Model test device and test method for force state of slewing cable at sheave saddle
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CCCC SECOND HIGHWAY CONSULTANTS CO LTD
- Filing Date
- 2025-08-14
- Publication Date
- 2026-07-21
Smart Images
Figure CN121007778B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of bridge engineering testing technology, specifically to a model test device and test method for the stress state of a slewing cable at the saddle. Background Technology
[0002] A suspension bridge is a structure with the main cable as the primary load-bearing component. It transfers the bridge deck load to the main tower and anchorages through a suspension system composed of the main cable and suspenders. Its lightweight structure and elegant design make it suitable as a load-bearing system for long-span bridges. Due to the simplicity of cable-laying technology, it is particularly suitable for crossing complex terrains such as canyons, straits, or wide rivers. The characteristics of a single-tower, single-cable suspension bridge are: the main cable is a single strand, originating from an anchorage on one side of the bridge tower, crossing the river via the main saddle of the tower, bypassing a specially designed slewing anchorage on the opposite bank, and then anchoring back to the anchorage on the originating bank. This single main cable, also known as the slewing main cable, is arranged in a U-shape in plan. The main cable path is: ground anchor - tower top main saddle - slewing saddle - slewing main saddle - slewing saddle - tower top main saddle - ground anchor (e.g., ...). Figure 1 (As shown); a set of slewing cable saddle systems (consisting of two slewing saddles and one slewing main saddle) is specially set up on the slewing anchorage foundation on the opposite bank of the bridge tower. At the slewing anchorage end, the strands of the main slewing cable of the single-tower single-cable suspension bridge after splitting enter the slewing saddle. The strands continuously bypass the slewing cable saddle system, then turn around and return to the ground anchor on the starting bank via the same path through the bridge tower main saddle.
[0003] The unique force mechanism of a single-tower, single-cable suspension bridge has a significant impact on the stress of various components of the bridge structure, differing from that of conventional suspension bridges, especially in the slewing cable saddle system. Revealing the force mechanism of the slewing main cable in the slewing cable saddle system of this type of bridge, and determining the variation law of the main cable's stress state at the slewing saddle, is an important theoretical basis, design basis, and construction guideline for the design and construction of this type of bridge.
[0004] Currently, research on the stress state of the main cable of a single-tower, single-cable suspension bridge within the slewing cable saddle system is virtually nonexistent, particularly lacking effective experimental methods to corroborate the results obtained through computer analysis. Establishing an effective model testing device is crucial for studying the stress state and variation patterns of the main cable of a single-tower, single-cable suspension bridge within the slewing cable saddle system. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a model test device and method for the stress state of a slewing cable at the slewing saddle, thereby enabling simulation tests of different stress states of the main cable of a single-tower single-cable suspension bridge at the slewing saddle.
[0006] To address the aforementioned technical problems, this invention provides a model test device for the stress state of a slewing cable at a slewing saddle, comprising a force-applying mechanism, a horizontal steering device, a slewing saddle device, and an anchoring device. The force-applying mechanism is used to connect to one end of the main cable specimen and apply tension to the main cable specimen. The anchoring device is used to fix the other end of the main cable specimen. The horizontal steering device and the slewing saddle device are arranged between the force-applying mechanism and the anchoring device for winding the main cable specimen. The horizontal steering device is used to turn the main cable specimen from vertical to horizontal and horizontally tangentially into the slewing saddle device. The slewing saddle device is used to simulate a slewing saddle.
[0007] In some embodiments, the horizontal steering device includes a first base, a support is disposed on the first base, and a steering pulley is rotatably disposed on the support, the axis of rotation of the steering pulley being perpendicular to the tangent at the inlet of the saddle device.
[0008] In some embodiments, the angle at which the support is mounted on the first base is adjustable, such that the angle of the rotation axis of the steering pulley is adjustable.
[0009] In some embodiments, the cable saddle device includes a horizontally arranged sector-shaped disk with a saddle groove on its arc side, the saddle groove being used to support the main cable specimen.
