Construction method of longitudinal shift and closure of double-rotating steel truss bridge above railway station

Abstract

A method for longitudinal shift and closure construction above a railway station for a double-rotating steel truss bridge. The method includes the following steps: longitudinal pre-biased assembly of a single-side steel truss; installation of a protective trolley at the front end of the closure of the steel truss; rotation of the steel truss; movement of the protective trolley to the closure mouth; longitudinal movement of the steel truss on the longitudinal movable support; and closure construction. The effect of the present invention is that the closure mouth of the steel truss is in the form of a single interface, which reduces the number of rod closure points and is more conducive to accelerating the closure speed and controlling the closure accuracy. Before the steel truss is rotated, a closed protective trolley is installed at each end of the beam on both sides. After the rotation is completed, the two protective trolleys are first pushed to the closure mouth and connected into a whole, so that the closure mouth is in a fully closed state, which can ensure the operational safety of the existing railway during the construction process. After the steel truss is rotated, the longitudinal jacking docking is achieved by utilizing the displacement of the longitudinal movable support on the single-side beam body, which can achieve rapid closure and reduce the construction period above the existing railway.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a longitudinal shifting and closure construction method above a railway station yard of a double-rotating steel truss bridge. Background Art

[0002] When a double-rotating steel truss bridge is closed above an existing railway yard, the closure must span multiple existing lines, all located above the railway. Therefore, the installation of closure members, the installation of the bridge deck, the girder recoating, and the associated high-strength bolting and welding work can significantly impact the existing railway, the overhead line, and other railway equipment, as well as the operational safety of trains. Currently, a common method for closure of steel truss bridges across rivers and streams is to reserve short sections of main truss members at the closure to connect the two beams. However, this method is not suitable for closure of steel truss bridges above railway yards. First, the short sections of closure members must be connected to the beams on both sides, resulting in multiple joints, difficult alignment, and a long construction process. Second, the closure is beneath the existing railway, requiring the installation of protective measures before construction. Whether installing or removing protective measures on the ground or on the bridge, this can significantly impact railway operations. Therefore, finding a method that ensures rapid closure while ensuring accuracy and implementing safety measures to effectively protect the closure to ensure the operational safety of the existing railway are key to the successful implementation of the project. However, effective methods are currently lacking. Summary of the Invention

[0003] In order to solve the above problems, the purpose of the present invention is to provide a longitudinal shift and closure construction method above a double-rotation steel truss bridge railway station.

[0004] To achieve the above-mentioned object, the present invention provides a method for longitudinal shifting and closure construction above a double-rotating steel truss bridge railway station, comprising the following steps performed in sequence:

[0005] 1) On one side of the railway yard, first install two longitudinal movable supports on the pad stone at the top of the main pier along the transverse direction of the bridge. Then, pre-deflect the longitudinal movable supports 30 cm toward the side span and lock them before assembling the steel truss on that side. Simultaneously, on the other side of the railway yard, assemble the steel truss on the pad stone at the top of the main pier using traditional methods.

[0006] 2) After the steel trusses are assembled, a protective trolley is installed at the front end of the joint of the steel trusses on both sides. The two sets of running wheels on both sides of the protective trolley use the permanent inspection vehicle track located under the steel trusses as running tracks;

[0007] 3) Utilizing a pre-installed steel truss rotation system between the upper and lower caps of the main pier, and with the aid of an auxiliary sliding system pre-installed in the middle of the side span, the steel truss is rotated using a through-type jack as traction power. The steel truss rotation system is equipped with an integrated rotation support. The upper end of the auxiliary sliding system is connected to the steel truss, and the lower end is equipped with running wheels. This cooperates with the side span weight to ensure that the side span is always weighted during the steel truss rotation process.

[0008] 4) After the steel truss is rotated, move the two protective trolleys toward each other to the joint and connect them with bolts. Cover the joint with fireproof cloth and nail it with steel strips. At the same time, tighten all the fastening devices on the two protective trolleys to lock the running wheels and prevent the protective trolleys from moving.

