Scale rotary cable anchoring loading device and testing method

Abstract

This invention relates to a scaled-down rotating cable anchoring loading device and testing method, belonging to the field of civil engineering structural testing and measurement. It addresses problems such as eccentric loading, impure force distribution, unstable load, and poor spatial adaptation in traditional scaled-down models. The device comprises a box, a pulley guiding mechanism, a steel beam, and a top loading device. The box is secured to the scaled-down anchors using clamps or backfill. The pulley guiding mechanism consists of guide rails, a sliding table, vertical pulleys, and two sets of horizontal traction pulleys, allowing for three-dimensional adjustment to ensure the horizontal guidance of the cable. The top loading device employs a jack structure, using a lifting piston rod to vertically raise and lower the loading arm synchronously, applying horizontal tension and possessing a self-locking pressure-holding function, enabling long-term stable load holding. The testing method involves device installation, anchor and cable placement, pulley leveling, pre-loading, self-locking pressure holding, and data acquisition to complete the test. This invention achieves pure horizontal, high-precision, stable, and controllable loading. It features a compact structure, simple operation, and accurate acquisition of mechanical parameters, making it suitable for cable anchored scaled-down model testing.

Description

Technical Field

[0001] This invention relates to the field of civil engineering structural testing and measurement technology, and in particular to a scaled-down rotating cable anchoring loading device and testing method. Background Technology

[0002] In the design and research of long-span bridges, such as suspension and cable-stayed bridges, scaled-down model tests play an irreplaceable role as a crucial means of studying bridge structural behavior and verifying design parameters. The simulation of bridge cable systems, especially the anchorage and tensioning systems of the main cables or stay cables, is directly related to the safety and durability assessment of bridge structures. In actual engineering projects, the main cables must withstand horizontal tensile forces of thousands or even tens of thousands of tons, which are transmitted to the foundation through the anchorage structure. Therefore, accurately simulating the mechanical response of anchorages under horizontal loads is of paramount importance for evaluating the load-bearing capacity, deformation characteristics, fatigue performance, and failure modes of the anchorage system.

[0003] Currently, traditional loading methods for scaled-down models mainly include direct tensioning with jacks, suspended weights, and some guide systems using fixed-position pulleys. While direct tensioning with jacks can provide significant tensile force, its loading axis is difficult to precisely align with the cable axis, especially within the confined space of a scaled-down model. Even slight eccentricity can generate significant additional bending moments on the anchors, causing the measured stress distribution to deviate severely from the actual working conditions. Furthermore, jack equipment is bulky and heavy, making it difficult to arrange flexibly on miniaturized model test benches, and requires complex reaction frame systems.

[0004] The suspended weight method applies tension by suspending a weight using pulleys. While structurally simple, it has significant drawbacks. First, the load is limited by the weight's mass, making continuous adjustment impossible. Second, the suspension system requires substantial vertical space, making it difficult to implement in laboratory environments with limited ceiling height. More importantly, this method cannot precisely apply a purely horizontal force; the angle between the suspension cable and the horizontal direction changes with model deformation, introducing uncontrollable vertical forces and affecting the accuracy of the test results.

[0005] Some existing studies use fixed-position pulleys for guidance, such as the fixed pulley mentioned in the loading device and method for static load testing disclosed in CN103512767A. However, since the pulley position is not adjustable, it cannot adapt to the test requirements of different anchoring heights and angles. During the loading process, the fixed pulley will experience frictional fluctuations due to changes in the cable path, affecting the accurate transmission of influence and thus the reliability of the test data.

[0006] For example, CN121224914A discloses a tensioning device and method for anchor cables. Although it provides a tensioning device that reduces the tension required by the tensioning device through a chain stopper and a lifting pulley mechanism, it is mainly aimed at tensioning anchor cables, rather than the precise application of horizontal force in a scaled-down model. Furthermore, when simulating the transmission of horizontal force in the main cable at the anchorage, this device still lacks an effective means to apply a precise, stable, directional, and long-term maintained horizontal force in a compact mechanism within a small-scale space.

[0007] For example, CN121877433A discloses a load testing platform for a jacking system. Although it provides a load testing platform for a jacking system capable of simultaneously applying vertical and lateral loads, its design is primarily for jacking systems, not for the anchoring and tensioning of bridge cable systems. Therefore, when simulating the horizontal force transmission of the main cable at the anchorage, this platform also cannot meet the requirements of accuracy, stability, constant direction, and long-term maintenance of horizontal force.

[0008] More critically, existing technologies generally lack an effective means to apply a precise, stable, directional, and long-term sustained horizontal force within a small-scale space using a compact mechanism. This technological gap severely restricts the accuracy and reliability of scaled-down model tests of anchoring systems, making it difficult for test data to accurately reflect the mechanical performance of anchors under actual working conditions, thus affecting the safety assessment of bridge designs.

