Physical model test device and method for simulating progressive failure of tunnel anchor

Abstract

The invention belongs to the technical field of tensile tests, and particularly discloses a physical model test device and method for simulating tunnel anchor progressive failure, the physical model test device 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 slidably arranged in the simulation saddle chamber, and the supporting mechanism is arranged on the simulation saddle chamber. And the adjustable anchoring simulation mechanism is arranged at the tail end of the simulation saddle chamber. According to the torsion type locking assembly, through torsion 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 and soil conditions, and the force bearing limit of the design scheme can be judged in cooperation with model selection of a metal cable; in addition, the simulation anchor cable for bearing tensile force is integrated with a circuit, and the effectiveness and the upper limit of bearing force of each splay cable are visually fed back according to whether a closed loop is disconnected or not.

Description

TECHNICAL FIELD

[0001] The present 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 the anchorage structure of a suspension bridge, and mainly transmits the tension of a main cable through the force bearing of a rock mass and an anchor body. The core feature is to significantly reduce the excavation amount and the amount of concrete by using the geological conditions of an anchor site, and the tunnel anchor is suitable for the construction of a suspension bridge of a mountainous highway.

[0003] The main form of the tunnel anchor is roughly as follows: 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 and soil structures, and each one 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 the 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 combined with the rock and soil condition data measured on site, the strength and tension limit of the design scheme are explored. SUMMARY

[0006] In view of the above, in order to overcome the defects of the prior art, the present application provides a physical model test device and method for simulating progressive failure of a tunnel anchor, which can change the clamping force of the conical elastic pressing sheet on the base by setting the torsion of the locking inner core, so as to match the firmness of the torsion type locking assembly with the actual rock and soil conditions, and cooperate with the selection of the metal cable to judge the bearing limit of the design scheme; Furthermore, the simulated anchor cable bearing tension and the circuit are integrated together, and the effectiveness and the bearing upper limit of each dispersed cable (dispersed rope) are intuitively fed back through whether the closed loop is disconnected; On the one hand, it can be used as a demonstration model and teaching aid to show the internal structure principle of the tunnel anchor and its working process, and on the other hand, it can set test parameters according to the detected rock and soil conditions and simulate, and provide reference data for bridge design in the design stage.

[0007] The technical scheme adopted by the present application is as follows: the present 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. 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.

[0008] 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.

[0009] 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.

[0010] As 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.

[0011] The base can be clamped by the tapered elastic pressing piece through 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 distribution of the clamping force of each group of torsion type locking assemblies can be simulated by adjusting the clamping force of each group of torsion type locking assemblies through a torque wrench according to the rock and soil conditions of the actual construction position.

[0012] 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 capable of abutting against the round bottom plate.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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 clamped in the fixed support, and the stretching assembly is arranged in the fixed support.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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. Step one: select appropriate material, diameter and length for each metal cable to match the designed 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; 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 concrete is poured and all the anchor rods are connected into a whole can be simulated; 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; 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 structural failure occurs, there are generally two forms, one is that a 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; Step five: whether the metal cable is broken or the base slips out of the locking inner core, the corresponding indicator light will be powered off and extinguished, therefore, by observing and recording the lighting of each indicator light, the simulation process can be analyzed in combination with the indication of the tension sensor.

[0023] The application has the following beneficial effects by adopting the above structure: (1) Through the simulation of anchor cable and simulation of 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 can also set test parameters according to the detected rock and soil conditions and perform simulation, thereby providing reference data for bridge design in the design stage.

[0024] (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 that the distribution of the clamping force of each group of torsion type locking assembly can be adjusted by the torque wrench to simulate the rock and soil conditions at the actual construction position.

[0025] (3) When the rubber plug is extruded and shrunk, the extrusion 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, and the defect that the concrete (or similar adhesive) can only be used once is overcome; in the case of repeated use, the test or demonstration process is more consistent with the actual situation.

[0026] (4) The anti-rebound assembly as a safety redundancy device is mainly used to avoid the problem that if the tension of the metal cable is too large, the anchor rod will slide too much in the rubber plug and hit the distribution disc when the base is separated from the locking inner core.

[0027] (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 or not, 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.

