Overturn-preventing device additionally arranged on single-column pier

Abstract

The utility model relates to an anti-overturning device additionally arranged on a single-column bridge pier, belongs to the field of bridge engineering, and particularly relates to a reinforcing structure for preventing an upper box girder of a single-column bridge from overturning. The potential safety hazard of rollover and overturning of an existing single-column pier is overcome, and the defects of a reinforcing method in the prior art are overcome. The device is mainly composed of a pier, a support, supporting feet and damping supporting pull rods. The device is arranged at the single-column pier, under the normal condition, the damping supporting pull rod and the box girder are in damping flexible connection, additional rigidity is not generated, the box girder is not restrained, and an original stress system of the box girder is not changed. When the upper structure of the bridge overturns under the eccentric stress effect of an overload vehicle, one side of the traction structure plays a supporting role, the other side of the traction structure plays a traction role, and the box girder is prevented from rollover and overturning. When the overloaded vehicle is driven away, the box girder is slowly reset under the damping effect, and the box girder cannot be impacted.

Description

Technical Field

[0001] The utility model relates to an anti-overturning device installed on a single-column bridge pier, belongs to the field of bridge engineering, and particularly relates to a reinforcement structure for preventing an upper box girder of a single-column bridge from overturning. Background Art

[0002] Urban flyovers mostly adopt cast-in-place continuous box girder structures. The multi-span continuous structure is a whole box girder. The two ends of the box girder are supported by abutments or cap beams, and the middle is supported by a single-column pier in the middle of the box girder. The single-column pier bridge has many advantages and characteristics such as simple structure, beautiful appearance, and small space under the bridge. This structure is widely used in urban flyovers and highway ramp bridges. However, due to the narrow top of the single-column pier, a single support point is often set in the transverse direction of the bridge. Under the eccentric load of the car, the lateral anti-overturning stability of the single-column pier continuous beam bridge is very unfavorable. In recent years, this type of bridge has experienced many overturning accidents under overload and eccentric load conditions. One of the factors is severe overloading.

[0003] Many seriously overloaded trucks or heavy vehicles drove along one side of the single-column pier bridge, causing serious eccentric loading of the bridge, causing one side of the bridge support to be vacant, and resulting in the lateral rollover of the bridge beam. In recent years, bridge management departments in many cities have taken some reinforcement and remedial measures for the existing single-column bridge piers. Common methods include adding cap beams and supports, adding supporting structures, etc. Adding supports on both sides of the cap beam increases the center distance of the supports, effectively improving the ability to resist overturning, and has a very good effect. However, this method also has certain defects. The support position of the added cap beam is located at the edge of the bottom plate of the box beam, which is the same as the support position of the abutments or cap beams at both ends. The support of the newly added cap beam of the single-column pier is on the same line as the support of the original abutments or cap beams at both ends. The overturning of the box beam is caused by the rotation along the abutment supports at both ends. The web of the box beam supports the seismic block. The web and seismic block are damaged, and the box beam overturns and slides. Therefore, the method of adding cap beams and supports can enhance the torsional strength of the box beam and the shear-torsion damage at the single-column pier. However, for eccentric loads exceeding a certain amount, the overturning rotating along the support line still poses a safety hazard. The method of adding a support structure is to add a support rod at the single column. One side of the newly added support structure plays a supporting role, which is equivalent to a support, and the other side plays a pulling role, which enhances the anti-overturning force of the box beam. However, this type of support structure is generally rigidly connected to the bridge piers and box girders. The support structure also imposes a large constraint on the box girder, limits the elastic deformation of the box girder, and changes the original force on the box girder, which is not conducive to the force on the box girder. Summary of the invention

[0004] The purpose of the utility model is to provide a single-column bridge pier with an anti-overturning device to solve the safety hazards of rollover and overturning of the existing single-column bridge piers and the defects of the existing reinforcement methods. It is mainly composed of a bridge pier, a support, a support foot, and a damping support rod. The device is arranged at the single-column bridge pier. Under normal circumstances, a damping flexible connection is adopted between the damping support rod and the box beam, which does not generate additional rigidity and does not constrain the box beam. When the upper structure of the bridge overturns under the eccentric force of an overloaded vehicle, one side of the pulling structure plays a supporting role and the other side plays a pulling role to prevent the box beam from rolling over. The beneficial effect is that under normal conditions, the additional support and pulling structure does not change the original force system of the box beam, does not constrain the cap beam and the box beam, and when tilting occurs, the pulling structure is slowly stressed under the action of damping, which reduces the impact force borne by the box beam. The two sides support and pull respectively, which plays a dual protection against overturning and improves the safety of the bridge.