[0009] Furthermore, current traditional scaled-down rotary cable anchorage testing devices generally suffer from problems such as manual screws or simple lever structures in the loading mechanism, which easily lead to issues like loading eccentricity, impure force distribution, and large load fluctuations. The pulley guiding system is fixed and cannot be adjusted, making it difficult to adapt to different model sizes and cable routes, and easily generating vertical components and lateral offsets, resulting in distorted test data. At the same time, conventional devices lack stable self-locking pressure holding functions, failing to meet key testing requirements such as long-term load holding, creep, and fatigue, and thus have limited applicability.

[0010] Existing devices generally suffer from insufficient support stiffness, loose structural layout, cumbersome adjustment, and inconvenient assembly and disassembly, making it difficult to simultaneously meet diverse testing requirements such as static loading, cyclic loading, and ultimate bearing capacity testing. These problems severely restrict test accuracy and data reliability, failing to provide precise support for bridge anchorage design. Therefore, developing a scaled-down rotating cable anchorage loading device and testing method that offers pure loading, precise guidance, stable load holding, and strong versatility has significant practical engineering needs and scientific research value. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a scaled-down rotating cable anchoring loading device and testing method, which solves the technical problems of cable loading eccentricity, impure force, and difficulty in maintaining stable load in traditional scaled-down model tests, and realizes a pure horizontal, high-precision, and long-term load-bearing cable anchoring performance test.

[0012] To achieve the above technical objectives, the present invention adopts the following technical solution: This invention provides a scaling-down rotating cable anchoring and loading device, which includes a housing, a pulley guide mechanism, and a steel beam mounted thereon. The housing is fixed with scaling-down anchors by mounting clamps or internal backfill, and the scaling-down anchors are connected to the cable. The pulley guide mechanism includes a guide rail, on which several sliding tables are mounted. The sliding tables can move and be positioned along the guide rail. Vertical pulleys, a first horizontal pulley, and a second horizontal pulley are respectively mounted on the guide rail and the sliding tables. A top loading device is mounted on the steel beam. The top loading device adopts a jack structure and is equipped with a lifting piston rod. The lifting piston rod rises and falls vertically and drives the loading arm to rise and fall synchronously. Several traction pulleys are also mounted on the steel beam.

[0013] The enclosure is constructed from welded steel plates, and its internal dimensions were determined based on the experimental scaling ratio. The first horizontal pulley, vertical pulley, and second horizontal pulley are all installed in pairs, independently adjustable via a sliding table and fixed to the guide rail with bolts. The first and second horizontal pulleys are installed vertically, while the vertical pulley is arranged horizontally; the three are staggered to achieve three-dimensional guidance of the cable, ensuring the cable remains horizontally stressed during loading. Each pulley is equipped with a pulley seat, and the pulley is rotatably mounted on the seat.

[0014] The top loading device also includes a fixed base mounted on a steel beam. The cylinder is vertically fixed above the fixed base, and the lifting piston rod is coaxially positioned inside the cylinder and performs linear telescoping motion in the vertical direction. A self-locking pressure-holding device is installed at the top of the lifting piston rod to maintain a constant load after loading is complete, achieving long-term stable load holding. A cross-shaped through-hole is radially located in the middle of the lifting piston rod, with a loading arm horizontally installed in one of the through-holes. The loading arm has an H-shaped structure, with guide holes in the middle of the vertical rods at both ends. Bushings are installed in the guide holes for threading and protecting cables. A steel base is located at the bottom of the steel beam, forming a support structure, and is installed on one side of the housing.

[0015] This invention also discloses a method for testing the anchorage of a scaled-down rotary cable, implemented using the aforementioned device. The steps include: device installation and leveling, anchor and cable arrangement, pulley position adjustment, pre-tightening loading and self-locking pressure maintenance, data acquisition, and mechanical performance testing. Before loading, a calibration test is conducted to establish a calibration curve of the lifting amount of the lifting piston rod and the cable tension, achieving precise load control. The mechanical performance testing includes cyclic loading tests and ultimate bearing capacity tests, which can obtain the fatigue characteristics, deformation patterns, ultimate bearing capacity, and failure modes of the anchorage system, providing reliable experimental basis for bridge cable anchorage design and safety assessment.

[0016] The present invention provides a scaling rotary cable anchoring loading device and testing method, which have the following beneficial effects: 1. This invention adopts a jack-type top loading device with pure vertical lifting. Through the structural design of the cylinder and piston rod coaxial linear cooperation, it fundamentally avoids the problems of deflection, swing and eccentricity during the loading process, ensuring the precise direction of the tensile force application and the pure force state, and greatly improving the loading stability and data reliability of the scale anchoring test.

[0017] 2. The present invention is equipped with a self-locking pressure-holding device in the top loading device, which can automatically lock the load and maintain constant pressure after loading is in place, and can achieve long-term stable load holding, effectively meeting the stringent requirements for load holding conditions in anchorage structure creep test, fatigue performance test, long-term durability performance test, etc.

[0018] 3. This invention uses a hydraulic jack or an electric jack as the core loading structure. The loading process is stable and continuous, with uniform force output and no impact. It can avoid the load fluctuations and systematic errors caused by traditional manual loading, significantly improve the authenticity, accuracy and repeatability of test data, and is suitable for high-precision scaled model tests.

