Expansion joint for bridges

Abstract

This application relates to the field of expansion joints, and in particular to an expansion joint for bridges. The joint comprises paired left and right comb-tooth components, each fixed to a pre-reserved base at an adjacent beam end of the bridge via anchoring assemblies. The left and right comb-tooth components are arranged opposite each other along the longitudinal axis of the bridge, forming an interlocking structure, with their overlapping area constituting a displacement compensation space. Each of the left and right comb-tooth components consists of a body with an anchor plate and a cantilevered comb-tooth plate extending horizontally from the body. The cantilevered comb-tooth plate employs a three-layer composite structure: an outer layer of wear-resistant and noise-reducing functional layer made of thermoplastic polyurethane elastomer; a middle layer for connecting the body, a rigid support layer made of steel plate; and a bottom layer of low-friction, wear-resistant padding. This expansion joint possesses anti-foreign object jamming and anti-tilting functions.

Description

Technical Field

[0001] This application relates to the field of expansion joints, and in particular to an expansion joint for bridges. Background Technology

[0002] In bridge structures, expansion joints are typically installed at bridge expansion joints to accommodate the expansion and contraction of the beams caused by temperature changes, concrete shrinkage and creep, and loads. Comb-shaped expansion joints, a common type, achieve expansion and contraction through the relative sliding of interlocking comb-shaped metal plates fixed to the ends of adjacent beams, ensuring the continuity of traffic flow on the bridge deck. This structural design aims to provide good vertical load-bearing capacity while allowing longitudinal displacement.

[0003] However, a common and critical problem in the practical application of existing comb-type expansion joints is the tendency for the comb plate, especially its free end (cantilever end), to warp. The main root cause of this problem lies in the structural characteristics of the comb and its working environment. The comb plate is typically a cantilever beam structure of considerable length, with one end fixed to the beam via an anchoring system and the other end extending above the expansion joint. When vehicle loads (especially heavy vehicles) pass quickly or brake at the expansion joint, the wheels exert a significant instantaneous vertical impact and upward force on the cantilever end of the comb plate. This impact easily induces bending vibration in the plate. More importantly, if small, hard foreign objects (such as stones, metal scraps, etc.) become lodged in the gap below the plate or at its meshing point, during normal bridge expansion and contraction, the lodged object acts as a fulcrum, converting the original longitudinal displacement into a powerful prying force on the plate. This levering effect creates a significant leverage between the root of the toothed plate (near the anchoring end) and the locking point, causing the cantilever end to break down and resist vertical displacement. This forces the toothed plate to bend and deform upwards, potentially leading to permanent warping or localized breakage. Furthermore, long-term, repeated bridge expansion and contraction movements and vibrations can cause minor loosening or uneven settlement in the anchoring system, weakening the constraint on the root of the toothed plate and further exacerbating the risk of warping. Once the toothed plate warps, it not only disrupts the bridge deck's flatness, causing vehicle bouncing, noise, and discomfort, but also affects the waterproof sealing performance of the device. In severe cases, the warped toothed plate may even scrape the vehicle's chassis or cause further structural tearing, posing a serious safety hazard. Utility Model Content

[0004] The purpose of this application is to overcome at least one deficiency of the prior art and to provide a bridge expansion joint with anti-foreign object jamming and anti-tilting functions.

[0005] To achieve the above objectives, this application discloses a bridge expansion joint, which includes paired left and right comb-tooth components, respectively fixed to reserved bases at adjacent beam ends of the bridge via anchoring assemblies. The left and right comb-tooth components are arranged opposite to each other along the longitudinal axis of the bridge to form an interlocking structure, and their overlapping area constitutes a displacement compensation space; the left and right comb-tooth components

[0006] All consist of a main body with anchor plates and cantilevered comb plates extending horizontally from the main body. The cantilevered comb plates adopt a three-layer composite structure: the outer layer is a wear-resistant and noise-reducing functional layer made of thermoplastic polyurethane elastomer, the middle layer used to connect the main body is a rigid support layer made of steel plate, and the bottom layer is a low-friction wear-resistant pad layer.

[0007] Below the cantilevered comb plates of the left and right comb components, there are high-damping vibration-damping displacement bearing groups fixed on the reserved base. Each bearing group contains two or more vibration-damping units arranged equidistantly along the transverse direction of the bridge. Each unit is fixed to the base through a pre-embedded sleeve. The vibration-damping unit is a rubber part with a tapered guide shoulder with a gradually decreasing diameter at the top. The adjacent vibration-damping units maintain a constant spacing of 20-40mm to form a vertical discharge channel.

