A physical model test device and method for simulating progressive failure of tunnel anchors

Abstract

The application belongs to the technical field of tensile test, and specifically discloses a physical model test device and method for simulating progressive failure of a tunnel anchor, which comprises an adjustable anchoring simulation mechanism, a simulation saddle chamber, a rubber plug and a supporting mechanism, the simulation saddle chamber is arranged on the supporting mechanism, the rubber plug is slidingly arranged in the simulation saddle chamber, and the adjustable anchoring simulation mechanism is arranged at the end of the simulation saddle chamber. Through the torsion force setting of the locking inner core, the clamping force of the conical elastic pressing piece on the base can be changed, so that the firmness of the torsion type locking assembly is matched with the actual rock-soil condition, the selection of the metal cable is matched, and the load bearing limit of the design scheme can be determined. Furthermore, the simulation anchor cable and the circuit that bear the tension are integrated together, and the effectiveness and the load bearing upper limit of each scattered cable are intuitively fed back through whether the closed loop is disconnected.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tensile test, and particularly relates to a physical model test device and method for simulating progressive failure of a tunnel anchor. BACKGROUND

[0002] The tunnel anchor is an engineering term of an anchor structure of a suspension bridge, and mainly transmits the tension of a main cable through force bearing of a rock mass and an anchor body. The core feature is to significantly reduce the excavation amount and the concrete amount by using the geological conditions of an anchor site, and the tunnel anchor is suitable for construction of a suspension bridge of a mountainous highway.

[0003] The main form of the tunnel anchor is that a saddle chamber is opened on a rock mass in a conical shape, and the main cable is spread in the saddle chamber and dispersed for anchoring.

[0004] The tunnel anchor has a huge volume and depends on special rock-soil structures, and each is unique, so it cannot be used for teaching, display, and cannot verify the principle and reliability through the way of a sample machine like a traditional device.

[0005] Therefore, it is necessary to design a device for simulating tension of the tunnel anchor, which can not only be used for display, but more importantly, can simulate the tension working condition of the anchor body in actual use, and can explore the strength and tension limit of the design scheme in combination with the rock-soil condition data measured on site. SUMMARY

[0006] In view of the above, in order to overcome the defects of the prior art, the application provides a physical model test device and method for simulating progressive failure of a tunnel anchor, which can change the clamping force of a conical elastic pressing sheet on a base through the torque setting of a locking inner core, so that the firmness of the torque type locking assembly is matched with the actual rock-soil condition, and the load limit of the design scheme can be judged in cooperation with the selection of a metal cable. Furthermore, the application integrates the simulated anchor cable bearing tension and the circuit together, and directly feeds back the effectiveness and load limit of each dispersed cable (dispersed rope) through whether the closed loop is disconnected or not. On the one hand, the application can be used as a demonstration model and a teaching aid to display the internal structure principle and working process of the tunnel anchor, and on the other hand, the application can set test parameters according to the detected rock-soil condition and perform simulation, so as to provide reference data for bridge design in the design stage.

[0007] The technical scheme adopted by the application is as follows: the application provides a physical model test device for simulating progressive failure of a tunnel anchor, which comprises an adjustable anchoring simulation mechanism, a simulated saddle chamber, a rubber plug and a supporting mechanism, the simulated saddle chamber is arranged on the supporting mechanism, the rubber plug is slidingly arranged in the simulated saddle chamber, and the adjustable anchoring simulation mechanism is arranged at the end of the simulated saddle chamber.

[0008] The adjustable anchoring simulation mechanism comprises a round bottom plate, a simulation anchor cable, a torsion type locking assembly and a light indication assembly, the round bottom plate is detachably arranged at the end of a simulation saddle chamber, the simulation anchor cable, the torsion type locking assembly and the light indication assembly are all arranged on the round bottom plate, the simulation anchor cable is composed of a metal cable, an anchor rod and a base, the base is arranged in the torsion type locking assembly, and the light indication assembly is arranged in the torsion type locking assembly.

[0009] The overall layout of the tunnel anchor can be simulated through the simulation anchor cable and the simulation saddle chamber, and then the stress condition of the tunnel anchor and the steel cable in actual use can be simulated by applying a pulling force to the simulation anchor cable as a whole, which can serve as a demonstration model and a teaching aid to display the internal structure principle and working process of the tunnel anchor, and can also set test parameters according to the detected rock and soil conditions and perform simulation and simulation, thereby providing reference data for bridge design in the design stage.