[0019] 4. The present invention designs a three-dimensional adjustable pulley guide mechanism. Through the cooperation of a movable slide table and a linear guide rail, the installation positions of the first horizontal pulley, the vertical pulley, and the second horizontal pulley can be freely adjusted to flexibly adapt to different model sizes and cable routes, ensuring that the cable remains in a horizontal stress state throughout the loading process.

[0020] 5. This invention provides a dedicated pulley seat structure for all guide pulleys, which allows the pulleys to rotate flexibly on the pulley seat with low frictional resistance. This effectively reduces the wear and damage of the cable during the guiding process, while also reducing test errors caused by system friction, and improving loading accuracy and the service life of the test components.

[0021] 6. The present invention adopts a pulley structure that combines vertical installation and horizontal arrangement, so that the first horizontal pulley, the second horizontal pulley and the vertical pulley form a three-dimensional guide, which completely eliminates the vertical component force, lateral offset and torsional tendency when the cable is under force, and ensures that the tension direction is pure and the force state is ideal.

[0022] 7. The present invention adopts a structure in which the linear guide rail and the slide table are precisely matched, which can realize stepless adjustment of the pulley position and bolt locking fixation. It has high positioning accuracy and convenient adjustment, and can quickly adapt to test models with different scale ratios and different anchoring forms, significantly improving the versatility and adaptability of the device.

[0023] 8. The present invention constructs a rigid support structure composed of a steel base and steel beams, which has high overall rigidity, strong load-bearing capacity, and minimal deformation under stress. It can keep the device stable without shaking or shifting under high load conditions, providing a reliable structural foundation for high-precision, high-load scaled anchoring tests.

[0024] 9. The present invention adopts a box structure formed by welding thick steel plates, which has high overall strength, good sealing performance and stable rigidity. The scaled anchor can be fixed by either internal soil filling or external clamps. It is compatible with various test scenarios such as rock and soil anchoring and concrete structure anchoring, and has a wide range of applications.

[0025] 10. The present invention designs an H-shaped cross-section loading arm structure, which has balanced force, strong bending resistance, and is not easily deformed during long-term use. The vertical rods at both ends are provided with guide holes and wear-resistant bushings, which can stably thread the cable and provide effective protection, avoiding the cable from being squeezed or scratched and affecting the test results.

[0026] 11. This invention adopts a motion structure in which the lifting piston rod and the cylinder are coaxially linearly coupled. The movement gap is small, the operation is smooth without jamming, swaying, or radial shaking, and the movement is truly pure vertical lifting motion. This ensures accurate and direct force transmission and improves the overall accuracy of the test system.

[0027] 12. The present invention optimizes the layout of the overall device, resulting in a compact structure, high integration, high space utilization, and a small footprint. It is particularly suitable for the limited space environment of laboratory scaled-down model tests, and also facilitates the arrangement of sensors, observation equipment and auxiliary test devices.

[0028] 13. The present invention sets up matching traction pulleys on the steel beam for multi-stage auxiliary guidance, which can adapt to the cable winding requirements of different lengths, heights and directions. It can complete the test of various anchoring forms without additional modification, greatly improving the versatility and flexibility of the device.

[0029] 14. This invention introduces a pre-loading calibration test method, which establishes a correspondence between the lifting amount of the lifting piston rod and the cable tension to achieve precise quantitative control of the load, effectively eliminates systematic errors, improves the test loading accuracy, and meets the requirements of high-precision anchoring tests at the scientific research level.

[0030] 15. This invention adopts a modular and detachable structural design. The components are reliably connected and easy to assemble and disassemble, enabling rapid assembly and transportation. It can be used in a fixed position in the laboratory or transported to the site to quickly build an experimental platform, meeting the testing needs of multiple scenarios and locations.

[0031] 16. This invention is compatible with multiple test loading modes and can carry out all types of anchorage performance tests, such as static graded loading, cyclic loading, fatigue loading, ultimate bearing capacity test, and long-term load creep test. One set of equipment can meet multiple scientific research and testing needs and has a high cost performance.

[0032] 17. The components of this invention adopt standardized and universal design, with simple structure, low processing difficulty, controllable manufacturing cost, convenient installation and maintenance, and easy replacement of vulnerable parts. It is suitable for mass production and wide-ranging application, and can effectively reduce the equipment cost of scale anchoring test.

