An experimental device and method for multi-factor feedback of the full amount of steel wire force transmission mechanism in a saddle

Abstract

The present invention relates to a test device and a test method for multi-factor feedback of the force transmission mechanism of a sufficient amount of steel wires in a saddle. The device mainly includes: a U-shaped groove base, a top loading system, a groove path adjustment system, a pressure measurement system, test steel wires, a steel wire extraction system, and a steel wire arrangement scanning system. The present invention is used to test the force transmission mechanism of a sufficient amount of main cable steel wires in a saddle, can synergistically feedback the influence of multiple factors such as the number and arrangement form of steel wires, and the groove path gap on force transmission, and can test the internal pressure distribution by extracting steel wires. The present invention breaks through the dilemma of few steel wires and limited investigated factors in previous similar model tests, and will provide valuable data support for the theoretical research on the mechanical behavior and slip characteristics between the main cable and the saddle of a suspension bridge, and contribute to the scientific design and reasonable application of multi-tower suspension bridges and other innovative cable structure systems.

Description

Technical Field

[0001] The invention belongs to the technical field of suspension bridges, and particularly relates to a test device and a test method for multi-factor feedback of the force transmission mechanism of a sufficient amount of steel wires in a saddle. Background Technique

[0002] Due to its excellent continuous spanning characteristics, the multi-tower suspension bridge is regarded as an ideal bridge form for spanning wide waters such as bays and straits, and has received increasing attention. Different from the traditional two-tower suspension bridge, an intermediate bridge tower is added in the design of the multi-tower suspension bridge. The main cable realizes continuous curve transformation at the top of each bridge tower through a saddle, and extends to each span to provide support for the bridge deck. This means that the stable connection between the main cable and the saddle is the key to ensuring the safety of the overall bridge structure. However, the multi-tower suspension bridge faces an extreme traffic condition of inter-span partial load. At this time, the anti-slip safety of the main cable in the saddle will be greatly challenged by the unbalanced cable force between spans, which has become a core problem restricting the reasonable application and development of the multi-tower suspension bridge.

[0003] The stable connection between the main cable and the saddle depends on the frictional force between their contact surfaces to resist the unbalanced cable force. Therefore, accurately measuring this frictional force is of decisive significance for ensuring the connection stability. According to Coulomb's friction law, the determination of the frictional force is based on the premise of mastering the contact force between each contact surface. When the main cable bends along the saddle under the action of a significant axial force, it will generate pressure at the bottom and side of the saddle groove. However, at present, there is still a lack of reliable calculation theories or methods for the force transmission between the main cable and the saddle groove, especially the lateral pressure. This limitation is mainly due to the difficulty of performing empirical tests on the multi-factor collaborative feedback of the force transmission mechanism of a sufficient amount of main cable steel wires in the saddle side limit system, which in turn leads to the lack of a basis for the construction and verification of relevant calculation theories.

[0004] Patent (application publication number CN107101764A) describes a test device specifically used to measure the lateral force of the main cable in the saddle. In the configuration of this device, the main cable is composed of multiple steel wires bundled together (referred to as a cable strand). To ensure the tensioning characteristics of the cable strand, its two ends need to be fixed on a large test bench. This design makes it natural for lateral force to be generated when the cable strand is tensioned and bends in the saddle groove. To measure this lateral force, the device uses an array of sensing elements. However, due to the scale, cost of the test, and the strong reaction force required to tension the cable strand, the method proposed in this patent can only measure the lateral force of a very small number of steel wire cable strands. Furthermore, its actual test vision is limited in terms of how the arrangement of the steel wires, the gap of the groove path, and other key factors affect the force transmission. In addition, the device does not simultaneously measure the contact force between the steel wires inside the main cable or the vertical pressure acting on the bottom of the saddle groove. Therefore, the data range that this test device can obtain is still very limited and cannot provide sufficient data support for relevant theoretical research.

[0005] The patent discloses "A device for measuring the friction force between steel wires in a parallel steel wire bundle" (CN2019200461063): The backing plate and the cover plate are arranged in parallel. One end of two springs is respectively connected to two edges of the backing plate, and the other end is respectively connected to two edges of the cover plate. Through holes or blind holes are provided on the backing plate, and through holes are provided on the cover plate. The diameter of the through holes is larger than the diameter of a single steel wire in the parallel steel wire bundle. The pressing head is connected to a compression testing machine and can pass through the through hole of the cover plate to push a steel wire in the parallel steel wire bundle, so as to study the mechanical characteristics when a wire break occurs at different positions in the parallel steel wire bundle in a bridge.