[0010] Further, the torsion type locking assembly comprises a locking inner core and an outer locking sleeve, the locking inner core is provided with a stepped hole, the base is slidingly arranged in the stepped hole, the side wall of the locking inner core is annularly and uniformly provided with a side window, the side window is provided with a cantilevered tapered elastic pressing piece, the tapered elastic pressing piece can clamp the base when it is contracted, the outer locking sleeve is provided with a tapered hole, the tapered elastic pressing piece is provided with an external thread, the tapered hole is provided with a matching internal thread, and the clamping force of the tapered elastic pressing piece on the base can be adjusted by relative rotation of the outer locking sleeve and the locking inner core.

[0011] As a preferred, the outer locking sleeve is provided with a rotating clasp part, the outer locking sleeve is rotatably arranged in the round bottom plate through the rotating clasp part, the locking inner core is provided with an outer hexagonal part one, and the outer locking sleeve is provided with an outer hexagonal part two.

[0012] The base can be clamped by the tapered elastic pressing piece through the relative rotation of the locking inner core and the outer locking sleeve, and the rotation torque of the locking inner core and the outer locking sleeve corresponds to the clamping force of the tapered elastic pressing piece on the base, so that the clamping force of each group of torsion type locking assemblies can be adjusted by a torque wrench to simulate the rock and soil conditions at the actual construction position.

[0013] Further, the simulation saddle chamber is composed of a straight cylinder part and a tapered part, the round bottom plate is detachably arranged at the end of the tapered part, the anchor rod is arranged in the through hole of the rubber plug and clamped by the rubber plug, the clamping force of the rubber plug on the anchor rod will also change when the rubber plug slides in the tapered part, and the rubber plug is annularly and uniformly provided with a top rod which can abut against the round bottom plate.

[0014] The rubber plug can increase the extrusion force and friction force on the anchor rod when being extruded and contracted, so as to simulate the condition that the anchor rod is integrated as a whole by pouring concrete, and the defect that the concrete (or similar adhesive) can only be used once is overcome; in the case of repeated use, the process of testing or demonstration is more consistent with the actual situation.

[0015] Further, the anti-rebound assembly includes a wire distribution disc, a shock-absorbing disc and an elastic sheet, the wire distribution disc is fixedly connected to the inner part of the straight cylinder, the metal cable is slidably arranged in the wire distribution disc, the shock-absorbing disc is slidably arranged in the straight cylinder, and the elastic sheet is arranged between the wire distribution disc and the shock-absorbing disc.

[0016] The anti-rebound assembly serves as a safety redundancy device, and is mainly used to avoid the problem that the anchor rod slides too much in the rubber plug and hits the wire distribution disc when the base is separated from the locking inner core, if the tension of the metal cable is too large.

[0017] As preferred, the light indication assembly includes a spring and an indicator lamp, the indicator lamp is arranged in the outer locking sleeve, the spring is arranged between the indicator lamp and the base and is fixedly connected with the indicator lamp, the simulated anchor cable and the light indication assembly can form a closed loop connected with the power supply, the above-mentioned loops are connected in parallel, and the metal cable is covered with an insulating layer.

[0018] The indicator lamps are connected in parallel, and the effectiveness of the corresponding anchor cable and the process of gradually destroying the tunnel anchor after reaching the upper limit of the bearing capacity can be intuitively judged by whether the branch is disconnected, which is of great significance for demonstration and simulation test.

[0019] Further, the support mechanism includes a table top and a stretching assembly, the table top is provided with a fixed support, the simulated saddle chamber is engaged in the fixed support, and the stretching assembly is arranged in the fixed support.

[0020] As preferred, the stretching assembly includes an electric push rod and a sliding plate, the electric push rod is fixedly connected to the fixed support, a cable connector of the electric push rod is located on the fixed support, the sliding plate is fixedly connected to the telescopic end of the electric push rod, and the end of the metal cable can be pulled through the sliding plate.

[0021] As further preferred, the stretching assembly further includes a tension sensor and a cable fixing disc, the end of the metal cable is arranged on the cable fixing disc, and the tension sensor is arranged between the cable fixing disc and the sliding plate.

[0022] The tension between the sliding plate and the cable fixing disc can be fed back through the tension sensor, and the elongation of the electric push rod can not only simulate the tensioning condition of the whole steel cable, but also feed back the maximum bearing limit of the current model.

[0023] The application further provides a use method of the physical model test device simulating progressive failure of a tunnel anchor, and specifically includes the following steps.

