Construction method for reconstructing steel truss girder into concrete simply supported beam

Abstract

The invention discloses a construction method for reconstructing a steel truss girder into a concrete simply supported beam. At present, many steel truss girder main body steel structures are seriously rusted, and steel girder connection node bolts flow plastic. The construction method comprises the following steps: constructing abutment guard piles, middle pier foundations and temporary piers; a jack is arranged at the beam end to jack up the steel truss beam; a middle pier support is installed, and a bridge abutment temporary support is installed; underneath passing through beams at bridge abutments on two sides, and mounting inclined struts; lowering the beam body, and dismantling the jack; bridge abutment concrete is chiseled away, and rebars are planted to the designed elevation of the top cap of the T-beam; dismantling the steel truss girder and replacing the T-beam by using the skylight point; and dismantling the temporary supporting structure. A line in the steel truss girder reconstruction process can operate safely, and the steel truss girder can be used for temporary stress in the reconstruction process or the system conversion process of similar bridges; on the premise of not being influenced by the external environment and not influencing the driving safety, train skylight points are fully utilized, and rapid reconstruction of the steel truss girder can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a construction method for rebuilding a steel truss beam into a concrete simply supported beam. Background Art

[0002] Steel structures have the advantages of high strength, low construction cost, light weight, short construction period, and factory production. Since the last century, my country has built a batch of steel trusses. At present, many bridges have been in service for more than 40 years. Affected by the live load of trains and the surrounding environment, a large area of ​​steel trusses have suffered from serious corrosion of the main steel structure, plastic flow of bolts at the connection nodes of steel beams, and serious shaking of trains when passing. Daily maintenance can no longer eliminate the defects and daily maintenance requires a lot of investment, which is difficult and endangers driving safety. It is urgent to improve the operation level of bridges through reconstruction to ensure driving safety.

[0003] Concrete simply supported beams have the characteristics of clear force, high degree of prefabrication, and convenient construction. They are often used as bridge reconstruction beams in locations not affected by external factors. At the same time, railway operations are busy and the skylight time is short. It is particularly important to ensure the normal passage of trains and fast construction speed during bridge reconstruction. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present invention provides a construction method for rebuilding a steel truss beam into a concrete simply supported beam, which is used for the rapid reconstruction of the steel truss beam without affecting the operation of the existing line.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A construction method for converting a steel truss beam into a concrete simply supported beam, characterized in that it comprises the following steps:

[0007] Step 1: Construction of abutment protection piles, middle pier foundations, and temporary piers;

[0008] Step 2: Set up jacks at the beam ends to lift up the steel truss; install the middle pier support and temporary abutment support; pass through the cross beams at the abutments on both sides and install diagonal braces; lower the beam and remove the jacks;

[0009] Step 3: Chisel away the abutment concrete and re-embed the reinforcement to the designed elevation of the T-beam top cap; use the skylight point to remove the steel trusses and replace the T-beams; remove the temporary support structure.

[0010] Further, step one is specifically as follows:

[0011] Step 1.1: Construct existing line abutment protection piles;

[0012] Step 1.2: During the construction of the pier pile foundation and the cap, the bridge pier adopts the open cut and full pouring foundation, and the lower embedded parts of the steel column are set simultaneously. During the reconstruction process, the column is connected to the lower embedded parts through the foundation flange and anchor bolts;

[0013] Step 1.3: Hoist the columns into place and connect them with the lower embedded parts. Use a crane to hoist them. Note that the hoisting weight of the crane should match the weight of the columns. After the hoisting is completed, assemble the diagonal braces and horizontal braces between the columns. The columns, diagonal braces and horizontal braces are connected by welding. Attention should be paid to the welding quality during the construction process.

[0014] Step 1.4: Use a crane to hoist the top crown beam and firmly connect it to the steel column with the column flange to form an overall stable system.

[0015] Further, step 2 is specifically as follows:

[0016] Step 2.1: Relocate various cables within the steel truss range;

[0017] Step 2.2: Use the skylight point to cut the rail at the end of the platform to release the stress of the seamless line, install the jack at the top beam position of the cross beam at the end of the steel truss beam; weld the support stiffening ribs on the lower chord of the newly built support node, and remove the original support of the steel truss beam; install the top beam body and install the plate rubber bearing at the middle pier;

[0018] Step 2.3: Pass under the steel beams at the abutments on both sides, install the pads and tension and compression PTFE rubber bearings, connect the steel columns and diagonally support the lowered beams, and remove the jacks;

[0019] Step 2.4: Restore the track, and the train will enter the speed limit operation state for a short period of time. It is strictly forbidden for vehicles to brake and stop within the range of this bridge.