[0005] The utility model is realized through the following technologies: a single-column bridge pier is equipped with an anti-overturning device, which is mainly composed of a bridge pier 1, a support 2, a support leg 3, and a damping support rod 4. The bridge pier 1 and the support 2 are the original structures of the bridge, the support leg 3 and the damping support rod 4 are newly added structures, and the box girder 5 is supported on the support 2. The support leg 3 is fixed on the upper part of the pier 1, and the damping support rod 4 is flexibly connected and supported on the support leg 3 and the bottom edge of the box girder 5 on both sides of the pier 1. Under normal circumstances, the damping support rod 4 does not generate additional stiffness and does not constrain the box girder 5. When the box girder 5 tilts under the action of an eccentric overloaded vehicle, the damping support rod 4 on the falling side of the box girder 5 is compressed. When it is compressed to a fully retracted state, the damping support rod 4 supports the box girder 5. The damping support rod 4 on the raised side of the box girder 5 is stretched. When it is fully stretched, the damping support rod 4 pulls the box girder 5 to prevent it from overturning. When the vehicle leaves, the box girder 5 slowly resets under the action of the damping support rod 4 to avoid impact on the box girder 5.

[0006] The support legs 3 are two symmetrical saddle-shaped components made of steel plates, mainly composed of an arc plate 6, an end plate 7, and a pad 8. The end plate 7 and the pad 8 are welded together and then welded to both sides of the arc plate 6. Reinforcing ribs 9 are welded between the arc plate 6 and the end plate 7. Assembling holes 10 are provided on the end plate 7 and the pad 8. A hinge hole 11 is provided at the end of the end plate 7. A grouting pipe 12 is provided on the outer side of the arc plate 6. A wire mesh 13 is welded on the inner side of the arc plate 6. An anchor hole 14 is provided on the arc plate 6.

[0007] The two symmetrical components of the support leg 3 are assembled into one piece by assembling screws 15 and installed on the pier 1. The holes for installing the support legs 3 are drilled on the outer wall of the pier 1 at the anchor holes 14 corresponding to the installation positions of the support legs 3. The support legs 3 are fixed to the upper part of the pier 1 by support leg anchor bolts 16. The gap between the wire mesh 13 on the inner side of the arc plate 6 and the outer side of the pier 1 is filled with cement slurry through the grouting pipe 12, and the support legs 3 are firmly anchored on the pier 1.

[0008] The damping support rod 4 is a liquid viscous damper, which is mainly composed of a cylinder body 17, a piston 18, a piston rod 19, a fixed handle 20, and a movable handle 21. The piston rod 19 is connected to the piston 18, and the fixed handle 20 is inserted into the hinge hole 11 of the support foot 3 by a hinge shaft 22. The lower end of the damping support rod 4 is hinged to the support foot 3, and the movable handle 21 and the piston rod 19 are threadedly connected. The movable handle 21 can be selected to adjust the installation length. The movable handle 21 is hinged to the hinge seat 23, and the hinge seat 23 is fixed to the outer wall of the bottom plate of the box beam 5 by a hinge seat fixing bolt 24. Under normal conditions, the tension stroke L1 of the damping support rod 4 is 2 to 5 times the compression stroke L2. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a cross-sectional view of the bridge of the utility model;

[0010] Figure 2 It is the plan view of the foot support;

[0011] Figure 3 It is a three-dimensional diagram of the legs;

[0012] Figure 4 Install the horizontal section for the brace legs;

[0013] Figure 5 Install elevations for the brace legs and damper brace tie rods;

[0014] Figure 6 This is the structural diagram of the damping support rod.

[0015] In the figure: 1-bridge pier, 2-support, 3-support foot, 4-damping support rod, 5-box girder, 6-arc plate, 7-end plate, 8-pad, 9-strengthening rib, 10-assembly hole, 11-hinge hole, 12-grouting pipe, 13-wire mesh, 14-anchor hole, 15-assembly screw, 16-support foot anchor bolt, 17-cylinder body, 18-piston, 19-piston rod, 20-fixed pull handle, 21-movable pull handle, 22-hinge shaft, 23-hinge seat, 24-hinge seat fixing bolt. DETAILED DESCRIPTION

[0016] In order for those skilled in the art to better understand the present invention, Figure 1 to Figure 6 To further illustrate the present invention, the contents mentioned in the implementation modes are not intended to limit the present invention.

