Dynamic load disturbance deep surrounding rock bias impact simulation device and operation method thereof

Abstract

A dynamic load disturbance deep surrounding rock bias impact simulation device comprises a lateral support constraint part, a spring cushion layer part and a force transmission device part, and the lateral support constraint part is arranged on a constraint bottom plate; the lateral supporting and restraining part comprises two opposite lateral restraining plates, and when the load applying nut is tightened, the two opposite lateral restraining plates can be close to each other by the load applying nut, so that lateral stress is applied to the cubic test piece located in the lateral supporting and restraining part; a rear restraint plate is arranged on the front portion between the two opposite lateral restraint plates, and a load transmission plate is further arranged in the middle of the rear restraint plate. A plurality of load applying bolt holes are formed in the restraining bottom plate and located on the outer side of the lateral restraining plate in the extending direction of the lateral restraining plate, a supporting screw penetrates through each load applying bolt hole, one end of each supporting screw penetrates through the restraining bottom plate, and the other end of each supporting screw penetrates through the spring cushion layer part and the force transmission device part. The device can perform stress simulation analysis on rock samples at different positions of a tunnel rock mass.

Description

Technical Field

[0001] The invention relates to a bias pressure impact simulation device, in particular to a dynamic load disturbance deep surrounding rock bias pressure impact simulation device and an operation method thereof. Background Art

[0002] The stability of tunnel rock mass is one of the most important issues in tunnel engineering, which is directly related to the safety, quality and progress of tunnel construction. During tunnel excavation, the surrounding rock mass will be disturbed, the original stress balance will be destroyed, and the stress redistribution and deformation of the rock mass will occur. When the tunnel is located in an area with high ground stress or complex geological conditions, a large amount of strain energy is stored inside the rock mass. After the tunnel is excavated, the original stress balance is broken, the ground stress is redistributed, and high ground stress is generated, which may cause a large impact on the rock mass. If the excavation method is improper or the support measures are insufficient, the deformation of the rock mass will be aggravated, and even the overall destruction and collapse of the tunnel will be caused. Therefore, it is extremely important to analyze the stress of the local rock mass of the excavated tunnel. The rock mass on the inner wall of the tunnel arch is directly exposed to the outside, and the geological conditions and stress characteristics are relatively complex. The vertical load is not uniform. Once the local rock mass is unstable due to static or dynamic load stress changes, it will be immediately transmitted to the entire tunnel along the direction of destruction, causing significant property losses and even casualties. Therefore, it is necessary to invent a device to simulate the actual eccentric stress condition of the tunnel rock mass and the damage caused to the rock mass by static and dynamic load impacts. Summary of the invention

[0003] In order to solve the above shortcomings, the present invention provides a dynamic load disturbance deep surrounding rock bias impact simulation device, which can perform stress simulation analysis on rock samples at different positions of the tunnel rock mass, has a simple structure, an assembly method, and high simulation authenticity.

[0004] Specifically, the present invention adopts the following technical scheme: It is characterized by: a dynamic load disturbance deep surrounding rock bias impact simulation device, including a lateral support constraint part, a spring cushion part and a force transmission device part, the lateral support constraint part is arranged on the constraint bottom plate; the lateral support constraint part includes two opposite lateral constraint plates, and four corner positions on each lateral constraint plate are provided with loading bolt holes, and the loading screw passes through the loading bolt hole to connect the two opposite lateral constraint plates, and a loading nut is arranged on the loading screw and on the outer side of the lateral constraint plate. When the loading nut is tightened, the loading nut can bring the two opposite lateral constraint plates closer to each other, thereby applying lateral stress to the cubic specimen located therein; between the two opposite lateral constraint plates A rear constraint plate is vertically arranged at the front part of the space, and the lower part of the rear constraint plate is in contact with the constraint bottom plate, and a load transfer plate is also arranged in the middle part of the rear constraint plate; a rear organic glass plate is vertically arranged at the rear part between the two opposite lateral constraint plates, and the rear constraint plate and the organic glass plate are respectively located on the inner sides of the loading screws; a plurality of loading bolt holes are arranged on the constraint bottom plate and on the outer sides of the lateral constraint plates along the extension direction of the lateral constraint plates, and a support screw is passed through each loading bolt hole, one end of the support screw passes through the constraint bottom plate, and the other end passes through the spring pad layer part and the force transmission device part, when the loading nuts located at both ends or one end of the support screw are tightened, the spring pad layer part and the force transmission device part can be squeezed toward the direction of the constraint bottom plate.

[0005] Further, the load transfer plate is fixed to the middle portion of the rear restraint plate by welding.

