Prestressed trestle structure and prestressed tendon tensioning method thereof

Abstract

The invention discloses a prestressed trestle structure which comprises a trestle main beam, a tensioning mechanism, a first anchorage device, a second anchorage device, a prestressed tendon tightness adjusting mechanism and a prestressed tendon used for pressing the lower side of the trestle main beam, the prestressed tendon is arranged on the trestle main beam in a penetrating mode, and the first anchorage device and the second anchorage device are arranged at the two ends of the prestressed tendon respectively. The first anchorage device is connected with the trestle main beam through a tensioning mechanism, the trestle main beam is provided with a limiting mechanism used for preventing the first anchorage device from returning, and the second anchorage device is connected with the trestle main beam through a prestressed tendon tightness adjusting mechanism. According to the prestressed trestle structure, prestress is transmitted to the trestle main beam through the first anchorage device, the second anchorage device, the limiting mechanism and the prestressed tendon tightness adjusting mechanism, so that the lower side of the trestle main beam is pressed, the bending resistance and the overall bearing capacity of the trestle main beam are improved, and the span of the trestle main beam can be increased. The invention further discloses a tensioning method of the prestressed tendons of the prestressed trestle structure.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel trestle and prestressed tendon tensioning method, in particular to a prestressed trestle structure and a prestressed tendon tensioning method thereof. Background Art

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

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a prestressed trestle structure which can improve the bearing capacity, increase the span of the trestle and compensate for the loss of prestress in long-term use.

[0004] The invention further provides a method for tensioning prestressed tendons of a prestressed trestle structure.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A prestressed trestle structure comprises a trestle main beam, a tensioning mechanism, a first anchor, a second anchor, a prestressed tendon tension adjustment mechanism and prestressed tendons for compressing the lower side of the trestle main beam, wherein the prestressed tendons are passed through the trestle main beam, the first anchor and the second anchor are respectively arranged at two ends of the prestressed tendons, the first anchor is connected to the trestle main beam through the tensioning mechanism and the trestle main beam is provided with a limiting mechanism for preventing the first anchor from retreating, and the second anchor is connected to the trestle main beam through the prestressed tendon tension adjustment mechanism.

[0007] As a further improvement of the above technical solution: the limiting mechanism includes two fixed blocks relatively arranged on the main beam of the pier, the prestressed tendons are located between the two fixed blocks, a moving block is clamped between each of the fixed blocks and the first anchor, and the moving block is connected to a moving block driving member.

[0008] As a further improvement of the above technical solution: a first inclined surface is provided on the moving block, and two second inclined surfaces are provided on the first anchor, and the two first inclined surfaces are in close contact with the two second inclined surfaces in a one-to-one correspondence.

[0009] As a further improvement of the above technical solution: the limiting mechanism also includes two relatively arranged guide blocks, a first guide channel is formed between the two guide blocks, the first anchor is located in the first guide channel, a second guide channel is formed between the guide block and the fixed block, and the movable block is located in the second guide channel.

[0010] As a further improvement of the above technical solution: the limiting mechanism is a limiting block.

[0011] As a further improvement of the above technical solution: a connecting piece is provided on the limit block, and the connecting piece is detachably connected to the trestle main beam.

[0012] As a further improvement of the above technical solution: the tensioning mechanism and the prestressed tendon tension adjustment mechanism both include at least one tensioning cylinder.

[0013] As a further improvement of the above technical solution: the front end of the trestle main beam is provided with front supporting legs, a front approach bridge and a swing driving component for driving the front approach bridge to swing up and down, and the rear end of the trestle main beam is provided with rear supporting legs, a running mechanism, a rear approach bridge and a swing driving component for driving the rear approach bridge to swing up and down.

[0014] As a further improvement of the above technical solution: the front supporting legs are of telescopic structure, a longitudinal moving trolley is provided on the main beam of the trestle, and a telescopic supporting leg is provided on the longitudinal moving trolley.