[0010] In some embodiments, the sector disk includes a plurality of sector units that are detachably connected to each other, the plurality of sector units are arranged concentrically, the arc sides of two adjacent sector units are smoothly connected, and the plurality of sector units are used to simulate cable saddles at different angles.
[0011] In some embodiments, a base plate is included, the base plate having a third mounting hole, the cable saddle device including a second base, the fan-shaped disk being mounted on the second base, the second base being mounted on the base plate through the third mounting hole, so that the position of the second base is adjustable, thereby simulating the linear changes of the main cable specimen.
[0012] In some embodiments, a top frame is included, which is located above the horizontal steering device. A main tower fixed pulley is provided on the top frame, which is used to simulate the main tower cable saddle. The main cable specimen is wound around the horizontal steering device through the main tower fixed pulley.
[0013] On the other hand, the present invention provides a test method for a model test apparatus utilizing the stress state of the slewing cable at the saddle, comprising:
[0014] Install the main cable specimen, and connect the anchoring device to the main cable specimen through a cable force gauge;
[0015] Adjust the horizontal steering device and the cable saddle device so that the main cable specimen enters and exits tangentially along the cable saddle device;
[0016] The force-applying mechanism pre-tensions the main cable specimen;
[0017] Strain sensors were installed at the points where the main cable specimen entered and exited the cable saddle device.
[0018] The force-applying mechanism clamps the main cable specimen. When the main cable specimen slips in the cable saddle device, the loading stops, and the test ends.
[0019] In some embodiments, combinations of different sector units are used to test the effect of changes in the saddle angle on the stress state of the main cable specimen.
[0020] In some embodiments, the cable saddle device is installed in different positions to conduct tests on the effect of changes in the linear shape of the main cable specimen on the stress state of the main cable specimen.
[0021] The beneficial effects of this invention are as follows:
[0022] 1. This invention constructs a dedicated test platform for the stress mechanism of the slewing cable saddle system of a single-tower, single-cable suspension bridge. By accurately simulating the state transition process of the main cable from vertical to horizontal stress, it realizes the study of the stress state of the slewing main cable at the saddle. This can guide engineering practices such as structural optimization design and construction tensioning technology of the slewing cable saddle system, and provide experimental evidence for computer simulation results.
[0023] 2. By setting an adjustable-angle steering pulley, the present invention not only realizes the state transformation of the main cable specimen from vertical plane force to horizontal force, but also ensures that the main cable specimen enters the cable saddle device tangentially.
[0024] 3. The angles of the second base and support of the present invention are adjustable, realizing the tangential movement of the cable saddle device and the calibration of the tangential entry and exit of the main cable specimen, effectively simulating the influence of the spatial linear change of the main cable on the force.
[0025] 4. The present invention adopts a modular fan-shaped disk unit design, which can quickly replace the fan-shaped disks with different central angles and accurately analyze the impact of the change of the cable saddle angle on the main cable force. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the single-tower, single-cable suspension bridge of the present invention;
[0027] Figure 2 This is a schematic diagram of the structure of the model test device of the present invention;
[0028] Figure 3 This is a side view of the horizontal steering device of the present invention;
[0029] Figure 4 This is a top view of the horizontal steering device of the present invention;
[0030] Figure 5 This is a schematic diagram of the structure of the sector-shaped disk of the present invention;
[0031] Figure 6 This is a schematic diagram of the saddle groove of the present invention;
[0032] Figure 7 This is a schematic diagram of the structure of the anchoring steel plate of the present invention;
[0033] Figure 8 This is a schematic diagram of the experiment conducted using module one of the present invention;
[0034] Figure 9 This is a schematic diagram of the experiment conducted using module two in this invention;
[0035] Figure 10 This is a schematic diagram illustrating the experiment conducted using Module 1 and Module 2 in this invention;
[0036] Figure 11 This is a schematic diagram of the sector-shaped disk of the present invention in the reference position;
[0037] Figure 12 This is a schematic diagram of the fan-shaped disk of the present invention moving 10cm in the direction of the rotating main saddle;
[0038] Figure 13 This is a schematic diagram of the fan-shaped disk of the present invention moving 10cm towards the main tower.
