Prestressed trestle

Abstract

The utility model discloses a prestress trestle which comprises a trestle main beam and a prestress rib used for applying prestress to the trestle main beam to enable the lower side of the trestle main beam to be pressed, a front supporting leg is arranged at the front end of the trestle main beam, and a rear supporting leg and / or a walking mechanism are / is arranged at the rear end of the trestle main beam. The two ends of the prestressed tendons are anchored to the middle of the trestle main beam through anchorage devices respectively. Or, the front ends of the prestressed tendons are anchored at the front end of the trestle main beam through anchorage devices, and the rear ends of the prestressed tendons are anchored at the rear end of the trestle main beam through anchorage devices. The prestressed trestle is low in construction cost, the span can be increased, and the bearing capacity can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel trestle bridges, in particular to a prestressed trestle bridge. Background Art

[0002] In recent years, my country's tunnel construction technology has achieved significant development, and improving construction efficiency has become a common pursuit in the industry. With the increase in the weight of construction machinery, construction units have put forward higher requirements for the span and load-bearing capacity of the trestle. At present, the vast majority of trestles adopt a front and rear two-point support structure during the construction process, as shown in a trestle design disclosed in Chinese patent document CN215210467U. In order to enable the trestles to adapt to longer spans or greater load requirements, existing technical solutions usually include the use of higher-strength steel or increasing the cross-sectional dimensions of the structural members in the direction of force. Although these methods can enhance the strength of the main load-bearing components, thereby improving the load-bearing capacity of the trestle, they also significantly increase the deadweight and assembly difficulty of the trestle, and are not conducive to saving construction costs, thereby affecting the economic benefits of the construction. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a prestressed trestle with low cost, increased span and improved bearing capacity.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A prestressed trestle comprises a trestle main beam and prestressed tendons for applying prestress to the trestle main beam so that the lower side of the trestle main beam is compressed, the front end of the trestle main beam is provided with a front support leg, the rear end of the trestle main beam is provided with a rear support leg and / or a running mechanism, the two ends of the prestressed tendons are respectively anchored to the middle part of the trestle main beam through anchors; or, the front end of the prestressed tendons is anchored to the front end of the trestle main beam through anchors, and the rear end of the prestressed tendons is anchored to the rear end of the trestle main beam through anchors.

[0006] As a further improvement of the above technical solution: the prestressed tendons are linear and located below the center of gravity of the cross section of the trestle main beam.

[0007] As a further improvement of the above technical solution: an avoidance groove is opened on the lower side of the trestle main beam, and the prestressed tendons are arranged in the avoidance groove.

[0008] As a further improvement of the above technical solution: the prestressed tendons are in the shape of an arc protruding downward and are located below the center of gravity of the cross-section of the trestle main beam. The prestressed tendons are provided with multiple fixed seats along the length direction. The trestle main beam is hinged with multiple supporting structural members along the length direction, and the lower ends of the supporting structural members are hinged to the corresponding fixed seats.

[0009] As a further improvement of the above technical solution: the prestressed tendons are in a downwardly protruding arc shape, and avoidance grooves are provided on the left and right sides of the trestle main beam, and the prestressed tendons are arranged in the avoidance grooves.

[0010] As a further improvement of the above technical solution: the front supporting legs are of telescopic structure.

[0011] As a further improvement of the above technical solution: a front approach bridge is provided at the front end of the trestle main beam and a rear approach bridge is provided at the rear end.

[0012] As a further improvement of the above technical solution: the front approach bridge and the rear approach bridge are both hinged to the trestle main beam, a swing driving member is provided between the front approach bridge and the front end of the trestle main beam to adjust the inclination angle of the front approach bridge, and a swing driving member is provided between the rear approach bridge and the rear end of the trestle main beam to adjust the inclination angle of the rear approach bridge.

[0013] As a further improvement of the above technical solution: a longitudinal moving trolley is provided on the main beam of the trestle, and the longitudinal moving trolley is provided with telescopic legs.

[0014] As a further improvement of the above technical solution: there are multiple prestressed tendons.