[0015] A method for tensioning prestressed tendons of a prestressed trestle structure comprises the following steps:

[0016] S1: Prestressed tendons are installed on the main beam of the trestle, the two ends of the prestressed tendons are connected to the first anchor and the second anchor respectively, and strain gauges are attached to the prestressed tendons;

[0017] S2: The prestressed tendon tension adjustment mechanism pulls the second anchor until the tension of the prestressed tendon meets the tensioning condition;

[0018] S3: The tensioning mechanism pulls the first anchor until the strain gauge shows that the prestress of the prestressed tendon reaches the design value;

[0019] S4: The limiting mechanism locks the first anchor.

[0020] Compared with the prior art, the advantages of the present invention are as follows: the prestressed trestle structure disclosed by the present invention has prestressed tendons passing through the trestle main beam, and the first anchor and the second anchor are respectively provided at both ends of the prestressed tendons, the first anchor is connected to the tensioning mechanism, and the second anchor is connected to the prestressed tendon tension adjustment mechanism. The prestressed tendon tension adjustment mechanism can adjust the tightness of the prestressed tendons before the tensioning mechanism is tensioned, which is conducive to ensuring the tensioning quality of the prestressed tendons. The tensioning mechanism can drive the prestressed tendons to extend in the tensioning direction by pulling the first anchor. When the prestress of the prestressed tendons is tensioned to the design value, the tensioning mechanism can stop providing tension and prevent the first anchor from retreating through the limiting mechanism, thereby preventing the prestressed tendons from retreating. The prestress of the prestressed tendons is transmitted to the trestle main beam through the first anchor, the second anchor, the limiting mechanism and the prestressed tension adjustment mechanism, so that the lower side of the trestle main beam is compressed. The application of this prestressing force significantly reduces the bending deformation of the trestle main beam under load, thereby improving the bending resistance and overall bearing capacity of the trestle main beam, and can increase the span of the trestle main beam. When the prestressing tendons lose prestress during long-term use, the prestressing tendons can be tensioned again by pulling the anchor through the tensioning mechanism to compensate for the prestressing loss.

[0021] The method for tensioning the prestressed tendons of a prestressed trestle structure disclosed by the present invention can monitor the prestress value of the prestressed tendons in real time by pasting strain gauges on the prestressed tendons, which is beneficial to ensuring that the prestress of the prestressed tendons after tensioning meets the requirements; the prestressed tendons are adjusted in tightness before tensioning, which is beneficial to preventing local stress concentration in the prestressed tendons during the tensioning process, and is also beneficial to reducing the prestress loss during the tensioning process, and is beneficial to ensuring the reliability of prestress transmission; both ends of the prestressed tendons can be pulled, which is beneficial for the prestress of the prestressed tendons after tensioning to reach the designed value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional structural schematic diagram of the limiting structure of the first embodiment of the prestressed trestle structure of the present invention.

[0023] Figure 2 It is a front view structural schematic diagram of the limiting structure of the first embodiment of the prestressed trestle structure of the present invention.

[0024] Figure 3 yes Figure 2 Schematic diagram of the structure of AA.

[0025] Figure 4 It is a structural schematic diagram of the anchorage of the first embodiment of the prestressed trestle structure of the present invention.

[0026] Figure 5 It is a structural schematic diagram of the moving block of the first embodiment of the prestressed trestle structure of the present invention.

[0027] Figure 6It is a front view structural schematic diagram of the first embodiment of the prestressed trestle structure of the present invention.

[0028] Figure 7 yes Figure 6 Schematic diagram of the structure of CC.

[0029] Figure 8 It is a schematic diagram of the top view of the structure of the first embodiment of the prestressed trestle structure of the present invention.

[0030] Fig. 9 yes Figure 6 Schematic diagram of the enlarged structure of part B.

[0031] Fig.10 yes Figure 6 Schematic diagram of the enlarged structure of part D.

[0032] Fig.11 It is a three-dimensional structural schematic diagram of the limiting structure of the second embodiment of the prestressed trestle structure of the present invention.