[0039] Reference numerals: 1. Force application mechanism; 2. Horizontal steering device; 21. First base; 22. Support; 23. Steering pulley; 24. First mounting hole; 3. Cable saddle device; 3. Second base; 31. Fan-shaped disk; 32. Saddle groove; 321. Module 1; 33. Module 2; 34. Anchoring device; 4. Anchoring steel plate; 41. Anchoring hole; 411. Base plate; 5. Third mounting hole; 51. Top frame; 6. Main tower pulley; 7. Transition pulley; 8. Main cable specimen; 9. Cable force gauge; 10. Strain sensor; 11. Detailed Implementation
[0040] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0041] like Figure 1 As shown, the stress state of the main cable changes from vertical plane stress to horizontal stress from the main saddle at the top of the tower (i.e., the main tower cable saddle) to the slewing main saddle, and its stress situation is relatively complex. Therefore, this invention establishes a model test device for the part of the stress state change.
[0042] like Figure 2As shown, this invention provides a model test device for the stress state of a slewing cable at a cable saddle, including a base plate 5 and a top frame 6. The top frame 6 is connected to the base plate 5 via columns. A force application mechanism 1, a horizontal steering device 2, and a cable saddle device 3 are installed on the base plate 5. An anchoring device 4 is installed on the columns. A main tower fixed pulley 7 and a transition fixed pulley 8 are installed on the top frame 6. One end of the main cable specimen 9 is connected to the force application mechanism 1, and the other end of the main cable specimen 9 passes sequentially around the transition fixed pulley 8, the main tower fixed pulley 7, the horizontal steering device 2, and the cable saddle device 3 before being connected to the anchoring device 4.
[0043] The force application mechanism 1 uses a hydraulic servo to apply tension to the main cable specimen 9. The main tower fixed pulley 7 and the transition fixed pulley 8 are arranged above the force application mechanism 1. The rotation axes of the main tower fixed pulley 7 and the transition fixed pulley 8 are parallel and located in the same plane. The transition fixed pulley 8 is used to ensure that the main cable specimen 9 is consistent with the direction of actuation of the hydraulic servo, that is, to ensure that the part of the main cable specimen 9 located between the transition fixed pulley 8 and the hydraulic servo is always vertical. The main tower fixed pulley 7 is used to simulate the cable saddle at the top of the main tower in an actual suspension bridge.
[0044] The top frame 6 can adopt a gantry frame or other structure, and the main tower fixed pulley 7 and the transition fixed pulley 8 can move horizontally and vertically on the horizontal plane.
[0045] like Figure 2 As shown, the horizontal steering device 2 includes a first base 21, a support 22, and a steering pulley 23. The first base 21 is fixed to the base plate 5 by welding or bolts. Figure 3 As shown, the support 22 is bolted to the top surface of the first base 21, and the steering pulley 23 is rotatably mounted on the support 22, as shown. Figure 4 As shown, the top of the first base 21 has an arc-shaped first mounting hole 24. The support 22 is fixed to the first base 21 by bolts that mate with the first mounting hole 24. Because the first mounting hole 24 is arc-shaped, the angle of the support 22 can be adjusted as needed, thereby adjusting the angle of the steering pulley 23. Figure 2 As shown, the main cable specimen 9 is wound around the steering pulley 23. The angle of the steering pulley 23 determines the direction of the main cable specimen 9 when it leaves the steering pulley 23. The part of the main cable specimen 9 located between the main tower fixed pulley 7 and the steering pulley 23 can be arranged vertically or inclined as needed. The part of the main cable specimen 9 located between the main tower fixed pulley 7 and the steering pulley 23 is subjected to vertical plane force. After the steering action of the steering pulley 23, the main cable specimen 9 becomes horizontally arranged, so that the main cable specimen 9 becomes a horizontally subjected state.