[0015] Compared with the prior art, the advantages of the present invention are that the bending moment generated at the mid-span position of the trestle main beam under the action of the load is large, and the prestressed tendons effectively transfer the prestress to the trestle main beam through the anchor. This process can offset part or all of the tensile stress caused by the load on the lower side of the mid-span of the trestle main beam. The application of this prestress significantly reduces the bending deformation of the trestle main beam under the action of the load, thereby improving its bending resistance and overall bearing capacity, so that the trestle main beam can be designed to be longer without sacrificing the bearing performance, thereby increasing the span. The prestressed tendons are connected to the trestle main beam through the anchor, and the maintenance and replacement of the prestressed tendons are convenient, which is conducive to extending the service life of the prestressed trestle. In addition, for existing trestle bridges that are not equipped with prestressed tendons, it is only necessary to stretch the prestressed tendons to the design tension and fix them to the original trestle structure through the anchor to complete the transformation, thereby giving it prestressed characteristics. The transformation is simple and the transformation cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the main structure of the prestressed trestle embodiment 1 of the present invention, in which the prestressed tendons are locally arranged on the main beam of the trestle.

[0017] Figure 2 yes Figure 1 Schematic diagram of the structure in the AA section direction.

[0018] Figure 3It is a top view structural schematic diagram of the local arrangement of prestressed tendons in the main beam of the prestressed trestle in Example 1 of the present utility model.

[0019] Figure 4 This is a schematic diagram of the main structure of the overall arrangement of prestressed tendons in the main beam of the prestressed trestle in Example 1 of the present invention.

[0020] Figure 5 yes Figure 4 Schematic diagram of the enlarged structure of part a.

[0021] Figure 6 This is a schematic diagram of the main structure of the second embodiment of the prestressed trestle of the present invention in which the prestressed tendons are locally arranged on the main beam of the trestle.

[0022] Figure 7 yes Figure 6 Schematic diagram of the structure in the BB section direction.

[0023] Figure 8 This is a schematic diagram of the main structure of the overall arrangement of prestressed tendons in the main beam of the prestressed trestle in Example 2 of the present invention.

[0024] Figure 9 yes Figure 8 Schematic diagram of the enlarged structure of part b.

[0025] Figure 10 This is a schematic diagram of the main structure of the prestressed trestle embodiment 3 of the present invention, in which the prestressed tendons are locally arranged on the trestle main beam.

[0026] Figure 11 yes Figure 10 Schematic diagram of the structure in the CC section direction.

[0027] Figure 12 This is a schematic diagram of the main structure of the overall arrangement of prestressed tendons in the main beam of the prestressed trestle in Example 3 of the present invention.

[0028] Figure 13 yes Figure 12 Schematic diagram of the enlarged structure of part c.

[0029] Figure 14 This is a schematic diagram of the main structure of the prestressed trestle embodiment 4 of the present invention, in which the prestressed tendons are locally arranged on the trestle main beam.

[0030] Figure 15 yes Figure 14 Schematic diagram of the structure in the DD section direction.

[0031] Figure 16 yes Figure 14 Schematic diagram of the enlarged structure of part d.

[0032] Figure 17 This is a schematic diagram of the main structure of the overall arrangement of prestressed tendons in the main beam of the prestressed trestle in the fourth embodiment of the present invention.

[0033] The numbers in the figure represent: 1. Main beam of trestle; 10. Swing drive member; 11. Traveling mechanism; 12. Avoidance groove; 13. Longitudinal movement trolley; 131. Telescopic support leg; 2. Prestressed tendons; 3. Front support leg; 4. Rear support leg; 5. Front approach bridge; 6. Rear approach bridge; 7. Anchor; 8. Fixed seat; 9. Support structure member. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In this utility model, unless otherwise specified or limited, the terms "assemble," "connect," "connect," "fix," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0037] Example 1