[0033] Fig.12 It is a front view structural schematic diagram of the limiting structure of the second embodiment of the prestressed trestle structure of the present invention.

[0034] Fig.13 It is a schematic diagram of the installation of the limit block of the second embodiment of the prestressed trestle structure of the present invention.

[0035] Fig.14 It is a structural schematic diagram of the connecting plate of the second embodiment of the prestressed trestle structure of the present invention.

[0036] Fig.15 yes Fig.13 Schematic diagram of the enlarged structure of part E in the middle.

[0037] Fig.16 The present invention is a flow chart of a method for tensioning prestressed tendons of a prestressed trestle structure.

[0038] The numbers in the figure represent: 1. trestle main beam; 11. front supporting leg; 12. rear supporting leg; 13. running mechanism; 14. front approach bridge; 15. rear approach bridge; 16. longitudinal movement trolley; 161. telescopic support leg; 2. tensioning mechanism; 31. first anchor; 32. second anchor; 311. second inclined surface; 4. prestressed tendon; 41. strain gauge; 5. limiting mechanism; 51. moving block; 511. first inclined surface; 52. moving block driving member; 53. fixed block; 54. guide block; 55. limiting block; 6. connecting member; 7. swing driving member; 8. protective sleeve; 9. prestressed tendon tightness adjustment mechanism. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] 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" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0041] In the present invention, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Embodiment 1

[0043] Figures 1 to 10 An embodiment of a prestressed trestle structure is shown. The prestressed trestle structure of this embodiment includes a trestle main beam 1, a tensioning mechanism 2, a first anchor 31, a second anchor 32, a prestressed tendon tension adjustment mechanism 9, and a prestressed tendon 4 for compressing the lower side of the trestle main beam 1. The prestressed tendon 4 is passed through the trestle main beam 1, and the first anchor 31 and the second anchor 32 are respectively arranged at both ends of the prestressed tendon 4. The first anchor 31 is connected to the trestle main beam 1 through the tensioning mechanism 2, and the trestle main beam 1 is provided with a limiting mechanism 5 for preventing the first anchor 31 from retreating. The second anchor 32 is connected to the trestle main beam 1 through the prestressed tendon tension adjustment mechanism 9. It should be noted that the number of prestressed tendons 4 fixed by the anchor 3 can be single or multiple, which is set according to actual use needs; in actual use, the two ends of the prestressed tendon 4 can be anchored in the middle of the pier main beam 1, or the front end of the prestressed tendon 4 can be anchored at the front end of the pier main beam 1, and the rear end of the prestressed tendon 4 can be anchored at the rear end of the pier main beam 1, which can be set as needed according to actual use conditions.

[0044] In the prestressed trestle structure of this embodiment, the prestressed tendon 4 is penetrated on the trestle main beam 1, and the first anchor 31 and the second anchor 32 are respectively provided at the two ends of the prestressed tendon 4. The first anchor 31 is connected to the tensioning mechanism 2, and the second anchor 32 is connected to the prestressed tendon tension adjustment mechanism 9. The prestressed tendon tension adjustment mechanism 9 can adjust the tightness of the prestressed tendon 4 before the tensioning mechanism 2 is tensioned, which is conducive to ensuring the tensioning quality of the prestressed tendon 4. The tensioning mechanism 2 can drive the prestressed tendon 4 to extend in the tensioning direction by pulling the first anchor 31. When the prestressed tendon 4 is tensioned until its prestress reaches the design value, the tensioning mechanism 2 can stop providing tension and prevent the prestressed tendon 4 from retreating through the limiting mechanism 5. The prestress of the prestressed tendon 4 is transmitted to the trestle main beam 1 through the first anchor 31, the second anchor 32, the limiting mechanism 5 and the prestressed tendon tension adjustment mechanism 9, so that the lower side of the trestle main beam 1 is compressed. The application of such prestress significantly reduces the bending deformation of the trestle main beam 1 under load, thereby improving the bending resistance and overall bearing capacity of the trestle main beam 1, and can increase the span of the trestle main beam 1. When the prestressed tendons 4 lose prestress during long-term use, the anchor 3 can be pulled again by the tensioning mechanism 2 to tension the prestressed tendons 4 to compensate for the prestress loss.