[0006] The following are the deficiencies of this document: First, it cannot simulate the actual conditions of the saddle of a suspension bridge. Second, when pulling out a steel wire in a parallel steel wire bundle, the forces in all directions of up, down, left, and right of the steel wire bundle cannot be measured. Third, the load-displacement curve of the steel wire cannot be drawn, and the actual friction force of the test steel wire at the pulling-out position cannot be accurately obtained.

[0007] In view of this, the present invention develops a test device and a test method for multi-factor feedback of the force transmission mechanism of a sufficient number of steel wires in a saddle, aiming to achieve multi-factor collaborative feedback on the force transmission mechanism of the main cable steel wires in the saddle, providing a necessary data basis for the force analysis and anti-slip verification between the main cable and the saddle, and having important practical significance for promoting the scientific design and reasonable application of multi-tower suspension bridges and other innovative cable structure systems. Summary of the Invention

[0008] The object of the present invention is to provide a test device for multi-factor feedback of the force transmission mechanism of a sufficient number of steel wires in a saddle, aiming to, when the main cable bends along the saddle under the action of an axial force, particularly consider the pressure exerted by the main cable on the bottom of the saddle groove and the lateral pressure, and at the same time consider the influence of the arrangement of the steel wires, the gap of the groove path, and other key factors on the pressure transmission, providing a data basis for the force analysis and anti-slip verification between the main cable and the saddle.

[0009] The object of the present invention is achieved as follows:

[0010] The test device proposed in the present invention includes a U-shaped slot seat, a top loading system, a slot adjustment system, a pressure measurement system, a test steel wire, a steel wire extraction system and a steel wire arrangement scanning system. Among them, the U-shaped slot seat is used to simulate the cable saddle structure and provide a space for placing and testing the test steel wire; the top loading system is used to apply vertical pressure to the test steel wire; the slot adjustment system flexibly changes the slot width by adjusting the adjustment plate to adapt to different steel wire arrangement forms; the pressure measurement system includes a lateral pressure sensor and a bottom pressure sensor, which are used to test the pressure transmitted by the test steel wire in real time; the test steel wire is a parallel steel wire for bridge cables, which is divided into short steel wires and long steel wires, and the test steel wire is placed in the slot according to the predetermined arrangement requirements; the steel wire extraction system is used to extract the long steel wire and test its force and displacement, and calculate the contact force between the steel wires based on this; the steel wire arrangement scanning system is used to collect the arrangement form of the test steel wire under various levels of loading conditions.

[0011] Preferably, the U-shaped groove seat is firmly welded by a saddle groove vertical plate, a saddle groove bottom plate and a stiffening plate, and the groove seat bottom plate is fixed to the ground or a test bench by anchor bolts to achieve a stable system.

[0012] Preferably, the top loading system is composed of at least one force transmission plate, one pressure sensor, one jack and its corresponding hydraulic control valve, which enables it to accurately control and measure the vertical pressure applied to the top of the test wire.

[0013] Preferably, the pressure measurement system is configured with at least two rows of lateral pressure sensors on each of the two side vertical surfaces inside the U-shaped groove to provide a lateral contact surface for the test steel wire and test the lateral force transmitted by the test steel wire in real time; and at least one bottom pressure sensor is configured at the bottom of the U-shaped groove to provide a bottom contact surface for the test steel wire and test the vertical force transmitted by the test steel wire in real time.

[0014] Preferably, the wire extraction system uses a through-type jack, a through-type pressure sensor and a wire clamp, and with the support of a transverse reaction plate, can extract the long wire step by step, and measure the force and displacement of the long wire during the extraction process.

[0015] Preferably, the steel wire arrangement scanning system includes at least one high-resolution scanner capable of capturing the arrangement morphology of the steel wires under various levels of loading conditions.

[0016] Another object of the present invention is to provide a test method for multi-factor feedback of the force transmission mechanism of sufficient steel wire in a cable saddle, which is applied to the above-mentioned test device for multi-factor feedback of the force transmission mechanism of sufficient steel wire in a cable saddle.

