Overline splicing and widening bridge based on prefabricated UHPC-T beam structure

Abstract

The utility model discloses an overline spliced bridge based on a prefabricated UHPC-T beam structure. The overline spliced bridge comprises T beams, steel cross beam components, shear key components and transverse prestressed tendons. The bottom of the T-beam is arranged on an abutment through a bridge support and comprises a web plate and a wing plate; the steel cross beam component is used for connecting and fixing the adjacent T beams, so that the adjacent T beams are connected into a whole to improve the structural strength and stability, the steel cross beam component comprises a pre-buried connecting seat pre-buried in a web and a steel cross beam, and the two ends of the steel cross beam are fixed to the pre-buried connecting seat of the adjacent T beams through high-strength bolts; the shear key component comprises key teeth and key grooves which are arranged on the two sides of the wing plate, and the key teeth of the adjacent T beams are embedded in the key grooves. The transverse prestressed tendons penetrate out of the wing plates to be tensioned, and the multiple T-beams are connected into a whole. According to the overline spliced bridge, the modularized UHPC-T beams are adopted, the structural height is reduced by means of the ultrahigh mechanical property of UHPC, and the overline spliced bridge adapts to the condition that the clearance under the bridge is limited; the shear keys are matched with the steel cross beams to replace a traditional cast-in-place wet joint and cross beam technology, old bridges do not need to be dismantled, the longitudinal section of a road does not need to be lifted, and the construction period is remarkably shortened.

Description

Technical Field

[0001] The embodiments of this utility model belong to the technical field of highway reconstruction and widening bridges, and more specifically, relate to a cross-line widening bridge based on a prefabricated UHPC-T beam structure. Background Technology

[0002] With the significant improvement in domestic infrastructure and people's living standards, regional economies have developed rapidly. This has led to an increasing contradiction between the growth in traffic volume and the existing service level of highways. In particular, highways built in China in the 1980s and 1990s, with their four lanes in both directions, are clearly unable to meet the current traffic volume, making highway reconstruction and expansion imminent.

[0003] With the continuous development of China's highway network, the number of intersections between reconstructed and expanded highways and existing highways has increased significantly. The widening design of overpasses has become a major challenge in highway reconstruction and expansion projects. Some older bridges were built a long time ago, with relatively low structural heights and pavement thicknesses. Given the limited clearance under the bridge, if conventional precast beams are used for widening, the high main beam height makes it difficult to meet the required clearance specifications (conventional precast beams need to meet span and load requirements; generally, the larger the span, the greater the bending moment the main beam needs to withstand. To meet structural strength and stiffness requirements, the main beam height is usually also higher; if the bridge's design load level is high, an even higher main beam height is needed to ensure its load-bearing capacity, reduce deformation and cracking, and ensure the bridge's safety and durability). Often, the solution is to demolish the old bridge and raise the longitudinal section of the route to meet the traffic conditions under the bridge, which greatly increases the project scale and cost. At the same time, using conventional precast beam construction requires cast-in-place diaphragms and wet joints, hindering traffic under the bridge, and the cast-in-place process also increases the construction period.

[0004] Therefore, there is an urgent need for a type of overpass widening bridge that can effectively reduce the height of the main beam, solve the problem of limited clearance under the bridge, avoid demolishing the old bridge or raising the longitudinal section of the route, and significantly reduce the scale and cost of the project. Summary of the Invention

[0005] To address the problems of limited clearance, large project scale, and high cost associated with existing widening bridge technologies, this invention provides a cross-line widening bridge based on a prefabricated UHPC-T beam structure to solve these issues.

[0006] To achieve the above objectives, this utility model provides a cross-line widening bridge based on a prefabricated UHPC-T beam structure, comprising multiple sets of T beams arranged parallel to each other along the bridge direction, with their bottoms supported on piers via bridge bearings, and including webs and flanges; the T beams are cast using ultra-high performance concrete.