[0006] Furthermore, the spring pad part includes an upper pressure plate and a lower pressure plate, and a plurality of limit columns are arranged below the upper pressure plate, each limit column is fixed with a spring, and a plurality of limit columns are also arranged on the upper part of the lower pressure plate, each limit column corresponds to the limit column on the upper pressure plate, so that the spring fixed on the limit column of the upper pressure plate can be passed through by the limit column on the lower pressure plate, so that the spring is fixed between the limit columns corresponding to the upper pressure plate and the lower pressure plate.

[0007] Further, all springs are divided into five groups, the springs in each group have the same spring coefficient, but the springs between each group have different spring coefficients; the spring coefficient of each group of springs gradually decreases in the direction toward the rear restraining plate.

[0008] Furthermore, a plurality of loading bolt holes are provided on both sides of the upper pressure plate, and each loading bolt hole corresponds to a loading bolt hole on the constraint bottom plate for the support screw to pass through.

[0009] Furthermore, the force transmission device includes a force transmission plate, a force transmission rod, and a force-bearing plate. A force transmission rod extending downward is fixed below the force transmission plate, and a force-bearing plate is fixed at the end of the force transmission rod. A force-bearing plate is fixed at the end of each force transmission rod. Reserved limiting holes are provided on the upper pressure plate and the lower pressure plate for the force transmission rod to pass through. A groove is provided on the bottom surface of the lower pressure plate, and the force-bearing plate can be embedded in the groove so that the force-bearing plate is flush with the surface of the lower pressure plate.

[0010] Furthermore, the simulation device is made of high-quality steel as a whole and is treated with an anti-rust process.

[0011] The invention also provides an operation method of a dynamic load disturbance deep surrounding rock bias impact simulation device. When a static load test is performed, the following steps are performed: placing a constraint bottom plate flat on a workbench, placing a prepared test piece for simulating a rock sample at a certain location of a tunnel under study on the constraint bottom plate; assembling a lateral support constraint part; assembling a rear constraint plate; pulling out an organic glass plate to manufacture an air-facing surface; embedding two force transmission plates in two parallel grooves reserved in a lower pressure plate; assembling a spring cushion layer; fixing a force transmission rod to the force transmission plate, and fixing a force receiving plate to the force transmission rod;

[0012] The loading screw rod passes through the loading bolts reserved on the lateral constraint plates on both sides, and the lateral constraint plates are tightened and fixed with loading nuts to simulate the lateral pressure in the left and right directions; the hydraulic jack is placed on the rear constraint plate, and pressure is gradually applied in the direction of the rear constraint plate until the required value of the test is reached; on the operating table where the test is conducted, the drop hammer is slowly dropped downward according to the target load parameters required for the test, and when it is about to contact the upper pressure plate of the device, the speed is slowed down again, so that the drop hammer can fall more slowly and evenly to apply static load to the specimen; and relevant experimental data are recorded;

[0013] After the static load test is completed, remove the device from the test bench, remove the spring cushion part and the load-bearing plate in turn, unscrew the load nuts on the left and right sides and the four load screws to remove the lateral restraint plate and the rear restraint plate.

[0014] When conducting a static load and impact test, perform the following steps: place the constraint base plate flat on the workbench, place the prepared specimen used to simulate a rock sample at a certain location in the tunnel under study on the constraint base plate; assemble the lateral support constraint part; assemble the rear constraint plate; pull out the plexiglass plate to create an air surface; embed the two force transfer plates in the two parallel grooves reserved in the lower pressure plate; assemble the spring cushion layer; fix the force transfer rod to the force transfer plate, and fix the force plate to the force transfer rod; fix the two parts together by passing the vertical support screw through the loading bolt holes reserved in the upper pressure plate and the constraint base plate, and tighten the loading nut to simulate the application of static load; the loading screw passes through the loading bolts reserved in the lateral constraint plates on both sides, and uses the loading nut to tighten and fix the lateral constraint plates to simulate the lateral pressure in the left and right directions; the hydraulic jack Place it on the rear constraint plate, and gradually apply pressure in the direction of the rear constraint plate until the required value of the test is reached; adjust the drop hammer to the top of the entire device, adjust the height of the drop hammer and other parameters, and then let the drop hammer fall, so that the drop hammer falls to the force transfer plate, and the impact reaches the force plate along the two force transfer rods, and then is transmitted to the spring cushion part and the specimen; record the relevant experimental data; after the impact test, remove the device from the test bench, vertically pull out the force transfer plate and force transfer rod fixed together from top to bottom in turn, remove the vertical support screws and load nuts fixed to the upper pressure plate and the constraint bottom plate, take out the spring cushion part and the force plate, take out the four horizontal load screws and load nuts, remove the lateral constraint plates and the rear constraint plate on the left and right sides, remove the broken specimen fragments and clean up the specimen debris generated during the destruction.