[0008] The low-friction, wear-resistant padding layer of the cantilever comb plate is directly attached to the upper surface of the shock absorption unit, forming a low-resistance sliding interface.

[0009] As an optional technical solution, a thickened part is provided at the connection between the root of the cantilever comb plate and the body. The thickness of the thickened part gradually decreases along the cantilever extension direction to the standard thickness of the comb plate.

[0010] As an optional technical solution, the bottom of the vertical discharge channel is provided with a chip removal hole that penetrates the reserved base.

[0011] As an optional technical solution, the lower surface of the low-friction wear-resistant pad layer is provided with a grid-like distribution of tiny depressions with uniform depth.

[0012] When the bridge undergoes longitudinal expansion and contraction, the left and right comb-tooth components slide relative to each other on the damping unit through the wear-resistant lining layer. The vibration energy generated during this process is dissipated by the high-energy-consuming rubber material of the damping unit. Foreign objects intruding into the device, after contacting the conical guide shoulder in the comb-tooth meshing area, are constrained by structural geometry and slide along the slope into the discharge channel, eventually falling out of the device through the bottom of the channel. The inclination angle of the conical guide shoulder is designed to accommodate the sliding condition of the foreign object's own weight, and the width of the discharge channel is greater than the upper limit of the conventional foreign object particle size, ensuring immediate discharge efficiency.

[0013] Compared with the prior art, this application has at least one of the following beneficial technical effects:

[0014] 1. Enhanced anti-foreign object jamming function: Through the design of conical guide shoulder and vertical discharge channel, it actively guides and immediately discharges intruding hard foreign objects, eliminates the lever prying effect caused by foreign objects jamming in the comb meshing area, and prevents the cantilever end from lifting.

[0015] 2. Improved anti-warping capability: Based on the shear energy dissipation mechanism of the high-damping damping unit, it absorbs and attenuates the instantaneous load caused by vehicle impact vibration and bridge expansion and contraction, enhances the bending stiffness and stability of the cantilever comb plate, and effectively suppresses bending deformation or warping.

[0016] 3. Optimized sliding interface: The three-layer composite structure combined with the low-friction pad layer on the upper surface of the damping unit forms a low-resistance sliding support, reducing the damage of long-term vibration and stress to the anchoring system and lowering the risk of warping.

[0017] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0018] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of one embodiment disclosed in this application.

[0020] Figure 2 This is a schematic diagram of the structure of a cantilever comb plate in one embodiment of this application. Detailed Implementation

[0021] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0022] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0023] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0024] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items. Example

[0025] This embodiment relates to a bridge expansion joint, as shown in the reference... Figure 1 , 2 The device consists of a pair of left comb-tooth components and a pair of right comb-tooth components 2. Both are fixed to pre-reserved bases 4 at adjacent beam ends of the bridge via anchoring components 3, and are arranged opposite each other along the longitudinal axis of the bridge to form an interlocking structure. The overlapping interlocking area provides displacement compensation space to accommodate longitudinal expansion and contraction deformation of the bridge caused by thermal expansion and contraction or loads. Simultaneously, key modules provide anti-obstruction and anti-tilting functions.

[0026] The anchoring assembly 3 includes pre-embedded bolts and matching washers, which reliably lock the bodies of the left comb tooth component 1 and the right comb tooth component 2 in the reserved base 4.

[0027] Preferably, the anchoring component 3 is made of high-strength alloy steel, and its pre-embedded depth is not less than 150mm, in order to transfer shear loads and ensure overall stability. Those skilled in the art will understand that the structural form of the anchoring component 3 can be adjusted according to the strength of the base concrete, such as increasing the area of ​​the gasket to disperse the anchoring force.

[0028] The main body of both the left comb tooth component 1 and the right comb tooth component 2 consists of a body 5 and a cantilever comb tooth plate 6. The body 5 integrates an anchor plate 7 for connection with the anchor component 3; the cantilever comb tooth plate 6 extends horizontally from the body 5, forming a free-end cantilever structure. The cantilever comb tooth plate 6 adopts a three-layer composite structure: the outer layer is a wear-resistant and noise-reducing functional layer 601 made of thermoplastic polyurethane elastomer, preferably 2-5mm thick, to provide road surface noise reduction and reduce material wear; the middle layer 602 is a rigid support layer made of steel plate, with a thickness greater than 10mm, directly connected to the body 5 to transmit bending moment; the bottom layer is a low-friction wear-resistant liner layer 603, preferably made of polytetrafluoroethylene composite material, with a friction coefficient of less than 0.1, to facilitate sliding operation. In a specific implementation scenario, when erecting a 32m simply supported beam, the cantilever length can be designed to be 1.2 times the beam end expansion / contraction to meet displacement compensation requirements.