[0033] 18. The present invention constructs a test system that is easy to operate, safe and stable. The overall control logic is clear and the operation process is simple. No complicated professional skills are required to complete the entire process of installation, debugging, loading and data acquisition, which significantly improves test efficiency and reduces the difficulty of test operation. Attached Figure Description

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a side view of the overall structure of the device of the present invention; Figure 3 This is a top view of the overall structure of the device of the present invention; Figure 4 This is a detailed structural diagram of the top loading device of the present invention; Figure 5 This is a schematic diagram showing the detailed structure of the pulley of the present invention; In the diagram: 1. Box body; 2. Steel base; 3. Steel beam; 4. First horizontal pulley; 5. Vertical pulley; 6. Second horizontal pulley; 7. Traction pulley; 8. Top loading device; 9. Slide table; 10. Guide rail; 11. Cable; 12. Fixed base; 13. Cylinder body; 14. Lifting piston rod; 15. Self-locking pressure holding device; 16. Loading arm. Detailed Implementation

[0035] The technical solutions of the present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1 like Figures 1 to 3 As shown, this embodiment provides a scaled-down rotary cable anchoring and loading device. This device consists of a housing 1, a support structure, a pulley guide mechanism, a traction pulley 7, and a top loading device 8. Through adjustable guidance and vertical lifting loading, it achieves purely horizontal, high-precision, stable, and controllable cable tension application. The specific structure is described below: like Figure 1As shown, the box 1 is made of welded steel plate, and its internal dimensions are determined according to the test scaling ratio. It is used to place the scaling anchors. The box 1 is fixed with the scaling anchors by clamping with installation clamps or by filling the inside with soil. The scaling anchors are connected by cable 11.

[0036] like Figure 1 and Figure 2 As shown, a steel base 2 is installed at the bottom of the steel beam 3. The steel base 2 and the steel beam 3 form a rigid support structure and are installed on one side of the box 1 to provide stable support for the whole device.

[0037] like Figure 1 , Figure 3 and Figure 5 As shown, the pulley guiding mechanism includes a guide rail 10, which is horizontally fixed on the steel beam 3. Several sliding tables 9 are mounted on the guide rail 10, and these tables can move horizontally along the guide rail 10 and are locked to the guide rail 10 with bolts. A first horizontal pulley 4, a vertical pulley 5, and a second horizontal pulley 6 are respectively mounted on the guide rail 10 via the sliding tables 9. The first horizontal pulley 4, vertical pulley 5, and second horizontal pulley 6 are all arranged in pairs and their positions can be independently adjusted via the sliding tables 9. The first horizontal pulley 4 and second horizontal pulley 6 are installed vertically, while the vertical pulley 5 is arranged horizontally. The three are arranged in an alternating pattern to form a three-dimensional guiding structure, ensuring that the cable 11 remains horizontally stressed during loading.

[0038] like Figure 5 As shown, the first horizontal pulley 4, the vertical pulley 5, the second horizontal pulley 6, and the traction pulley 7 are all equipped with pulley seats. The pulleys are rotatably mounted on the pulley seats, which ensures smooth rotation and low friction, thus guaranteeing the stable operation of the cable 11.

[0039] like Figure 1 and Figure 3 As shown, several traction pulleys 7 are also installed on the steel beam 3 to assist in guidance and further straighten the direction of the cable 11.

[0040] like Figure 4 As shown, the top loading device 8 adopts a hydraulic jack structure, including a fixed base 12, a cylinder 13, a lifting piston rod 14, a self-locking pressure-holding device 15, and a loading arm 16. The fixed base 12 is fixedly installed on the steel beam 3, and the cylinder 13 is vertically fixed above the fixed base 12. The lifting piston rod 14 is coaxially arranged inside the cylinder 13 and can perform purely linear extension and retraction in the vertical direction. The self-locking pressure-holding device 15 is installed at the top of the lifting piston rod 14, which maintains a constant load after loading is in place, achieving long-term stable load holding. A cross-shaped through hole is radially opened in the middle of the lifting piston rod 14, and the loading arm 16 is horizontally installed in one of the through holes. The loading arm 16 has an H-shaped structure, with guide holes in the middle of the vertical rods at both ends. Bushings are installed in the guide holes for threading and protecting the cable 11. When the lifting piston rod 14 lifts and lowers vertically, it drives the loading arm 16 to lift and lower synchronously, applying a horizontal tension to the cable 11.

[0041] Example 2 In another preferred embodiment, based on Embodiment 1, this embodiment provides a scaled-down rotary cable anchoring device, such as... Figures 1 to 3 As shown, this embodiment is a high-precision electrically controlled scaled rotary cable anchoring and loading device. The overall layout is the same as that of Embodiment 1, but the structure and precision are further optimized.

[0042] like Figure 1 , Figure 3 and Figure 5 As shown, the guide rail 10 is a precision linear guide rail. The slide table 9 and the guide rail 10 have high precision and move smoothly, which can realize the precise positioning of the first horizontal pulley 4, the vertical pulley 5 and the second horizontal pulley 6. Each pulley is equipped with a high-strength pulley seat, and the pulleys rotate flexibly, which is suitable for high-frequency cyclic loading scenarios.

[0043] like Figure 4 As shown, the top loading device 8 adopts an electric jack structure, and the lifting piston rod 14 is driven by a motor, which can realize automatic lifting and precise displacement control; the self-locking pressure holding device 15 adopts an electric self-locking structure, which has stable pressure holding and high reliability, meeting the requirements of cyclic loading and long-term load holding.

