A bridge multi-directional reset device

Abstract

This invention discloses a multi-directional repositioning device for bridges, comprising at least three blocks, anchor rods, an upper force transmission rod, a lower force transmission rod, a compression block, a sleeve, a disc spring, and a screw. Each block corresponds to a compression block, and the blocks are installed on the piers. One end of the anchor rod is pre-embedded in the main beam. Each upper force transmission rod is rotatably installed on the anchor rod, and each upper force transmission rod is rotatably connected to a compression block. Each compression block is rotatably connected to a lower force transmission rod. The sleeve is fitted onto the anchor rod and located below the upper force transmission rods. The other end of each lower force transmission rod is rotatably connected to the lower part of the sleeve. The screw is installed on the anchor rod via a matching thread, and the disc spring is fitted onto both the screw and the anchor rod. This multi-directional repositioning device for bridges provides limiting and repositioning functions for any relative displacement between the main beam and the pier in any direction; it has a simple structure and is not easily damaged; under earthquakes, the anchor rods can prevent beam collapse, and components other than the anchor rods are replaceable; it has a leverage effect; and it has minimal impact on the overall stress of the bridge.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering technology, and specifically relates to a device that can reset the main beam. Background Technology

[0002] Under the influence of loads such as temperature and vehicles, the relative position between the main beam and the piers changes. When these loads disappear, the lack of effective reset capability between the main beam and piers makes it difficult for them to return to their original position, thus affecting the safety and comfort of bridge traffic, especially for curved bridges. Currently, common technologies include installing blocks or elastic supports (such as rubber bearings), which can prevent large relative displacements between the main beam and piers to a certain extent, thus ensuring traffic safety and comfort. Blocks are typically installed on the main beam and piers. When the relative displacement between the main beam and pier is large, the blocks collide, preventing further displacement of the main beam. However, the blocks themselves do not have reset capability; once the main beam shifts, external force is required to push it back into place. The working principle of rubber bearings in limiting main beam displacement is equivalent to installing a horizontal spring between the main beam and the pier. The greater the relative displacement between the main beam and the pier, the greater the reaction force provided by the spring, thus providing a certain reset capability. However, rubber products have poor durability and are easily sheared.

[0003] With the development of my country's economy, traffic volume is increasing, and load levels are also rising, increasing the risk of main beam displacement in the future. Patent application 202211291087.3 discloses a buffer limit reset device for beam end gap adjustment and monitoring, including an elastic element, an outer guide sleeve assembly, an inner guide sleeve assembly, an angle adjustment mechanism, a pressure plate, an adjustment plate assembly, a pre-embedded assembly, a locking assembly, and a displacement monitoring element; the outer guide sleeve assembly, the inner guide sleeve assembly, and the angle adjustment mechanism are all located inside the elastic element, and the inner guide sleeve assembly is located along the outer... The guide sleeve assembly moves along its axis; the elastic element has pressure plates at both ends, and the angle adjustment mechanism at one end connects the outer guide sleeve assembly to the corresponding pressure plate, while the angle adjustment mechanism at the other end connects the inner guide sleeve assembly to the corresponding pressure plate; the pressure plates are sequentially connected to the adjustment plate assembly and the embedded assembly, with two sets of embedded assemblies located at both ends of the entire buffer limiting and resetting device; the two sets of pressure plates form a cuboid frame through several sets of locking assemblies, and the displacement monitoring element is installed inside the cuboid frame. This device only works for unidirectional displacement of the bridge, requires a large number of springs to provide sufficient recovery capacity, and only provides sufficient recovery capacity when the main beam displacement exceeds the limit. Its function is singular, and the device has a high probability of failure under extreme loads, and it does not provide constraint after failure.

[0004] There is an urgent need to design a device that can limit the multi-directional displacement of the main beam and help the main beam to return to its original position. At the same time, the device should have a reasonable stress distribution, simple construction, economy, reliability and easy installation. It is also necessary to provide corresponding construction methods. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide a multi-directional resetting device for bridges, which enables limiting and resetting functions in any direction of relative displacement between the main beam and the pier; it has clear force transmission, a simple structure that is not easily damaged; in extreme cases, the anchor rod can act as a shear bar to prevent the beam from falling, and the components other than the anchor rod can be replaced.