[0017] The structure and principle of the utility model are as follows: a single-column bridge pier is equipped with an anti-overturning device, which is used at the single-column bridge pier of the existing continuous bridge, and is mainly composed of a bridge pier 1, a support 2, a support leg 3, and a damping support rod 4. The bridge pier 1 and the support 2 are the original structures of the bridge, and the support leg 3 and the damping support rod 4 are newly added structures. The box beam 5 is supported on the support 2, the support leg 3 is fixed on the bridge pier 1, and the damping support rod 4 is flexibly connected and supported on both sides of the bridge pier 1 at the bottom edge of the support leg 3 and the box beam 5. Figure 1 Cross-sectional view of the bridge. Under normal circumstances, the damping support rod 4 does not generate additional stiffness and does not constrain the box girder 5. When the box girder 5 tilts under the action of an eccentric overloaded vehicle, the damping support rod 4 on the falling side of the box girder 5 is compressed. When compressed to a fully retracted state, the damping support rod 4 supports the box girder 5. The damping support rod 4 on the raised side of the box girder 5 is stretched. When stretched to a fully extended state, the damping support rod 4 pulls the box girder 5 to prevent the box girder 5 from overturning. When the vehicle leaves, the box girder 5 slowly resets under the action of the damping support rod 4 to avoid impact on the box girder 5.

[0018] The support legs 3 are two symmetrical saddle-shaped components, which are fixedly installed on the upper part of the single-column bridge pier 1. The support legs 3 are made of steel plates with a thickness of 16~22mm, which is determined by calculation according to the structure of the box girder 5. The support legs 3 are mainly composed of an arc plate 6, an end plate 7, and a pad 8. The end plate 7 and the pad 8 are welded together and then welded to both sides of the arc plate 6. A reinforcing rib 9 is welded between the arc plate 6 and the end plate 7 to enhance the connection strength between the arc plate 6 and the end plate 7. Assembly holes 10 are provided on the end plate 7 and the pad 8 for bolt fixation after the two support legs 3 components are butt-jointed. A hinge hole 11 is provided at the end of the end plate 7 for installing the damping support rod 4. A grouting pipe 12 is provided on the outer side of the arc plate 6 for grouting the gap between the support legs 3 and the bridge pier 1. Two grouting pipes 12 are provided on the outer side of the arc plate 6. The grouting pipes 12 are made of steel pipes with a diameter of 50~70mm and a length of 50~100mm. A steel mesh 13 is welded on the inner side of the arc plate 6 to enhance the anchoring strength between the support leg 3 and the bridge pier 1. The edge of the steel mesh 13 is 10-20mm smaller than the edge of the arc plate 6. The steel mesh 13 can be a finished welded steel mesh with a wire diameter of 3-5mm and a grid spacing of 30-50mm. One side of the vertical steel wire is welded to the inner wall of the arc plate 6, and the welding point spacing is one point every 2-3 grids. Anchor holes 14 are provided on the arc plate 6 to fix the support leg 3 on the bridge pier 1. Figure 2 Footing plan, Figure 3 Three-dimensional diagram of the support leg. All steel components need to be hot-dip galvanized after processing to improve the rust resistance of the steel components.

[0019] The concrete surface of the position where the support leg 3 is installed on the pier 1 is roughened to facilitate the combination with grouting. Corresponding to the anchor hole 14 at the installation position of the support leg 3, a hole for installing the support leg 3 is drilled on the outer wall of the pier 1. The two symmetrical components of the support leg 3 are docked on the pier 1 and assembled into one piece using the assembly screw 15 and installed on the pier 1. The support leg anchor bolt 16 is passed through the anchor hole 14 on the support leg 3 and inserted into the drilled hole on the pier 1. The support leg anchor bolt 16 nut is tightened, and the expansion bolt is anchored to the pier 1 to fix the support leg 3 to the upper part of the pier 1. The support leg anchor bolt 16 can be an expansion bolt with a diameter of M12~M18 and a length of 100~150mm. After the support leg 3 is docked, a gap for installing the damping support rod 4 is formed between the two end plates 7 due to the occupation of the pad 8. The lower part of the gap between the curved plate 6 and the bridge pier 1 is filled with polyurethane sealant. After the sealant is cured, cement slurry is filled into the gap between the inner side of the curved plate 6 and the outer side of the bridge pier 1 through the grouting pipe 12. The cement slurry is pure cement slurry, and the water-cement ratio is controlled between 0.5 and 0.8. The grouting pipe 12 is connected to the grouting pipe of the grouting machine with a rubber tube. The grouting machine is started to start grouting. When the cement slurry overflows from the upper part of the support leg 3, the grouting is stopped. The connecting rubber tube is tied with iron wire, and the cement slurry on the upper part of the support leg 3 is smoothed. After the cement slurry is cured, the support leg 3 is firmly anchored on the bridge pier 1. The horizontal section of the support leg 3 is shown in FIG. Figure 4 , the installation elevation of the support leg 3 is shown in Figure 5 After the support legs 3 are installed, the steel pipe of the grouting pipe 12 is cut off along the outer edge of the arc plate 6.