[0044] like Figure 4 As shown, the loading arm 16 maintains an H-shaped structure, and the inner bushing of the guide hole is made of wear-resistant material, which can effectively reduce the wear of the cable 11 and extend the test life.

[0045] The remaining structure is the same as in Example 1, and will not be described again here.

[0046] Example 2 In another preferred embodiment, based on Embodiment 1, this embodiment provides a scaled-down rotary cable anchoring device, such as... Figure 1 , Figure 3 and Figure 5 As shown, this embodiment is a portable, detachable, and field-suitable scaled-down rotary cable anchoring and loading device, with a structure further optimized based on Embodiment 1.

[0047] like Figure 1 As shown, the box 1 adopts a modular steel plate welded structure, which can be disassembled and transported. Its internal size can be adapted to various scale models. The scale anchors can be quickly fixed by clamps or backfilling. The anchors are connected by cables 11.

[0048] like Figure 1 and Figure 2 As shown, the steel base 2 and the steel beam 3 are connected by bolts, which can be quickly disassembled and assembled, and the overall support has high rigidity and is easy to transport.

[0049] like Figure 1 , Figure 3 and Figure 5 As shown, the guide rail 10 in the pulley guide mechanism is a quick-release linear guide rail, and the slide table 9 is equipped with a quick-locking handle, allowing adjustment of the positions of the first horizontal pulley 4, the vertical pulley 5, and the second horizontal pulley 6 without tools. Each pulley is equipped with a high-strength pulley seat, allowing the pulleys to rotate flexibly on the pulley seats. The three are arranged in an alternating pattern to form a three-dimensional guide, ensuring that the cable 11 is subjected to horizontal force throughout its entire length. Multiple sets of traction pulleys 7 are installed on the steel beam 3 to adapt to the guiding requirements of cables 11 of different lengths and directions.

[0050] like Figure 4 As shown, the top loading device 8 adopts a split hydraulic / electric dual-purpose jack structure. The fixed base 12 is detachably connected to the steel beam 3, the cylinder body 13 is vertically arranged, and the lifting piston rod 14 can extend and retract vertically. The top is equipped with a self-locking pressure holding device 15, which can realize the switching between manual and electric pressure holding. A cross-shaped through hole is opened in the middle of the lifting piston rod 14 to install the H-shaped loading arm 16. Wear-resistant bushings are installed in the guide holes at both ends to protect the cable 11. The lifting piston rod 14 lifts and lowers purely vertically, driving the loading arm 16 to move synchronously, so as to achieve stable horizontal loading.

[0051] This embodiment is quick to assemble and disassemble, and highly applicable, suitable for indoor model testing, on-site scale testing, and rapid switching between multiple scenarios.

[0052] Example 4 In another preferred embodiment, based on Embodiment 1, this embodiment provides a method for testing the anchoring of a scaled-down slewing cable, employing the scaled-down slewing cable anchoring loading device described in Embodiment 1, combined with... Figures 1-5 The steps for conducting a static loading test on scaled-down anchors are as follows: Step 1: Device Installation like Figure 1 As shown, the box 1 is fixed on the horizontal test platform, and the steel base 2, steel beam 3, pulley guide mechanism, traction pulley 7 and top loading device 8 are installed to complete the overall leveling and fixing.

[0053] Step 2, Component Layout like Figure 1 As shown, the scaled anchor is fixed inside the box 1 by clamps or backfill; one end of the cable 11 is connected to the anchor, and the other end passes through the first horizontal pulley 4, the vertical pulley 5, the second horizontal pulley 6, and the traction pulley 7 in sequence, and finally enters the guide hole of the loading arm 16.

[0054] Step 3, Guidance Calibration like Figure 3 , Figure 5 As shown, adjust the position of each slide 9 on the guide rail 10 to keep the cable 11 horizontally extended, and then lock the slide 9 after confirmation.

[0055] Step 4: Loading and Holding Pressure like Figure 4 As shown, the pre-tightened cable 11 is activated, the top loading device 8 is started, and the lifting piston rod 14 is driven to make a pure vertical lifting motion. The loading arm 16 applies a horizontal tension to the cable 11. After the target load is reached, the self-locking pressure holding device 15 is used to self-lock and hold the pressure.

[0056] Step 5: Data Acquisition To maintain load stability, the specific steps for collecting stress, displacement, and tensile force data are as follows: Example 5 In another preferred embodiment, based on embodiments 1 to 4, this embodiment provides a method for testing the anchoring of a scaled-down slewing cable, employing the scaled-down slewing cable anchoring loading device described in embodiment 2, combined with... Figures 1-5 The steps for conducting a high-performance anchoring test are as follows: Step 1: Device Installation and Calibration like Figure 1 As shown, the installation, leveling and fixing of the box body 1, support structure, pulley guide mechanism, traction pulley 7 and electric top loading device 8 are completed.

[0057] Step 2: Anchor and cable installation like Figure 1 and Figure 5 As shown, fix the tapered anchor, thread the cable 11, adjust the position of the pulley to make the cable 11 horizontal, and lock the slide table 9.