[0045] See Figures 1 to 3 Furthermore, in this embodiment, the limiting mechanism 5 includes two fixed blocks 53 arranged relatively on the trestle main beam 1, the prestressed tendon 4 is located between the two fixed blocks 53, and a moving block 51 is clamped between each fixed block 53 and the first anchor 31, and the moving block 51 is connected to a moving block driving member 52. After the tensioning mechanism 2 tensions the prestressed tendon 4 into place, the moving block driving member 52 pushes the moving block 51 to be clamped between the corresponding anchor 3 and the fixed block 53. At this time, the tensioning mechanism 2 no longer provides tension, and the first anchor 31 will squeeze the moving block 51 to transmit the prestress of the prestressed tendon 4 to the fixed block 53, and the fixed block 53 will then transmit the prestress to the trestle main beam 1 to compress the lower part of the trestle main beam 1.

[0046] See Figure 1 , Figure 2 , Figure 4 and Figure 5Further, in this embodiment, a first inclined surface 511 is provided on the moving block 51, and two second inclined surfaces 311 are provided on the first anchor 31. The two first inclined surfaces 511 can be closely attached to the two second inclined surfaces 311 in one-to-one correspondence. The moving block 51 can adapt to various prestressing tendon 4 tensioning requirements and has good adaptability. Specifically, when the prestressing value required to be achieved by tensioning the prestressing tendon 4 is small, the first anchor 31 needs to move a short distance under the pull of the tensioning mechanism 2, and the moving block driving member 52 drives the moving block 51 to move a short distance so that the first inclined surface 511 can be pressed against the second inclined surface 311, thereby allowing the moving block 51 to transmit prestress; when the prestressing value required to be achieved by tensioning the prestressing tendon 4 is large, the first anchor 31 needs to move a long distance under the pull of the tensioning mechanism 2, and the moving block driving member 52 drives the moving block 51 to move a long distance so that the first inclined surface 511 can be pressed against the second inclined surface 311, thereby allowing the moving block 51 to transmit prestress. When the prestressed tendon 4 loses prestress during long-term use, after the tensioning mechanism 2 tensions the prestressed tendon 4 again, the moving block driver 52 can drive the moving block 51 to move a certain distance so that the first inclined surface 511 is pressed against the second inclined surface 311, thereby ensuring that the prestress is well transmitted. It should be noted that after the prestressed tendon 4 is tensioned for the first time, the tensioning mechanism 2 can be separated from the first anchor 31 and removed from the trestle main beam 1. When a second tensioning is required, the moving block driver 52 can be used to push the moving block 51 to squeeze the anchor 3, thereby driving the anchor 3 to move to tension the prestressed tendon 4, thereby improving the utilization rate of the tensioning mechanism 2 and saving the layout cost. The moving block driver 52 can be a driving component such as an oil cylinder, an air cylinder or an electric push rod.

[0047] See Figure 1 and Figure 2 Furthermore, in the present embodiment, the limiting mechanism 5 also includes two guide blocks 54 arranged opposite to each other, a first guide channel is formed between the two guide blocks 54, the first anchor 31 is located in the first guide channel, which is beneficial to improve the stability and accuracy of the first anchor 31 when driving the prestressed tendon 4 to move, a second guide channel is formed between the guide block 54 and the fixed block 53, the moving block 51 is located in the second guide channel, which is beneficial to improve the stability and accuracy of the moving block 51 when moving. It should be noted that in other embodiments, a first guide groove and a second guide groove may also be provided on the trestle main beam 1, the limiting mechanism 5 is placed in the first guide groove, the first anchor 31 is placed in the second guide groove, the two opposite groove walls in the first guide groove may be equivalent to the fixed block 53 and the guide block 54, and the two opposite groove walls in the second guide groove may be equivalent to the two guide blocks 54.