[0020] Further, step three is specifically as follows:

[0021] Step 3.1: Since the distance from the rail surface to the pier top of the simply supported T-beam is higher than that of the steel truss beam, it is necessary to chisel out part of the existing line abutment cap and tray to ensure the force of the simply supported box beam;

[0022] Step 3.2: Plant reinforcement, tie the top cap steel bars and pour concrete to the designed elevation of the T-beam top cap. Construct support pads to prepare for replacing the T. The construction process should minimize interference with railway operations. Construction should be stopped in advance when a train passes through the line to ensure the safety of construction and railway operation.

[0023] Step 3.3: Use the skylight point to dismantle the steel truss and replace the T-beam. The steel truss is dismantled and the simply supported T-beam is installed by crane. During the hoisting process, attention should be paid to safety and efficiency to ensure that the construction is completed within the railway skylight time;

[0024] Step 3.4: After the lifting is completed, all kinds of cables are moved back within the bridge range, and the bridge deck and track structure are constructed. Train operations will be resumed after all safety monitoring and inspections meet the conditions for safe railway operation.

[0025] Furthermore, in step 1, diagonal braces, horizontal braces and vertical braces are arranged between the columns, and are connected by welding. The columns are 630×16 steel columns, the horizontal braces and vertical braces are 133*8 round steels, and the diagonal braces are 299*16 round steels;

[0026] The crown beam and the column are firmly spliced ​​with the column flange to form an overall stable system; the column is firmly spliced ​​with the foundation through the foundation flange and the ground angle bolts to form an overall stable system.

[0027] Furthermore, in step two, a steel crossbeam is set on the column and connected to the crown beam through a plate rubber bearing to form a force system; before the steel truss is dropped, its lower chord is polished and tightened, and a steel pad and a stiffening plate are set to improve the force of the steel truss at the position of the plate rubber bearing; an H-shaped steel is set on the top of the diagonal brace and welded to the crossbeam.

[0028] Beneficial effects of the present invention:

[0029] 1) The line in the process of steel truss reconstruction of the present invention can be operated safely and can be used for temporary stress during the reconstruction of similar bridges or system conversion;

[0030] 2) The present invention can realize the rapid reconstruction of steel trusses by making full use of the skylight points of the train without being affected by the external environment and without affecting the driving safety;

[0031] 3) The method for rebuilding a concrete simply supported beam of the present invention is easy to construct and can provide a reference for other projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a full bridge elevation view of the present invention;

[0033] Figure 2 This is a cross-sectional view of the intermediate temporary pier of the present invention;

[0034] Figure 3 It is a longitudinal section view of the intermediate temporary pier of the present invention;

[0035] Figure 4 This is a cross-sectional view of a temporary pier of an abutment of the present invention;

[0036] Figure 5 This is a longitudinal section of the temporary pier of the abutment of the present invention;

[0037] Figure 6 This is a structural diagram of the steel support facade of the present invention;

[0038] Figure 7 This is a large-scale drawing of the connection between the column and the foundation of the present invention;

[0039] Figure 8 This is a large-scale drawing of the connection between the horizontal brace and the diagonal brace of the present invention;

[0040] Fig. 9This is a large-scale drawing of the connection between the column and the cross brace of the present invention;

[0041] Fig.10 This is a large-scale drawing of the connection between the upright column and the horizontal brace and diagonal brace of the present invention;

[0042] Fig.11 This is a large-scale drawing of the connection between the crown beam and the cross beam of the present invention;

[0043] Fig.12 This is a construction completion diagram of the present invention;

[0044] In the figure, 1-column, 2-cross brace, 3-diagonal brace, 4-crown beam, 5-cross beam, 6-protective pile, 7-column flange, 8-foundation flange, 9-embedded steel plate, 10-anchor bolt, 11-stiffening plate, 12-steel pad, 13-support, 14-vertical brace, 15-H-shaped steel. DETAILED DESCRIPTION

[0045] The present invention is described in detail below in conjunction with specific implementation modes.

[0046] like Figure 1 As shown, the present invention realizes the reconstruction of steel truss beam into concrete simply supported beam by constructing a temporary support structure; the temporary support structure includes columns 1, cross braces 2, diagonal braces 3, crown beams 4, cross beams 5, protective piles 6, column flanges 7, foundation flanges 8, embedded steel plates 9, anchor bolts 10, stiffening plates 11, steel pads 12, supports 13, vertical braces 14, and H-shaped steels 15.