[0024] Step one: select appropriate material, diameter and length for each metal cable to match the designed numerical value, and then adjust the fastening force corresponding to the actual situation for each adjustable anchoring simulation mechanism according to the actually measured rock-soil conditions of the construction site; at this time, two wrenches or sleeves are required to be connected with the outer hexagonal part one and the outer hexagonal part two, at least one of which is a torque wrench, the torque value is set corresponding to the actual rock-soil conditions of the anchor point, the locking inner core and the outer locking sleeve are relatively rotated through the wrench, the extrusion force of the conical elastic pressing sheet on the base can be increased through the threaded cooperation, until the set value of the torque wrench is reached;

[0025] Step two: after the adjustment of all the torque type locking assemblies is completed, the round bottom plate is installed at the end of the conical part, in this process, the round bottom plate will resist the top rod and extrude the rubber plug towards the deep part of the conical part, due to the gradual narrowing of the conical part, the extrusion force of the rubber plug on the anchor rod continues to increase in this process, and finally the situation that the actual concrete is poured and all the anchor rods are connected into a whole can be simulated;

[0026] Step three: the other end of the metal cable is connected to the cable fixing disc, at this time, the extension of the electric push rod can increase the distance between the sliding plate and the simulated saddle chamber, in this process, the metal cable gradually changes from relaxation to tension, the overall tension of the metal cable can be fed back through the tension sensor, which corresponds to the actual steel cable tension of the bridge, whether the metal cable between the distribution disc and the cable fixing disc needs to be twisted can also be determined according to actual needs;

[0027] Step four: in the initial state, all the indicator lights are powered on and lit, in the process of continuously increasing tension, if the bearing capacity of the tunnel anchor reaches the upper limit and the structure is damaged, there are generally two forms, one is that a certain metal cable is broken, which indicates that the anchoring position of the scattered cable is not reasonable, resulting in uneven stress of each scattered cable, or there are problems in material and diameter selection, which need to be reevaluated in combination with the tension sensor value at this time, if the value of the tension sensor has not reached the designed value, it indicates that there is a problem in the design of the steel cable; the other is that the simulated anchor cable itself is not damaged, but the base slips out of the locking inner core, since the locking force of the locking inner core corresponds to the rock-soil conditions, if the value of the tension sensor at this time has not reached the designed value, it indicates that there is a defect in the rock-soil conditions of this part, the position of the tunnel anchor or the internal anchor point distribution needs to be redesigned;

[0028] Step five: no matter the metal cable breaks or the base slips from the locking inner core, the corresponding indicator light will be powered off and extinguished, so by observing and recording the lighting of each indicator light, combined with the indication of the tension sensor, the entire simulation process can be analyzed.

[0029] The beneficial effects achieved by the application with the above structure are as follows:

[0030] (1) By simulating the anchor cable and the simulation saddle room, the overall layout of the tunnel anchor can be simulated, and then by applying tension to the whole simulation anchor cable, the stress condition of the tunnel anchor and the steel cable in actual use can be simulated, which can be used as a demonstration model and teaching aid to show the internal structure principle and working process of the tunnel anchor, and on the other hand, test parameters can be set according to the detected rock and soil conditions, and simulation can be carried out to provide reference data for bridge design in the design stage.

[0031] (2) By the relative rotation of the locking inner core and the outer locking sleeve, the base can be clamped by the conical elastic pressing sheet, and the rotation torque of the locking inner core and the outer locking sleeve also corresponds to the clamping force of the conical elastic pressing sheet on the base, so the distribution of the clamping force of each group of torsion type locking assembly can be simulated by adjusting the clamping force of each group of torsion type locking assembly by the torque wrench.

[0032] (3) When the rubber plug is squeezed and shrunk, the squeezing force and friction force on the anchor rod can be increased, so as to simulate the condition that the anchor rod is connected into a whole by pouring concrete, overcoming the defect that the concrete (or similar adhesive) can only be used once; in the case of repeated use, the test or demonstration process is more consistent with the real situation.

[0033] (4) The anti-rebound assembly as a safety redundancy device is mainly to avoid the problem that if the tension of the metal cable is too large when the base separates from the locking inner core, the anchor rod will slide too much in the rubber plug and hit the distribution box.

[0034] (5) All indicator lights are connected in parallel, and the effectiveness of the corresponding cable can be intuitively judged by whether the branch is disconnected, and the process of gradually destroying the tunnel anchor after reaching the load limit can be shown, which is of great significance for both demonstration and simulation test.