[0009] 5) Start the longitudinal movement of the steel truss on the longitudinal movable support. First, set two jacks on the main span side of the pad stone at the top of the main pier on this side, and set two jacks on the side span side of the pad stone. The jack uses the pad stone as a reaction seat, and the front end force point is the beam drop block. During the longitudinal movement, first push the jack on the side span side out 20cm to support the beam drop block on this side, and then cut off the multiple bolts on the longitudinal movable support to release the connection of the longitudinal movable support. After that, the jack is returned to the top. At this time, the steel truss will start to move toward the mid-span, and use the jacks on the side span side to alternately push the beam until the force toward the mid-span is eliminated. Then the jacks on the main span side start to push out, 5cm each time. During the longitudinal movement, the support points of the steel truss For the auxiliary slide systems at the middle of the main pier and the side span, the auxiliary sliding systems continue to bear the pressure and move longitudinally with the steel truss. When the steel truss on that side is close to being in place, the four jacks mentioned above are used to jack out alternately to adjust the plane direction of the front end of the steel truss so that the steel trusses on both sides are accurately docked. After the longitudinal movement is completed, the auxiliary slide system is lifted and the elevation of the front end of the steel truss is continued to be adjusted, thereby achieving the precise positioning of the main truss connection hole group. In addition, the locking state of the protective trolley needs to be released before the longitudinal movement. During the movement of the steel truss, the running wheels on the protective trolley will slide on the running track with the movement of the steel truss to ensure the safety of the protective trolley during the longitudinal movement. After the longitudinal movement is completed, the locking state of the protective trolley is immediately restored.

[0010] 6) The closure construction is carried out on the protective trolley. First, the main truss members are connected, and the construction workers stand in the lifting vehicle to perform the operation; then the bridge deck and boom are hoisted using the mobile crane, and the position of the mobile crane is within the range of the main truss; the parallel connecting members are then hoisted using the mobile crane; then, the prefabricated crash barrier is installed, and the closure is repainted; finally, the protective trolley is evacuated to the main pier for dismantling.

[0011] In step 1), the longitudinal movable support includes a support lower hem, a support upper hem and multiple bolts; the support lower hem is a horizontally arranged plate-like structure, which is installed at the designed position on the pad stone using embedded bolts; the support upper hem is located above the support lower hem, and is composed of a top plate and an intermediate block protruding downward from the middle of the bottom surface of the top plate, wherein the center line of the top plate in the front-to-back direction deviates from the center line of the support lower hem by 30 cm toward the side span; multiple bolts are vertically arranged at intervals, and the upper and lower ends are respectively connected to the top plate and the support lower hem, for locking the support; the top plate and the steel truss are connected by bolts.

[0012] The bolts are φ20mm bolts, and there are 12 of them.

[0013] In step 2), the protective trolley is a light steel truss structure, the bottom is fully covered with aluminum plates, railings are set around, the railings are closed with wire mesh, and skirting boards are set at the bottom of the railings. It is powered by a gasoline generator and driven by an electric motor or manual cranking, and fastening devices are provided on the front and rear sides of the running wheels.

[0014] In step 5), the jack is a 400t jack.

[0015] The longitudinal shift and closure construction method above a railway station yard of a double-rotating steel truss bridge provided by the present invention has the following beneficial effects:

[0016] 1. The closure of the steel truss beam is in the form of a single interface, which reduces the number of closure points of the rods and is more conducive to accelerating the closure speed and controlling the closure accuracy.

[0017] 2. Before the steel truss is rotated, a closed protective trolley is installed at each end of the beam. After the rotation is completed, the two protective trolleys are pushed to the joint to connect them into a whole, so that the joint is in a fully closed state, which can ensure the operational safety of the existing railway during the construction process.

[0018] 3. After the steel truss is rotated, the longitudinal push-to-joint connection is achieved by utilizing the displacement of the longitudinal movable support on one side of the beam, which can achieve rapid closure and reduce the construction period above the existing railway.

[0019] 4. The fully enclosed protective trolley is a light steel structure that can prevent welding slag, bolts and rainwater from falling onto the existing railway. The lightweight structure has little effect on the deflection of the beam body. The split and combined parts can effectively reduce the length and weight of the protective trolley. The strong load-bearing capacity can cope with the impact load of the falling joint rods. It can move on its own and can quickly close and remove the joint.

[0020] 5. When the longitudinal jacking of the beam is achieved by utilizing the displacement of the longitudinal movable support, the jacking equipment is installed at the top of the pier, without the need for large-scale temporary facilities. At the same time, jacks are set up before and after the support, and cross-jacking can achieve adjustment of the plane direction of the front end of the joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of the longitudinal shift and closure construction method above the railway station of the double-rotation steel truss bridge provided by the present invention.