[0015] In the process of tightening the loading nuts, it is necessary to pay attention to make the upper pressure plate drop evenly and horizontally, that is, the loading nuts on the left and right sides should drop the same distance until the height required for the experiment. In order to prevent the upper pressure plate from dropping unevenly, tighten the loading nuts in sequence in a "Z" shape, that is, first tighten the loading nut on the left side of the first thin plate, then tighten the loading nut on the right side of the first thin plate, and then tighten the left and right ends of each thin plate in turn. The height of the drop can be controlled by measuring and recording uniformly or recording the total number of turns required. Since the ten loading nuts have the same drop height and the spring stiffness coefficients are different, the static load applied to the specimen is also different, that is, eccentric force, which simulates the actual engineering stress condition.

[0016] The present invention has the following advantages:

[0017] Universality: This device can be used to test tunnel rock masses in different environments.

[0018] Convenience: This device greatly facilitates the detection and early warning of rock masses at stress-weak locations, improves detection efficiency, reduces construction time, and reduces related costs.

[0019] Flexibility: This device can perform stress simulation analysis on rock samples at different locations in the tunnel rock mass.

[0020] Safety: Through stress and damage analysis of rock samples at different positions, this device can carry out more scientific and effective reinforcement, support, lining, etc. of weak stress parts or parts with significant damage trends. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional diagram of the overall structure of a dynamic load disturbance deep surrounding rock bias impact simulation device described in the present invention;

[0022] Figure 2 This is a front view of the overall structure of a dynamic load disturbance deep surrounding rock bias impact simulation device according to the present invention;

[0023] Figure 3 It is a back view of the overall structure of a dynamic load disturbance deep surrounding rock bias impact simulation device according to the present invention;

[0024] Figure 4 It is a three-dimensional stereogram of the lateral support constraint part of the dynamic load disturbance deep surrounding rock bias impact simulation device described in the present invention;

[0025] Figure 5 It is a three-dimensional stereogram of the components of the spring cushion layer of the dynamic load disturbance deep surrounding rock bias impact simulation device described in the present invention;

[0026] Figure 6 It is a three-dimensional diagram of the spring cushion layer of a dynamic load disturbance deep surrounding rock bias impact simulation device described in the present invention;

[0027] Figure 7 It is a schematic diagram of a force transmission device of a dynamic load disturbance deep surrounding rock bias impact simulation device according to the present invention;

[0028] Figure 8 It is an overall schematic diagram of the spring cushion layer part and the force transmission device embedded in a dynamic load disturbance deep surrounding rock bias impact simulation device described in the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0030] like Figure 1-8As shown, the dynamic load disturbance deep surrounding rock bias impact simulation device of the present invention includes a lateral support constraint part, a spring cushion part and a force transmission device part, and the lateral support constraint part is arranged on the constraint bottom plate 7; the lateral support constraint part includes two opposite lateral constraint plates 4, and each lateral constraint plate 4 is provided with a loading bolt hole 13 at four corner positions, and the loading screw 5 passes through the loading bolt hole 13 to connect the two opposite lateral constraint plates 4, and a loading nut 6 is arranged on the loading screw 5 and on the outer side of the lateral constraint plate 4. When the loading nut 6 is tightened, the loading nut 6 can bring the two opposite lateral constraint plates 4 closer to each other, thereby applying lateral stress to the cubic specimen located therein. A rear restraint plate 8 is vertically arranged at the front between the two opposing lateral restraint plates 4, the lower part of which is in contact with the restraint bottom plate 7, and a load transfer plate 9 is also arranged at the middle of the rear restraint plate 8, and the load transfer plate 9 is fixed to the middle of the rear restraint plate 8 by welding or the like. A rear organic glass plate 14 is vertically arranged at the rear between the two opposing lateral restraint plates 4, and the rear restraint plate 8 and the organic glass plate 14 are respectively located on the inner side of the load-applying screw 5, so that the rear restraint plate 8 and the organic glass plate 14 can be prevented from being separated from the simulation device. The organic glass plate 14 is usually used as an observation window and can be removed.

[0031] The lateral constraint plates 4 on the left and right sides are used to simulate the left and right radial rock masses along the tunnel, and the load transfer plate 9 and the rear constraint plate 8 are used to simulate the rock masses away from the tunnel. The load transfer plate 9 is used to disperse the stress and transfer the load more evenly to the rear constraint plate 8 and then to the prepared cubic specimen. The constraint bottom plate 7 is used to simulate the bottom rock mass.