[0028] (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 tensioning condition of the whole steel cable, but also feedback the maximum load limit of the current model. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a perspective view of a physical model test device for simulating the gradual destruction of a tunnel anchor proposed by the present application; Figure 2 It is a front view of a physical model test device for simulating the gradual destruction of a tunnel anchor proposed by the present application; Figure 3 It is a left view of a physical model test device for simulating the gradual destruction of a tunnel anchor proposed by the present application; Figure 4 It is a perspective view of an adjustable anchoring simulation mechanism; Figure 5 is a front view of the adjustable anchoring simulation mechanism; Figure 6 is a front view of the adjustable anchoring simulation mechanism; Figure 5 is a sectional view along the section line A-A in the middle; Figure 7 is a front view of the adjustable anchoring simulation mechanism; Figure 3 is a sectional view along the section line B-B in the middle; Figure 8 is a half-section structural schematic diagram of the adjustable anchoring simulation mechanism; Figure 9 is an exploded structural schematic diagram of the adjustable anchoring simulation mechanism; Figure 10 is a front view of the adjustable anchoring simulation mechanism; Figure 6 is a local enlarged view of I in the middle; Figure 11 is a front view of the adjustable anchoring simulation mechanism; Figure 7 is a local enlarged view of II in the middle; Figure 12 is a schematic diagram of a parallel circuit of each indicator light; Figure 13 is a lighting-off schematic diagram of the indicator light on the round bottom plate; Figure 14 is a simulation installation schematic diagram for exploring the bearing upper limit of the rock mass.

[0030] 1. adjustable anchoring simulation mechanism, 2. simulation saddle chamber, 3. rubber plug, 4. anti-rebound assembly, 5. support mechanism, 6. round bottom plate, 7. simulation anchor cable, 8. torsion type locking assembly, 9. light indication 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 hexagonal part one, 19. side window, 20. conical elastic pressing sheet, 21. conical hole, 22. rotating clasp part, 23. outer hexagonal part two, 24. straight cylinder part, 25. conical part, 26. wire distribution disc, 27. shock absorbing disc, 28. elastic sheet, 29. table top, 30. stretching assembly, 31. fixed support, 32. electric push rod, 33. sliding plate, 34. tension sensor, 35. cable fixing disc, 36. jacking rod.

[0031] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, illustrate the application, and are used to explain the application, and do not constitute a limitation on the application. DETAILED DESCRIPTION

[0032] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments; based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0033] 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 device or element 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.

[0034] As shown in Figures 1-11 The present application provides a physical model test device for simulating progressive failure of a tunnel anchor, which comprises 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 arranged on the support mechanism 5, the rubber plug 3 is slidingly arranged in the simulation saddle chamber 2, and the adjustable anchoring simulation mechanism 1 is arranged at the end of the simulation saddle chamber 2. 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 indicating 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 indicating assembly 9 are all arrayed 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 indicating assembly 9 is arranged in the torsion type locking assembly 8.

[0035] Through the simulation anchor cable 7 and the simulation saddle chamber 2, the overall layout of the tunnel anchor can be simulated, and then by applying tension to the whole simulation anchor cable 7, the stress condition of the tunnel anchor and the steel cable in actual use can be simulated. On the one hand, it can be used as a demonstration model and a teaching aid to display the internal structure principle of the tunnel anchor and its working process, and on the other hand, it can 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.

[0036] 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.

[0037] The outer locking sleeve 14 is provided with a rotating clamping ring part 22, the outer locking sleeve 14 is rotatably arranged in the circular bottom plate 6 through the rotating clamping ring part 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.

[0038] 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 to simulate the rock and soil conditions of the actual construction position.

[0039] The simulation saddle chamber 2 is composed of a straight cylinder part 24 and a tapered part 25, the circular 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 changes 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 that can abut against the circular bottom plate 6.

[0040] When the rubber plug 3 is extruded and contracted, the extrusion 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 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.

[0041] The anti-rebound assembly 4 is also included, and the anti-rebound assembly 4 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 inside of the straight cylinder part 24, the metal wire cable 10 is slidingly arranged in the wire distribution disc 26, the shock absorbing disc 27 is slidingly 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.

[0042] The anti-rebound assembly 4 is a safety redundancy device, which is mainly used to avoid the problem that 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 when the base 12 is separated from the locking inner core 13.