[0007] A steel crossbeam component connecting adjacent T-beams includes a pre-embedded connecting seat embedded in the web and a steel crossbeam; both ends of the steel crossbeam are fixedly connected to the corresponding pre-embedded connecting seats on adjacent T-beams by high-strength bolts; a shear key component enabling rapid positioning and docking of adjacent T-beams includes key teeth and keyways separately disposed on both sides of the flange, with the key teeth on adjacent T-beams embedded in the keyways; and transverse prestressing tendons, which extend from the flange along the transverse direction of the bridge for tensioning, connecting multiple T-beams into one.

[0008] Furthermore, the pre-embedded connecting seat is provided in multiple sets along the longitudinal direction of the bridge on the side of the web, including a pre-embedded plate and a connecting plate. The pre-embedded plate is pre-embedded in the web; the connecting plate is vertically fixed on the outside of the pre-embedded plate.

[0009] Furthermore, each of the pre-embedded plates is provided with two sets of connecting plates in parallel, and the connecting plates are provided with multiple sets of first through holes for passing high-strength bolts.

[0010] Furthermore, the steel beam is made of high-strength steel plate, and its side is provided with multiple sets of stiffening ribs at intervals.

[0011] Furthermore, multiple sets of key teeth are spaced apart along the bridge direction on one side of the wing plate, and the keyway is located at a corresponding position on the other side of the wing plate; the key teeth and keyway are structurally compatible.

[0012] Furthermore, the key teeth are characterized by a trapezoidal structure, with a key length generally ranging from 100mm to 300mm, a key width ranging from 50mm to 100mm, and a key depth ranging from 50mm to 100mm; the inclination angle of the inclined surface at the end of the keyway is less than 30°.

[0013] Furthermore, a sealing adhesive layer is provided between the key teeth and keyways that are interlocked.

[0014] Furthermore, the widened bridge also includes cast-in-place connecting components, a bridge deck paving layer, and guardrails.

[0015] In summary, compared with the prior art, the above-described technical solution conceived by this utility model can achieve the following beneficial effects:

[0016] (1) The cross-line widening bridge of this utility model has a low structural height and strong adaptability: it adopts prefabricated UHPC-T beams and utilizes the high strength characteristics of ultra-high performance concrete to effectively reduce the height of the main beam, solve the problem of limited clearance under the bridge, avoid demolishing the old bridge or raising the longitudinal section of the route, and significantly reduce the scale and cost of the project.

[0017] (2) The cross-line widening bridge of this utility model is quick to construct and has little interference. It replaces the traditional cast-in-place diaphragm and wet joint with a modular assembly system of shear keys and steel crossbeams, realizing factory prefabrication and rapid on-site assembly, shortening the construction period and reducing traffic interference under the bridge.

[0018] (3) The cross-line widening bridge of this utility model has excellent integrity and good durability. The transverse prestressed tendons and key teeth-keyways work together to enhance the transverse integrity of the widening bridge. The UHPC material and sealing adhesive layer improve crack resistance and seepage prevention performance, and extend the service life of the structure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the connection structure between adjacent T-beams in an embodiment of this utility model;

[0020] Figure 2 This is a structural schematic diagram of the shear key component in an embodiment of this utility model;

[0021] Figure 3 This is a front view of the steel beam component in an embodiment of this utility model;

[0022] Figure 4 This is a top view of the steel beam component in an embodiment of this utility model;

[0023] Figure 5 This is a diagram showing the connection structure between the spliced ​​bridge and the old bridge in an embodiment of this utility model.