[0032] All components are mechanically connected. The constraint bottom plate 7 is placed on a horizontal workbench. The prepared 300mm×300mm×300mm cubic specimen is placed on the constraint bottom plate 7. Four load-applying screws 5 and load-applying nuts 6 are used to fix the left and right lateral constraint plates 4, and clamp the rear constraint plate 8 (the load transfer plate 9 and the rear constraint plate 8 are welded together) and the opposite organic glass plate (this plate can be taken away during the test to simulate the free surface of the tunnel inner wall). The pressure from the left and right rock masses on the specimen is simulated by tightening the load-applying nuts 6.

[0033] On the constraint bottom plate 7 and at the outer side of the lateral constraint plate 4, a plurality of loading bolt holes are provided along the extension direction of the lateral constraint plate 4, such as Figure 1 As shown, five loading bolt holes are left on the left and right, and a support screw 3 passes through each loading bolt hole. One end of the support screw 3 passes through the constraint base plate 7, and the other end passes through the spring cushion layer and the force transmission device part. When the loading nuts 6 located at both ends or one end of the support screw 3 are tightened, the spring cushion layer and the force transmission device part can be squeezed toward the constraint base plate 7.

[0034] The spring cushion layer includes an upper pressing plate 2 and a lower pressing plate 10. A plurality of limiting columns 12 are arranged below the upper pressing plate. A spring 11 is fixed on each limiting column 12. All springs are divided into five groups. The springs in each group have the same stiffness coefficient, but the springs between each group have different stiffness coefficients. Moreover, the stiffness coefficient of each group of springs gradually decreases in the direction toward the rear constraint plate 8. The purpose of designing each group of springs so that the stiffness coefficient gradually decreases in the direction of the rear constraint plate is to simulate the actual engineering situation in which the stress gradually decreases in the direction away from the inner wall of the tunnel. A plurality of loading bolt holes 13 are also arranged on both sides of the upper pressing plate. Each loading bolt hole 13 corresponds to the loading bolt hole 13 on the constraint bottom plate 7 for the support screw 3 to pass through.

[0035] A plurality of limiting posts 12 are also provided on the upper part of the lower pressing plate 10, each limiting post 12 corresponds to a limiting post on the upper pressing plate, so that the spring fixed on the limiting post of the upper pressing plate can be passed through by the limiting post on the lower pressing plate, so that the spring is fixed between the limiting posts corresponding to the upper and lower pressing plates. The limiting posts and the upper and lower pressing plates are integrated and used to fix the position of the spring.

[0036] The force transmission device comprises a force transmission plate 1, a force transmission rod 15 and a force bearing plate 16. A force transmission rod 15 extending downward is fixed below the force transmission plate 1, and a force bearing plate 16 is fixed to the end of the force transmission rod 15. In the figure, a force bearing plate 16 is fixed to the end of each force transmission rod 15.

[0037] Both the upper pressing plate 2 and the lower pressing plate 10 are provided with reserved limiting holes for the force transmission rod 15 to pass through. A groove is provided on the bottom surface of the lower pressing plate 10, and the force plate 16 can be embedded in the groove, so that the force plate 16 is flush with the surface of the lower pressing plate 10. After the force transmission rod 15 passes through the limiting holes on the upper pressing plate 2 and the lower pressing plate 10, it is fixedly connected with the force plate 16 in the groove. For example, an internal thread is provided on the force plate 16, and an external thread is provided on the force transmission rod 15. The force plate 16 is fixed to the force transmission rod 15 by rotating the force transmission rod 15. The upper end of the force transmission rod 15 is plugged into the force transmission plate, or fixed by other means. In one embodiment, the upper end of the force transmission rod 15 is integrally formed with the force transmission plate 1. In this case, the lower end of the force transmission rod can be fixed to the force plate 16 by a nut to ensure that the lower surface of the force plate is flat and fits the cubic specimen.

[0038] Place the prepared cubic specimen on the constraint bottom plate, and assemble the lateral support constraint part, the upper spring cushion part and the force transmission device part in sequence. The impact test is different from the static load test, and the steps in the assembly process are different, which will be explained in the specific implementation method below.

[0039] Preferably, the device is made entirely of high-quality steel.

[0040] Preferably, the devices are all treated with an anti-rust process.

[0041] Preferably, each key component of the device can be manufactured and installed according to construction requirements.

[0042] The dynamic load disturbance deep surrounding rock bias impact simulation device of the present invention uses different parts in different experiments, so the assembly methods are different.