[0043] The light indication assembly 9 comprises a spring 15 and an indicator lamp 16, the indicator lamp 16 is arranged in the outer locking sleeve 14, the spring 15 is arranged between the indicator lamp 16 and the base 12 and is fixedly connected with the indicator lamp 16, the anchor cable 7 and the light indication assembly 9 can form a closed loop connected with the power supply, the loops are connected in parallel, and the metal cable 10 is externally covered with an insulating layer.

[0044] All the indicator lamps 16 are connected in parallel, and the effectiveness of the corresponding anchor cable can be directly judged by whether the branch is disconnected, and the process of gradually destroying the tunnel anchor after reaching the upper limit of the bearing force can be directly displayed, which is of great significance for display and simulation test.

[0045] The support mechanism 5 comprises a table top 29 and a stretching assembly 30, the table top 29 is provided with a fixed support 31, the simulation saddle chamber 2 is clamped in the fixed support 31, and the stretching assembly 30 is arranged in the fixed support 31.

[0046] The stretching assembly 30 comprises an electric push rod 32 and a sliding plate 33, the electric push rod 32 is fixedly connected in the fixed support 31, the cable joint of the electric push rod 32 is located on the fixed support 31, the sliding plate 33 is fixedly connected to the telescopic end of the electric push rod 32, and the end of the metal cable 10 can be pulled through the sliding plate 33.

[0047] The stretching assembly 30 further comprises a tension sensor 34 and a cable fixing disc 35, the end of the metal 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.

[0048] The tension between the sliding plate 33 and the cable fixing disc 35 can be fed back through the tension sensor 34, and the elongation of the electric push rod 32 can not only simulate the tensioning working condition of the whole steel cable, but also feed back the maximum bearing limit of the current model.

[0049] As shown in Figure 12 , 13 , the indicator lamps 16 are connected in parallel, the anchor cable 7 and the spring 15 both act as conductors in the branch, the base 12 is in contact with the spring 15 in the initial state, and the indicator lamp 16 will be extinguished no matter whether the metal cable 10 is broken or the base 12 slips off the locking inner core 13, so the failure of each anchor cable can be directly displayed by observing the indicator lamp 16 on the round bottom plate 6.

[0050] As shown in Figure 14As shown, the tunnel anchor body is composed of a conical anchor plug body and two equal-sectioned cylindrical bodies at both ends. The tunnel anchor is buried in a material similar to the rock mass in the actual direction, which is equivalent to the entire metal cable 10 being fixed on the circular base plate 6, and the arrow indicates the direction of the pulling force. When the strength of the tunnel anchor itself is sufficient, the upper limit of the bearing capacity of the entire system is limited by the rock mass. When the pulling force 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.

[0051] In specific use, if the device is used for simulation verification, the user first needs to select appropriate materials, diameters and lengths for each metal cable 10 to match the designed values, and then adjust the tightening force of each adjustable anchoring simulation mechanism 1 according to the actual rock and soil conditions measured at the construction site. At this time, two wrenches or sleeves are needed to connect the outer hex portion 18 and the outer hex portion 23, at least one of which is a torque wrench. The torque value is set according to the actual rock and soil conditions of the anchor point. The locking inner core 13 and the outer locking sleeve 14 are rotated relative to each other, and the extrusion force of the conical elastic pressing sheet 20 on the base 12 is increased through threaded cooperation until the set value of the torque wrench is reached.

[0052] After all the torque type locking assemblies 8 are adjusted, the circular base plate 6 is installed at the end of the conical portion 25. During this process, the circular base plate 6 will push against the top rod 36 and extrude the rubber plug 3 towards the depth of the conical portion 25. Due to the gradual narrowing of the conical portion 25, the extrusion force of the rubber plug 3 on the anchor rod 11 continues to increase during this process, and finally the situation where the concrete is poured and all the anchor rods 11 are connected into a whole can be simulated. 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.

[0053] The other end of the metal cable 10 is connected to the cable fixing disc 35. At this time, the extension of the electric push rod 32 can increase the distance between the sliding plate 33 and the simulation saddle chamber 2. During this process, the metal cable 10 gradually changes from relaxation to tension. The overall tension of the metal cable 10 can be fed back through the tension sensor 34, which corresponds to the actual bridge cable tension. The metal cable 10 between the distribution disc 26 and the cable fixing disc 35 can also be twisted according to actual needs.