[0035] (6) The tension between the sliding plate and the cable fixing disc can be fed back by the tension sensor, and the extension of the electric push rod can not only simulate the whole tension of the steel cable, but also feedback the maximum load limit of the current model. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A perspective view of a physical model test device for simulating the gradual destruction of a tunnel anchor is proposed for the application;

[0037] Figure 2 A front view of a physical model test device for simulating progressive failure of a tunnel anchor according to the present application;

[0038] Figure 3 A left view of a physical model test device for simulating progressive failure of a tunnel anchor according to the present application;

[0039] Figure 4 A perspective view of the adjustable anchoring simulation mechanism;

[0040] Figure 5 A front view of the adjustable anchoring simulation mechanism;

[0041] Figure 6 A cross-sectional view along the section line A-A in FIG. 1; Figure 5

[0042] A cross-sectional view along the section line B-B in FIG. 1; Figure 7 Figure 3 A half-section structural schematic of the adjustable anchoring simulation mechanism;

[0043] Figure 8 An exploded structural schematic of the adjustable anchoring simulation mechanism;

[0044] Figure 9 A partial enlarged view of position I in FIG. 1;

[0045] Figure 10 Figure 6 A partial enlarged view of position II in FIG. 1;

[0046] Figure 11 A schematic diagram of the parallel circuit of the indicator lights; Figure 7

[0047] A schematic diagram of the lighting-off of the indicator lights on the round bottom plate; Figure 12

[0048] A schematic diagram of the simulation installation for exploring the upper limit of the bearing capacity of a rock mass. Figure 13

[0049] Figure 14 A schematic diagram of the simulation installation for exploring the upper limit of the bearing capacity of a rock mass.

[0050] ​​​Wherein, 1, adjustable anchoring simulation mechanism, 2, simulate saddle chamber, 3, rubber plug, 4, anti-rebound assembly, 5, support mechanism, 6, round bottom plate, 7, simulate anchor cable, 8, torsion type locking assembly, 9, light indicating assembly, 10, metal cable, 11, anchor rod, 12, base, 13, locking inner core, 14, outer locking sleeve, 15, spring, 16, indicator light, 17, stepped hole, 18, outer hex portion one, 19, side window, 20, conical elastic pressing piece, 21, conical hole, 22, rotating clasp portion, 23, outer hex portion two, 24, straight cylinder portion, 25, tapered portion, 26, wire distribution disc, 27, shock absorbing disc, 28, elastic sheet, 29, table top, 30, tension assembly, 31, fixed support, 32, electric push rod, 33, sliding plate, 34, tension sensor, 35, cable fixing disc, 36, jacking rod.

[0051] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, and are used to explain the present application together with embodiments of the present application, and do not constitute a limitation on the present application. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0053] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0054] As Figures 1-11 shown, the present application proposes a physical model test device for simulating tunnel anchor progressive failure, which comprises an adjustable anchoring simulation mechanism 1, a simulated saddle chamber 2, a rubber plug 3 and a support mechanism 5, the simulated saddle chamber 2 is arranged on the support mechanism 5, the rubber plug 3 is slidingly arranged in the simulated saddle chamber 2, and the adjustable anchoring simulation mechanism 1 is arranged at the end of the simulated saddle chamber 2.

[0055] The adjustable anchoring simulation mechanism 1 comprises a round bottom plate 6, a simulation anchor cable 7, a torsion type locking assembly 8 and a light indication assembly 9, the round bottom plate 6 is detachably arranged at the end of the simulation saddle chamber 2, the simulation anchor cable 7, the torsion type locking assembly 8 and the light indication assembly 9 are all arranged on the round bottom plate 6, the simulation anchor cable 7 is composed of a metal cable 10, an anchor rod 11 and a base 12, the base 12 is arranged in the torsion type locking assembly 8, and the light indication assembly 9 is arranged in the torsion type locking assembly 8.

[0056] The overall layout of the tunnel anchor can be simulated through the simulation anchor cable 7 and the simulation saddle chamber 2, and then the stress condition of the tunnel anchor and the steel cable in actual use can be simulated by applying a pulling force to the simulation anchor cable 7 as a whole, on the one hand, the simulation mechanism can be used as a demonstration model and a teaching aid to display the internal structure principle and working process of the tunnel anchor, and on the other hand, the simulation mechanism can also set test parameters according to the detected rock and soil conditions and simulate, thereby providing reference data for bridge design in the design stage.