[0046] like Figure 2As shown, the cable saddle device 3 includes a second base 31 and a sector-shaped disk 32. A third mounting hole 51 is provided on the base plate 5. The second base 31 is fixed to the base plate 5 by bolts and the third mounting hole 51. A second mounting hole is provided on the top of the second base 31. The sector-shaped disk 32 is fixed to the top of the second base 31 by bolts and the second mounting hole. Figure 6 As shown, a saddle groove 321 is formed on the arc-shaped side of the sector-shaped disk 32. After the main cable specimen 9 leaves the steering pulley 23, it is horizontally wound in the saddle groove 321. The sector-shaped disk 32 is used to simulate the cable saddle, and the stress state of the main cable specimen 9 at the sector-shaped disk 32 is similar to that in the actual situation. Multiple sets of the second and third mounting holes 51 can be set according to experimental requirements, making the position of the second base 31 on the base plate 5 adjustable, and the position of the sector-shaped disk 32 on the second base 31 adjustable.
[0047] To simulate cable saddles at different angles, the sector-shaped disk 32 of this invention includes multiple sector-shaped units, which are detachably connected and arranged concentrically, with the arc sides of adjacent sector-shaped units smoothly connected. Figure 5 The diagram illustrates two sector-shaped units, Module 1 (33) and Module 2 (34). Both Module 1 (33) and Module 2 (34) are bolted to the second base 31. Module 1 (33) has a lug on its side, and Module 2 (34) has a clearance groove on its upper surface that mates with the lug, allowing the lug to be inserted into the groove. Both the lug and the clearance groove have threaded holes, allowing Module 1 (33) and Module 2 (34) to be securely connected using bolts. Similarly, when three, four, or more sector-shaped units are used, a lug can be provided on one side of each sector-shaped unit, and a clearance groove can be provided on the top of the other side, allowing multiple sector-shaped units to be connected sequentially.
[0048] like Figure 7 As shown, the anchoring device 4 includes two anchoring steel plates 41. Multiple waist-shaped holes are opened on the anchoring steel plates 41. The two anchoring steel plates 41 are fixed to both sides of the column by bolts. An anchoring holes 411 are opened on the anchoring steel plate 41 near the cable saddle device 3. The main cable specimen 9 can pass through the anchoring hole 411 and be connected to the other anchoring steel plate 41, which is suitable for the anchoring needs of different numbers of steel wires.
[0049] The model test device for the stress state of the slewing cable at the slewing saddle can be used to conduct tests on the influence of changes in the slewing saddle angle and the influence of changes in the main cable alignment.
[0050] Test methods for investigating the effects of changes in the cable saddle angle include:
[0051] S1. Select the corresponding sector element based on the required cable saddle angle for analysis, for example, ... Figure 8 As shown, you can first select module 1.33 (simulate a central angle of 25.633°).
[0052] S2. Fix one end of the main cable specimen 9 to the pull ring of the hydraulic servo, and let the other end go vertically upward around the transition fixed pulley 8, then around the main tower fixed pulley 7, the steering fixed pulley 23, and the cable saddle device 3 in sequence, and finally pass through the anchor hole 411 of the anchoring steel plate 41 near the cable saddle device 3, and anchor it to the anchoring steel plate 41 away from the cable saddle device 3. Install the cable force gauge 10 between the anchoring steel plate 41 away from the cable saddle device 3 and the main cable specimen 9.
[0053] S3. Adjust the position of the second base 31 so that the tangent at the outlet of the cable saddle device 3 is perpendicular to the anchoring steel plate 41. The outlet of the cable saddle device 3 is the end of the saddle groove 321 of the fan-shaped disk 32 that is close to the anchoring steel plate 41. Adjust the support 22 so that the rotation axis of the steering pulley 23 is perpendicular to the tangent at the inlet of the cable saddle device 3. The inlet of the cable saddle device 3 is the end of the saddle groove 321 of the fan-shaped disk 32 that is away from the anchoring steel plate 41, thereby ensuring that the main cable specimen 9 enters and exits tangentially along the cable saddle model.
[0054] S4. Adjust the hydraulic servo, pre-tension the main cable specimen 9 to eliminate nonlinear effects, and test the anchorage strength.