[0022] Figure 2 This is a schematic diagram of the process of pre-biased assembly of a single-sided steel truss using longitudinal movable supports in the present invention.

[0023] Figure 3 This is a schematic diagram of the installation state of the longitudinal movable support in the present invention.

[0024] Figure 4 It is a schematic diagram of the connection status of the steel truss swivel and the protective trolley in the present invention.

[0025] Figure 5 This is a schematic diagram of the state in which the closure mouth is sealed by using a protective trolley in the present invention.

[0026] Figure 6 This is the jack arrangement diagram for longitudinal movement.

[0027] Figure 7 It is a schematic diagram of the pushing state during longitudinal movement in the present invention. DETAILED DESCRIPTION

[0028] This construction method is based on the Guangming Road overpass, a transportation center project in a certain city, that spans the Beijing-Shanghai High-Speed ​​Railway and the Beijing-Shanghai Railway. The steel trusses in this project are assembled on both sides and then rotated synchronously to span the Beijing-Shanghai High-Speed ​​Railway and the Beijing-Shanghai Railway. The closure is located above the four lines of the Beijing-Shanghai Railway. The span of the steel trusses on the side adjacent to the Beijing-Shanghai High-Speed ​​Railway is (119+138)m, and the span of the steel trusses on the side adjacent to the Beijing-Shanghai Railway is (119+130)m. The bridge width is 32.2m, with a main truss spacing of 24.2m and a 4m-wide cantilever arm on the outer side. When assembling the steel trusses on the Beijing-Shanghai Railway side, longitudinal movable supports are used to offset them 30cm to the side span. This offset ensures that the steel trusses on both sides do not collide during the rotation process and that the safety distance is 8.6cm. At the same time, all the rods are hoisted during assembly, and a 2m bridge deck is reserved at the closure for later installation.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1-Figure 7 As shown, the longitudinal shift and closure construction method above the railway station yard of the double-rotating steel truss bridge provided by the present invention includes the following steps performed in sequence:

[0031] 1) On the railway yard side, first install two piers on the top of the main pier 3 along the bridge transverse direction. Figure 3The longitudinal movable support 2 shown is then pre-deflected 30 cm toward the side span on the longitudinal movable support 2 and locked before assembling the steel truss girder 1 on that side. Simultaneously, on the other side of the railway yard, the steel truss girder 1 on the other side is assembled on the pad stone 3 on top of the main pier according to the traditional method.

[0032] The longitudinal movable support 2 includes a support lower hem 2-1, a support upper hem 2-2, and a plurality of bolts 2-3; the support lower hem 2-1 is a horizontally arranged plate-like structure, which is installed at the designed position on the pad stone 3 using pre-embedded bolts; the support upper hem 2-2 is located above the support lower hem 2-1, and is composed of a top plate and an intermediate block protruding downward from the middle of the bottom surface of the top plate, wherein the center line of the top plate in the front-to-back direction deviates from the center line of the support lower hem 2-1 by 30 cm toward the side span; a plurality of bolts 2-3 are vertically arranged at intervals, and the upper and lower ends are respectively connected to the top plate and the support lower hem 2-1 for locking the support; the top plate is connected to the steel truss 1 by bolts;

[0033] In this embodiment, the bolts 2 - 3 are φ20 mm bolts, and there are 12 of them.

[0034] 2) After the steel truss 1 is assembled, a protective trolley 4 is installed at the front end of the joint of the steel truss 1 on both sides. The two sets of running wheels on both sides of the protective trolley 4 use the permanent inspection vehicle track located under the steel truss 1 as the running track;

[0035] The protective trolley 4 is a light steel truss structure, with the bottom fully covered with aluminum plates, railings set around it, wire mesh closed on the railings, and skirting boards set at the bottom of the railings. It is powered by a gasoline generator and driven by an electric motor or manual cranking, and fastening devices are provided on the front and rear sides of the running wheels.

[0036] 3) Utilizing a steel truss rotation system pre-installed between the upper and lower caps of the main pier, and with the aid of an auxiliary sliding system 8 pre-installed in the middle of the side span, the steel truss 1 is rotated using a through-type jack as traction power. The steel truss rotation system is equipped with an integrated rotation support. The upper end of the auxiliary sliding system 8 is connected to the steel truss 1, and the lower end is equipped with running wheels. These wheels cooperate with the side span weight to ensure that the side span weight is always applied during the rotation of the steel truss 1.