[0038] Figures 1 to 5 The present invention shows an embodiment of a prestressed trestle bridge. The prestressed trestle bridge of this embodiment includes a trestle main beam 1 and a prestressed tendon 2 for applying prestress to the trestle main beam 1 so that the lower side of the trestle main beam 1 is compressed. The front end of the trestle main beam 1 is provided with a front support leg 3, and the rear end of the trestle main beam 1 is provided with a rear support leg 4 and a running mechanism 11. The two ends of the prestressed tendon 2 can be anchored to the middle part of the trestle main beam 1 by anchors 7 (see FIG. Figure 1 ), the front end of the prestressed tendon 2 can also be anchored to the front end of the trestle main beam 1 through the anchor 7, and the rear end of the prestressed tendon 2 can be anchored to the rear end of the trestle main beam 1 through the anchor 7 (see Figure 4). Of course, in other embodiments, the rear end of the trestle main beam 1 may also be provided with only the rear support legs 4 or the running mechanism 11, and the details will not be repeated here. It should be noted that the front refers to the direction of tunnel excavation, and the rear is opposite to the front direction; the left and right directions are the width directions of the trestle main beam 1 or the tunnel. The prestressed tendons 2 can be steel wire ropes, steel strands or steel wire bundles, etc. The anchor 7 can be pre-made into a whole with the cable, and then the prestressed tendons 2 are tensioned in the form of anchors, and finally the anchor 7 is fixed to the trestle main beam 1, which can ensure the reliability of prestress transmission and facilitate the replacement of the prestressed tendons 2 in the later stage; the anchor 7 can also be first fixed to the trestle main beam 1, and then the prestressed tendons 2 are tensioned, and finally the prestressed tendons 2 are anchored to the anchor 7, which is beneficial to ensure the connection strength between the anchor 7 and the trestle main beam 1 after anchoring.

[0039] In the prestressed trestle of this embodiment, the bending moment caused by the load at the mid-span position of the trestle main beam 1 is relatively large, and the prestressed tendons 2 effectively transfer the prestress to the trestle main beam 1 through the anchor 7, which can offset part or all of the tension caused by the load on the lower side of the mid-span of the trestle main beam 1. The application of this prestressed force significantly reduces the bending deformation of the trestle main beam 1 under the load, thereby improving its bending resistance and overall bearing capacity, so that the trestle main beam 1 can be designed to be longer without sacrificing the bearing performance, thereby increasing the span. The prestressed tendons 2 are connected to the trestle main beam 1 through the anchor 7, and the maintenance and replacement of the prestressed tendons 2 are convenient, which is conducive to extending the service life. In addition, for existing trestle bridges that are not provided with prestressed tendons 2, it is only necessary to stretch the prestressed tendons 2 to the design tension and fix them to the original trestle structure through the anchor 7 to complete the transformation, thereby giving it prestressed characteristics, simple transformation, and low transformation cost.

[0040] See Figure 1 、 Figure 4 as well as Figure 5 Furthermore, in this embodiment, the prestressed tendons 2 are linear and located below the trestle main beam 1. The linear prestressed tendons 2 are easy to tension and anchor.

[0041] See Figure 2 Furthermore, in this embodiment, multiple prestressed tendons 2 are provided. These tendons 2 are arranged side by side below the center of gravity of the cross section of the trestle main beam 1. The number and size of the prestressed tendons 2 are determined based on the size of the trestle main beam 1 and the load it is to bear. Multiple prestressed tendons 2 can apply greater prestress to the trestle main beam 1, further improving the safety and stability of the trestle main beam 1 during use. Of course, in other embodiments, depending on actual needs, only one prestressed tendon may be provided.

[0042] Furthermore, in this embodiment, the front support legs 3 are telescopic, allowing them to adapt to terrain conditions of varying heights by extending and retracting, providing stable and effective support for the trestle main beam 1, thereby ensuring stability and safety during use. Furthermore, when the trestle needs to move forward or backward, the front support legs 3 can be retracted upward and separated from the ground. The front support legs 3 can be driven to extend and retract by components such as oil cylinders, pneumatic cylinders, or electric push rods, and the details will not be repeated here.