[0057] The torsion type locking assembly 8 comprises a locking inner core 13 and an outer locking sleeve 14, the locking inner core 13 is provided with a stepped hole 17, the base 12 is slidingly arranged in the stepped hole 17, the side wall of the locking inner core 13 is annularly and uniformly provided with a side window 19, the side window 19 is provided with a cantilevered tapered elastic pressing piece 20, the tapered elastic pressing piece 20 can clamp the base 12 when it is contracted, the outer locking sleeve 14 is provided with a tapered hole 21, the tapered elastic pressing piece 20 is provided with an external thread, the tapered hole 21 is provided with a matching internal thread, and the clamping force of the tapered elastic pressing piece 20 on the base 12 can be adjusted by the relative rotation of the outer locking sleeve 14 and the locking inner core 13.

[0058] The outer locking sleeve 14 is rotatably arranged in the round bottom plate 6 through a rotating clasp 22, the locking inner core 13 is provided with an outer hexagonal part 18, and the outer locking sleeve 14 is provided with an outer hexagonal part 23.

[0059] The base 12 can be clamped by the tapered elastic pressing piece 20 through the relative rotation of the locking inner core 13 and the outer locking sleeve 14, and the rotation torque of the locking inner core 13 and the outer locking sleeve 14 corresponds to the clamping force of the tapered elastic pressing piece 20 on the base 12, so that the clamping force of each group of torsion type locking assemblies 8 can be adjusted by a torque wrench, and the distribution can simulate the rock and soil conditions of the actual construction position.

[0060] The simulation saddle chamber 2 is composed of a straight cylinder part 24 and a tapered part 25, the round bottom plate 6 is detachably arranged at the end of the tapered part 25, the anchor rod 11 is arranged in the through hole of the rubber plug 3 and clamped by the rubber plug 3, the clamping force of the rubber plug 3 on the anchor rod 11 will also change when the rubber plug 3 slides in the tapered part 25, and the rubber plug 3 is annularly and uniformly provided with a top rod 36 which can abut against the round bottom plate 6.

[0061] When the rubber plug 3 is squeezed and shrunk, the squeezing force and friction force on the anchor rod 11 can be increased, so as to simulate the situation that the anchor rod 11 is integrated by pouring concrete, and the defect that the concrete (or similar adhesive) can only be used once is overcome; in the case of repeated use, the process of testing or demonstration is more consistent with the real situation.

[0062] The anti-rebound assembly 4 further comprises a wire distribution disc 26, a shock-absorbing disc 27 and an elastic sheet 28, the wire distribution disc 26 is fixedly connected to the inner part of the straight cylinder part 24, the metal wire cable 10 is slidably arranged in the wire distribution disc 26, the shock-absorbing disc 27 is slidably arranged in the straight cylinder part 24, and the elastic sheet 28 is arranged between the wire distribution disc 26 and the shock-absorbing disc 27.

[0063] The anti-rebound assembly 4 serves as a safety redundancy device, mainly to avoid the problem that when the base 12 is separated from the locking inner core 13, if the tension of the metal wire cable 10 is too large, the anchor rod 11 will slide too much in the rubber plug 3 and hit the wire distribution disc 26.

[0064] The light indicating assembly 9 comprises a spring 15 and an indicating lamp 16, the indicating lamp 16 is arranged in the outer locking sleeve 14, the spring 15 is arranged between the indicating lamp 16 and the base 12 and is fixedly connected with the indicating lamp 16, the anchor cable 7 and the light indicating assembly 9 can form a closed loop connected with the power supply, the above-mentioned groups of loops are connected in parallel, and the metal wire cable 10 is covered with an insulating layer.

[0065] All the indicating lamps 16 are connected in parallel, and through the disconnection of the branch, the effectiveness of the corresponding anchor cable can be directly judged, and the process of gradually destroying the tunnel anchor after reaching the upper limit of the bearing capacity can be displayed, which is of great significance for both demonstration and simulation test.

[0066] The supporting mechanism 5 comprises a table top 29 and a stretching assembly 30, the table top 29 is provided with a fixed support 31, the saddle chamber 2 is clamped in the fixed support 31, and the stretching assembly 30 is arranged in the fixed support 31.

[0067] The stretching assembly 30 comprises an electric push rod 32 and a sliding plate 33, the electric push rod 32 is fixedly connected to the fixed support 31, the cable joint of the electric push rod 32 is located on the fixed support 31, and the sliding plate 33 is fixedly connected to the telescopic end of the electric push rod 32, and the end of the metal wire cable 10 can be pulled through the sliding plate 33.

