A three-way anti-fall beam device

Abstract

This invention discloses a three-way anti-falling beam device, comprising a conical cylinder housed in an opening at the bottom of the main beam; a flange fixedly connected to the conical cylinder; an anchoring nail, one end of which is fixed to the outer surface of the conical cylinder, and the other end cast into the main beam; and a limiting rod, the top of which passes through the conical cylinder and is fixed to the flange, and the bottom of which is inserted into a pre-drilled hole in the pier and fixed therein. This invention is ingeniously conceived, effectively limiting the relative displacement of the upper and lower structures of the bridge in the longitudinal, transverse, and vertical directions under seismic action without affecting the normal displacement of the main beam during operation, thus reducing the probability of beam falling damage and significantly improving the seismic performance of the bridge.

Description

Technical Field

[0001] This invention relates to a bridge beam anti-fall device, and more particularly to a three-way beam anti-fall device. Background Technology

[0002] Earthquakes are sudden natural disasters, and this is a factor that bridge design must consider. Past earthquake damage surveys have revealed that beam collapse is the most frequent, most severe, and most difficult type of earthquake damage to repair. Through in-depth research into the mechanism of beam collapse, the academic and engineering communities have reached a consensus that anti-beam collapse devices have clearly defined stresses and working mechanisms, and are the main measures to limit the relative displacement of the superstructure and substructure of bridges and reduce the risk of beam collapse.

[0003] my country's bridge seismic design code clearly stipulates that measures to prevent beam collapse must be adopted in areas with seismic fortification intensity of 6 degrees or above. However, the design of anti-beam collapse devices currently lacks a unified standard, and in practice, designers often set up some simple anti-beam collapse devices based on their own judgment. Statistics show that commonly used anti-beam collapse devices include concrete blocks, elasto-plastic steel blocks, pin-type anti-beam collapse devices, cable-stayed anti-beam collapse devices, chain-type anti-beam collapse devices, and SMA anti-beam collapse devices. All of these anti-beam collapse devices use initial clearances to meet normal operational requirements and limit the impact requirements under seismic loads by incorporating limiting components. For seismic loads aligned with the limiting direction, these anti-beam collapse devices are effective in limiting the displacement of the main beam. However, according to structural mechanics theory, the motion of an object exists in three directions: two horizontal directions and one vertical direction. For bridges, these three directions are the longitudinal, transverse, and vertical directions. Under current technological conditions, the direction of seismic forces cannot be accurately predicted. When seismic forces occur in directions different from the limiting direction, the anti-falling beam device is ineffective and cannot achieve its purpose of limiting the displacement of the main beam. In other words, an anti-falling beam device with a single-directional limiting function cannot effectively prevent the relative displacement between the upper and lower structures of a bridge under multi-directional seismic forces. Therefore, the development of a multi-directional anti-falling beam device is imperative. Summary of the Invention

[0004] Given that common unidirectional anti-fall beam devices cannot limit multidirectional seismic displacement, this invention discloses a three-directional anti-fall beam device based on the mechanism of bridge beam falling. The device aims to limit the relative displacement between the upper and lower structures of a bridge under seismic action in different directions, reduce the probability of beam falling damage, and thus improve the seismic performance of the bridge.

[0005] To solve the above-mentioned technical problems, the technical solution adopted in this application is:

[0006] A three-way anti-falling beam device, characterized in that it comprises:

[0007] A tapered cylinder, wherein the tapered cylinder is housed in an opening at the bottom of the main beam;

[0008] A flange, wherein the flange and the tapered cylinder are fixedly connected;

[0009] Anchor pins, one end of which is fixed to the outer surface of the tapered cylinder, and the other end is cast into the main beam;

[0010] A limiting rod, the top of which passes through a tapered cylinder and is fixed to a flange, and the bottom of which is inserted into a pre-drilled hole in the pier and fixed therein.

[0011] Furthermore, the top 5 cm of the limiting rod is tapped.

[0012] Furthermore, the top of the limiting bar is secured to the flange by means of a gasket and an anchor bolt.

[0013] Furthermore, spot welding is used to fix the top of the limiting rod to the anchor bolt, the bolt to the gasket, the gasket to the flange, the flange to the tapered cylinder, and the tapered cylinder to the anchor nail.

[0014] Furthermore, the horizontal clearance between the limiting rod and the lower edge of the conical cylinder should be equal to the design horizontal displacement of the bridge support.

[0015] Furthermore, the reserved holes for the bridge piers are located at the midpoint of the line connecting the centers of the bridge bearings.

[0016] Furthermore, the limiting rod is vertically set at the center of the reserved hole in the pier, and the size of the reserved hole in the pier should meet the requirements for pouring high-performance concrete.