[0017] Another object of the present invention is achieved like this:

[0018] The test method is as follows: First, fix the bottom of the U-shaped trough seat to the ground or the test bench; according to the arrangement width of the test steel wires, determine the number or thickness of the adjusting plates in the trough seat through subtraction conversion, and place the adjusting plates on the two vertical sides of the saddle trough; install lateral pressure sensors successively close to the adjusting plates on both sides of the trough path, and install bottom pressure sensors at the bottom of the trough, so as to form a trough path for placing the test steel wires and a pressure test system; place the test steel wires in the trough path according to the arrangement requirements, and the number of steel wires should be close to the actual trough path to meet the requirement of sufficient quantity; if it is necessary to extract and pull the steel wires during the test to measure the contact force between the steel wires, select typical positions to set long steel wires; start the top loading system, gradually apply the vertical force, and collect information such as pressure and steel wire arrangement after each stage of loading is completed; according to the working condition setting, if it is necessary to extract and pull the steel wires, start the steel wire extraction system, continuously extract and pull the steel wires until there is an obvious turning point in the load-displacement curve of the steel wires, indicating that the steel wires reach the "critical slip state"; if it is not necessary to extract and pull the steel wires, use the top loading system to continue loading gradually, and at the same time collect the information of each sensor and scanner until the loading is completed; gradually remove the top pressure, and at the same time collect the information of the sensors and scanners during the unloading stage to obtain the force and arrangement characteristics of the steel wires during the unloading stage, and determine whether to cycle the loading-unloading according to the need; after the loading and unloading of this working condition are completed, remove the relevant equipment and take out the test steel wires; repeat the above steps to conduct the test of the next working condition.

[0019] Compared with the prior art, the present invention has the following characteristics and advantages:

[0020] 1. The present invention can accurately simulate the actual situation of the contact and friction between the saddle of the suspension bridge and the main cable. The installation quantity of the test steel wires in the U-shaped trough seat is close to the actual trough path, meeting the requirement of sufficient quantity.

[0021] 2. In the top loading system of the present invention, the jack continuously loads step by step, and at the same time collects the information of the top, side, and bottom pressure sensors and the scanner until the loading is completed. At the same time, collect the information of multiple pressure sensors and the scanner during the unloading stage to obtain the force and arrangement characteristics of the steel wires during the unloading stage.

[0022] 3. According to the contact and force boundary conditions of the steel wires, the present invention selects the edge row steel wires, internal steel wires, or bottom layer steel wires, etc. as the extraction points, continuously loads through the through-hole jack, and draws the load-displacement curve of the steel wires. When there is an obvious turning point in the load-displacement curve of the steel wires, it is obvious that the steel wires reach the "critical slip state", and record the extraction force at this time as the total friction force of the steel wires.

[0023] The present invention is used to test the force transmission mechanism of a sufficient number of main cable wires in a saddle, which can jointly feedback the influence of multiple factors such as the number and arrangement form of wires, and the groove clearance on force transmission, and can test the internal pressure distribution by pulling out wires. The present invention breaks through the dilemma of few wire numbers and limited investigation factors in previous similar model tests, and will provide valuable data support for the theoretical research on the mechanical behavior and slip characteristics between the main cable and the saddle of a suspension bridge, and contribute to the scientific design and reasonable application of multi-tower suspension bridges and other innovative cable structure systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Figure 1 The front view of a test device for multi-factor feedback of the force transmission mechanism of a sufficient number of wires in a saddle;

[0026] Figure 2 The left view of a test device for multi-factor feedback of the force transmission mechanism of a sufficient number of wires in a saddle;

[0027] Figure 3 The top view of a test device for multi-factor feedback of the force transmission mechanism of a sufficient number of wires in a saddle;

[0028] Figure 4 The three-dimensional view of a test device for multi-factor feedback of the force transmission mechanism of a sufficient number of wires in a saddle;

[0029] In the figure: 1 - (top) reaction frame, 2 - (top) jack, 3 - stiffening plate, 4 - adjusting plate, 5 - lateral pressure sensor, 6 - (groove seat) vertical plate (rectangular plate), 7 - (groove seat) bottom plate (rectangular plate), 8 - (top) pressure sensor, 9 - vertical reaction plate, 10 - gasket, 11 - fastening bolt, 12 - short wire, 13 - long wire, 14 - bottom pressure sensor, 15 - anchor bolt, 16 - wire clamp, 17 - through-hole jack, 18 - through-hole pressure sensor, 19 - lateral reaction plate, 20 - force transmission plate, 21 - scanner, 22 - displacement gauge. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following will describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0031] The object of the present invention is to provide a test device and a test method for multi-factor feedback of the force transmission mechanism of a sufficient amount of steel wires in a saddle, so as to overcome the limitations in the prior art.

