A rock crack penetration device and test method for simulating tunnel excavation

Abstract

The invention discloses a rock fissure penetration device and a testing method for simulating tunnel excavation, comprising a pressure test box, vertical jacks arranged in pairs, horizontal jacks arranged in pairs, a sealing fixture assembly, a seepage water pressure loading module, an impact force application module, a fissure development monitoring module and a control system. Two horizontal jacks and two vertical jacks are arranged in the pressure test box, and an oil filling port and an oil outlet are arranged on the pressure test box, so as to simulate the true triaxial stress state of the rock sample. The impact force application module can be used to simulate the natural rock stress state, realize the influence of the shock wave generated by the blasting excavation of the simulated tunnel on the unexcavated part of the rock mass, find the relationship between the seepage fissure and the seepage water pressure, the rock stress state and the impact disturbance, provide data support for tunnel excavation, and apply it in practice to improve the stability and safety of tunnel construction.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering construction, and in particular to a rock crack penetration device and a testing method for simulating a tunnel excavation process. Background Art

[0002] Underwater tunnels are passages built under rivers, lakes and oceans for cars or trains to travel. They provide passages through waters for railways, urban roads, highways, subways and various municipal public or special pipelines. Especially in areas with developed karst landforms, there are intricate cracks underground, which are prone to form underground rivers or underground lakes. When a tunnel is built underground, mechanical operations will cause the unexcavated rock mass to suffer certain impact stresses, resulting in stress redistribution in some areas of the surrounding rock, and the cracks between the tunnel and the underground river will accelerate the development, so that the cracks between the tunnel and the underground river are connected, and a large amount of water will gush into the tunnel, endangering people's lives and property. In order to solve this kind of problem, it is necessary to find the influence and law of the disturbance on the cracks under the stress state of natural rock.

[0003] Since the development of seepage fissures is complex and changeable, the existing technology mainly relies on unidirectional or bidirectional stress, which cannot simulate the true triaxial stress state well and fails to solve such problems well. The main reason is that the crack penetration caused by impact disturbance during tunnel excavation and the law of sudden crack development and seepage water pressure have not been found. Therefore, it is necessary to design a device and test method that can simulate the crack penetration during tunnel excavation. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a rock crack penetration device for simulating the process of tunnel excavation.

[0005] The present invention also provides a method for testing a rock fracture penetration device in a simulated tunnel excavation process using the first embodiment.

[0006] According to the first aspect of the present invention, there is provided a rock crack penetration device for simulating tunnel excavation, comprising: a pressure test box, vertical jacks arranged in pairs, horizontal jacks arranged in pairs, a sealing fixture assembly, a seepage water pressure loading module, an impact force application module, a crack development monitoring module and a control system, wherein the top of the pressure test box is provided with an oil filling port, the bottom of the pressure test box is provided with an oil outlet, the vertical jacks are relatively arranged on the bottom and top surfaces of the pressure test box, the horizontal jacks are relatively arranged on the opposite sides of the pressure test box, and the vertical jacks and the horizontal jacks are relatively arranged on the opposite sides of the pressure test box. The sealing clamp assembly is arranged in the pressure test box through a sealing sleeve, and is clamped by the vertical jack and the horizontal jack. The sealing clamp assembly includes a sealing cavity for placing a rock sample, and the rock sample is provided with a rock sample crack. The seepage water pressure loading module is used to provide water pressure to the rock sample crack of the rock sample, and the impact force module is used to apply impact disturbance to the rock sample. The crack development monitoring module includes a crack detector and a probe, and the probe is used to detect the rock sample. The probe is connected to the crack detector, and the control system is connected to the crack detector, the seepage water pressure loading module and the impact force module.