[0058] Step 3: Calibration before loading like Figure 4 As shown, a calibration test was conducted to establish a calibration curve of the lifting amount of the lifting piston rod 14 and the tension of the cable 11, so as to achieve precise load control.

[0059] Step 4: Cyclic Loading Test Start the top loading device 8, control the lifting piston rod 14 to perform reciprocating vertical lifting motion, apply cyclic load, and test the fatigue performance and cumulative deformation of the anchoring system.

[0060] Step 5: Ultimate bearing capacity test Gradually increase the load until the anchor fails, record the ultimate load and failure mode, and complete the full performance test.

[0061] Step 6, End of Experiment Unload the load, shut down the device, remove the components, and restore the device to its initial state.

[0062] Example 6 In another preferred embodiment, based on embodiments 1 to 6, this embodiment provides a method for testing the anchoring of a scaled-down slewing cable, employing the scaled-down slewing cable anchoring loading device described in embodiment 3, combined with... Figures 1-5 The following steps were taken to test the long-term load-bearing and creep performance of the scaled-down anchoring system: Step 1: Install and fix the device like Figure 1 As shown, the box 1 is stably fixed on the test platform, and the assembly and leveling of the steel base 2, steel beam 3, guide rail 10, slide table 9, pulleys, traction pulley 7 and top loading device 8 are completed.

[0063] Step 2: Installation of test specimen and cable like Figure 1 and Figure 5 As shown, a scaling anchor is fixed inside the housing 1, and the cable 11 is passed through the first horizontal pulley 4, the vertical pulley 5, the second horizontal pulley 6 and the traction pulley 7 in sequence, and finally connected to the loading arm 16. The path is adjusted to keep the cable 11 horizontal.

[0064] Step 3: Quick positioning and locking Adjust the position of slide 9 to ensure a smooth guide path, and lock slide 9 to ensure no slippage during loading.

[0065] Step 4: Graded loading and long-term load maintenance like Figure 4 As shown, after the pre-tensioned cable 11 is activated, the top loading device 8 is started, driving the lifting piston rod 14 to rise vertically and apply tension in stages; after each load is in place, it is locked by the self-locking pressure holding device 15 to maintain a constant load.

[0066] Step 5: Creep Data Acquisition Displacement, strain, cable tension, and other data were continuously collected within a set load holding time to observe the creep law and long-term stability of the anchoring structure.

[0067] Step 6: Staged unloading and end of the test After the load is held, control the lifting piston rod 14 to slowly descend and unload in stages; after the test is completed, remove the test piece and restore the device to its initial state.

[0068] In the preferred embodiment, the housing 1 is constructed from welded steel plates, and its internal dimensions are determined based on the test scaling ratio. This design, with the welded steel plates providing housing 1 with high strength and good rigidity, ensures reliable bearing of various forces during the test. Determining the internal dimensions according to the test scaling ratio allows for precise adaptation to test scenarios with different scaling ratios. This enables a more accurate reflection of the stress characteristics of anchors of different sizes when simulating actual anchoring conditions, reducing errors caused by dimensional mismatches. It provides a reliable foundation for the accurate analysis of subsequent test data, allowing the test results to be more realistically applied to practical engineering design and evaluation.

[0069] In the preferred embodiment, the first horizontal pulley 4, the vertical pulley 5, and the second horizontal pulley 6 are all arranged in pairs and independently adjustable via the slide table 9. They are fixed to the guide rail 10 with bolts. The first horizontal pulley 4 and the second horizontal pulley 6 are installed vertically, while the vertical pulley 5 is arranged horizontally. This staggered arrangement achieves three-dimensional guidance for the cable 11, ensuring that the cable 11 remains horizontally stressed during loading. This configuration, with its paired and independently adjustable pulleys, allows for flexible adaptation to different directions of the cable 11, while the bolt fixation ensures the stability of the pulley positions. The three-dimensional guidance ensures uniform stress on the cable 11, avoiding additional stress caused by force skew, reducing the risk of cable 11 damage, improving test accuracy, and allowing the anchor to be tested under conditions closer to actual working conditions, providing a strong guarantee for accurate performance evaluation.

[0070] In the preferred embodiment, the first horizontal pulley 4, the vertical pulley 5, the second horizontal pulley 6, and the traction pulley 7 are equipped with pulley seats, on which pulleys are rotatably mounted. This configuration provides a stable support structure for the pulleys, and the rotatable mounting allows the pulleys to rotate flexibly under load. This effectively reduces friction between the pulleys and the cable 11, lowers energy loss, and ensures smooth movement of the cable 11 during loading. Simultaneously, the stable pulley seats prevent the pulleys from shifting under load, ensuring the accuracy of the force direction on the cable 11, improving the reliability and repeatability of the test, and making the test results more valuable.