[0032] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] As Figures 1 - 3 shown, the present invention provides a test device for multi-factor feedback of the force transmission mechanism of a sufficient amount of steel wires in a saddle, including a U-shaped groove seat, a top loading system, a groove path adjustment system, a pressure measurement system, test steel wires, a steel wire extraction system and a steel wire arrangement scanning system.

[0034] A test device for multi-factor feedback of the force transmission mechanism of a sufficient amount of steel wires in a saddle, which is used to simulate the saddle structure and provide a test space for the placement and testing of test steel wires: the left and right vertical plates 6 are welded to the horizontal bottom plate 7 in parallel, the length of the left and right vertical plates is the same as the width of the horizontal bottom plate, and the outer edges of the three are flush. Two stiffening plates 3 are welded symmetrically on the left and right sides of the horizontal bottom plate outside the left and right vertical plates. Four anchor bolts 15 are provided on the horizontal bottom plate for fixing the U-shaped groove seat on the ground or the test bench; a bottom pressure sensor 14 is provided on the horizontal base plate in the U-shaped groove seat, and an adjusting plate 4 and a lateral pressure sensor 5 are sequentially provided on the inner sides of the left and right vertical plates in the U-shaped groove seat. A number of test steel wires are stacked in the space of the U-shaped groove seat. The reaction frame 1 is composed of two identical vertical plates and a top plate connected end to end. The reaction frame 1 is welded to the top end faces of the two vertical plates of the U-shaped groove seat. The jack 2 is vertically installed on the bottom surface of the top plate of the reaction frame 1. The jacking part of the jack sequentially presses downward on the upper part of a number of test steel wires in the U-shaped groove seat through a pressure sensor 8 and a force transmission plate 20;

[0035] The number of test steel wires consists of short steel wires 12 with a length equal to the width of the horizontal bottom plate of the U-shaped groove seat and the whole located within the space of the U-shaped groove seat, and long steel wires 13 for extraction and testing, with one end extending out of the space of the U-shaped groove seat;

[0036] It also has a mechanism that can perform a drawing test on long steel wires set at any position within the space of the U-shaped groove base: The end face of one plate of the L-shaped left vertical reaction plate is welded to the front end face of the left vertical plate of the U-shaped groove base. The other plate of the left vertical reaction plate is parallel to the front end face of the U-shaped groove base, and a vertical notch is opened on the other plate. The length of the vertical notch can cover the stacking height of the test steel wires. The L-shaped right vertical reaction plate is symmetrically welded to the front end face of the right vertical plate of the U-shaped groove base with the left vertical reaction plate. The transverse reaction plate 19 with a transverse notch is fixed to the vertical notches of the left and right vertical reaction plates through a pair of bolts 11 and gaskets 10. The length of the transverse notch of the transverse reaction plate can cover the transverse width of the test steel wires stacked within the U-shaped groove. The outward extension section of the long steel wire to be drawn is extended out from the transverse notch of the transverse reaction plate, and then sequentially passes through the through-hole type pressure sensor 18 and the through-hole type jack 17 and is anchored by the wire clamp 16; the needle of the displacement meter 22 is parallel to the long steel wire and contacts the outer end face of the long steel wire; when the wire is drawn, the jacking part of the through-hole type jack applies an outward force to the wire clamp. At the same time, the reaction force of this force presses the through-hole type jack and the through-hole type pressure sensor against the transverse reaction plate. As the loading force of the jack is applied, the pressure sensor timely detects the corresponding pressure signal.

[0037] A scanner 21 for collecting the arrangement state of the test steel wires under various loading states is installed at the back of the U-shaped groove base. The displacement meter, the pressure sensor 8, the lateral pressure sensing port 5, and the bottom pressure sensor are respectively connected to the data acquisition instrument.

[0038] The scanner is a scanner configured with a high-resolution frequency camera.