[0068] The stretching assembly 30 further comprises a tension sensor 34 and a cable fixing disc 35, the end of the metal wire cable 10 is arranged on the cable fixing disc 35, and the tension sensor 34 is arranged between the cable fixing disc 35 and the sliding plate 33.

[0069] The tension between the sliding plate 33 and the cable fixing disc 35 can be fed back through the tension sensor 34, and through the elongation of the electric push rod 32, the overall tensioning working condition of the steel cable can be simulated, and the maximum bearing limit of the current model can be fed back.

[0070] As shown in Figure 12 , 13 , each group of indicator lights 16 is connected in parallel, the anchor cable 7 and the spring 15 act as conductors in the branch, and the base 12 is in contact with the spring 15 in the initial state. Whether the metal cable 10 is broken or the base 12 slips from the locking inner core 13, the indicator light 16 will be extinguished. Therefore, by observing the indicator light 16 on the round bottom plate 6, the failure of each scattered cable can be directly displayed.

[0071] As shown in Figure 14 , the tunnel anchor body in the figure is composed of a circular truncated cone anchor plug body and two equal-section cylinders at both ends. The tunnel anchor is buried in a material similar to the physical properties of the rock mass according to the actual direction. At this time, it is equivalent to that the metal cable 10 is completely fixed on the round bottom plate 6, and the arrow represents the direction of the tension; when the strength of the tunnel anchor itself is sufficient, the bearing limit of the whole system is limited by the rock mass; when the tension of the tunnel anchor is too large, cracks will appear in the rock mass near the tunnel anchor, and the tunnel anchor will also be gradually destroyed at this time.

[0072] In specific use, if the device is used for simulation verification, the user first needs to select appropriate material, diameter and length for each metal cable 10 to match the designed numerical value, and then adjust the tightening force of each adjustable anchor simulation mechanism 1 according to the actual rock and soil conditions measured on the construction site; at this time, two wrenches or sleeves are needed to connect the outer hexagonal part one 18 and the outer hexagonal part two 23, at least one of which is a torque wrench, and the torque value is set according to the actual rock and soil conditions of the anchor point. By rotating the locking inner core 13 and the outer locking sleeve 14 through the wrench, the extrusion force of the conical elastic pressing piece 20 on the base 12 can be increased through threaded cooperation until the set value of the torque wrench is reached.

[0073] After adjusting all the torque type locking assemblies 8, the round bottom plate 6 is installed at the end of the conical part 25. During this process, the round bottom plate 6 will resist the top rod 36 and extrude the rubber plug 3 towards the depth of the conical part 25. Due to the gradual narrowing of the conical part 25, the extrusion force of the rubber plug 3 on the anchor rod 11 continues to increase during this process, and finally the situation that the concrete is poured and all the anchor rods 11 are connected into a whole can be simulated in reality.

[0074] The role of concrete is to connect all the anchor rods 11 into a whole, but if the torque type locking assembly 8 has failed, the concrete alone cannot fix the anchor rod 11. At this time, the anchor rod 11 will move in the concrete under the action of external tension until the tension is reduced.

[0075] The other end of the metal cable 10 is connected to the cable fixing disc 35, at this time the distance between the sliding plate 33 and the simulation saddle chamber 2 can be increased by the elongation of the electric push rod 32, in this process the metal cable 10 gradually changes from slack to tension, the overall tension of the metal cable 10 can be fed back through the tension sensor 34, this tension corresponds to the actual bridge cable tension, whether the metal cable 10 between the distribution disc 26 and the cable fixing disc 35 needs to be twisted can also be determined according to actual needs.

[0076] In the initial state, all the indicator lights 16 are powered on and lit, during the process of continuously increasing tension, if the anchor site rock mass quality is good, the tunnel anchor bearing reaches the upper limit and the structure is damaged, there are generally two forms: one is that a metal cable 10 breaks, which indicates that the anchor position design of the scattered cable is unreasonable, leading to uneven stress of each scattered cable, or there are problems in material and diameter selection, which needs to be reevaluated combined with the value of the tension sensor 34 at this time, if the value of the tension sensor 34 has not reached the design value, it means that the design of the cable is a problem; The other is that the simulation anchor cable 7 is not damaged itself, but the base 12 slips out of the locking inner core 13, since the locking force of the locking inner core 13 corresponds to the rock and soil conditions, if the value of the tension sensor 34 at this time has not reached the design value, it means that the rock and soil conditions at this part are defective, the overall position of the tunnel anchor or the internal anchor point distribution position needs to be redesigned.