[0043] See Figure 1 and Figure 4 Furthermore, a front approach bridge 5 is provided at the front end of the trestle main beam 1 and a rear approach bridge 6 is provided at the rear end. Both the front approach bridge 5 and the rear approach bridge 6 are hinged to the trestle main beam 1. A swing drive 10 is provided between the front approach bridge 5 and the front end of the trestle main beam 1 to adjust the inclination of the front approach bridge 5. A swing drive 10 is provided between the rear approach bridge 6 and the rear end of the trestle main beam 1 to adjust the inclination of the rear approach bridge 6. The inclination of the front approach bridge 5 and the rear approach bridge 6 can be changed according to different connection requirements to facilitate the up and down movement of vehicles. The adaptability is good. At the same time, when the trestle needs to move forward and backward, it can be swung upward to separate from the ground. In this embodiment, the swing drive 10 is preferably an oil cylinder, which has a large output force and is reliable to use. Of course, in other embodiments, the swing drive 10 can also use a drive component such as a cylinder or an electric cylinder, which will not be described in detail.

[0044] See Figure 1 、 Figure 4 and Figure 5 Furthermore, in this embodiment, a longitudinal movement trolley 13 is provided on the trestle main beam 1, and a telescopic support leg 131 is provided on the longitudinal movement trolley 13. Through the cooperation of the longitudinal movement trolley 13, the telescopic support leg 131, the front support leg 3, and the running mechanism 11, the trestle main beam 1 can be moved in the direction of tunnel excavation without the need for other lifting construction equipment, which is convenient for movement and does not occupy additional tunnel space. The specific moving process is as follows: the longitudinal moving trolley 13 is initially parked on one side close to the front supporting leg 3, and the telescopic leg 131 is in a retracted state. When it is necessary to drive the trestle main beam 1 to move, the telescopic leg 131 is first extended and abutted against the ground, and then the front supporting leg 3 is retracted to separate it from the ground. Subsequently, the running mechanism 11 drives the trestle main beam 1 forward a certain distance, so that the front supporting leg 3 is extended and abutted against the ground, and the telescopic leg 131 is retracted and separated from the ground. After the longitudinal moving trolley 13 returns to its original position, the telescopic leg 131 is extended again to abut against the ground. The above steps are repeated until the trestle main beam 1 is moved forward to the specified position.

[0045] Example 2

[0046] Figures 6 to 9 Another embodiment of the prestressed trestle of the present invention is shown. The prestressed trestle of this embodiment is substantially the same as that of the first embodiment, except that:

[0047] In this embodiment, an avoidance groove 12 is provided on the lower side of the trestle main beam 1, and the prestressed tendons 2 are arranged in the avoidance groove 12. Specifically, the avoidance groove 12 is provided inside the trestle main beam 1.

[0048] Compared with the first embodiment, the prestressed tendons 2 in this embodiment are arranged in the avoidance groove 12, which is not easy to be damaged by contact with the ground or other construction machinery, etc., and the working environment is safer, which is conducive to reducing maintenance costs.

[0049] Example 3

[0050] Figures 10 to 13 Another embodiment of the prestressed trestle of the present invention is shown. The prestressed trestle of this embodiment is substantially the same as that of the first embodiment, except that:

[0051] In this embodiment, the prestressed tendons 2 are in a downwardly protruding arc shape and are located below the center of gravity of the cross section of the trestle main beam 1. The prestressed tendons 2 are provided with multiple fixing seats 8 along the length direction. The trestle main beam 1 is hinged with multiple supporting structural members 9 along the length direction. The lower ends of the supporting structural members 9 are hinged to the fixing seats 8. Specifically, the supporting structural member 9 is a strut. Multiple prestressed tendons 2 can be provided on the same fixing seat 8 (see Figure 11 ), which can save material costs, and each prestressed tendon 2 can also be provided with a separate fixing seat 8.

[0052] In the prestressed trestle of this embodiment, the prestressed tendons 2 are in a downwardly convex arc shape, which makes their lever arm longer. Under the same prestress, the ability of the trestle main beam 1 to resist bending moment can be effectively improved. When the trestle main beam 1 bears a load, the load is transmitted to the supporting structure 9 through the trestle main beam 1, and then transmitted to the fixing seat 8 through the supporting structure 9, and finally reaches the prestressed tendons 2 through the fixing seat 8, so that the prestressed tendons 2 are deformed downward while being subjected to opposite tension at both ends, thereby increasing the pressure exerted by the prestressed tendons 2 on the trestle main beam 1, so that the trestle main beam 1 can enhance its own anti-bending ability when bearing load, thereby improving the bearing capacity of the trestle main beam 1. Compared with the first embodiment, the prestressed trestle of this embodiment has a stronger bearing capacity and higher structural reliability and safety.