[0048] See Figure 6Further, in this embodiment, the tensioning mechanism 2 and the prestressed tendon tension adjustment mechanism 9 each include at least one tensioning cylinder, which is connected to the trestle main beam 1 and (the first anchor 31 or the second anchor 32). The tensioning cylinder has a large output force, is reliable to use, and is easy to maintain. In general, only the tensioning cylinder of the tensioning mechanism 2 is needed to tension the prestressed tendon 4. However, when the prestressed tendon 4 to be tensioned is too long, the prestress of the prestressed tendon 4 cannot reach the design value if it is tensioned only by the tensioning cylinder of the tensioning mechanism 2. At this time, the tensioning cylinder of the prestressed tendon tension adjustment mechanism 9 can intervene to tension the prestressed tendon 4, which is conducive to ensuring that the prestress of the prestressed tendon 4 can reach the design value; in addition, the first anchor 31 and the second anchor 32 at both ends of the prestressed tendon 4 are respectively connected with tensioning cylinders, which can effectively prevent the failure of the tensioning cylinder of the tensioning mechanism 2 to tension the prestressed tendon 4 during long-term use, which is conducive to ensuring reliability during long-term use.

[0049] See Figure 3 and Figure 7 Furthermore, in this embodiment, both sides of the trestle main beam 1 are provided with prestressed tendons 4. The bearing capacity of the trestle main beam 1 is further improved, and the span of the trestle main beam 1 is increased.

[0050] See Figure 3 Furthermore, in this embodiment, the prestressed trestle structure also includes a protective sleeve 8, which is sleeved on the prestressed tendon 4 to prevent the prestressed tendon 4 from being damaged by friction with the trestle main beam 1 during the tensioning process and causing loss of prestress, and to prevent the prestressed tendon 4 from being rusted in the humid environment of the tunnel and causing loss of prestress.

[0051] See Figure 6 Furthermore, in this embodiment, the prestressed tendons 4 are in a downwardly convex arc shape, which can effectively improve the ability of the trestle main beam 1 to resist bending moment. Of course, in other embodiments, the prestressed tendons 4 can also be set to be linear, which is specifically arranged according to actual construction and use conditions, and will not be repeated.

[0052] See Figure 6 , Fig. 9 and Fig.10Furthermore, in the present embodiment, the front end of the trestle main beam 1 is provided with a front supporting leg 11, a front approach bridge 14 and a swing driving member 7 for driving the front approach bridge 14 to swing up and down, and the rear end of the trestle main beam 1 is provided with a rear supporting leg 12, a running mechanism 13, a rear approach bridge 15 and a swing driving member 7 for driving the rear approach bridge 15 to swing up and down. The inclination angles of the front approach bridge 14 and the rear approach bridge 15 can be adjusted by the swing driving member 7 to adapt to different docking conditions. It is more convenient for vehicles to get on and off, and when the trestle needs to move forward and backward, it can be swung upward to separate from the ground. It should be noted that the front refers to the direction of tunnel excavation. The swing driving member 7 can specifically be a driving mechanism such as an oil cylinder, an air cylinder or an electric push rod.

[0053] See Figure 6 , Fig. 9 and Fig.10 Further, in this embodiment, the front support leg 11 is a telescopic structure, a longitudinal movement trolley 16 is provided on the trestle main beam 1, and a telescopic support leg 161 is provided on the longitudinal movement trolley 16. The longitudinal movement trolley 16 can cooperate with the front support leg 11, the running mechanism 13 and the telescopic support leg 161 to realize the forward step-by-step movement of the trestle main beam 1. The specific moving process is as follows: initially, the longitudinal movement trolley 16 is parked on the trestle main beam 1 near the front supporting leg 11. When the trestle needs to be moved, the telescopic leg 161 is first extended to make it contact with the ground, and then the front supporting leg 11 rises and separates from the ground. The two swing driving parts 7 respectively drive the front approach bridge 14 and the rear approach bridge 15 to swing upward and separate from the ground, and then the running mechanism 13 moves forward, which can drive the trestle main beam 1 together with the front supporting leg 11, rear supporting leg 12, front approach bridge 14 and rear approach bridge 15 connected thereto to move forward as a whole. After walking a certain distance, the front supporting leg 11 descends to make it contact with the ground, the telescopic leg 161 rises and separates from the ground, and the longitudinal movement trolley 16 drives the telescopic leg 161 to move forward. After it is in place, the telescopic leg 161 is extended again, and the above steps are repeated until the trestle main beam 1 moves to the specified position.