[0071] In the preferred embodiment, the top loading device 8 further includes a fixed base 12, which is mounted on the steel beam 3. The cylinder 13 is vertically fixed above the fixed base 12. The lifting piston rod 14 is coaxially disposed inside the cylinder 13 and performs linear telescopic movement in the vertical direction. A self-locking pressure-holding device 15 is provided at the top of the lifting piston rod 14 to maintain a constant load after loading is completed, achieving long-term stable load holding. With the above configuration, the fixed base 12 ensures the stable installation of the cylinder 13, enabling accurate transmission of the loading force. The linear telescopic movement of the lifting piston rod 14 can precisely control the magnitude and direction of the loading force. The self-locking pressure-holding device 15 can prevent the load from slackening or decreasing. In long-term load holding tests, it can continuously and stably apply the load, providing reliable conditions for studying the performance changes of anchors under long-term stress, and enabling the test results to more accurately reflect the long-term stress conditions in actual engineering.

[0072] In the preferred embodiment, the lifting piston rod 14 has a radially arranged cross-shaped through hole in the middle. A loading arm 16 is horizontally installed within one of these holes. The loading arm 16 is H-shaped, with guide holes at the middle of its two vertical rods. Bushings are installed within these guide holes for threading and protecting the cable 11. This arrangement provides the loading arm 16 with flexible installation positions through the cross-shaped through hole, and the H-shaped loading arm 16 has high structural strength and can evenly distribute the loading force. The design of the guide holes and bushings ensures good protection for the cable 11 during threading, reducing wear. Simultaneously, this structure ensures that the loading force is accurately transmitted to the cable 11, resulting in uniform stress on the cable 11, improving the accuracy of the test, and allowing the anchor to be tested under a more reasonable stress state, providing strong support for accurately evaluating its performance.

[0073] In the preferred embodiment, a steel base 2 is provided at the bottom of the steel beam 3, forming a support structure which is installed on one side of the housing 1. This configuration provides the steel beam 3 and steel base 2 with a support structure possessing high strength and good rigidity, effectively withstanding various forces generated during loading. Installed on one side of the housing 1, it helps to rationally distribute the center of gravity of the entire device, enhancing its stability. Under complex conditions such as cyclic loading and ultimate loading, this support structure prevents the device from shaking and deforming, ensuring the relative positional stability of each component during the test, reducing errors caused by device instability, and improving the reliability and safety of the test.

[0074] In the preferred embodiment, a calibration test is conducted before load loading in step 5 to establish a calibration curve relating the lifting amount of the lifting piston rod 14 to the tension of the cable 11, thereby achieving precise load control. This setup, through the calibration test and the establishment of the calibration curve, clearly reveals the correspondence between the lifting amount of the lifting piston rod 14 and the tension of the cable 11. During actual loading, the lifting amount of the lifting piston rod 14 can be accurately controlled according to the required tension, achieving precise load application. This avoids experimental errors caused by inaccurate load control, allows the test to be conducted under more precise conditions, improves the quality of experimental data, provides a reliable basis for accurately analyzing the mechanical properties of the anchor, and helps to further explore the laws governing its performance changes.

[0075] In the preferred embodiment, the mechanical performance testing in step 5 includes cyclic loading tests and ultimate bearing capacity tests. Cyclic loading tests assess fatigue performance and cumulative deformation, while ultimate bearing capacity tests determine the ultimate bearing capacity and failure mode of the anchor. This configuration allows cyclic loading tests to simulate the repeated stress conditions experienced by anchors in actual engineering projects, accurately testing their fatigue performance and cumulative deformation, and understanding their performance changes over long-term use. Ultimate bearing capacity tests determine the maximum load the anchor can withstand and its failure mode, clarifying its ultimate bearing capacity and failure mode. Combining these two tests provides a comprehensive evaluation of the mechanical performance of anchors under different working conditions, offering rich and accurate data support for bridge anchorage design, optimization, and safety assessment.

[0076] In summary, the scaled-down rotating cable anchoring loading device and testing method proposed in this invention effectively solves the technical problems existing in traditional scaled-down model tests, such as loading eccentricity, impure force, difficulty in maintaining stable load, low guiding accuracy, poor device versatility, and limited applicable scenarios. Through structural innovation and functional integration, it overcomes the technical defects of conventional test devices, such as unstable loading, inconvenient adjustment, and large data errors, at their root.

[0077] From a technical implementation perspective, this invention adopts a purely vertical lifting and loading structure driven by hydraulic or electric jacks, combined with a self-locking pressure holding device 15, to achieve loading without deflection or swaying and with a constant load over a long period of time; at the same time, it adopts a three-dimensional adjustable pulley guide and staggered arrangement to ensure that the cable is subjected to horizontal force throughout the entire process, without vertical force component or lateral offset, which greatly improves the loading accuracy and the purity of force.

[0078] From the perspective of system composition, the present invention, through the design of rigid support structure, modular box 1, H-type loading arm 16 and standardized pulley seat, makes the device have high overall rigidity, small deformation, convenient disassembly and assembly, and flexible adjustment. It can be compatible with various scaled models and anchoring forms, and meet the needs of all types of tests such as static, cyclic, fatigue, creep and ultimate bearing capacity, and its versatility and practicality are significantly improved.