[0007] Beneficial effects: This rock crack penetration device simulates the process of tunnel excavation. Two horizontal jacks and two vertical jacks are set in the pressure test box, and oil filling ports and oil outlets are set on the pressure test box to simulate the true triaxial stress state of the rock sample. In conjunction with the impact force module, it can simulate the natural rock stress state, and realize the impact of the shock wave generated by the blasting excavation of the simulated tunnel on the un-excavated part of the rock mass, find the relationship between the seepage cracks and the seepage water pressure, the rock stress state, and the impact disturbance, and provide data support for tunnel excavation. Applying it in practice can improve the stability and safety of tunnel construction.

[0008] According to the rock fracture penetration device for simulating tunnel excavation process described in the embodiment of the first aspect of the present invention, it is characterized in that: the seepage water pressure loading module includes a water tank, a water-isolating piston, a high-pressure water pipe and a first gas reservoir, the high-pressure water pipe connects the rock sample fracture with the water tank, the water-isolating piston is arranged in the water tank, the water-isolating piston can move along the water tank, one end of the first gas reservoir is connected to the water tank, and a first launch valve is arranged at the outlet of the first gas reservoir, and the water-isolating piston moves by controlling the first launch valve to be opened or closed.

[0009] According to the rock fracture penetration device for simulating tunnel excavation in the process of tunnel excavation described in the embodiment of the first aspect of the present invention, the seepage water pressure loading module also includes a water pressure sensor, and the water pressure sensor is arranged on the pipeline between the high-pressure water pipe, the water tank and the first gas storage.

[0010] According to the rock fracture penetration device for simulating tunnel excavation process described in the embodiment of the first aspect of the present invention, the water tank is a rectangular parallelepiped, a water stop valve is provided at the connection end between the high-pressure water pipe and the water tank, and a rubber piston is provided at the outlet end of the high-pressure water pipe.

[0011] According to the rock crack penetration device for simulating tunnel excavation during the first aspect of the embodiment of the present invention, the sealing fixture assembly includes an upper cover plate, a lower cover plate, a left pressure plate, a right pressure plate and two side plates, a sealing plate is placed between the left pressure plate, the right pressure plate and the rock sample, the sealing plate and the rock sample are adhered to each other through a silicone rubber seal, and the high-pressure water pipe connects the rock sample crack to the water tank through the left pressure plate or the right pressure plate.

[0012] According to the rock fracture penetration device for simulating tunnel excavation process described in the embodiment of the first aspect of the present invention, sealing strips are arranged between the upper cover plate, the lower cover plate, the left pressure plate and the right pressure plate.

[0013] According to the rock crack penetration device for simulating tunnel excavation in the process of tunnel excavation described in the embodiment of the first aspect of the present invention, the impact force application module includes a second gas reservoir, an impact part and a sleeve, the outlet of the second gas reservoir is provided with a second launch valve, one end of the sleeve is connected to the outlet of the second gas reservoir, and the other end of the sleeve is connected to the sealing clamp assembly, the impact part is arranged in the sleeve, and the control system is connected to the second launch valve, and the second launch valve is controlled to be opened or closed, so that the impact part applies impact disturbance to the rock sample.

[0014] According to the rock fracture penetration device for simulating tunnel excavation in the first aspect of the embodiment of the present invention, the impact part includes a striker and an incident rod, and the striker is located between the outlet of the second gas storage device and the front end of the incident rod.

[0015] According to the rock fracture penetration device for simulating tunnel excavation in the first aspect of the present invention, the impact force application module includes a spring and an impact part, and the impact part applies impact disturbance to the rock sample by controlling the spring to reset.

[0016] According to a second aspect of the present invention, a testing method is provided, using the rock crack penetration device for simulating tunnel excavation in the first aspect of the present invention, comprising:

[0017] Prepare a rock sample, manufacture the sealing fixture assembly according to the size of the rock sample, mechanically process the rock sample to form an artificial rock sample crack, clean it with alcohol, and coat the minimum stress surface of the rock sample with silicone rubber;

[0018] Adjusting the vertical jack and the horizontal jack so that the rock sample is placed in the center and assembling the rock sample joint;

[0019] The control system controls the seepage water pressure loading module to provide water pressure to the rock sample cracks in the rock sample,

[0020] The control system controls the vertical jack to apply vertical stress to the rock sample, and the control system controls the transverse jack to apply transverse stress to the rock sample.