[0047] The construction method of the steel truss beam reconstruction concrete simply supported beam of the present invention comprises the following steps:

[0048] Step 1: Construction of abutment protection piles, middle pier foundation, and temporary piers, specifically:

[0049] Step 1.1: construct the existing line abutment protection pile 6, using a 1.25m diameter pile foundation;

[0050] Step 1.2: During the construction of the pier pile foundation and the cap, the bridge pier adopts the open cut and full pouring foundation, and the lower embedded parts of the steel column 1 are set simultaneously. During the reconstruction process, the column 1 is connected to the lower embedded parts through the foundation flange 8 and the anchor bolts 10;

[0051] Step 1.3: Hoist the column 1 into place and connect it with the lower embedded parts. Use a crane to hoist it. Note that the hoisting weight of the crane should be compatible with the weight of the column. After the hoisting is completed, assemble the diagonal brace 2 and the horizontal brace 3 between the columns. The columns, diagonal braces and horizontal braces are connected by welding. Pay attention to the welding quality during the construction process.

[0052] Step 1.4: The top crown beam 4 is hoisted by a crane, and is firmly connected to the steel column 1 with the column flange 7 to form an overall stable system.

[0053] like Figure 2 , 3 As shown in , 8, 9, and 10, a diagonal brace 3, a horizontal brace 2, and a vertical brace 14 are provided between the columns 1, and are connected by welding. The column (1) is made of 630×16 steel column, the horizontal brace (2) and the vertical brace 14 are made of 133*8 round steel, and the diagonal brace 3 is made of 299*16 round steel;

[0054] The crown beam 4 and the column 1 are firmly spliced ​​with the column flange 7 to form an overall stable system; the column 1 is firmly spliced ​​with the foundation through the foundation flange 8 and the ground angle bolts 10 to form an overall stable system.

[0055] Step 2: Set up jacks at the beam ends to lift up the steel truss; install the middle pier support and temporary abutment support; pass through the cross beams at the abutments on both sides and install diagonal braces; lower the beam and remove the jacks; specifically:

[0056] Step 2.1: Relocate various cables within the steel truss range;

[0057] Step 2.2: Use the skylight point to cut the rail at the end of the platform to complete the stress release of the seamless line, install the jack at the top beam position of the cross beam at the end of the steel truss beam; weld the support stiffening rib 11 on the lower chord of the newly built support node, and remove the original support of the steel truss beam; install the top beam body and install the plate rubber bearing 13 at the middle pier;

[0058] Step 2.3: Pass under the steel cross beam 5 at the abutments on both sides, install the pad 12 and the tension and compression PTFE plate rubber bearing 13, connect the steel column diagonal brace 3, lower the beam body, and remove the jack;

[0059] Step 2.4: Restore the track, and the train will enter the speed limit operation state for a short period of time. It is strictly forbidden for vehicles to brake and stop within the range of this bridge.

[0060] like Figure 4 , 5 As shown in Figures 6, 7 and 11, the steel crossbeam 5 is arranged on the column 1 and is connected to the crown beam 4 through the plate rubber bearing 13 to form a force system; before the steel truss is dropped, its lower chord is polished and tightened, and a steel pad 12 and a stiffening plate 11 are arranged to improve the force of the steel truss at the position of the plate rubber bearing 13; an H-shaped steel 15 is arranged on the top of the diagonal brace and welded to the crossbeam 5.

[0061] Step 3: Chisel away the abutment concrete and re-plant the reinforcement to the design elevation of the T-beam top cap; use the skylight point to remove the steel truss and replace the T-beam; remove the temporary support structure; specifically:

[0062] Step 3.1: Since the distance from the rail surface to the pier top of the simply supported T-beam is higher than that of the steel truss beam, it is necessary to chisel out part of the existing line abutment cap and tray to ensure the force of the simply supported box beam;

[0063] Step 3.2: Plant reinforcement, tie the top cap steel bars and pour concrete to the designed elevation of the T-beam top cap. Construct support pads to prepare for replacing the T. The construction process should minimize interference with railway operations. Construction should be stopped in advance when a train passes through the line to ensure the safety of construction and railway operation.

[0064] Step 3.3: Use the skylight point to dismantle the steel truss and replace the T-beam. The steel truss is dismantled and the simply supported T-beam is installed by crane. During the hoisting process, attention should be paid to safety and efficiency to ensure that the construction is completed within the railway skylight time;

[0065] Step 3.4: After the lifting is completed, all kinds of cables are moved back to the bridge area, and the bridge deck and track structure are constructed. After all safety monitoring and inspection meet the railway safety operation conditions, train operation will be resumed. Fig.12 shown.

[0066] In the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", and "fix" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] The content of the present invention is not limited to the embodiments listed, and any equivalent changes made to the technical solution of the present invention by ordinary technicians in this field after reading the description of the present invention are covered by the claims of the present invention.