[0043] Static load test:

[0044] The lateral support constraint part is composed of the lateral constraint plates 4 on the left and right sides, the constraint bottom plate 7, four transverse load-applying screws 5, four load-applying nuts 6, the rear constraint plate 8, the load transfer plate 9 (the load transfer plate 9 is welded to the rear constraint plate 8) and the organic glass plate 14. Among them, the lateral constraint plates 4 on the left and right sides represent the rock mass along the radial direction of the tunnel excavation. The welded body of the load transfer plate 9 and the rear constraint plate 8 and the organic glass plate 14 clamp the cubic specimen and vertically clamp it between the two lateral constraint plates. Among them, the welded body of the load transfer plate 9 and the rear constraint plate 8 represents the rock mass away from the direction of the tunnel, the constraint bottom plate 7 represents the rock mass below, and the organic glass plate 14 has no actual function and is taken away during the test, so that the surface in the direction of the front constraint plate is in an air-exposed state. The purpose of this design is to simulate the actual engineering condition where the rock mass on the inner wall of the tunnel is not loaded, that is, the rock mass on the inner wall of the tunnel is directly exposed to the air. Place the constraint base plate 7 flat on the workbench, and place the prepared specimen (300mm×300mm×300mm) for simulating a rock sample at a certain location in the tunnel under study on the constraint base plate. Four loading screws 5 are passed through the eight loading bolt holes 13 reserved in the lateral constraint plates 4 on both sides. The lateral constraint plates 4 are tightened and fixed with loading nuts 6 to simulate the lateral pressure in the left and right directions. The pressure of squeezing the specimen can be used to simulate the static load effect of the left and right rock masses along the radial direction of tunnel excavation on the test rock sample represented by the specimen.

[0045] The hydraulic jack is placed at the rear constraint plate 8, and pressure is gradually applied in the direction of the rear constraint plate 8 until the value required by the test is reached. The welded whole of the load transfer plate 9 and the rear constraint plate 8 is used to withstand the pressure applied by the hydraulic jack in the central area of ​​the constraint plate 8. This pressure represents the static load of the rock mass away from the tunnel direction on the specimen. The main function of the load transfer plate 9 is to evenly distribute the concentrated load generated by the hydraulic jack to the rear constraint plate 8 on the one hand, to avoid the stress concentration phenomenon that is not wanted in the project, and on the other hand, to prevent the concentrated load from the hydraulic jack from being too large to cause deformation of the rear constraint plate 8, that is, to play the role of protecting the device components.

[0046] When conducting the test, the spring cushion layer and the force transmission device components should be assembled into a whole. Before assembly, the organic glass plate 14 is pulled out to make the free surface. The two force transmission plates 16 are embedded in the two parallel grooves reserved in the lower pressure plate 10. Therefore, the spring cushion layer and the force transmission plate 16 of the force transmission device are assembled together. After the side panels surround the prepared 300mm×300mm×300mm cubic specimen, the spring cushion layer and the force transmission device are embedded as a whole and placed directly above the lateral support constraint.

[0047] At this point, the entire device is assembled. The prepared cubic specimen represents the rock sample at the inner wall of the tunnel under study. The specimen is squeezed by the lateral constraint plates 4 on the left and right sides due to the action of the load screw 5 and the load nut 6, simulating the force in the left and right directions on the specimen, that is, the static load of the rock mass in the radial direction of the tunnel excavation direction on the rock sample. Since the force generated by the rock mass from the inner wall of the tunnel to the vertical direction away from the tunnel is not uniform when it is impacted, but gradually decreases, that is, the vertical force on the specimen is not uniform, but eccentric. In order to simulate this actual engineering situation, springs with different stiffness coefficients are set to simulate this situation.

[0048] In addition, at the front restraint plate, the specimen is directly exposed to the air. It is designed to be air-proof, and this surface of the specimen is not subjected to force. One point that needs to be noted is that the hydraulic jack mentioned in the previous step should apply pressure to the load transfer plate 9 instead of directly acting on the rear restraint plate 8. The load transfer plate 9 distributes the force from the jack more dispersedly over the entire rear restraint plate 8, and finally makes the force transmitted to the specimen surface more uniform. This simulated radial force from the far end of the tunnel on the rock sample is better presented.

[0049] The whole device is placed directly above the test bench. At this time, the specimen is subjected to the extrusion force from the nuts and screws in the left and right directions and the pressure from the hydraulic jack at the rear, and all the forces are static pressure. The target load parameters required for the test are used to make the drop hammer slowly fall directly downward on the operating table where the test is conducted. When it is about to contact the upper pressure plate 2 of the device, the speed is slowed down again, so that the drop hammer applies a static load to the specimen at a slower and uniform speed. The pressure is transmitted to the lower pressure plate 10 and the force plate 16 through the upper spring cushion layer, and finally transmitted to the specimen through the lower pressure plate 10 and the force plate 16. Since the springs 11 of several groups have different stiffness coefficients under the same deformation, the load effects applied to the specimen are different. Specifically, the spring 11 close to the organic glass plate 14 has the highest stiffness coefficient. According to Hooke's law (F=k·x), the pressure generated under the same deformation is the largest, which means that the rock mass close to the tunnel wall is subjected to the maximum pressure. On the contrary, the spring 11 close to the rear restraining plate 8 has the lowest stiffness coefficient, so the pressure generated under the same deformation condition is the smallest, that is, the rock mass far from the tunnel wall is subjected to the smallest pressure. As the distance from the tunnel wall increases, the static pressure on the rock mass gradually decreases and eventually tends to a stable state.