[0006] The technical solution adopted in this invention is:

[0007] A multi-directional resetting device for bridges includes at least three blocks, anchor rods, upper force transmission rods, lower force transmission rods, compression blocks, sleeves, disc springs, and screws. Each block corresponds to one compression block. The device is characterized in that: the blocks are all installed on the bridge piers; one end of the anchor rod is pre-embedded in the main beam; each upper force transmission rod is rotatably installed on the anchor rod; each upper force transmission rod is rotatably connected to a compression block; each compression block is rotatably connected to a lower force transmission rod; the sleeve is fitted onto the anchor rod and located below the upper force transmission rod; the other end of each lower force transmission rod is rotatably connected to the lower part of the sleeve; the screw is installed on the anchor rod via a matching thread; and the disc spring is fitted onto both the screw and the anchor rod. Twisting the screw compresses the disc spring, which drives the sleeve upward, simultaneously causing the force transmission rod to rotate, thus causing each compression block to engage and compress the corresponding block.

[0008] The invention also includes several helical springs, with one helical spring installed between each pair of extrusion blocks, one above and one below, to keep the extrusion blocks in a vertical position.

[0009] The blocks are evenly distributed on the bridge piers.

[0010] The anchor bolt is located directly above all the stops.

[0011] The beneficial effects of this invention are: the multi-directional resetting device for bridges of this invention provides limiting and resetting functions for any relative displacement between the main beam and the pier in any direction; the force transmission is clear, the structure is simple and not easily damaged; under earthquakes, the anchor rods can act as shear bars to prevent beam collapse, and the components other than the anchor rods can be replaced; it has a lever effect; and it has little impact on the overall stress of the bridge. Attached Figure Description

[0012] Figure 1 This is a structural schematic diagram of an embodiment of the present invention.

[0013] Figure 2 This is a plan view of an embodiment of the present invention.

[0014] The structure shown in the diagram is as follows:

[0015] 1-Stop block, 2-Anchor rod, 3-Upload force rod, 4-Download force rod, 5-Extrusion block, 6-Sleeve, 7-Helical spring, 8-Disc spring, 9-Screw, 10-Pier, 11-Main beam. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but these descriptions do not constitute a limitation on the present invention.

[0017] like Figure 1-2 As shown, the present invention discloses a multi-directional resetting device for bridges, comprising four blocks 1, anchor rods 2, four upward force transmission rods 3, four downward force transmission rods 4, four compression blocks 5, a sleeve 6, eight helical springs 7, a disc spring 8, and a screw 9. The four blocks 1 are evenly distributed and installed on the piers 10. One end of the anchor rod 2 is pre-embedded in the main beam 11. Four upward force transmission rods 3 are rotatably installed on the anchor rods 2. Each upward force transmission rod 3 is rotatably connected to a compression block 5, and each compression block 5 is rotatably connected to a downward force transmission rod 4. The sleeve 6 is fitted onto the piers 10. The anchor rod 2 is located above and below the transmission rod 3. The other ends of the four lower transmission rods 4 are rotatably connected to the lower part of the sleeve 6. A helical spring 7 is installed between each pair of extrusion blocks 5, keeping the extrusion blocks 5 in a vertical position. The screw 9 is installed on the anchor rod 2 through a matching thread between it and the anchor rod 2. The disc spring 8 is sleeved on the screw 9 and the anchor rod 2. Twisting the screw 9 will compress the disc spring 8. The disc spring 8 will drive the sleeve 6 to move upward, and at the same time drive the transmission rod 4 to rotate, so that each extrusion block 5 will fit and extrude the corresponding stop block 1.

[0018] The installation steps of this invention are as follows:

[0019] Step 1, Installing Stop Block 1 and Determining the Length of Corresponding Components: Four stop blocks 1 are pre-installed on pier 10, symmetrically distributed. Based on the installation space conditions, determine the lengths of the following components: upper force transmission rod L1, lower force transmission rod L2, disc spring (stiffness k) l1, helical spring l2 (stiffness negligible compared to disc spring), and sleeve h. 1；

[0020] Step 2, pre-embed anchor rods in the main beam: pre-embed anchor rods 2 into the main beam 11 and position them directly above the four blocks 1;

[0021] Step 3, install the upper force transmission rod 3, lower force transmission rod 4, sleeve 6 and compression block 5: Rotately install four upper force transmission rods 3 on the anchor rod 2 respectively, rotatably connect a compression block 5 to each upper force transmission rod 3, rotatably connect a lower force transmission rod 4 to each compression block 5, sleeve 6 is fitted on the anchor rod 2 and located below the upper force transmission rods 3, and the other end of the four lower force transmission rods 4 is rotatably connected to the lower part of the sleeve 6.

[0022] Step 4, Install the helical spring 7: At this time, the reset device is in a relaxed state, and the helical spring can be easily installed. Install one helical spring 7 between each pair of extrusion blocks 5, both above and below, to keep the extrusion blocks 5 in a vertical state.