[0054] See Figure 3 and Figure 7 As a preferred embodiment, the trestle main beam 1 is assembled from multiple hollow steel beams, which reduces the deadweight of the trestle main beam 1 and improves the bearing capacity of the trestle main beam 1.

[0055] Embodiment 2

[0056] Figures 11 to 15Another embodiment of a prestressed trestle structure is shown. The prestressed trestle structure of this embodiment is substantially the same as that of the first embodiment, except that the limiting mechanism 5 in this embodiment is a limiting block 55, and a connecting member 6 is provided on the limiting block 55, and the connecting member 6 is detachably connected to the trestle main beam 1. Specifically, the connecting member 6 includes a connecting plate provided on the limiting mechanism 5, and the connecting plate is connected to the trestle main beam 1 by bolts, and the trestle main beam 1 is provided with a plurality of bolt holes along the tensioning direction of the prestressed tendons 4. After the tensioning mechanism 2 tensions the prestressed tendons 4 into place, the limiting block 55 is fixed to the trestle main beam 1 at the corresponding position of the trestle main beam 1, so that the limiting block 55 can withstand the pressure from the first anchor 31, and transmit the pressure to the trestle main beam 1, thereby applying prestress to the trestle main beam 1. Compared with the first embodiment, the limiting mechanism 5 of this embodiment is simpler and more convenient to replace and maintain.

[0057] Embodiment 3

[0058] Fig.16 An embodiment of a method for tensioning prestressed tendons of a prestressed trestle structure is shown. The specific steps of the method for tensioning prestressed tendons of this embodiment are as follows:

[0059] S1: a prestressed tendon 4 is inserted into the main beam 1 of the trestle, two ends of the prestressed tendon 4 are connected to a first anchor 31 and a second anchor 32 respectively, and a strain gauge 41 is attached to the prestressed tendon 4;

[0060] S2: The prestressed tendon tension adjustment mechanism 9 pulls the anchor 3 connected thereto until the tension of the prestressed tendon 4 meets the tensioning condition;

[0061] S3: the tensioning mechanism 2 pulls the first anchor 31 until the strain gauge 41 shows that the prestress of the prestressed tendon 4 reaches the design value;

[0062] S4: The limiting mechanism 5 locks the first anchor 31 .

[0063] It should be noted that, in the first embodiment, the limiting mechanism 5 locks the first anchor 31 by means of the moving block driving member 52 driving the moving block 51 to move so that the first inclined surface 511 is in close contact with the second inclined surface 311 on the corresponding anchor 3; in the second embodiment, the limiting mechanism 5 locks the first anchor 31 by means of arranging the limiting block 55 in close contact with the anchor 3, and fixing the limiting block 55 on the pier main beam 1 through the connecting member 6.

[0064] The method for tensioning the prestressed tendons of the prestressed trestle structure of the present embodiment can monitor the prestress value of the prestressed tendons 4 in real time by pasting strain gauges 41 on the prestressed tendons 4, which is beneficial to ensuring that the prestress of the prestressed tendons 4 after tensioning meets the requirements; the prestressed tendons 4 are adjusted in tightness before tensioning, which is beneficial to preventing local stress concentration in the prestressed tendons 4 during the tensioning process, and is also beneficial to reducing the prestress loss during the tensioning process, and is beneficial to ensuring the reliability of prestress transmission; both ends of the prestressed tendons 4 can be pulled, which is beneficial for the prestress of the prestressed tendons 4 after tensioning to reach the designed value.