[0039] Another set of left and right symmetric vertical reaction plates and another transverse reaction plate are symmetrically arranged before and after the U-shaped groove base, the left and right vertical reaction plates, and the transverse reaction plate. The other transverse reaction plate is fixed to the other set of left and right symmetric vertical reaction plates through another pair of bolts and gaskets. The scanner 21 is fixed to the transverse notch of the other transverse reaction plate through bolts and gaskets.

[0040] The displacement meter 22 is installed and fixed on the outer side of one plate of the right vertical reaction plate in front of the U-shaped groove base through a right-angle bent rod member.

[0041] The jack 2, the pressure sensor 8, and the force transmission plate 20 are arranged in alignment.

[0042] Adjust the thickness of the force transmission plate 20 to adapt to the insufficient stroke of the jack 2 between the reaction frame and the force transmission plate; adjust the thickness of the adjustment plate 4 to adapt to the arrangement of test steel wires with different widths within the U-shaped groove base.

[0043] The U-shaped trough seat is firmly welded by the saddle trough vertical plate 6, the saddle trough bottom plate 7, and the stiffening plate 3, and then fixed to the ground or the test bench by the anchor bolts 15 to realize a stable system.

[0044] The top loading system includes a top reaction frame 1, a top jack 2, a top pressure sensor 8, and a force transmission plate 20; the top reaction frame 1 is welded to the slot seat vertical plate 6, and the top jack 2, the top pressure sensor 8 and the force transmission plate 20 are arranged from top to bottom inside the frame; by adjusting the thickness of the force transmission plate 20, the insufficient stroke between the top reaction frame 1 and the top jack 2 can be adapted; the top pressure sensor 8 is connected to the data acquisition instrument to test the pressure applied by the top jack 2 in real time.

[0045] The groove adjustment system is composed of adjustment plates 4 arranged on both sides of the U-shaped groove seat. The number and thickness of the adjustment plates 4 are determined according to the groove width required for the steel wire arrangement. Specifically, the total thickness of the adjustment plate = the groove width of the U-shaped groove seat - the thickness of the left and right lateral pressure sensors 5 - the groove width required for the steel wire arrangement (i.e., the width of the horizontal bottom plate), thereby forming grooves of different widths to adapt to different steel wire arrangements.

[0046] The pressure measurement system is equipped with at least two rows of lateral pressure sensors 5 on both side facades in the U-shaped groove seat to provide a lateral contact surface for the test steel wire and test the lateral force transmitted by the test steel wire in real time; at least one bottom pressure sensor 14 is arranged at the bottom of the U-shaped groove seat to provide a bottom contact surface for the test steel wire and test the vertical force transmitted by the test steel wire in real time.

[0047] The test steel wires are parallel steel wires for bridge cables, which are orderly placed in the groove formed by the lateral pressure sensor 5 and the bottom pressure sensor 14. The test steel wires include short steel wires 12 and long steel wires 13, among which the short steel wires 12 are in the majority, and their length matches the length of the U-shaped groove seat; a small number of long steel wires 13 are set in typical positions, with a single end extending, and are used for drawing to measure and estimate the internal pressure of the steel wires.

[0048] The wire extraction system includes a vertical reaction plate 9, a transverse reaction plate 19, a through-type jack 17, a through-type pressure sensor 18, a gasket 10, a fastening bolt 11, a wire clamp 16, and a displacement meter 22; the vertical reaction plate 9 is an L-shaped plate, one end face of which is welded to the slot seat vertical plate 6, and the other plate face is vertically grooved; the transverse reaction plate 19 is a middle slotted flat plate, which passes through the long steel wire 13 to be extracted, and is fixed to the vertical reaction plate 9 by the gasket 10 and the fastening bolt 11; the through-type pressure sensor 18 and the through-type jack 17 pass through the long steel wire 13, and the long steel wire 13 is anchored by the wire clamp 16; the needle of the displacement meter 22 is parallel to the long steel wire and contacts with the exposed end of the long steel wire 13; the through-type pressure sensor 18 and the displacement meter 22 are connected to the data acquisition instrument to test the force and displacement of the long steel wire 13 during the extraction process respectively.

[0049] The wire arrangement scanning system fixes the scanner 21 on the rear transverse reaction plate 19 in the same fixing manner as the wire drawing measurement system, and at least one high-resolution camera is set as the scanner 21 to collect the wire arrangement forms under various loading states.