[0037] 4) After the steel truss 1 is rotated, the two protective trolleys 4 are moved toward each other to the joint and connected with bolts. The joint is covered with fireproof cloth and nailed with strip steel plates. At the same time, all the fastening devices on the two protective trolleys 4 are tightened, thereby locking the running wheels to prevent the protective trolleys 4 from moving;

[0038] 5) Start the longitudinal movement of the steel truss 1 on the longitudinal movable support 2. When the steel truss 1 moves longitudinally and the longitudinal movable support 2 is unlocked, a force toward the mid-span direction will be generated under the influence of the steel truss 1 and the longitudinal movable support 2, causing the steel truss 1 on this side to move toward the mid-span direction. To ensure safety, two jacks 5 are first set on the main span side of the pad stone 3 on the top of the main pier 7 on this side, and two jacks 5 are set on the side span side of the pad stone 3. The jacks 5 use the pad stone 3 as a reaction seat, and the front end force point is the beam drop block 6. During longitudinal movement, first push the jack 5 on the side span side out 20 cm to support the beam drop block 6 on this side, and then cut off the multiple bolts 2-3 on the longitudinal movable support 2 to release the connection of the longitudinal movable support 2, and then the jacks 5 are pushed back. At this time, the steel truss 1 will start to move toward the mid-span direction, and the jacks 5 on the side span side are used to alternately support the beam until the force toward the mid-span direction is eliminated. ; Then the jacks 5 on the main span side start to push out, 5 cm each time; during the longitudinal movement, the support points of the steel truss beam 1 are the main pier 7 and the auxiliary slide system 8 in the middle of the side span. The auxiliary sliding system 8 continues to bear the pressure and moves longitudinally with the steel truss beam 1; when the steel truss beam 1 on this side is close to being in place, the above four jacks 5 are used to push out alternately to adjust the plane direction of the front end of the steel truss beam 1 so that the steel truss beams 1 on both sides are accurately docked; after the longitudinal movement is completed, jacking is carried out at the auxiliary slide system 8, and the elevation of the front end of the steel truss beam 1 is continued to be adjusted, thereby achieving the precise positioning of the main truss connection hole group; in addition, the locking state of the protective trolley 4 must be released before the longitudinal movement. During the movement of the steel truss beam 1, the running wheels on the protective trolley 4 will slide on the running track with the movement of the steel truss beam 1 to ensure the safety of the protective trolley 4 during the longitudinal movement; after the longitudinal movement is completed, the locking state of the protective trolley 4 is immediately restored;

[0039] In this embodiment, the jack 5 is a 400t jack.

[0040] 6) Closure construction is carried out on the protective trolley 4. First, the main truss members are connected, and the construction workers stand in the lifting vehicle to perform the operation; then the bridge deck and boom are hoisted using the mobile crane, and the position of the mobile crane is within the range of the main truss; the parallel connecting members are also hoisted using the mobile crane; then, the prefabricated crash barrier is installed, and the closure is repainted; finally, the protective trolley 4 is evacuated to the main pier for dismantling.