[0020] The damping support rod 4 is a liquid viscous damper, which is mainly composed of a cylinder body 17, a piston 18, a piston rod 19, a fixed handle 20, and a movable handle 21. The piston rod 19 is connected to the piston 18. The fixed handle 20 uses a hinge shaft 22 to penetrate the hinge hole 11 of the support foot 3. The lower end of the damping support rod 4 is hinged to the support foot 3. The movable handle 21 and the piston rod 19 are threadedly connected. The installation length can be adjusted by rotating the movable handle 21. A hole for installing the hinge seat 23 is drilled at the bottom edge of the box girder 5. When drilling holes at the bottom of the box girder 5, the prestressed steel strands should be avoided according to the design drawing of the box girder 5. The hinge seat 23 is fixed to the outer wall of the bottom plate of the box girder 5 with a hinge seat fixing bolt 24. The movable handle 21 is hinged to the hinge seat 23. When installing the hinge seat 23, the movable handle 21 can be rotated to fine-tune the installation length so that the installation size is just right after the hinge seat 23 is fixed. See Figure 6Structural diagram of the damping support rod. Under normal conditions, the tension stroke L1 and the compression stroke L2 should be reserved when the damping support rod 4 is installed. The damping support rod 4 can be compressed or stretched. The tension stroke L1 of the damping support rod 4 is 2 to 5 times the compression stroke L2. For example, the stroke of the damping support rod 4 is 100 mm. When installing, adjust the piston 18 to a tension stroke L1 of 75 mm and a compression stroke L2 of 25 mm. At this time, the tension stroke L1 is 3 times the compression stroke L2. When overturning occurs, the damping support rod 4 on the side of the box beam 5 that falls is compressed by 25 mm to support the box beam 5, and the damping support rod 4 on the side that rises is stretched by 75 mm to pull the box beam 5.

[0021] The box beam 5 will produce a small elastic deformation under the action of the vehicle load. If a rigid connection support is used, the vehicle load will produce a small elastic deformation under normal circumstances, and stress will be generated due to the restriction of the support. These additional stresses are not considered when designing the box beam 5, and will have an adverse effect on the structure of the box beam 5 over time. The support of the utility model adopts a flexible connection with a damping effect. Under normal circumstances, the box beam 5 is not restricted and no additional stress is generated. The small elastic deformation produced by the vehicle load is within the damping stroke range and does not affect the force of the box beam 5. When the box beam 5 overturns and tilts, the strong overturning force of the box beam 7 stretches the piston rod 19 by pulling the movable handle 21. The piston 18 is provided with a throttle hole. When the movable handle 21 stretches or compresses the piston rod 19, the hydraulic oil flows from one side of the piston 18 to the other side through the throttle hole. The hydraulic oil has a viscous resistance. When the hydraulic oil flows through the throttle hole, the flow rate is limited, so that the piston 18 can only move slowly in the oil cylinder, which plays a damping role. When a larger vehicle load acts on one side of the box beam 5, the box beam 5 tilts, and the damping support rod 4 on the overturned side is compressed. When the compression stroke L2 is reached, the damping support rod 4 supports the box beam 5, which is equivalent to a support. The other side of the box culvert 5 tilts up, and the damping support rod 4 stretches. When the stretching stroke L1 is reached, the damping support rod 4 pulls the box beam 5, and under the action of supporting one side and pulling the other side, the box beam 5 is prevented from overturning. When the overloaded vehicle leaves, the box beam 5 slowly resets under the action of damping, and will not cause impact on the box beam 5.

[0022] The parameters of the damper 5 should be determined according to the bridge structure, including damping force F, damping index α, stroke, installation size, etc. There are many specifications of dampers currently used in buildings and bridges. They can be purchased according to the parameters required by the reinforced bridge, or the dampers can be customized according to the parameters.