[0050] As Figures 1 - 3 Shown are respectively the elevation view, left view and top view of the implementation device of the present invention. It can be seen that the vertical reaction frames 9 and transverse reaction frames 19 before and after the invention device and their connection manners are the same. The scanner 21 and the transverse reaction plate 19 are also connected by a gasket 10 and fastening bolts 11.

[0051] Based on the test method with multi-factor feedback on the force transmission mechanism of sufficient main cable wires in the saddle of the test device disclosed in the present invention, the basic implementation steps are in the following order: Fix the bottom of the U-shaped groove seat to the ground or the test bench with anchor bolts 15 → Fill the U-shaped groove seat with adjusting plates 4, and the total thickness = the width of the U-shaped groove seat - the thickness of the lateral pressure sensor 5 - the groove width required for wire arrangement. Thus, determine the thickness and quantity of the installed adjusting plates 4 → Install the lateral pressure sensors 5 inside the U-shaped groove seat closely adjacent to the adjusting plates 4, and the quantity in the height direction is determined by the wire arrangement height → Install the bottom pressure sensor 14 at the bottom of the U-shaped groove seat, and its width is determined according to the wire arrangement width → Place the test wires in the groove according to the required arrangement requirements. The number of wires should be close to the number of single grooves in the actual saddle (about 1500). The length of the short wire 12 is the same as the groove length (about 30 cm can be approximately taken). The long wire 13 is arranged at typical positions in the groove, and it extends unidirectionally on one side, leaving enough length for extraction and testing → Install the force transmission plate 20, the top pressure sensor 8, and the top jack 2 in sequence on the top of the test wires, and the three are arranged concentrically → Connect the top pressure sensor 8, the lateral pressure sensors 5, and the bottom pressure sensor 14 to the data acquisition instrument → Start the top jack 2 and begin the first-stage loading → Stabilize for 3 minutes, collect the test data of each sensor, and start the wire arrangement scanner 21 to capture the wire arrangement image → According to the test conditions, if it is necessary to extract the wire, pass the horizontal reaction plate 19 through the long wire 13 to be extracted and fix it to the vertical reaction plate 9. Then, pass the through-hole pressure sensor 18 and the through-hole jack 17 through the long wire 13 in sequence and anchor them with wire clamps 16. Set the displacement gauge 22 to measure the displacement at the wire end. Then, connect the through-hole pressure sensor 18 and the displacement gauge 22 to the data acquisition instrument. Finally, start the through-hole jack 17 to continuously load until there is an obvious turning point in the wire load-displacement curve, indicating that the wire reaches the "critical slip state". Record the extraction force at this time, which is the total friction force of the wire. Based on this, the contact force between the wires can be deduced as a comparison for relevant theoretical results → If it is not necessary to extract the wire in this condition, use the top jack 2 to continue subsequent levels of loading. At the same time, similar to the above, collect the information of each sensor and the scanner until the loading reaches the target level → After the loading is completed, gradually remove the pressure of the top jack 2, and at the same time collect the information of the sensors and the scanner during the unloading stage to obtain the wire force and arrangement characteristics during the unloading stage → According to the need, decide whether to cycle the loading and unloading → Until the loading and unloading of this condition are completed, remove the relevant equipment and take out the test wires → Repeat the above steps to conduct the test for the next condition.

[0052] Among them, the test conditions refer to the differential settings of factors such as the number and arrangement form of the test wires, the gap of the grooves, and whether to extract the wires, forming a test group that can test the influence laws of multiple factors.

[0053] Among them, the setting of the long steel wire 13 in the groove should be classified according to the contact and force boundary conditions of the steel wire. For example, it can be divided into side row steel wires, internal steel wires, bottom layer steel wires, etc. Several steel wires of each type should be selected as the extraction points, that is, the long steel wire 13 is set here.

[0054] The characteristic of the "critical slip state" is that under the action of a certain level of extraction force, the load-displacement curve shows a "sharp rise" turning point, indicating that the critical slip of the extracted steel wire has occurred; among them, the load is measured by the through-hole type pressure sensor 18, and the displacement is measured by the displacement meter 22.

[0055] The arrangement images of the steel wires in each state collected by the steel wire arrangement scanner 21 can be digitally reconstructed by advanced methods such as image recognition to obtain the steel wire arrangement coordinate information.