[0024] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-T-beam, 11-web plate, 12-wing plate, 2-steel crossbeam member, 21-embedded connecting seat, 211-embedded plate, 212-connecting plate, 22-steel crossbeam, 23-high-strength bolt, 24-stiffening rib, 3-shear key member, 31-key tooth, 32-keyway, 4-transverse prestressing tendon, 5-bridge bearing, 6-pier, 7-cast-in-place connecting member, 8-bridge deck paving layer, 9-guardrail. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0026] like Figure 1-5As shown, this utility model provides a cross-line widening bridge based on a prefabricated UHPC-T beam structure, including a T beam 1, a steel crossbeam component 2, a shear key component 3, and transverse prestressing tendons 4. The T-beams 1 are arranged in a corresponding number of sets parallel to the bridge direction according to the expansion width requirements. Their bottoms are supported on the piers 6 via bridge supports 5, and include a web 11 and a flange 12. The steel crossbeam component 2 connects and fixes adjacent T-beams 1, so that multiple sets of T-beams 1 are connected into one, improving the structural strength and stability. It includes a pre-embedded connecting seat 21 embedded in the web 11 and a steel crossbeam 22, the two ends of which are fixedly connected to the corresponding pre-embedded connecting seats 21 on the adjacent T-beams 1 by high-strength bolts 23. The shear key component 3 includes key teeth 31 and keyways 32 respectively provided on both sides of the flange 12. The key teeth 31 on the adjacent T-beams 1 are embedded in the keyways 32. The transverse prestressing tendons 4 pass through corrugated pipes arranged in the transverse direction of the flange 12, connecting multiple T-beams 1 into one, improving the transverse integrity and crack resistance of the beam. This utility model of a widened overpass adopts modular T-beams 1, which are made of ultra-high performance concrete (UHPC). UHPC has superior mechanical properties and can effectively reduce the structural height, making the widened overpass adaptable to various situations where the clearance under the bridge is limited. By using a shear key system in combination with a steel crossbeam system, the traditional precast structure, cast-in-place wet joints, and cast-in-place crossbeam process can be replaced. This eliminates the need to demolish the old bridge and raise the longitudinal section of the road, avoiding unnecessary waste and significantly shortening the construction period.

[0027] like Figure 1-2 As shown in this embodiment of the invention, the T-beam 1 is a prefabricated modular component. It is cast using ultra-high performance concrete (UHPC) according to the required width expansion and bridge beam length. The prefabricated UHPC-T-beam components, once cured, are numbered and transported one-to-one to the designated pier 6 for installation. By using UHPC to cast the T-beam 1, it possesses superior mechanical properties, effectively reducing the structural height and allowing the overpass widening to better adapt to various situations where under-bridge clearance is limited. Multiple sets of the T-beam 1 are arranged parallel to each other along the bridge on the fixed pier 6 for assembly and widening, thereby meeting the overpass widening design requirements.

[0028] like Figure 2 As shown, when adjacent T-beams 1 are assembled and widened, the positioning and docking are quickly completed by the shear key component 3. The shear key component 3 restricts the relative displacement between adjacent T-beams 1 through the mechanical interlocking action between the tooth grooves, thereby effectively transmitting shear force and bending moment, so that multiple sets of T-beams 1 can work together to jointly bear the load.

[0029] The shear key component 3 includes key teeth 31 and keyways 32. Multiple sets of key teeth 31 are spaced along the longitudinal direction on one side of the flange 12, and the keyways 32 are located at corresponding positions on the other side of the flange 12. The key teeth 31 and keyways 32 are structurally compatible. Furthermore, the key teeth 31 are trapezoidal structures with a key length generally of 100mm-300mm, a key width of 50mm-100mm, and a key depth of 50mm-100mm. The inclined angle of the end face of the keyway 32 is less than 30°.

[0030] When prefabricating T-beam 1, the dimensions and positions of the key teeth and keyways must be precisely controlled to ensure accuracy. Otherwise, problems such as the key teeth failing to fit smoothly into the keyways or excessive gaps after fitting may occur, affecting the connection effect. During installation, ensure that the key teeth 31 and keyways 32 are clean and free of debris, oil, etc., to ensure a tight fit. The keyway connection method can effectively improve the overall rigidity of the T-beam structure, allowing T-beam 1 to work better under load, enhancing structural stability, and also improving space utilization and saving materials.

[0031] Furthermore, a sealing and bonding layer is provided between the key teeth 31 and the keyway 32 that are fitted together. The sealing and bonding layer is formed by applying sealant to the key teeth 31 and the keyway 32 respectively. After the two are fitted together, the gap between them is sealed. The sealing and bonding layer can fill the tiny gaps between the key teeth and the keyway, increase the friction and adhesion between them, make the connection more solid, and effectively prevent liquids, gases and other media from leaking through the gaps between the key teeth and the keyway, which would cause cracks to appear inside the concrete of the shear key member 3, corrode the internal steel bars of the T beam 1, deform the T beam 1 structure, and lose its original design bearing capacity.