[0050] After the static load test is completed, remove the device from the test bench, remove the spring cushion part (and the two force-bearing plates 16 embedded in the lower pressure plate 10 of the spring cushion part) in turn, unscrew the eight load-applying nuts 6 and the four load-applying screws 5 on the left and right sides, remove the lateral constraint plates 4 and the rear constraint plates 8. During the disassembly process, the operator should hold the lateral constraint plates 4 and the rear constraint plates 8 to prevent sudden collapse of the side plates and cause safety accidents, remove the test pieces damaged by fracturing and clean the test bench.

[0051] Static load + impact test

[0052] The impact test is similar to the static load test in the steps of assembling the lateral support constraint part. After the lateral constraint plates 4 and the rear constraint plate 8 on both sides are clamped by the load screws 5 and the load nuts 6, the hydraulic jack first applies a certain pressure to the load transfer plate 9 but does not reach the maximum value designed for the test. The steps in the embedded spring cushion layer and the force transmission device are also different from the static load test: in the static load test, only the force plate 16 in the force transmission device is used, while the impact test also uses the force transmission rod 15 and the force plate 16. The two vertical force transmission rods 15 are tightened on the force transmission plate 1 using the pre-processed threads, and the two fixed force transmission rods 15 are vertically inserted into the spring cushion layer through the upper pressure plate limiting holes 17 reserved in the upper pressure plate 2 and the lower pressure plate limiting holes 18 reserved in the lower pressure plate. The two extended force transmission rods 15 fall down and press on the two force plates 16, and the two force plates 16 are just embedded in the two grooves reserved below the lower pressure plate 10. The spring cushion layer part and the force transmission device part are assembled as a whole, and the spring cushion layer and the force transmission device are embedded as a whole and placed above the test piece that has been laterally enclosed. Next, ten vertical support screws 3 fix the two parts through the loading bolt holes 13 reserved in the upper pressure plate 2 and the constraint bottom plate 7, and tighten the loading nuts 6 to simulate the application of static loads. In the process of tightening the load nuts, it is necessary to pay attention to making the upper pressure plate 2 drop evenly and horizontally, that is, the ten load nuts 6 on the left and right sides should drop the same distance until the height required for the experiment. In order to prevent the upper pressure plate 2 from dropping unevenly, each load nut 6 can be tightened in a "Z"-shaped sequence (it can be seen intuitively from the figure that the upper pressure plate 2 is welded by five thin plates), that is, first tighten the load nut 6 on the left side of the first thin plate, then tighten the load nut 6 on the right side of the first thin plate, and then tighten the left and right ends of each thin plate in turn. The height of the drop can be controlled by measuring and recording uniformly or recording the total number of turns required. Since the ten load nuts 6 drop to the same height and the spring 11 has different stiffness coefficients, the static load applied to the specimen is also different, that is, eccentric force, which simulates the actual engineering force condition.

[0053] After assembly, before being impacted by the upper hammer, compared with the specimen only affected by static load, the specimen is not only squeezed by the lateral constraint plates 4 on the left and right sides, but the spring pad layer above the specimen is also squeezed in the vertical direction due to the action of ten vertical support screws 3 and load nuts 5. This simulates that the rock sample not only bears forces in the left and right directions, but also is subjected to static loads from the vertical rock mass.

[0054] The device is placed on the test bench, and the drop hammer is adjusted to be just above the entire device. After adjusting the height and other parameters of the drop hammer, the drop hammer is dropped so that it falls to the force transmission plate 1. The impact reaches the force plate 16 along the two force transmission rods 15, and is then transmitted to the spring cushion layer and the test piece. This impact is different from static load, and simulates the influence of dynamic load disturbance caused by improper excavation, engineering blasting, fault development, stress redistribution and other reasons on tunnel rock. When the drop hammer contacts the force transmission plate 1 and the spring cushion part, a uniform descending height will be generated. Since the deformation amounts of the several groups of springs 11 are the same but the stiffness coefficients are different, the load effects on the specimens are also different. The stiffness coefficient of the spring 11 closer to the organic glass plate is the largest. According to Hooke's law F=k·x, the pressure generated under the same deformation amount is also greater, that is, the rock mass closest to the tunnel wall is subjected to the greatest impact. Conversely, the stiffness coefficient of the spring 11 closer to the rear constraint plate 8 is the smallest, so the pressure generated under the same deformation amount is also smaller, that is, the rock mass farther from the tunnel wall is subjected to the least impact. As the distance away from the tunnel wall becomes farther and farther, the impact on the rock mass gradually decreases and tends to be stable.