[0055] S5. Attach strain sensors 11 to the inlet and outlet positions of the main cable specimen 9 near the cable saddle device 3;
[0056] S6. The main cable specimen 9 was initially tensioned using a hydraulic servo device, followed by graded loading, and strain and stress data were recorded respectively. The first loading tension was 10% of the cable strand breaking strength, and the load was increased step by step thereafter.
[0057] S7. When the main cable specimen 9 slips in the saddle groove 321, stop the machine, record the strain and stress data of the main cable specimen 9 throughout the process, and complete one test; the method for judging whether slip has occurred is: by real-time monitoring of the load-displacement curve recorded in the test, if there is an obvious change in the curve (such as a sudden change in value, a change in slope, etc.), it can be considered that slip has occurred, and the test should be stopped.
[0058] S8. Replace Module 1 33 in step S1 with Module 2 34 (simulating a central angle of 51.266°) and Module 1 33 + Module 2 34 (simulating a central angle of 76.899°), as follows: Figure 9 , 10 As shown, repeat steps S1-S7 to continue testing the remaining two central angles.
[0059] Test methods for assessing the impact of main cable shape variations include:
[0060] S1, such as Figure 11 As shown, determine the reference position of the sector disk 32, and select the corresponding sector unit according to the required analysis of the cable saddle angle;
[0061] S2. Fix one end of the main cable specimen 9 to the pull ring of the hydraulic servo, and let the other end go vertically upward around the transition fixed pulley 8, then around the main tower fixed pulley 7, the steering fixed pulley 23, and the cable saddle device 3 in sequence, and finally pass through the anchor hole 411 of the anchoring steel plate 41 near the cable saddle device 3, and anchor it to the anchoring steel plate 41 away from the cable saddle device 3. Install the cable force gauge 10 between the anchoring steel plate 41 away from the cable saddle device 3 and the main cable specimen 9.
[0062] S3. Adjust the position of the second base 31 so that the tangent at the outlet of the cable saddle device 3 is perpendicular to the anchoring steel plate 41. The outlet of the cable saddle device 3 is the end of the saddle groove 321 of the fan-shaped disk 32 that is close to the anchoring steel plate 41. Adjust the support 22 so that the rotation axis of the steering pulley 23 is perpendicular to the tangent at the inlet of the cable saddle device 3. The inlet of the cable saddle device 3 is the end of the saddle groove 321 of the fan-shaped disk 32 that is away from the anchoring steel plate 41, thereby ensuring that the main cable specimen 9 enters and exits tangentially along the cable saddle model.
[0063] S4. Adjust the hydraulic servo, pre-tension the main cable specimen 9 to eliminate nonlinear effects, and test the anchorage strength.
[0064] S5. Attach strain sensors 11 to the inlet and outlet positions of the main cable specimen 9 near the cable saddle device 3;
[0065] S6. The main cable specimen 9 was initially tensioned using a hydraulic servo device, followed by graded loading, and strain and stress data were recorded respectively. The first loading tension was 10% of the cable strand breaking strength, and the load was increased step by step thereafter.
[0066] S7. When the main cable specimen 9 slides in the saddle groove 321, stop the machine, record the strain and stress data of the main cable specimen 9 throughout the process, and complete the test corresponding to the reference position.
[0067] S8. Move the second base 31 10cm tangentially towards the main saddle (i.e., the direction of the anchoring steel plate 41) and the main tower (i.e., the direction of the horizontal steering device 2), respectively. Figure 12 , 13 As shown, the tangential direction of the cable saddle is the direction of the tangent line at the midpoint of the arc-shaped side of the cable saddle device 3. Figure 7 As shown, the position of the anchoring steel plate 41 is adjusted by using the waist-shaped hole of the anchoring steel plate 41 to achieve a coarse adjustment of the connection angle between the main cable specimen 9 and the anchoring device 4. The main cable specimen 9 is passed through different anchoring holes 411 on the anchoring steel plate 41 to achieve a fine adjustment of the connection angle between the main cable specimen 9 and the anchoring device 4, so that the main cable specimen 9 leaves the cable saddle device 3 tangentially. Repeat steps S1-S7 to complete the test of different line shapes.
[0068] S9. Replace the sector unit in step S1, change the angle of sector disk 32, and repeat steps S1-S8 to complete the test of different linear shapes under other central angles.