[0065] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A prestressed trestle structure, characterized in that: The invention comprises a trestle main beam (1), a tensioning mechanism (2), a first anchor (31), a second anchor (32), a prestressed tendon tension adjustment mechanism (9), and a prestressed tendon (4) for compressing the lower side of the trestle main beam (1); the prestressed tendon (4) is passed through the trestle main beam (1); the first anchor (31) and the second anchor (32) are respectively arranged at two ends of the prestressed tendon (4); the first anchor (31) is connected to the trestle main beam (1) through the tensioning mechanism (2); and the trestle main beam (1) is provided with a limiting mechanism (5) for preventing the first anchor (31) from retreating; and the second anchor (32) is connected to the trestle main beam (1) through the prestressed tendon tension adjustment mechanism (9).

2. The prestressed trestle structure according to claim 1, characterized in that: The limiting mechanism (5) comprises two fixed blocks (53) arranged relatively on the trestle main beam (1), the prestressed tendon (4) is located between the two fixed blocks (53), a moving block (51) is clamped between each of the fixed blocks (53) and the first anchor (31), and the moving block (51) is connected to a moving block driving member (52).

3. The prestressed trestle structure according to claim 2 is characterized in that: The moving block (51) is provided with a first inclined surface (511), and the first anchor (31) is provided with two second inclined surfaces (311), and the two first inclined surfaces (511) and the two second inclined surfaces (311) are in close contact with each other in a one-to-one correspondence.

4. The prestressed trestle structure according to claim 2, characterized in that: The limiting mechanism (5) further comprises two guide blocks (54) arranged opposite to each other, a first guide channel is formed between the two guide blocks (54), the first anchor (31) is located in the first guide channel, a second guide channel is formed between the guide block (54) and the fixed block (53), and the movable block (51) is located in the second guide channel.

5. The prestressed trestle structure according to claim 1, characterized in that: The limiting mechanism (5) is a limiting block (55).

6. The prestressed trestle structure according to claim 5, characterized in that: The limit block (55) is provided with a connecting piece (6), and the connecting piece (6) is detachably connected to the trestle main beam (1).

7. The prestressed trestle structure according to claim 1 is characterized in that: The tensioning mechanism (2) and the prestressed tendon tension adjustment mechanism (9) both include at least one tensioning cylinder.

8. The prestressed trestle structure according to any one of claims 1 to 7, characterized in that: The front end of the trestle main beam (1) is provided with a front supporting leg (11), a front approach bridge (14) and a swing driving member (7) for driving the front approach bridge (14) to swing up and down, and the rear end of the trestle main beam (1) is provided with a rear supporting leg (12), a running mechanism (13), a rear approach bridge (15) and a swing driving member (7) for driving the rear approach bridge (15) to swing up and down.

9. The prestressed trestle structure according to claim 8, characterized in that: The front supporting leg (11) is a telescopic structure, a longitudinal moving trolley (16) is provided on the trestle main beam (1), and a telescopic supporting leg (161) is provided on the longitudinal moving trolley (16).

10. The method for tensioning prestressed tendons of a prestressed trestle structure according to any one of claims 1 to 9, characterized in that: The steps include: S1: a prestressed tendon (4) is inserted into the main beam (1) of the trestle, two ends of the prestressed tendon (4) are respectively connected to a first anchor (31) and a second anchor (32), and a strain gauge (41) is attached to the prestressed tendon (4); S2: the prestressed tendon tension adjustment mechanism (9) pulls the second anchor (32) until the tension of the prestressed tendon (4) meets the tensioning condition; S3: the tensioning mechanism (2) pulls the first anchor (31) until the strain gauge (41) shows that the prestress of the prestressed tendon (4) reaches the design value; S4: The limiting mechanism (5) locks the first anchor (31).

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