel pipe support close to the pier column is arranged on the existing pile cap, and the steel pipe support away from the pier column is arranged on the enlarged foundation.

4. The method of claim 3, wherein the method further comprises: When the enlarged foundation is constructed, a second cement soil replacement layer is constructed on the side of the existing pile cap of the pier column away from the existing high-speed rail line, and then a second concrete cushion layer is constructed above the second cement soil replacement layer, so as to complete the construction of the enlarged foundation.

5. The method of claim 4, wherein the method further comprises: In step 2, a plurality of steel pipe groups are first constructed on the transverse foundation, a distribution beam is arranged above each steel pipe group, a bearing crossbeam is installed on the plurality of distribution beams, and each distribution beam is perpendicular to the bearing crossbeam.

6. The method of claim 5, wherein the method further comprises: In the steel pipe group, a plurality of transverse connecting rods are installed between adjacent steel pipes; and a plurality of Z-shaped connecting systems are installed between adjacent steel pipe groups.

7. The method of claim 5, wherein the method further comprises: A plurality of pier body embedded parts are arranged on the pier column, and a supporting arm is installed between the steel pipe group close to the pier column and the pier body embedded part on the pier column, so as to connect the steel pipe support and the pier column to each other.

8. The method of claim 1, wherein the method further comprises: In step 3, after the box girder cast-in-place formwork is erected, the box girder cast-in-place formwork is pre-pressed and loaded, the pre-pressed loading is loaded in stages according to 60%-110% of the total construction load, and after each stage of loading, a set time is set to observe the settlement of the cast-in-place support system.

9. The method of claim 1, wherein the method further comprises: In step 5, the sliding shoe is directly pressed against the bottom of the cast-in-place box girder as part of the bottom die of the box girder cast-in-place formwork; a counterforce seat is arranged on the side of the sliding way close to the existing high-speed rail line, and the counterforce seat is connected with a steel strand; The sliding shoe is provided with a clearance hole, the steel strand penetrates through the clearance hole on the sliding shoe, and a continuous jack is arranged on the side of the sliding shoe away from the existing high-speed rail line, and the continuous jack is connected with the steel strand.

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