[0053] Example 4

[0054] Figures 14 to 17 Another embodiment of the prestressed trestle of the present invention is shown. The prestressed trestle of this embodiment is substantially the same as that of the third embodiment, except that:

[0055] In this embodiment, escape grooves 12 are provided on both sides of the trestle main beam 1. Multiple prestressed tendons 2 are arranged side by side within these grooves, while the fixing bases 8 and supporting structure 9 are eliminated. Specifically, the escape grooves 12 extend through the interior of the trestle main beam 1. Compared with the third embodiment, this prevents the curved prestressed tendons 2 from protruding downward from the trestle main beam 1, ensuring normal operation in low-clearance environments.

[0056] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the present invention, or modify it into equivalent embodiments with equivalent variations. Therefore, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the content of the present invention and are based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A prestressed trestle, characterized by: The invention comprises a trestle main beam (1) and a prestressed tendon (2) for applying prestress to the trestle main beam (1) so that the lower side of the trestle main beam (1) is compressed. The front end of the trestle main beam (1) is provided with a front support leg (3), and the rear end of the trestle main beam (1) is provided with a rear support leg (4) and / or a running mechanism (11). The two ends of the prestressed tendon (2) are respectively anchored to the middle part of the trestle main beam (1) through an anchor (7); or, the front end of the prestressed tendon (2) is anchored to the front end of the trestle main beam (1) through the anchor (7), and the rear end of the prestressed tendon (2) is anchored to the rear end of the trestle main beam (1) through the anchor (7).

2. The prestressed trestle according to claim 1, characterized in that: The prestressed tendons (2) are linear and located below the center of gravity of the cross section of the trestle main beam (1).

3. The prestressed trestle according to claim 2, characterized in that: An avoidance groove (12) is provided on the lower side of the trestle main beam (1), and the prestressed tendons (2) are arranged in the avoidance groove (12).

4. The prestressed trestle according to claim 1, characterized in that: The prestressed tendons (2) are in a downwardly protruding arc shape and are located below the center of gravity of the cross section of the trestle main beam (1). The prestressed tendons (2) are provided with a plurality of fixing seats (8) along the length direction. The trestle main beam (1) is hingedly provided with a plurality of supporting structural members (9) along the length direction. The lower ends of the supporting structural members (9) are hingedly connected to the fixing seats (8).

5. The prestressed trestle according to claim 1, characterized in that: The prestressed tendons (2) are in a downwardly protruding arc shape, and avoidance grooves (12) are provided on the left and right sides of the trestle main beam (1), and the prestressed tendons (2) are arranged in the avoidance grooves (12).

6. The prestressed trestle according to claim 1, characterized in that: The front supporting legs (3) are of telescopic structure.

7. The prestressed trestle according to claim 1, characterized in that: The front end of the trestle main beam (1) is provided with a front approach bridge (5) and the rear end is provided with a rear approach bridge (6).

8. The prestressed trestle according to claim 7, characterized in that: The front approach bridge (5) and the rear approach bridge (6) are both hinged to the trestle main beam (1); a swing driving member (10) is provided between the front approach bridge (5) and the front end of the trestle main beam (1) to adjust the inclination angle of the front approach bridge (5); and a swing driving member (10) is provided between the rear approach bridge (6) and the rear end of the trestle main beam (1) to adjust the inclination angle of the rear approach bridge (6).

9. The prestressed trestle according to any one of claims 1 to 8, characterized in that: A longitudinal moving trolley (13) is provided on the main beam of the trestle bridge (1), and a telescopic supporting leg (131) is provided on the longitudinal moving trolley (13).

10. The prestressed trestle according to any one of claims 1 to 8, characterized in that: The prestressed tendons (2) are provided in plurality.

Images