[0021] The control system controls the oil injection port to apply oil pressure, thereby simulating a natural stress state.

[0022] The control system controls the impact force application module to apply impact disturbance to the rock sample, and the crack development monitoring module detects the extension of the rock sample cracks and sends the information to the control system.

[0023] Beneficial effect: This test method, by adopting the rock crack penetration device in the simulated tunnel excavation process of the first aspect embodiment, simulates the natural rock stress state, can find the relationship between seepage cracks and seepage water pressure, rock stress state, and impact disturbance, and provide data support for tunnel excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0025] Figure 1 This is a schematic diagram of a rock crack penetration device from a first perspective during a simulated tunnel excavation process according to an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of a rock fracture penetration device in a simulated tunnel excavation process according to an embodiment of the present invention from a second viewing angle;

[0027] Figure 3 This is a schematic diagram of the structure of a sealing fixture assembly according to an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of the seepage water pressure loading module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0032] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0033] Reference Figure 1 and Figure 2 A device for simulating rock crack penetration during tunnel excavation includes: a pressure test box 100, vertical jacks 200 arranged in pairs, horizontal jacks 300 arranged in pairs, a sealing clamp assembly 400, a seepage water pressure loading module 500, an impact force application module 800, a crack development monitoring module 600 and a control system.

[0034] like Figure 1 and Figure 2 , wherein an oil filling port 110 is provided at the top of the pressure test box 100, and an oil outlet 120 is provided at the bottom of the pressure test box 100. Specifically, the pressure test box 100 includes a bottom plate, a top plate, front and rear side plates, and left and right side plates, which enclose a sealed cavity, and the vertical jacks 200 are respectively arranged on the bottom plate and the top plate, and the vertical jacks 200 are arranged in a relatively clamped manner. The transverse jacks 300 are arranged on the left and right side plates, and the transverse jacks 300 are arranged in a relatively clamped manner. A clamping area is formed as a whole between the vertical jack 200 and the transverse jack 300.

[0035] The vertical jack 200 and the transverse jack 300 are arranged in the pressure test box 100 through the sealing sleeve. Specifically, through holes are reserved in the bottom plate, top plate and side plate of the pressure test box 100, and the sealing sleeve is inserted into the pressure test box 100 through the through hole. The transverse jack and the vertical jack are arranged in the sealing sleeve. In addition, there is a sealing strip between the pressure chamber of the pressure test box 100 and the sealing sleeve. During the process of tightening the screws, the sealing strip is compressed to ensure airtightness. Four screw holes are arranged on the upper and lower, left and right pressure plates of the sealing fixture assembly, and a homogeneous sealing strip is also required to achieve sealing.

[0036] The sealing clamp assembly 400 is disposed in the clamping area. The sealing clamp assembly 400 is clamped by the vertical jack 200 and the horizontal jack 300. The sealing clamp assembly 400 includes a sealing cavity for placing a rock sample. The rock sample is provided with a rock sample fracture.

[0037] The vertical jack 200 and the horizontal jack 300 provide the maximum principal stress and the shear stress respectively. They are independent systems and can be operated by a computer to apply pressure. The oil filling port 110 is used to inject hydraulic oil into the pressure chamber of the pressure test box 100, and the confining pressure is achieved by the oil pressure in the pressure chamber. The pressure test box 100 is made of a material with relatively large rigidity.

[0038] The vertical jack 20, the horizontal jack 300 and the oil pressure are used to realize true triaxial stress. During the realization process, the rock sample needs to be stabilized in the pressure chamber of the pressure test box 100 first, and aligned with the central force point of the jack. After fixing, the test is carried out through the operation interface of the computer. The high-pressure water pipe is at the minimum stress surface. Before the rock sample is pushed into the pressure chamber, the joint of the water tank needs to be connected to the interface reserved for the rock sample through the high-pressure water pipe. The jack and hydraulic oil set in the pressure chamber can better simulate the true triaxial stress state of rock.