[0055] After the impact test, remove the device from the test bench, pull out the force transfer plate 1 and force transfer rod 15 fixed together vertically from top to bottom in turn, remove the vertical support screw 3 and load nut 6 fixed to the upper pressure plate 2 and the constraint bottom plate 7, take out the spring cushion part and the force plate 16, take out the four horizontal load screws 5 and load nuts 6, remove the lateral constraint plates 4 and the rear constraint plates 8 on the left and right sides, remove the broken specimen fragments and clean up the specimen debris generated during the destruction, check whether the various components of the device are deformed or damaged, and reassemble them for recycling.

[0056] By analyzing the degree of rock mass damage, it is convenient to detect and warn the rock mass at the weak stress position, and improve the detection efficiency. It reduces the construction time and related costs, and can carry out more scientific and effective reinforcement, support, lining, etc. for the weak stress position or the position with significant damage trend, thus achieving the purpose of manufacturing the dynamic load disturbance deep surrounding rock bias impact simulation device.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A dynamic load disturbance deep surrounding rock bias impact simulation device, characterized by: It includes a lateral support constraint part, a spring cushion part and a force transmission device part, wherein the lateral support constraint part is arranged on the constraint bottom plate; the lateral support constraint part includes two opposite lateral constraint plates, and loading bolt holes are opened at four corner positions on each lateral constraint plate, and the loading screw passes through the loading bolt hole to connect the two opposite lateral constraint plates, and a loading nut is arranged on the loading screw and on the outer side of the lateral constraint plate. When the loading nut is tightened, the loading nut can bring the two opposite lateral constraint plates closer to each other, thereby applying lateral stress to the cubic specimen located therein; a rear constraint plate is vertically arranged at the front part between the two opposite lateral constraint plates, and the rear constraint plate The lower part is in contact with the constraint base plate, and a load transfer plate is also arranged in the middle part of the rear constraint plate; a rear organic glass plate is vertically arranged at the rear part between the two opposite lateral constraint plates, and the rear constraint plate and the organic glass plate are respectively located on the inner side of the loading screw; a plurality of loading bolt holes are arranged on the constraint base plate and on the outer side of the lateral constraint plate along the extension direction of the lateral constraint plate, and a support screw is passed through each loading bolt hole, one end of the support screw passes through the constraint base plate, and the other end passes through the spring pad part and the force transmission device part, when the loading nuts located at both ends or one end of the support screw are tightened, the spring pad part and the force transmission device part can be squeezed toward the direction of the constraint base plate.

2. The dynamic load disturbance deep surrounding rock bias impact simulation device according to claim 1 is characterized by: The load transfer plate is fixed to the middle portion of the rear restraining plate by welding.

3. The dynamic load disturbance deep surrounding rock bias impact simulation device according to claim 1, characterized in that: The spring cushion layer part includes an upper pressure plate and a lower pressure plate. A plurality of limit columns are arranged below the upper pressure plate, each of which is fixed with a spring. A plurality of limit columns are also arranged on the upper part of the lower pressure plate, each limit column corresponds to the limit column on the upper pressure plate, so that the spring fixed on the limit column of the upper pressure plate can be passed through by the limit column on the lower pressure plate, thereby fixing the spring between the limit columns corresponding to the upper and lower pressure plates.

4. The dynamic load disturbance deep surrounding rock bias impact simulation device according to claim 3 is characterized by: All springs are divided into five groups. The springs in each group have the same spring rate, but the springs between each group have different spring rates. The spring rate of each group of springs gradually decreases in a direction toward the rear restraining plate.

5. The dynamic load disturbance deep surrounding rock bias impact simulation device according to claim 3 is characterized by: A plurality of loading bolt holes are also provided on both sides of the upper pressure plate, and each loading bolt hole corresponds to a loading bolt hole on the constraint bottom plate for a supporting screw to pass through.

6. The dynamic load disturbance deep surrounding rock bias impact simulation device according to claim 1, characterized in that: The force transmission device includes a force transmission plate, a force transmission rod, and a force-bearing plate. A force transmission rod extending downward is fixed below the force transmission plate, and a force-bearing plate is fixed at the end of the force transmission rod. A force-bearing plate is fixed at the end of each force transmission rod. Reserved limiting holes are provided on the upper pressure plate and the lower pressure plate for the force transmission rod to pass through. A groove is provided on the bottom surface of the lower pressure plate, and the force-bearing plate can be embedded in the groove so that the force-bearing plate is flush with the surface of the lower pressure plate.