[0032] like Figure 3-4 As shown, the steel crossbeam component 2 is used to connect and fix adjacent T-beams 1, so that multiple sets of T-beams 1 are connected into one, thereby improving the structural strength and stability. It includes a pre-embedded connecting seat 21 and a steel crossbeam 22.

[0033] The pre-embedded connecting seat 21 is provided in multiple sets along the longitudinal direction of the bridge on the side of the web plate 11. It includes a pre-embedded plate 211 and a connecting plate 212. The pre-embedded plate 211 is pre-embedded in the web plate 11 and is tied and fixed with the reinforcing steel in the web plate 11. After pouring concrete, it is fixed and connected to the web plate 11 as a whole. The connecting plate 212 is vertically fixed on the outside of the pre-embedded plate 211. Furthermore, each pre-embedded plate 211 is provided with two sets of connecting plates 212 in parallel. The connecting plate 212 is provided with multiple sets of first through holes for passing high-strength bolts 23.

[0034] The steel beam 22 is made of high-strength steel plate, and a second through hole is provided on the plate at both ends of the beam. By attaching the two ends of the steel beam 22 to the pre-embedded connecting seat 21 on the adjacent T beam 1, the second through hole is aligned with the first through hole. Then, high-strength bolts 23 are used to pass through the second through hole and the first through hole in sequence, thereby fixing the steel beam 22 to the connecting plate 212.

[0035] Preferably, the steel beam 22 is provided with multiple sets of stiffening ribs 4 at intervals on the side of the plate, which can improve the load-bearing capacity of the steel beam 22, enabling it to better withstand various loads, such as concentrated loads and uniformly distributed loads, reduce the deformation of the steel beam 22 under load, and prevent excessive bending, deflection, etc.

[0036] like Figure 1 As shown, the transverse prestressing tendon 4 is used to connect multiple T-beams 1 into one body, improving the transverse integrity and crack resistance of the beam. Multiple sets of corrugated pipes are provided in the transverse direction between the upper and lower layers of steel mesh in the flange 12. After the multiple T-beams 1 are spliced ​​and assembled, the transverse prestressing tendon 4 is passed through the corrugated pipe for tensioning and fixing, and the corrugated pipe is grouted and sealed.

[0037] By incorporating transverse prestressing tendons 4, transverse pressure is applied to the widened bridge to resist transverse bending moment, ensuring that the concrete of T-beam 1 does not exhibit transverse shear tensile stress under torsional force, thereby improving the crack resistance of the beam concrete.

[0038] like Figure 5 As shown in the embodiment of this utility model, the widened bridge also includes cast-in-place connecting components 7, bridge deck paving layer 8, and guardrail 9.

[0039] The cast-in-place connecting member 7 connects the widened bridge and the top cast-in-place layer of the old bridge. It is a T-shaped concrete component, formed by roughening the top of the T-beam 1 and the top of the old bridge, binding the reinforcing bars, and then casting concrete after formwork. The bridge deck paving layer 8 is formed by laying asphalt concrete on the cast-in-place layer. The guardrail 9 is fixed on the top of the outermost T-beam 1 and is mainly used to prevent vehicles from falling off the side of the bridge.

[0040] The construction of the overpass widening bridge of this utility model includes the following steps:

[0041] S100: Based on the expansion width requirements and bridge beam length, ultra-high performance concrete (UHPC) was used to cast T-beam 1;

[0042] S200: Construction is carried out on the side of the old bridge, the pier base 6 is poured, and the bridge bearing 5 is fixedly installed on the corresponding position on the pier base 6.

[0043] S300: Transport the cured T-beams 1 sequentially to the piers 6 and hoist them onto the corresponding bridge bearings 5 ​​for installation;

[0044] S400: Adjacent T-beams 1 are assembled by inserting key teeth 31 into keyways 32 and are connected as one unit by steel crossbeam components 2;

[0045] S500: After all T-beam 1 assembly work is completed, the transverse prestressed tendons 4 passing through the corrugated pipe are tensioned and fixed, and then the inside of the corrugated pipe is grouted and sealed.

[0046] S600: Complete the construction of the bridge deck pouring layer, cast-in-place connecting components 7, bridge deck paving layer 8 and guardrail 9 in sequence, and hand over the road for traffic after acceptance.