Claims

1. A construction method for rebuilding a concrete simply supported beam with a steel truss beam, characterized in that: The steps include: Step 1: Construction of abutment protection piles, middle pier foundations, and temporary piers; Step 2: Set up jacks at the beam ends to lift up the steel truss; install the middle pier support and temporary abutment support; pass through the cross beams at the abutments on both sides and install diagonal braces; lower the beam and remove the jacks; Step 3: Chisel away the abutment concrete and re-embed the reinforcement to the designed elevation of the T-beam top cap; use the skylight point to remove the steel trusses and replace the T-beams; remove the temporary support structure.

2. The construction method of converting a steel truss beam into a concrete simply supported beam according to claim 1, characterized in that: Step 1 is as follows: Step 1.1: construct existing line abutment protection piles (6); Step 1.2: During the construction of the pier pile foundation and the cap, the bridge pier adopts an open cut and full pouring foundation, and the lower embedded parts of the steel column (1) are set simultaneously. During the reconstruction process, the column (1) is connected to the lower embedded parts through the foundation flange (8) and the anchor bolts (10); Step 1.3: Hoist the column (1) into place and connect it with the lower embedded parts. Use a crane to hoist it. Note that the hoisting weight of the crane should be compatible with the weight of the column. After the hoisting is completed, assemble the diagonal braces (2) and horizontal braces (3) between the columns. The columns, diagonal braces and horizontal braces are connected by welding. During the construction process, attention should be paid to the welding quality. Step 1.4: The top crown beam (4) is hoisted by a crane and firmly connected to the steel column (1) with the column flange (7) to form an overall stable system.

3. The construction method of converting a steel truss beam into a concrete simply supported beam according to claim 2, characterized in that: Step 2 is as follows: Step 2.1: Relocate various cables within the steel truss range; Step 2.2: Use the skylight point to cut the rail at the end of the platform to complete the stress release of the seamless line, install a jack at the top beam position of the cross beam at the end of the steel truss beam; weld the support stiffening rib (11) on the lower chord of the newly built support node, and remove the original support of the steel truss beam; install the top beam body and install the plate rubber support (13) at the middle pier; Step 2.3: Pass through the steel cross beams (5) at the abutments on both sides, install the pads (12) and the tension and compression PTFE rubber bearings (13), connect the steel column diagonal braces (3), lower the beam body, and remove the jacks; Step 2.4: Restore the track, and the train will enter the speed limit operation state for a short period of time. It is strictly forbidden for vehicles to brake and stop within the range of this bridge.

4. The construction method of converting a steel truss beam into a concrete simply supported beam according to claim 3, characterized in that: Step three is as follows: Step 3.1: Since the distance from the rail surface to the pier top of the simply supported T-beam is higher than that of the steel truss beam, it is necessary to chisel out part of the existing line abutment cap and tray to ensure the force of the simply supported box beam; Step 3.2: Plant reinforcement, tie the top cap steel bars and pour concrete to the designed elevation of the T-beam top cap. Construct support pads to prepare for replacing the T. The construction process should minimize interference with railway operations. Construction should be stopped in advance when a train passes through the line to ensure the safety of construction and railway operation. Step 3.3: Use the skylight point to dismantle the steel truss and replace the T-beam. The steel truss is dismantled and the simply supported T-beam is installed by crane. During the hoisting process, attention should be paid to safety and efficiency to ensure that the construction is completed within the railway skylight time; Step 3.4: After the lifting is completed, all kinds of cables are moved back within the bridge range, and the bridge deck and track structure are constructed. Train operations will be resumed after all safety monitoring and inspections meet the conditions for safe railway operation.

5. The construction method of converting a steel truss beam into a concrete simply supported beam according to claim 4, characterized in that: In step 1, diagonal braces (3), transverse braces (2) and vertical braces (14) are arranged between the columns (1) and connected by welding. The columns (1) are made of 630×16 steel columns, the transverse braces (2) and vertical braces (14) are made of 133*8 round steel, and the diagonal braces (3) are made of 299*16 round steel. The crown beam (4) and the column (1) are firmly spliced ​​with the column flange (7) to form an overall stable system; the column (1) is firmly spliced ​​with the foundation through the foundation flange (8) and the ground angle bolts (10) to form an overall stable system.

6. The construction method of converting a steel truss beam into a concrete simply supported beam according to claim 5, characterized in that: In step 2, a steel crossbeam (5) is arranged on the column (1) and connected to the crown beam (4) through a plate rubber bearing (13) to form a force-bearing system; before the steel truss beam is dropped, its lower chord is polished and tightened, and a steel pad (12) and a stiffening plate (11) are arranged to improve the force of the steel truss beam at the position of the plate rubber bearing (13); an H-shaped steel (15) is arranged at the top of the diagonal brace and welded to the crossbeam (5).

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