[0017] Furthermore, the horizontal stiffness K of the device H =3EI / L1 3 Vertical stiffness K V =EA / L2, where E is the elastic modulus of the limiting rod, I is the moment of inertia of the limiting rod section, A is the cross-sectional area of ​​the limiting rod, L1 is the length of the limiting rod between the bottom surface of the main beam and the top surface of the pier, and L2 is the length of the limiting rod between the bottom surface of the flange and the top surface of the pier.

[0018] In another aspect, this application also claims protection for a construction method of a three-way anti-fall beam device according to any of the foregoing items. When using a precast concrete main beam, the three-way anti-fall beam device is first embedded in the bottom of the main beam, then installed with the main beam, the bottom of the limiting rod is inserted into the reserved hole of the pier, and finally high-performance concrete is poured to complete the anchoring.

[0019] In another aspect, this application also claims protection for the construction method of the three-way anti-fall beam device according to any of the foregoing items, which, when using cast-in-place concrete main beams, firstly inserts the bottom of the limiting rod into the reserved hole of the pier, secondly pours high-performance concrete to complete the anchoring, and finally embeds the three-way anti-fall beam device in the main beam reinforcement to complete the casting.

[0020] The three-way anti-fall beam device of the present invention is ingeniously designed. While not affecting the normal displacement of the main beam during operation, it can effectively limit the relative displacement of the upper and lower structures of the bridge in the longitudinal, transverse and vertical directions under the action of earthquake, reduce the probability of beam falling earthquake damage and greatly improve the seismic performance of the bridge. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a cross-sectional view of a three-way anti-fall beam device.

[0023] Figure 2 This is an AA cross-sectional view of a three-way anti-fall beam device.

[0024] Figure 3 This is a BB cross-sectional view of a three-way anti-fall beam device. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] A three-way anti-falling beam device of the present invention includes:

[0027] A tapered cylinder 5 is housed in an opening at the bottom of the main beam 9;

[0028] Flange 4, which is fixedly connected to the tapered cylinder 5;

[0029] Anchor nail 6, one end of which is fixed to the outer surface of the tapered cylinder 5 and the other end is cast into the main beam 9; preferably, the anchor nail 6 can be a welded stud.

[0030] A limiting rod 1 is provided, the top of which passes through the conical cylinder 5 and is fixed to the flange 4. The bottom of the limiting rod 1 is inserted into and fixed in the pier pre-drilled hole 8 at the top of the pier 10. Preferably, the bottom of the limiting rod 1 is anchored in the pier pre-drilled hole 8 by pouring high-performance concrete. Preferably, the limiting rod 1 can be a steel rod or angle iron.

[0031] Because there is a gap between the limiting rod 1 and the conical cylinder 5 in this application, during normal operation, the main beam will deform together with the limiting rod, forming a relative displacement with the pier. However, the limiting rod does not contact the conical cylinder, so it does not affect the normal displacement of the bridge. Under seismic action, the main beam will move together with the limiting rod. When the limiting rod contacts the conical cylinder, the three-way anti-falling beam device begins to function, limiting the further increase of the relative displacement between the main beam and the pier, thereby preventing the beam from falling.

[0032] The working mechanism of this three-way anti-fall beam device in the vertical plane is as follows: During normal operation, the bridge bearings are under compression, and there is no vertical relative displacement between the main beam and the pier; under seismic action, when the seismic tensile force of the bridge bearing is greater than its dead load pressure, the bearing is under tension, and the main beam will detach from the pier. At this time, the limiting rod is under tension, sharing the tensile force of the bearing, thereby limiting the relative displacement between the main beam and the pier and preventing the main beam from falling off.

[0033] In the embodiments of this application, the top 5 cm of the limiting rod 1 is tapped.

[0034] In an embodiment of this application, the top of the limiting rod 1 is fixed to the flange 4 by means of a gasket 3 and an anchor bolt 2.

[0035] In the embodiments of this application, the conical cylinder 5 adopts a structure with a small top and a large bottom.

[0036] In the embodiments of this application, spot welding is used to fix the top of the limiting rod 1 to the anchor bolt 2, the bolt 2 to the gasket 3, the gasket 3 to the flange 4, the flange 4 to the tapered cylinder 5, and the tapered cylinder 5 to the anchor nail 6.

[0037] In the embodiments of this application, the horizontal clearance between the limiting rod 1 and the lower edge of the conical cylinder 5 should be equal to the design horizontal displacement of the bridge support 7.

[0038] In the embodiments of this application, the reserved hole 8 of the pier is located at the midpoint of the line connecting the centers of the bridge bearings 7.