[0077] Whether the metal cable 10 breaks or the base 12 slips out of the locking inner core 13, the corresponding indicator light 16 will be powered off and extinguished, so by observing and recording the lighting of each indicator light 16, combined with the indication of the tension sensor 34, the entire simulation process can be analyzed.

[0078] The anti-rebound assembly 4 as a safety redundancy device is mainly to avoid the problem that if the tension of the metal cable 10 is too large when the base 12 separates from the locking inner core 13, the anchor rod 11 slides too much in the rubber plug 3 and hits the distribution disc 26.

[0079] If this device is only used for display, the selection requirement of the metal cable 10 is not high, the torsional force size and precision requirement of the torsional locking assembly 8 is also not high, at this time the simulation saddle chamber 2 can be replaced with transparent material, the angle of the table top 29 can also be adjusted to facilitate the audience to show the stress and the process of being gradually damaged.

[0080] As another new embodiment of the present application: when the strength of the tunnel anchor itself is sufficient and the strength of the rock mass is relatively insufficient, the load bearing upper limit of the entire system is limited by the rock mass; when this working condition is explored, firstly, the rock mass at the construction site needs to be sampled and its physical properties are analyzed, then materials such as cement and sand are mixed to obtain a material with similar physical properties to the rock mass sample (in proportion, if the simulated tension is one thousandth of the actual tension, then the strength of the rock mass material is also one thousandth), and then the device is buried in the material with similar physical properties to the rock mass according to the actual direction, at this time the connection strength between the metal cable 10 and the torsion type locking assembly 8 is sufficient.

[0081] When the tension is applied, since the strength of the tunnel anchor itself is sufficient, it will apply pressure to the surrounding rock mass as a whole, and when the pressure is too large, the rock mass will crack; the data of the tension sensor 34 can feedback the tension at this time, and then feedback the tension upper limit of this position.

[0082] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0083] The above describes the present application and its embodiments, which are not limited, and the drawings only show one of the embodiments of the present application, and the actual structure is not limited thereto. In general, if a person skilled in the art is inspired by it, without departing from the purpose of the present application, without creative design, similar structure and embodiments of the technical solution can be designed, which should belong to the protection scope of the present application.

Claims

1. A physical model test apparatus for simulating the progressive failure of tunnel anchors, characterized in that: It includes an adjustable anchoring simulation mechanism (1), a simulation saddle chamber (2), a rubber plug (3) and a support mechanism (5). The simulation saddle chamber (2) is located on the support mechanism (5), the rubber plug (3) is slidably located in the simulation saddle chamber (2), and the adjustable anchoring simulation mechanism (1) is located at the end of the simulation saddle chamber (2). The adjustable anchoring simulation mechanism (1) includes a circular base plate (6), a simulated anchor cable (7), a torque locking assembly (8), and a light indicator assembly (9). The circular base plate (6) is detachably located at the end of the simulated saddle chamber (2). The simulated anchor cable (7), the torque locking assembly (8), and the light indicator assembly (9) are all arrayed on the circular base plate (6). The simulated anchor cable (7) is composed of a metal cable (10), an anchor rod (11), and a base (12). The base (12) is located in the torque locking assembly (8), and the light indicator assembly (9) is located in the torque locking assembly (8). The torque locking assembly (8) includes a locking inner core (13) and an outer locking sleeve (14). The locking inner core (13) is provided with a stepped hole (17). The base (12) is slidably disposed in the stepped hole (17). The side wall of the locking inner core (13) is provided with side windows (19) evenly distributed in a ring. The side window (19) is provided with a cantilevered conical elastic pressure plate (20). The conical elastic pressure plate (20) can clamp the base (12) when it is contracted. The outer locking sleeve (14) is provided with a conical hole (21). The conical elastic pressure plate (20) is provided with an external thread. The conical hole (21) is provided with a matching internal thread. The clamping force of the conical elastic pressure plate (20) on the base (12) can be adjusted by the relative rotation of the outer locking sleeve (14) and the locking inner core (13). The simulated saddle chamber (2) consists of a straight cylindrical part (24) and a conical part (25). The circular bottom plate (6) is detachably located at the end of the conical part (25). The anchor rod (11) is located in the through hole of the rubber plug (3) and is held by the rubber plug (3). When the rubber plug (3) slides in the conical part (25), the clamping force on the anchor rod (11) will also change. The rubber plug (3) is evenly distributed with top rods (36) that can abut against the circular bottom plate (6).