Claims

1. A method for longitudinal shifting and closure construction of a double-rotating steel truss bridge above a railway station, characterized by: The construction method comprises the following steps performed in sequence: 1) On one side of the railway yard, first, two longitudinal movable supports (2) are installed on the pad stone (3) on the top of the main pier along the transverse direction of the bridge, and then the steel truss beam (1) on this side is assembled after pre-deflecting 30 cm toward the side span on the longitudinal movable supports (2) and locking them; at the same time, on the other side of the railway yard, the steel truss beam (1) on the other side is assembled on the pad stone (3) on the top of the main pier according to the traditional method; 2) After the steel truss (1) is assembled, a protective trolley (4) is installed at the front end of the joint of the steel truss (1) on both sides. The two sets of running wheels on both sides of the protective trolley (4) use the permanent inspection vehicle track located under the steel truss (1) as the running track; 3) Utilizing a steel truss beam rotation system pre-installed between the upper and lower pedestals of the main pier, and simultaneously with the aid of an auxiliary sliding system (8) pre-installed in the middle of the side span, a through-type jack is used as a traction force to rotate the steel truss beam (1); wherein the steel truss beam rotation system is provided with an integrated rotation support, the upper end of the auxiliary sliding system (8) is connected to the steel truss beam (1), and the lower end is provided with a running wheel, which cooperates with the side span weight, and always serves as the side span weight during the rotation of the steel truss beam (1); 4) After the steel truss (1) is rotated, the two protective trolleys (4) are moved toward each other to the joint and connected with bolts. The joint is covered with fireproof cloth and nailed with strip steel plates. At the same time, all the fastening devices on the two protective trolleys (4) are tightened, thereby locking the running wheels to prevent the protective trolleys (4) from moving; 5) Start the longitudinal movement of the steel truss (1) on the longitudinal movable support (2). First, two jacks (5) are set on the main span side of the pad stone (3) at the top of the main pier (7) on this side, and two jacks (5) are set on the side span side of the pad stone (3); the jacks (5) use the pad stone (3) as a reaction seat, and the front end force point is the beam drop block (6); during the longitudinal movement, first push the jack (5) on the side span side out 20cm to support the beam drop block (6) on this side, and then cut off the multiple bolts (2-3) on the longitudinal movable support (2) to release the connection of the longitudinal movable support (2), and then the jack (5) is returned to the top. At this time, the steel truss (1) will start to move towards the mid-span direction, and use the jacks (5) on the side span side to alternately push the beam until the force towards the mid-span direction is eliminated; then the jacks (5) on the main span side start to push out, each time 5cm; during the longitudinal movement, the steel truss The supporting points of (1) are the main pier (7) and the auxiliary sliding system (8) in the middle of the side span. The auxiliary sliding system (8) continues to bear the pressure and moves longitudinally with the steel truss (1). When the steel truss (1) on this side is close to being in place, the four jacks (5) are used to alternately push out to adjust the plane direction of the front end of the steel truss (1) so that the steel trusses (1) on both sides are accurately docked. After the longitudinal movement is completed, the auxiliary sliding system (8) is lifted and the elevation of the front end of the steel truss (1) is continuously adjusted to achieve the accurate positioning of the main truss connection hole group. In addition, the locking state of the protective trolley (4) needs to be released before the longitudinal movement. During the movement of the steel truss (1), the running wheels on the protective trolley (4) will slide on the running track along with the movement of the steel truss (1) to ensure the safety of the protective trolley (4) during the longitudinal movement. After the longitudinal movement is completed, the locking state of the protective trolley (4) is immediately restored. 6) Carry out the joint closure construction on the protective trolley (4). First, connect the main truss members. The construction workers stand in the lifting vehicle to perform the operation. Then use the truck crane to complete the lifting of the bridge deck and the boom. The position of the truck crane is within the range of the main truss. Then use the truck crane to complete the lifting of the parallel rods. Afterwards, install the prefabricated anti-collision wall and repaint the joint mouth. Finally, evacuate the protective trolley (4) to the main pier for dismantling.

2. The method for longitudinal shifting and closure construction above a railway station yard of a double-rotating steel truss bridge according to claim 1 is characterized by: In step 1), the longitudinal movable support (2) includes a support lower hem (2-1), a support upper hem (2-2) and a plurality of bolts (2-3); the support lower hem (2-1) is a horizontally arranged plate-like structure, which is installed at a designed position on the pad stone (3) using pre-embedded bolts; the support upper hem (2-2) is located above the support lower hem (2-1), and is composed of a top plate and an intermediate block formed by protruding downward from the middle of the bottom surface of the top plate, wherein the center line of the top plate in the front-back direction deviates from the center line of the support lower hem (2-1) by 30 cm toward the side span; a plurality of bolts (2-3) are vertically arranged at intervals, and the upper and lower ends are respectively connected to the top plate and the support lower hem (2-1) for locking the support; the top plate and the steel truss (1) are connected by bolts.

3. The method for longitudinal shifting and closure construction above a railway station yard of a double-rotating steel truss bridge according to claim 2 is characterized by: The bolts (2-3) are φ20mm bolts, and the number is 12.

4. The method for longitudinal shifting and closure construction above a railway station yard of a double-rotating steel truss bridge according to claim 1 is characterized by: In step 2), the protective trolley (4) is a light steel truss structure, the bottom is fully covered with aluminum plates, railings are set around, the railings are closed with wire mesh, and a skirting board is set at the bottom of the railings. It is powered by a gasoline generator and driven by an electric motor or manual cranking, and fastening devices are provided on the front and rear sides of the running wheels.

5. The method for longitudinal shifting and closure construction above a railway station yard of a double-rotating steel truss bridge according to claim 1 is characterized by: In step 5), the jack (5) is a 400t jack.

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