[0056] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the above details, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0057] In the present invention, the principle and implementation manner of the present invention are elaborated. The above description is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, there will be changes in the specific implementation manner and application scope according to the idea of the present invention. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. An experimental device for multi-factor feedback of the force transmission mechanism of sufficient steel wires in a cable saddle, characterized in that, U-shaped groove base for simulating saddle structure and providing test steel wire placement and test space: The left and right vertical plates (6) are welded to the horizontal bottom plate (7) in parallel. The lengths of the left and right vertical plates are the same as the width of the horizontal bottom plate, and the outer edges of the three are flush. Two stiffening plates (3) are welded symmetrically on the left and right sides of the horizontal bottom plate at the positions outside the left and right vertical plates. Four anchor bolts (15) are provided on the horizontal bottom plate for fixing the U-shaped groove base to the ground or test bench. A bottom pressure sensor (14) is provided on the horizontal base plate inside the U-shaped groove base. An adjusting plate (4) and a lateral pressure sensor (5) are sequentially provided on the inner sides of the left and right vertical plates in the U-shaped groove base. A number of test steel wires are stacked in the space of the U-shaped groove base. The reaction frame (1) is formed by connecting the end-to-end of two identical vertical plates and a top plate. The reaction frame (1) is welded to the top end faces of the two vertical plates of the U-shaped groove base. The jack (2) is vertically installed on the bottom surface of the top plate of the reaction frame (1). The jacking part of the jack sequentially presses downward on the upper part of a number of test steel wires in the U-shaped groove base through a pressure sensor (8) and a force transfer plate (20). The number of test steel wires consists of short steel wires (12) with a length equal to the width of the horizontal bottom plate of the U-shaped groove base and entirely located within the space of the U-shaped groove base, and long steel wires (13) for the test of extraction to be pulled out, with one end extending out of the space of the U-shaped groove base. There is also a mechanism capable of performing extraction tests on the long steel wires set at any position within the space of the U-shaped groove base: The end face of one plate of the L-shaped left vertical reaction plate is welded to the front end face of the left vertical plate of the U-shaped groove base. The other plate of the left vertical reaction plate is parallel to the front end face of the U-shaped groove base, and a vertical notch is opened on the other plate. The length of the vertical notch can cover the stacking height of the test steel wires. The L-shaped right vertical reaction plate is symmetrically welded to the front end face of the right vertical plate of the U-shaped groove base with the left vertical reaction plate. The transverse reaction plate (19) with a transverse notch is fixed to the vertical notches of the left and right vertical reaction plates through a pair of bolts (11) and washers (10). The length of the transverse notch of the transverse reaction plate can cover the transverse width of the stacked test steel wires in the U-shaped groove. The outward extension section of the long steel wire to be pulled out extends out from the transverse notch of the transverse reaction plate, then sequentially passes through a through-hole pressure sensor (18) and a through-hole jack (17), and is anchored through a steel wire clamp (16). The needle of the displacement meter (22) is parallel to the long steel wire and contacts the outer end face of the long steel wire. A scanner (21) for collecting the arrangement state of the test steel wires under various loading states is installed at the back of the U-shaped groove base. The displacement meter (22), pressure sensor (8), lateral pressure sensor (5), and bottom pressure sensor (14) are respectively connected to a data acquisition instrument.

2. The test device for multi-factor feedback of the full amount of steel wire force transmission mechanism in the saddle, characterized in that, The scanner is a scanner configured with a high-resolution frequency camera.

3. The test device for multi-factor feedback of the sufficient steel wire force transmission mechanism in the saddle, according to claim 2, is characterized in that, Another set of vertically symmetric reaction plates and another horizontal reaction plate are symmetrically arranged in front and behind the U-shaped groove base, with the left and right vertical reaction plates and the horizontal reaction plate. The another horizontal reaction plate is fixed on the another set of left and right symmetric vertical reaction plates through another pair of bolts and gaskets. The scanner (21) is fixed on the horizontal notch of the another horizontal reaction plate through bolts and gaskets.

4. The test device for multi-factor feedback of the full amount of steel wire force transmission mechanism in the saddle according to claim 3, characterized in that, The displacement gauge (22) is installed and fixed on the outer side of a plate of the right vertical reaction plate in front of the U-shaped groove base through a right-angled bent rod.

5. The test device for multi-factor feedback of the sufficient steel wire force transmission mechanism in the saddle, according to claim 4, is characterized in that The jack (2), the pressure sensor (8) and the force transfer plate (20) are arranged in alignment.