[0054] In the initial state, all the indicator lights 16 are powered on and lit. During the process of continuously increasing tension, if the rock mass quality of the anchorage area is good, 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 10 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 selection and diameter selection. It is necessary to reevaluate 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 indicates that there is a problem with the design of the steel cable. The other is that the anchor cable 7 is not damaged itself, but the base 12 slips from 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 has not reached the design value at this time, it indicates that there is a defect in the rock and soil conditions at this position, and the overall position of the tunnel anchor or the internal anchor point distribution position needs to be redesigned.

[0055] Whether the metal cable 10 is broken or the base 12 slips from the locking inner core 13, the corresponding indicator light 16 will be powered off and extinguished. Therefore, by observing and recording the lighting of each indicator light 16, the tension sensor 34 can be combined to analyze the entire simulation process.

[0056] The anti-rebound assembly 4 is a safety redundancy device, 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 box 26.

[0057] If the device is only used for display, the selection requirement of the metal cable 10 is not high, and the torsion size and precision requirement of the torsion type locking assembly 8 is also not high. At this time, the simulation saddle chamber 2 can be replaced with a transparent material, or the angle of the table top 29 can be adjusted to facilitate the display of the stress and the process of being gradually damaged to the audience.

[0058] 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 upper limit of the bearing capacity of the entire system is limited by the rock mass; when this working condition is explored, first, the rock mass at the construction site needs to be sampled and its physical properties 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, for example, if the simulated tension is one thousandth of the actual tension, the strength of the rock mass material is also one thousandth), and then the device is buried in the material similar to the rock mass in the actual direction. At this time, the connection strength between the metal cable 10 and the torsion type locking assembly 8 is sufficient. When 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. 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 upper limit of the tension at this position.

[0059] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other presenters can develop. It is also possible, however, that the present application will be practiced in a manner not specifically recited herein, without departing from the spirit and scope of the present application.

[0060] The above description of the present application and its embodiments is not restrictive, and the embodiments shown in the drawings are only 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 device for simulating progressive failure of tunnel anchors, characterized by: The invention comprises an adjustable anchoring simulation mechanism (1), a simulation saddle chamber (2), a rubber plug (3) and a support mechanism (5), wherein the simulation saddle chamber (2) is arranged on the support mechanism (5), the rubber plug (3) is slidably arranged in the simulation saddle chamber (2), and the adjustable anchoring simulation mechanism (1) is arranged at the end of the simulation saddle chamber (2); The adjustable anchoring simulation mechanism (1) comprises a circular bottom plate (6), a simulated anchor cable (7), a torsion locking assembly (8) and a light indication assembly (9); the circular bottom plate (6) is detachably arranged at the end of the simulated saddle chamber (2); the simulated anchor cable (7), the torsion locking assembly (8) and the light indication assembly (9) are arranged in an array on the circular bottom 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 arranged in the torsion locking assembly (8); and the light indication assembly (9) is arranged in the torsion locking assembly (8).

2. A physical model test device for simulating progressive failure of tunnel anchors according to claim 1, characterized in that: The torsion locking assembly (8) includes a locking core (13) and an outer locking sleeve (14), the locking core (13) is provided with a stepped hole (17), the base (12) is slidably arranged in the stepped hole (17), the side wall of the locking core (13) is evenly distributed with side windows (19) in an annular shape, the side windows (19) are provided with a cantilevered conical elastic pressing piece (20), the conical elastic pressing piece (20) can clamp the base (12) when it shrinks, the outer locking sleeve (14) is provided with a conical hole (21), the conical elastic pressing piece (20) is provided with an external thread, and the conical hole (21) is provided with an internal thread matching the same, and the clamping force of the conical elastic pressing piece (20) on the base (12) can be adjusted by relative rotation of the outer locking sleeve (14) and the locking core (13).

3. A physical model test device for simulating progressive failure of tunnel anchors according to claim 2, characterized in that: The outer locking sleeve (14) is provided with a rotating snap ring portion (22), and the outer locking sleeve (14) is rotatably arranged in the circular bottom plate (6) by rotating the snap ring portion (22). The locking inner core (13) is provided with an outer hexagonal portion 1 (18), and the outer locking sleeve (14) is provided with an outer hexagonal portion 2 (23).