7. A dynamic load disturbance deep surrounding rock bias impact simulation device according to any one of claims 1 to 6, characterized in that: The simulation device is made of high-quality steel as a whole and is treated with an anti-rust process.

8. The method for operating the dynamic load disturbance deep surrounding rock bias impact simulation device according to any one of claims 1 to 6, characterized in that: When conducting a static load test, the following steps are performed: placing the constraint bottom plate flat on the workbench, placing the prepared specimen for simulating a rock sample at a certain location of the tunnel under study on the constraint bottom plate; assembling the lateral support constraint part; assembling the rear constraint plate; pulling out the organic glass plate to make an air-facing surface; embedding two force transfer plates in two parallel grooves reserved in the lower pressure plate; assembling the spring cushion layer; fixing the force transfer rod to the force transfer plate, and fixing the force plate to the force transfer rod; The loading screw rod passes through the loading bolts reserved on the lateral constraint plates on both sides, and the lateral constraint plates are tightened and fixed with loading nuts to simulate the lateral pressure in the left and right directions; the hydraulic jack is placed on the rear constraint plate, and pressure is gradually applied in the direction of the rear constraint plate until the required value of the test is reached; on the operating table where the test is conducted, the drop hammer is slowly dropped downward according to the target load parameters required for the test, and when it is about to contact the upper pressure plate of the device, the speed is slowed down again, so that the drop hammer can fall more slowly and evenly to apply static load to the specimen; and relevant experimental data are recorded; After the static load test is completed, remove the device from the test bench, remove the spring cushion part and the load-bearing plate in turn, unscrew the load nuts on the left and right sides and the four load screws to remove the lateral restraint plate and the rear restraint plate.

9. The method for operating the dynamic load disturbance deep surrounding rock bias impact simulation device according to any one of claims 1 to 6, characterized in that: When conducting a static load and impact test, perform the following steps: place the constraint base plate flat on the workbench, place the prepared specimen used to simulate a rock sample at a certain location in the tunnel under study on the constraint base plate; assemble the lateral support constraint part; assemble the rear constraint plate; pull out the plexiglass plate to create an air surface; embed the two force transfer plates in the two parallel grooves reserved in the lower pressure plate; assemble the spring cushion layer; fix the force transfer rod to the force transfer plate, and fix the force plate to the force transfer rod; fix the two parts together by passing the vertical support screw through the loading bolt holes reserved in the upper pressure plate and the constraint base plate, and tighten the loading nut to simulate the application of static load; the loading screw passes through the loading bolts reserved in the lateral constraint plates on both sides, and uses the loading nut to tighten and fix the lateral constraint plates to simulate the lateral pressure in the left and right directions; the hydraulic jack Place it on the rear constraint plate, and gradually apply pressure in the direction of the rear constraint plate until the required value of the test is reached; adjust the drop hammer to the top of the entire device, adjust the height of the drop hammer and other parameters, and then let the drop hammer fall, so that the drop hammer falls to the force transfer plate, and the impact reaches the force plate along the two force transfer rods, and then is transmitted to the spring cushion part and the specimen; record the relevant experimental data; after the impact test, remove the device from the test bench, vertically pull out the force transfer plate and force transfer rod fixed together from top to bottom in turn, remove the vertical support screws and load nuts fixed to the upper pressure plate and the constraint bottom plate, take out the spring cushion part and the force plate, take out the four horizontal load screws and load nuts, remove the lateral constraint plates and the rear constraint plate on the left and right sides, remove the broken specimen fragments and clean up the specimen debris generated during the destruction.

10. The method for operating the dynamic load disturbance deep surrounding rock bias impact simulation device according to claim 9, characterized in that: In the process of tightening the loading nuts, it is necessary to pay attention to making the upper pressure plate drop evenly and horizontally, that is, the loading nuts on the left and right sides should drop the same distance until the height required for the experiment. In order to prevent the upper pressure plate from dropping unevenly, tighten the loading nuts in sequence in a "Z" shape, that is, first tighten the loading nut on the left side of the first thin plate, then tighten the loading nut on the right side of the first thin plate, and then tighten the left and right ends of each thin plate in turn. The height of the drop can be controlled by measuring and recording uniformly or recording the total number of turns required. Since the ten loading nuts have the same drop height and the spring stiffness coefficients are different, the static load applied to the specimen is also different, that is, eccentric force, which simulates the actual engineering stress condition.

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