[0039] In the embodiments of this application, the limiting rod 1 is vertically positioned at the center of the reserved hole 8 in the pier, and the size of the reserved hole 8 should meet the requirements for pouring high-performance concrete. Preferably, the depth of the reserved hole 8 in the pier should be greater than the anchorage length of the limiting rod 1.

[0040] In the embodiments of this application, the horizontal stiffness K of the three-way anti-fall beam device H =3EI / L1 3 Vertical stiffness K V=EA / L2, where E is the elastic modulus of the limiting rod 1, I is the moment of inertia of the section of the limiting rod 1, A is the cross-sectional area of ​​the limiting rod 1, L1 is the length of the limiting rod 1 between the bottom surface of the main beam 9 and the top surface of the pier 10, and L2 is the length of the limiting rod 1 between the bottom surface of the flange 4 and the top surface of the pier 10.

[0041] This application also discloses the construction method of the aforementioned three-way anti-fall beam device. When using a precast concrete main beam, the three-way anti-fall beam device is first embedded in the bottom of the main beam 9, and then hoisted and installed with the main beam 9. The bottom of the limiting rod 1 is inserted into the reserved hole 8 of the pier, and finally high-performance concrete is poured to complete the anchoring.

[0042] When using cast-in-place concrete main beams, first insert the bottom of the limiting rod 1 into the reserved hole 8 of the pier, then pour high-performance concrete to complete the anchoring, and finally embed the three-way anti-falling beam device into the steel reinforcement of the main beam 9 to complete the pouring.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-way anti-falling beam device, characterized in that, include: A conical cylinder (5) is housed in an opening at the bottom of the main beam (9); Flange (4), wherein the flange (4) and the tapered cylinder (5) are fixedly connected; Anchor nail (6), one end of which is fixed to the outer surface of the tapered cylinder (5), and the other end is cast into the main beam (9); The top of the limiting rod (1) passes through the conical cylinder (5) and is fixed on the flange (4). The bottom of the limiting rod (1) is inserted into the reserved hole (8) of the pier and fixed. There is a gap between the limiting rod (1) and the conical cylinder (5). The top of the limiting rod (1) is fixed to the flange (4) by a gasket (3) and an anchor bolt (2); The top of the limiting rod (1) is fixed to the anchor bolt (2), the anchor bolt (2) is fixed to the gasket (3), the gasket (3) is fixed to the flange (4), the flange (4) is fixed to the tapered cylinder (5), and the tapered cylinder (5) is fixed to the anchor nail (6) by spot welding. The horizontal stiffness K of the device H =3EI / L1 3 Vertical stiffness K V =EA / L2, where E is the elastic modulus of the limiting rod (1), I is the moment of inertia of the section of the limiting rod (1), A is the cross-sectional area of ​​the limiting rod (1), L1 is the length of the limiting rod (1) between the bottom surface of the main beam (9) and the top surface of the pier (10), and L2 is the length of the limiting rod (1) between the bottom surface of the flange (4) and the top surface of the pier (10). Under the action of an earthquake, the main beam (9) moves together with the limiting rod (1). When the limiting rod (1) comes into contact with the conical cylinder (5), the three-way anti-falling beam device begins to play its role, limiting the further increase of the relative displacement between the main beam (9) and the pier, thereby preventing the beam from falling.

2. The three-way anti-falling beam device according to claim 1, characterized in that, The top 5 cm of the limiting rod (1) is tapped.

3. A three-way anti-falling beam device according to claim 1 or 2, characterized in that, The horizontal clearance between the limiting rod (1) and the lower edge of the conical cylinder (5) should be equal to the design horizontal displacement of the bridge support (7).

4. A three-way anti-falling beam device according to claim 1 or 2, characterized in that, The reserved hole (8) of the pier is located at the midpoint of the line connecting the centers of the bridge bearing (7).

5. A three-way anti-falling beam device according to claim 1 or 2, characterized in that, The limiting rod (1) is vertically set at the center of the reserved hole (8) of the pier. The size of the reserved hole (8) of the pier should meet the requirements for pouring high-performance concrete.

6. The construction method of the three-way anti-falling beam device according to any one of claims 1 to 5, characterized in that, When using a precast concrete main beam, the three-way anti-falling beam device is first embedded in the bottom of the main beam (9), then hoisted and installed along with the main beam (9), the bottom of the limit bar (1) is inserted into the reserved hole (8) of the pier, and finally high-performance concrete is poured to complete the anchoring.

7. The construction method of the three-way anti-falling beam device according to any one of claims 1 to 5, characterized in that, When using cast-in-place concrete main beams, first insert the bottom of the limiting rod (1) into the reserved hole (8) of the pier, then pour high-performance concrete to complete the anchoring, and finally embed the three-way anti-falling beam device in the reinforcement of the main beam (9) to complete the pouring.

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