4. The physical model test device for simulating progressive failure of a tunnel anchor according to claim 1, characterized in that: The simulated saddle chamber (2) is composed of a straight cylindrical portion (24) and a tapered portion (25); the circular bottom plate (6) is detachably arranged at the end of the tapered portion (25); the anchor rod (11) is arranged in the through hole of the rubber plug (3) and is clamped by the rubber plug (3); when the rubber plug (3) slides in the tapered portion (25), the clamping force on the anchor rod (11) also changes; and a push rod (36) capable of supporting the circular bottom plate (6) is evenly distributed on the rubber plug (3) in an annular shape.

5. The physical model test device for simulating progressive failure of tunnel anchors according to claim 4, characterized in that: The invention also includes an anti-rebound component (4), wherein the anti-rebound component (4) includes a line distribution plate (26), a shock-absorbing plate (27) and an elastic sheet (28), wherein the line distribution plate (26) is fixedly connected to the interior of the straight tube portion (24), the metal cable (10) is slidably arranged in the line distribution plate (26), the shock-absorbing plate (27) is slidably arranged in the straight tube portion (24), and the elastic sheet (28) is arranged between the line distribution plate (26) and the shock-absorbing plate (27).

6. The physical model test device for simulating progressive failure of a tunnel anchor according to claim 3, characterized in that: The light indication assembly (9) includes a spring (15) and an indicator light (16), wherein the indicator light (16) is arranged in the outer locking sleeve (14), and the spring (15) is arranged 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 indication assembly (9) can form a closed circuit connected to a power source, and the above-mentioned groups of circuits are connected in parallel. The outside of the metal cable (10) is covered with an insulating layer.

7. A physical model test device for simulating progressive failure of tunnel anchors according to claim 6, characterized in that: The support mechanism (5) comprises a table (29) and a stretching assembly (30); a fixed bracket (31) is provided on the table (29); the simulated saddle chamber (2) is engaged in the fixed bracket (31); and the stretching assembly (30) is provided in the fixed bracket (31).

8. The physical model test device for simulating progressive failure of a tunnel anchor according to claim 7, characterized in that: The stretching assembly (30) includes an electric push rod (32) and a slide plate (33), wherein the electric push rod (32) is fixedly connected to a fixed bracket (31), a cable connector of the electric push rod (32) is located on the fixed bracket (31), and the slide plate (33) is fixedly connected to the telescopic end of the electric push rod (32), and the end of the metal cable (10) can be pulled by the slide plate (33).

9. The physical model test device for simulating progressive failure of tunnel anchors according to claim 8, characterized in that: The stretching assembly (30) further includes a tension sensor (34) and a cable fixing disk (35), the end of the metal cable (10) is arranged on the cable fixing disk (35), and the tension sensor (34) is arranged between the cable fixing disk (35) and the slide plate (33).

10. A method for using the physical model test device for simulating progressive failure of tunnel anchors according to claim 9, characterized in that: The steps include: Step 1: According to the actual geotechnical conditions measured at the construction site, adjust the tightening force corresponding to the actual situation for each adjustable anchoring simulation mechanism (1); use a wrench to relatively rotate the locking inner core (13) and the outer locking sleeve (14), and increase the squeezing force of the conical elastic pressing piece (20) on the base (12) by threaded engagement until the set value of the torque wrench is reached; Step 2: After all the torsion locking components (8) are adjusted, the round bottom plate (6) is installed at the end of the tapered portion (25). During this process, the squeezing force of the rubber plug (3) on the anchor rod (11) continues to increase, and finally it is possible to simulate the actual pouring of concrete and connect 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 distance between the slide plate (33) and the simulated saddle chamber (2) can be increased by extending the electric push rod (32). During this process, the metal cable (10) gradually changes from being relaxed to being stretched. The overall tension borne by the metal cable (10) can be fed back through the tension sensor (34); Step 4: In the initial state, all indicator lights (16) are powered on and illuminated. As the tension continues to increase, if the bearing capacity of the tunnel anchor reaches its upper limit and structural damage occurs, the cause of the 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 powered off and extinguished. By observing and recording the lighting conditions of each indicator light (16), combined with the reading of the tension sensor (34), the entire simulation process can be analyzed.

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