6. The test device for multi-factor feedback of the full amount of steel wire force transmission mechanism in the saddle according to any one of claims 1 to 5, characterized in that, Adjust the thickness of the force transfer plate (20) to adapt to the insufficient stroke of the jack (2) between the reaction frame and the force transfer plate; adjust the thickness of the adjustment plate (4) to adapt to the arrangement of test steel wires with different widths in the U-shaped groove base.

7. A test method for a test device adopting the multi-factor feedback of the sufficient wire force transmission mechanism in a saddle according to any one of claims 1 to 6, characterized in that, It includes the following steps: Fix the bottom of the U-shaped groove base to the ground or the test bench with anchor bolts (15); fill the adjustment plate (4) in the U-shaped groove base, and its total thickness = the width of the U-shaped groove base - the thickness of the lateral pressure sensor (5) - the groove width required for the arrangement of steel wires, and determine the thickness and quantity of the installed adjustment plate (4) from this total thickness; install the lateral pressure sensors (5) in sequence closely against the adjustment plate (4) inside the U-shaped groove base, and the quantity in the height direction is determined by the arrangement height of the steel wires; install the bottom pressure sensor (14) at the bottom of the U-shaped groove base, and its width is determined according to the arrangement width of the steel wires; place the test steel wires in the groove according to the required arrangement requirements, the length of the short steel wires (12) is the same as the length of the groove, and the long steel wires (13) are arranged at typical positions in the groove, and they extend unilaterally, and enough length for extraction and testing must be reserved; Install the force transfer plate (20), the top pressure sensor (8) and the top jack (2) in sequence on the top of the test steel wires, and the three are arranged in alignment; connect the top pressure sensor (8), the lateral pressure sensor (5) and the bottom pressure sensor (14) to the data acquisition instrument; Start the top jack (2) to start the first-stage loading; stabilize for 3 minutes, collect the test data of each sensor, and start the steel wire arrangement scanner (21) to capture the steel wire arrangement image; according to the test conditions, if it is necessary to extract the steel wires, pass the horizontal reaction plate (19) through the long steel wire (13) to be extracted and then fix it to the vertical reaction plate (9), then pass the through-hole pressure sensor (18) and the through-hole jack (17) through the long steel wire (13) in sequence and anchor them with wire clamps (16), set the displacement gauge (22) to measure the displacement of the steel wire end, then connect the through-hole pressure sensor (18) and the displacement gauge (22) to the data acquisition instrument, and finally start the through-hole jack (17) to continuously load until there is an obvious turning point in the steel wire load-displacement curve, indicating that the steel wire reaches the "critical slip state", record the extraction force at this time, which is the total friction force of the steel wire, and the contact force between the steel wires can be calculated therefrom; If wire extraction is not required in this working condition, the top jack (2) is used to continue subsequent loading at each level, and the information of each sensor and scanner is collected until the loading reaches the target level. After the loading is completed, the pressure of the top jack (2) is gradually removed, and the information of the sensors and scanners during the unloading stage is collected to obtain the force and arrangement characteristics of the wires during the unloading stage. According to the need, decide whether to cycle the loading and unloading until the loading and unloading of this working condition are completed, remove the relevant equipment, and take out the test wires. Repeat the above steps to conduct the test for the next working condition. The test working condition refers to the differential setting of the number and arrangement form of the test wires, the gap of the groove path, and whether to extract the wires, so as to form a test group that can test the influence law of multiple factors. Among them, the setting of the long wires (13) in the groove path should be classified according to the contact and force boundary conditions of the wires, and can be divided into side-column wires, internal wires, and bottom-layer wires. Several wires of each type should be selected as the extraction points, that is, the long wires (13) are set here. The "critical slip state" means that under the action of a certain level of wire extraction force, a "sharp rise" turning point appears in the load-displacement curve, indicating that the critical slip of the extracted wire has occurred. Among them, the load is measured by the through-hole pressure sensor (18), and the displacement is measured by the displacement meter (22). The arrangement images of the wires at each level collected by the wire arrangement scanner (21) are digitally reconstructed by the image recognition method to obtain the wire arrangement coordinate information.

8. The test method of a test device for multi-factor feedback of the full amount of steel wire force transmission mechanism in a cable saddle according to claim 7, characterized in that, The number of the wires is 1500, and the length of the short wires is 30 cm.

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