[0029] A high-damping vibration-damping displacement support group 8 is installed below the low-friction wear-resistant liner layer 603 of the cantilever comb plate 6. This support group is fixed to the reserved base 4, and each group includes two or more vibration-damping units 801 arranged equidistantly along the transverse direction of the bridge. Each vibration-damping unit 801 is fixed to the base via a pre-embedded sleeve and is made of rubber. The top of the vibration-damping unit 801 forms a tapered guide shoulder with a gradually decreasing diameter, preferably with a cone angle of 30°-45°, to guide the sliding of foreign objects; a constant spacing of 20-40mm is maintained between adjacent vibration-damping units 801, forming a vertical rejection channel 802. The low-friction wear-resistant liner layer 603 of the cantilever comb plate 6 is directly attached to the upper surface of the vibration-damping unit 801, forming a low-resistance sliding interface. Preferably, the width of the discharge channel 802 is designed to be 25-35mm, which is greater than the upper limit of the particle size of conventional bridge surface foreign objects (such as stones) (usually ≤15mm), to ensure smooth discharge of foreign objects.

[0030] When the bridge undergoes longitudinal expansion and contraction deformation, the left comb tooth component 1 and the right comb tooth component 2 slide relative to each other on the damping unit 801 via a wear-resistant liner. The vibration energy generated during this process (such as the impact of passing vehicles) is dissipated by the high-energy-consuming rubber material of the damping unit 801 through shear deformation. Foreign objects intruding into the device, after contacting the conical guide shoulder in the comb tooth meshing area, are constrained by structural geometry (such as the cone inclination angle) and slide along the inclined surface into the rejection channel 802, eventually falling out of the device through the bottom of the channel. Those skilled in the art will understand that the track reinforcing steel plate is a conventional compressive structure in cantilever structures, used to strengthen the bending stiffness of the cantilever end.

[0031] In summary, during operation, this expansion joint eliminates the lever effect caused by foreign object blockage through the active foreign object guidance mechanism of the conical guide shoulder and vertical discharge channel, preventing the cantilever end from tilting. At the same time, relying on the shear energy dissipation mechanism of the high-damping damping unit, it absorbs instantaneous loads, enhances the bending stability of the cantilever comb plate, and ensures the smooth realization of bridge expansion and contraction deformation.

[0032] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A bridge expansion joint, characterized in that, The device includes a pair of left and right comb tooth components, which are fixed to the reserved bases at the adjacent beam ends of the bridge by anchoring components. The left and right comb tooth components are arranged opposite each other along the longitudinal axis of the bridge to form an interlocking structure, and their overlapping area constitutes a displacement compensation space. Both the left and right comb tooth components consist of a body with an anchor plate and a cantilevered comb tooth plate extending horizontally from the body. The cantilevered comb tooth plate adopts a three-layer composite structure. The surface layer is a wear-resistant and noise-reducing functional layer made of thermoplastic polyurethane elastomer. The middle layer used to connect the body is a rigid support layer made of steel plate. The bottom layer is a low-friction wear-resistant pad layer. Below the cantilevered comb plates of the left and right comb components, there are high-damping vibration-damping displacement bearing groups fixed on the reserved base. Each bearing group contains two or more vibration-damping units arranged equidistantly along the transverse direction of the bridge. Each unit is fixed to the base through a pre-embedded sleeve. The vibration-damping unit is a rubber part with a tapered guide shoulder with a gradually decreasing diameter at the top. The adjacent vibration-damping units maintain a constant spacing of 20-40mm to form a vertical discharge channel. The low-friction, wear-resistant padding layer of the cantilever comb plate is directly attached to the upper surface of the shock absorption unit, forming a low-resistance sliding interface.

2. The bridge expansion joint as described in claim 1, characterized in that, The cantilevered comb plate has a thickened section at the connection between the root and the body. The thickness of the thickened section gradually decreases along the cantilever extension direction to the standard thickness of the comb plate.

3. The bridge expansion joint as described in claim 1, characterized in that, The bottom of the vertical discharge channel is provided with a chip removal hole that penetrates the reserved base.

4. The bridge expansion joint as described in claim 1, characterized in that, The lower surface of the low-friction wear-resistant liner layer has a grid-like distribution of tiny depressions with uniform depth.

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