[0023] Step 5, install the disc spring 8 and screw on the detachable screw 9: Place the disc spring 8 onto the screw 9, then install the screw 9 onto the anchor rod 2 via the matching thread between the screw 9 and the anchor rod 2. The disc spring 8 is located on both the screw 9 and the anchor rod 2. Twisting the screw 9 will compress the disc spring 8, causing the sleeve 6 to move upwards, simultaneously rotating the force transmission rod 4, so that each pressure block 5 engages with and presses against the corresponding stop block 1.

[0024] Assuming that the bridge may experience transverse displacement (longitudinal displacement) under external load, the force required for the main girder to return to its original position is F = 80 kN, and the force required for a single compression block to preload onto the stop block is F. fw0 =20kN, angle α=45°, α is the angle between the upper force rod and the horizontal direction, angle β=60°, β is the angle between the lower force rod and the horizontal direction, k=1000kN / m, friction is not considered for now.

[0025] Continue to twist the screw until the preload of the extrusion block is F. fw0 =20kN, at this time the additional compression of the disc spring is Δl1, and only Δl1 needs to be obtained to make the force applied by the compression block to the stop block F. fw0 =20kN. Since the four compression blocks are symmetrical, the reset device will not generate additional force on the main beam and pier.

[0026] For ease of calculation, it is assumed that the deformation of the disc spring and the spring force have a linear relationship, and the additional force F is... Δth as follows:

[0027] F Δth =k×Δl1 (1)

[0028] k is the stiffness coefficient of the disc spring. Assuming the axial force of the upper transmission rod is f1 and the axial force of the lower transmission rod is f2, the following relationship holds:

[0029] f1×sin(α)=f2×sin(β) (2)

[0030] F fw0 =f1×cos(α)+f2×cos(β) (3)

[0031] F Δth =n×f2×sin(β),n=4 (4)

[0032] By combining formulas (1), (2), (3), and (4), Δl1 can be obtained, and the results are as follows:

[0033] Δl1=n×F fw0 ÷(k×(cot(α)+cot(β)))

[0034] Given n=4, F fw0 =20kN, α=45°, β=60°, k=1000kN / m, the calculated value is 50.6mm, which means that the disc spring needs to be compressed by 50.6mm to obtain the preload required for the extrusion block.

[0035] Under external load, a relative transverse displacement Δl is generated between the main beam and the pier. At this time, the three compression blocks leave the stop block, and only one compression block has a force with the stop block. In formula (4), n becomes 1. When Δl approaches 0 infinitely, the small changes of α and β can be ignored. The forces are as follows:

[0036] F jy =80kN

[0037] In other words, as long as Δl > 0, there will be a reaction force greater than 80kN between the main beam and the pier. Under external load, the reset device can release some of the internal force through deformation, keeping the bridge structure within a safe range. When the external load disappears, the reaction force transmitted by the reset device to the pier and main beam is greater than the force required for the main beam to reset, causing the main beam to return to its original position. Alternatively, depending on the actual situation, the compression block can be set to not contact the stop block, or the compression block can only apply a very small force to the stop block. Only when Δl is large enough will a sufficiently large restoring force be generated. This setting allows for a certain displacement between the main beam and the pier under external load, and the small displacement does not change the overall stress of the structure.

Claims

1. A multi-directional resetting device for bridges, comprising at least three stops, anchor bolts, an upper force transmission rod, a lower force transmission rod, a compression block, a sleeve, a disc spring, and a screw, wherein each stop corresponds to one compression block, characterized in that: All the stops are installed on the bridge piers. One end of the anchor rod is pre-embedded in the main beam. Each load-transmitting rod is rotatably installed on the anchor rod. Each load-transmitting rod is rotatably connected to a compression block. Each compression block is rotatably connected to a lower load-transmitting rod. The sleeve is fitted on the anchor rod and located below the load-transmitting rod. The other end of each lower load-transmitting rod is rotatably connected to the lower part of the sleeve. The screw is installed on the anchor rod through a matching thread between it and the anchor rod. The disc spring is fitted on the screw and the anchor rod.

2. The bridge multi-directional reset device according to claim 1, characterized in that: It also includes several helical springs, with one helical spring installed between each pair of extrusion blocks, one on the top and one on the bottom.

3. A bridge multi-directional reset device according to claim 1 or 2, characterized in that: The blocks are evenly distributed on the bridge piers.

4. A bridge multi-directional reset device according to claim 1 or 2, characterized in that: The anchor bolt is located directly above all the stops.

Images