[0047] This utility model of a widened overpass has a low structural height and strong adaptability: it adopts precast UHPC-T beams and utilizes the high strength characteristics of ultra-high performance concrete to effectively reduce the height of the main beam, solve the problem of limited clearance under the bridge, avoid the demolition of the old bridge or raising the longitudinal section of the route, and significantly reduce the scale and cost of the project.

[0048] This utility model of a cross-line widening bridge allows for rapid construction and minimal disruption. It replaces the traditional cast-in-place diaphragms and wet joints with a modular assembly system of shear keys and steel crossbeams, enabling factory prefabrication and rapid on-site assembly, shortening the construction period and reducing traffic interference on roads under the bridge.

[0049] The cross-line widening bridge of this utility model has excellent integrity and durability. The transverse prestressed tendons and key teeth-keyways work together to enhance the transverse integrity of the widening bridge. UHPC material and sealing bonding layer improve crack resistance and seepage prevention performance, and extend the service life of the structure.

[0050] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A widened overpass bridge based on a prefabricated UHPC-T beam structure, characterized in that, include: Multiple sets of T-beams (1) are arranged parallel to each other along the bridge direction. Their bottoms are supported on the piers (6) by bridge bearings (5), including webs (11) and flanges (12). The T-beams (1) are cast using ultra-high performance concrete. The steel crossbeam component (2) that connects the adjacent T beams (1) into one unit includes a pre-embedded connecting seat (21) embedded in the web plate (11) and a steel crossbeam (22); the two ends of the steel crossbeam (22) are fixedly connected to the corresponding pre-embedded connecting seats (21) on the adjacent T beams (1) by high-strength bolts (23); The shear key component (3) that enables the adjacent T beams (1) to quickly complete the positioning and docking includes key teeth (31) and keyways (32) separately provided on both sides of the flange (12), with the key teeth (31) on the adjacent T beams (1) embedded in the keyways (32); And transverse prestressing tendons (4), which extend from inside the wing plate (12) along the transverse direction of the bridge for tensioning, connecting multiple T beams (1) into one.

2. The overpass widening bridge based on a prefabricated UHPC-T beam structure according to claim 1, characterized in that, The pre-embedded connecting seat (21) is provided in multiple sets along the longitudinal direction of the bridge on the side of the web plate (11), including a pre-embedded plate (211) and a connecting plate (212). The pre-embedded plate (211) is pre-embedded in the web plate (11); the connecting plate (212) is vertically fixed on the outside of the pre-embedded plate (211).

3. A cross-line widening bridge based on a prefabricated UHPC-T beam structure according to claim 2, characterized in that, Each of the pre-embedded plates (211) is provided with two sets of connecting plates (212) in parallel. The connecting plates (212) are provided with multiple sets of first through holes for passing high-strength bolts (23).

4. A cross-line widening bridge based on a prefabricated UHPC-T beam structure according to any one of claims 1-3, characterized in that, The steel beam (22) is made of high-strength steel plate, and multiple sets of stiffening ribs (24) are provided at intervals on the side of the plate.

5. A cross-line widening bridge based on a prefabricated UHPC-T beam structure according to any one of claims 1-3, characterized in that, The key teeth (31) are provided in multiple sets along the longitudinal direction on one side of the wing plate (12), and the keyway (32) is provided at the corresponding position on the other side of the wing plate (12); the key teeth (31) and the keyway (32) are structurally compatible.

6. A cross-line widening bridge based on a prefabricated UHPC-T beam structure according to any one of claims 1-3, characterized in that, The key teeth (31) are trapezoidal structures, with a key length of 100mm-300mm, a key width of 50mm-100mm, and a key depth of 50mm-100mm; the inclined angle of the end face of the keyway (32) is less than 30°.

7. A cross-line widening bridge based on a prefabricated UHPC-T beam structure according to any one of claims 1-3, characterized in that, A sealing adhesive layer is also provided between the key teeth (31) and keyways (32) that are fitted together.

8. A cross-line widening bridge based on a prefabricated UHPC-T beam structure according to any one of claims 1-3, characterized in that, The widened bridge also includes cast-in-place connecting components (7), a bridge deck paving layer (8), and guardrails (9).

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