[0023] After all components are installed, they are uniformly treated for rust prevention. The steel components such as the support leg 3 are hot-dip galvanized and have good rust prevention capabilities. However, the removed grouting pipe 12 and the damaged parts still need to be treated for rust prevention. The entire support leg 3 including the mounting bolts, the hinge seat 23 and the hinge seat fixing bolts 24 can be uniformly treated for rust prevention by painting. First, two coats of rust prevention paint are applied, and then two coats of decorative topcoat are applied. The decorative topcoat is preferably medium gray. The damping support rod 4 is a product that already has good rust prevention measures and does not need additional rust prevention treatment.

[0024] The description and drawings of this application are only a specific implementation method and are not restrictive. Under the guidance of this application, technicians in this field can make many forms without departing from the scope of protection of the purpose of this application, all of which are within the scope of protection of this application.

Claims

1. A single-column bridge pier equipped with an anti-overturning device, characterized in that: The invention mainly comprises a bridge pier (1), a support (2), a support foot (3), and a damping support rod (4). The bridge pier (1) and the support (2) are the original structures of the bridge, and the support foot (3) and the damping support rod (4) are newly added structures. The box girder (5) is supported on the support (2), the support foot (3) is fixed on the upper part of the bridge pier (1), and the damping support rod (4) is flexibly connected and supported on both sides of the bridge pier (1) at the support foot (3) and the bottom edge of the box girder (5). Under normal circumstances, the damping support rod (4) does not generate additional stiffness and does not constrain the box girder (5). When the box girder (5) is subjected to the action of an eccentric overloaded vehicle, the damping support rod (4) will be deformed. When the box girder (5) tilts, the damping support rod (4) on the side where the box girder (5) falls is compressed. When compressed to a fully retracted state, the damping support rod (4) supports the box girder (5). The damping support rod (4) on the side where the box girder (5) tilts is stretched. When stretched to a fully extended state, the damping support rod (4) pulls the box girder (5) to prevent the box girder (5) from tipping over. Under normal conditions, the stretching stroke L1 of the damping support rod (4) is 2 to 5 times the compression stroke L2. When the vehicle leaves, the box girder (5) slowly returns to its original position under the action of the damping support rod (4) to prevent the box girder (5) from being impacted.

2. The anti-overturning device installed on the single-column bridge pier according to claim 1 is characterized in that: The support legs (3) are two symmetrical saddle-shaped components made of steel plates, and are mainly composed of an arc plate (6), an end plate (7), and a cushion block (8). The end plate (7) and the cushion block (8) are welded together and then welded to both sides of the arc plate (6). A reinforcing rib (9) is welded between the arc plate (6) and the end plate (7). An assembling hole (10) is provided on the end plate (7) and the cushion block (8). A hinge hole (11) is provided at the end of the end plate (7). A grouting pipe (12) is provided on the outer side of the arc plate (6). A steel wire mesh (13) is welded on the inner side of the arc plate (6). An anchor hole (14) is provided on the arc plate (6).

3. The anti-overturning device installed on the single-column bridge pier according to claim 1 or 2 is characterized in that: The two symmetrical components of the support leg (3) are assembled into one piece by means of assembly screws (15) and installed on the pier (1). A hole for installing the support leg (3) is drilled on the outer wall of the pier (1) at a position corresponding to the anchor hole (14) at the installation position of the support leg (3). The support leg (3) is fixed to the upper part of the pier (1) by means of a support leg anchor bolt (16). The gap of the wire mesh (13) between the inner side of the arc plate (6) and the outer side of the pier (1) is filled with cement slurry by means of a grouting pipe (12), and the support leg (3) is firmly anchored on the pier (1).

4. The anti-overturning device installed on the single-column bridge pier according to claim 1 is characterized in that: The damping support rod (4) is a liquid viscous damper, which is mainly composed of a cylinder body (17), a piston (18), a piston rod (19), a fixed handle (20), and a movable handle (21). The piston rod (19) is connected to the piston (18). The fixed handle (20) is inserted into the hinge hole (11) of the support foot (3) by a hinge shaft (22). The lower end of the damping support rod (4) is hinged to the support foot (3). The movable handle (21) and the piston rod (19) are connected by threads. The installation length can be adjusted by rotating the movable handle (21). The movable handle (21) is hinged to the hinge seat (23). The hinge seat (23) is fixed to the outer wall of the bottom plate of the box beam (5) by a hinge seat fixing bolt (24).

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