[0079] The present invention has a complete technical solution, a reasonable structural design, and a reliable implementation method. It has significant novelty in terms of loading form, guiding system, pressure holding mechanism and overall layout. It has outstanding creativity in terms of test accuracy, scope of application and efficiency. It can provide high-precision and high-stability equipment and methods for scaled-down model tests of bridge cable anchorage, and has important scientific research value and broad engineering application prospects.

Claims

1. A tapered rotary cable anchoring and loading device, characterized in that: It includes a box body (1) and a pulley guide mechanism and a steel beam (3) installed on it; the box body (1) is fixed with a clamp or the box body (1) is filled with soil to fix the tapered anchor, and the tapered anchor is connected with a cable (11); the pulley guide mechanism includes a guide rail (10), and several slides (9) are installed on the guide rail (10). The slides (9) move along the guide rail (10). Vertical pulleys (5), first horizontal pulleys (4) and second horizontal pulleys (6) are installed on the guide rail (10) respectively through the slides (9); a top loading device (8) is installed on the steel beam (3). The top loading device (8) adopts a jack structure and is equipped with a lifting piston rod (14). The lifting piston rod (14) lifts vertically and drives the loading arm (16) to lift synchronously; several traction pulleys (7) are also installed on the steel beam (3).

2. The tapered rotary cable anchoring and loading device according to claim 1, characterized in that: The box (1) is made of welded steel plates, and its internal dimensions are determined according to the experimental scaling ratio.

3. The tapered rotary cable anchoring and loading device according to claim 1, characterized in that: The first horizontal pulley (4), the vertical pulley (5), and the second horizontal pulley (6) are all set in pairs and can be independently adjusted by the slide table (9). They are fixed to the guide rail (10) with bolts. The first horizontal pulley (4) and the second horizontal pulley (6) are installed vertically, and the vertical pulley (5) is arranged horizontally. The three are arranged in an alternating manner to achieve three-dimensional guidance of the cable (11) so that the cable (11) remains in a horizontal stress state during the loading process.

4. The tapered rotary cable anchoring and loading device according to claim 1, characterized in that: The first horizontal pulley (4), the vertical pulley (5), the second horizontal pulley (6) and the traction pulley (7) are provided with pulley seats, and pulleys are rotatably mounted on the pulley seats.

5. The tapered rotary cable anchoring and loading device according to claim 1, characterized in that: The top loading device (8) also includes a fixed base (12), which is installed on the steel beam (3). The cylinder (13) is vertically fixed above the fixed base (12). The lifting piston rod (14) is coaxially arranged inside the cylinder (13) and moves in a straight line in the vertical direction. The top of the lifting piston rod (14) is equipped with a self-locking pressure holding device (15) to maintain a constant load after loading is in place, thus achieving long-term stable load holding.

6. The tapered rotary cable anchoring and loading device according to claim 1, characterized in that: The lifting piston rod (14) has a radially arranged cross-shaped through hole in the middle. A loading arm (16) is horizontally installed in one of the through holes. The loading arm (16) is H-shaped. Guide holes are provided in the middle of the vertical rods at both ends. Bushings are installed in the guide holes for threading and protecting the cable (11).

7. The tapered rotary cable anchoring and loading device according to claim 1, characterized in that: The bottom of the steel beam (3) is provided with a steel base (2), which together form a support structure and is installed on one side of the box (1).

8. A method for testing the anchorage of a scaled-down rotary cable, characterized in that, The method of using the tapered rotary cable anchoring and loading device according to any one of claims 1 to 7 includes the following steps: Step 1: Fix the test chamber (1) to the horizontal test platform, and install the steel beam (3), pulley guide mechanism, traction pulley (7) and top loading device (8); Step 2: Fix the scale anchor inside the box (1) with clamps or fill soil, connect one end of the cable (11) to the anchor, and pass the other end through the first horizontal pulley (4), vertical pulley (5), second horizontal pulley (6), and traction pulley (7) in sequence before connecting to the loading arm (16). Step 3: Adjust and fix the positions of each slide (9) and guide rail (10) to keep the cable (11) horizontally extended; Step 4: Pre-tighten the cable (11), start the top loading device (8) to drive the lifting piston rod (14) to make a pure vertical lifting motion, apply horizontal tension to the cable (11) through the loading arm (16), and use the self-locking pressure holding device (15) to self-lock and hold pressure after loading is in place; Step 5: Keep the load stable, collect mechanical data and complete the mechanical performance test.

9. The method for anchoring a scaled-down rotary cable according to claim 8, characterized in that: Before loading the load as described in step 5, a calibration test is conducted to establish a calibration curve of the lifting amount of the lifting piston rod (14) and the tension of the cable (11) to achieve precise load control.

10. The test method according to claim 8, characterized in that: The mechanical performance tests described in step 5 include cyclic loading tests and ultimate bearing capacity tests. Cyclic loading tests measure fatigue performance and cumulative deformation, while ultimate bearing capacity tests determine the ultimate bearing capacity and failure mode of the anchor.

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