2. The physical model test device for simulating the progressive failure of a tunnel anchor according to claim 1, characterized in that: The outer locking sleeve (14) is provided with a rotating retaining ring (22). The outer locking sleeve (14) is rotatably disposed in the round bottom plate (6) through the rotating retaining ring (22). The locking inner core (13) is provided with an outer hexagonal part one (18), and the outer locking sleeve (14) is provided with an outer hexagonal part two (23).

3. The physical model test device for simulating the progressive failure of tunnel anchors according to claim 1, characterized in that: It also includes an anti-rebound component (4), which includes a cable distributor (26), a shock absorber (27), and an elastic sheet (28). The cable distributor (26) is fixed inside the straight cylinder (24), the metal cable (10) is slidably disposed in the cable distributor (26), the shock absorber (27) is slidably disposed in the straight cylinder (24), and the elastic sheet (28) is disposed between the cable distributor (26) and the shock absorber (27).

4. The physical model test device for simulating the progressive failure of a tunnel anchor according to claim 2, characterized in that: The light indicator assembly (9) includes a spring (15) and an indicator light (16). The indicator light (16) is located in the outer locking sleeve (14). The spring (15) is located between the indicator light (16) and the base (12) and is fixedly connected to the indicator light (16). The simulated anchor cable (7) and the light indicator assembly (9) can form a closed loop connected to the power supply. The above-mentioned loops are connected in parallel. The metal cable (10) is covered with an insulating layer.

5. The physical model test device for simulating the progressive failure of a tunnel anchor according to claim 4, characterized in that: The support mechanism (5) includes a platform (29) and a tensioning component (30). A fixed bracket (31) is provided on the platform (29). The simulated saddle chamber (2) is fitted in the fixed bracket (31). The tensioning component (30) is located in the fixed bracket (31).

6. The physical model test device for simulating the progressive failure of a tunnel anchor according to claim 5, characterized in that: The tensioning assembly (30) includes an electric actuator (32) and a sliding plate (33). The electric actuator (32) is fixed in a fixed bracket (31). The cable connector of the electric actuator (32) is located on the fixed bracket (31). The sliding plate (33) is fixed to the telescopic end of the electric actuator (32). The end of the metal cable (10) can be pulled by the sliding plate (33).

7. The physical model test apparatus for simulating the progressive failure of a tunnel anchor according to claim 6, characterized in that: The tensioning assembly (30) also includes a tension sensor (34) and a cable retainer (35), with the end of the metal cable (10) located on the cable retainer (35) and the tension sensor (34) located between the cable retainer (35) and the slide plate (33).

8. A method of using the physical model test apparatus for simulating the progressive failure of a tunnel anchor according to claim 7, characterized in that, Includes the following steps: Step 1: Based on the actual soil and rock conditions measured at the construction site, adjust the tightening force of each adjustable anchoring simulation mechanism (1) to match the actual situation; use a wrench to rotate the locking inner core (13) and the outer locking sleeve (14) relative to each other, and increase the squeezing force of the conical elastic pressure plate (20) on the base (12) through the threaded connection until the torque wrench setting value is reached; Step 2: After adjusting all the torque locking components (8), install the round bottom plate (6) at the end of the conical part (25). During this process, the squeezing force of the rubber plug (3) on the anchor rod (11) continues to increase, eventually simulating the situation of pouring concrete and connecting all the anchor rods (11) into a whole. Step 3: The other end of the metal cable (10) is connected to the cable fixing plate (35). At this time, the extension of the electric push rod (32) can increase the distance between the slide plate (33) and the simulated saddle chamber (2). During this process, the metal cable (10) gradually changes from slack to tension. The tension sensor (34) can provide feedback on the overall tension borne by the metal cable (10). Step 4: In the initial state, all indicator lights (16) are powered on and lit. As the tension continues to increase, if the load of the tunnel anchor reaches the upper limit and structural damage occurs, the cause of structural damage can be fed back based on the form of damage and the value of the tension sensor (34). Step 5: Whether the metal cable (10) breaks or the base (12) slips out of the locking core (13), the corresponding indicator light (16) will be de-energized and turned off. By observing and recording the lighting status of each indicator light (16), and combining the reading of the tension sensor (34), the entire simulation process can be analyzed.

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