[0069] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A model test device for the stress state of a slewing cable at the saddle, characterized in that: The system includes a force-applying mechanism (1), a horizontal steering device (2), a cable saddle device (3), an anchoring device (4), a base plate (5), and a top frame (6). The top frame (6) is connected to the base plate (5) via columns. The force-applying mechanism (1), the horizontal steering device (2), and the cable saddle device (3) are installed on the base plate (5). The anchoring device (4) is installed on the columns. The top frame (6) is equipped with a main tower fixed pulley (7) and a transition fixed pulley (8). One end of the main cable specimen (9) is connected to the force-applying mechanism (1). The force-applying mechanism (1) is used to apply tension to the main cable specimen (9). The anchoring device (4) is used to fix the other end of the main cable specimen (9). The anchoring device (4) is connected to the main cable specimen (9) via a cable force gauge (10). Next, the horizontal turning device (2) and the cable saddle device (3) are arranged between the force application mechanism (1) and the anchoring device (4) for the winding of the main cable specimen (9). The horizontal turning device (2) is used to turn the main cable specimen (9) from vertical to horizontal and enter the cable saddle device (3) horizontally and tangentially. The cable saddle device (3) is used to simulate the cable saddle. The main tower fixed pulley (7) is used to simulate the main tower cable saddle. The other end of the main cable specimen (9) passes through the transition fixed pulley (8), the main tower fixed pulley (7), the horizontal turning device (2), and the cable saddle device (3) in sequence, and then connects to the anchoring device (4). Strain sensors (11) are installed at the positions where the main cable specimen (9) enters and leaves the cable saddle device (3). The horizontal steering device (2) includes a first base (21), a support (22) is provided on the first base (21), and a steering pulley (23) is rotatably provided on the support (22). The rotation axis of the steering pulley (23) is perpendicular to the tangent at the inlet of the saddle device (3). The angle at which the support (22) is mounted on the first base (21) is adjustable, so that the angle of the rotation axis of the steering pulley (23) is adjustable; The cable saddle device (3) includes a horizontally arranged fan-shaped disk (32), and a saddle groove (321) is opened on the arc side of the fan-shaped disk (32), which is used to support the main cable test piece (9).
2. The model test device for the stress state of the slewing cable at the saddle according to claim 1, characterized in that: The sector disk (32) includes multiple sector units, which are detachably connected to each other. The multiple sector units are arranged concentrically, and the arc sides of two adjacent sector units are smoothly connected. The multiple sector units are used to simulate cable saddles at different angles.
3. The model test device for the stress state of the slewing cable at the saddle according to claim 1, characterized in that: The base plate (5) has a third mounting hole (51). The cable saddle device (3) includes a second base (31). The fan-shaped disk (32) is mounted on the second base (31). The second base (31) is mounted on the base plate (5) through the third mounting hole (51), so that the position of the second base (31) is adjustable, thereby simulating the linear change of the main cable specimen (9).
4. A test method for a model test apparatus for the stress state of a slewing cable at a saddle according to any one of claims 1 to 3, characterized in that: include: Install the main cable test piece (9), and connect the anchoring device (4) to the main cable test piece (9) through the cable force gauge (10); Adjust the horizontal steering device (2) and the cable saddle device (3) so that the main cable specimen (9) enters and exits tangentially along the cable saddle device (3); The force-applying mechanism (1) pre-tensions the main cable specimen (9); Strain sensors (11) are installed at the positions where the main cable specimen (9) enters and leaves the cable saddle device (3). The force-applying mechanism (1) applies load to the main cable specimen (9). When the main cable specimen (9) slides in the cable saddle device (3), the loading stops and the test ends.
5. The test method according to claim 4, characterized in that: By using combinations of different sector units, an experiment was conducted to investigate the effect of changes in the angle of the cable saddle on the stress state of the main cable specimen (9).
6. The test method according to claim 5, characterized in that: The cable saddle device (3) was installed in different positions to test the effect of the change in the linear shape of the main cable specimen (9) on the stress state of the main cable specimen (9).