[0039] The pressure chamber of the pressure test box 100 is realized by two pairs of piston jacks and hydraulic oil, and the oil pressure is fully covered. The disturbance of the surrounding rock can be simulated by changing the size of the jack, and the rock stress state in the natural state can be well simulated.

[0040] Reference Figure 1 , Figure 2 as well as Figure 3 Specifically, the sealing fixture assembly 400 includes an upper cover plate 410, a lower cover plate 420, a left pressure plate 430, a right pressure plate 440 and two side plates. A sealing plate 450 is placed between the left pressure plate 430, the right pressure plate 440 and the rock sample, and the sealing plate 450 and the rock sample are sealed with silicone rubber.

[0041] like Figure 3As shown, the upper cover plate 410, the lower cover plate 420, the left pressure plate 430, the right pressure plate 440 and the two side plates need to be manufactured according to the size of the rock sample. A sealing strip is arranged between the upper cover plate 410, the lower cover plate 420, the left pressure plate 430 and the right pressure plate 440. The sealing strip may be a silicone rubber strip. The sealing strip is to ensure the flexibility between the upper cover plate 410, the lower cover plate 420, the left pressure plate 430 and the right pressure plate 440. The silicone rubber strip has good sealing and pressure bearing properties and will not react with hydraulic oil. After the test, it can still ensure integrity, ensuring that the rock sample can be in a sealed environment during the test.

[0042] A sealing strip is provided between the upper cover plate 410, the lower cover plate 420, the left pressure plate 430, and the right pressure plate 440, and the high-pressure water pipe 530 connects the rock sample fissure to the water tank 510 through the left pressure plate 430 or the right pressure plate 440. Specifically, the rock sample fissure is provided on one side of the right pressure plate 440, and the right pressure plate 440 is provided with a vertical hole, and the high-pressure water pipe 530 is installed through the vertical hole, and the bottom end can be connected to the rock sample fissure, so that the sealing of the sealed cavity can be ensured.

[0043] The rock sample is sealed and stored in the pressure test box 100 through the sealing cavity of the sealing fixture assembly 400. The rock sample has good sealing performance. The silicone rubber used will not react with the oil input from the oil filling port 110 and has strong pressure resistance. It can be as similar to the surrounding conditions of the rock in the natural state as possible, making the test more accurate.

[0044] Reference Figure 1 , Figure 2 and Figure 4 The seepage water pressure loading module 500 is used to provide water pressure to the rock sample fissures of the rock sample. The seepage water pressure loading module 500 includes a water tank 510, a water-isolating piston 520, a high-pressure water pipe 530 and a first gas storage device 540. The high-pressure water pipe 530 connects the rock sample fissures with the water tank 510. The water-isolating piston 520 is arranged in the water tank 510. The water-isolating piston 520 can move along the water tank 510. One end of the first gas storage device 540 is connected to the water tank 510. The outlet of the first gas storage device 540 is provided with a first launch valve 541. By controlling the first launch valve 541 to be opened or closed, the water-isolating piston 520 moves.

[0045] The water tank 510 is a rectangular parallelepiped. The water tank 510 is set to be a rectangular parallelepiped, and the water-isolating piston 520 moves horizontally along the water tank 510. The thrust generated by the water-isolating piston 520 will be converted into water pressure in the cracks, thereby realizing the simulation of water pressure. The water tank 510 and the water-isolating piston 520 are divided into two parts, one part is connected to the rock sample cracks through a high-pressure water pipe 530, and this part has water, and the other part is connected to the first gas storage 540. The water tank 510 is set to be a rectangular parallelepiped so that the water-isolating piston 520 moves horizontally, which can ensure the accuracy of the experiment. The specific length of the water tank 510 can be set according to actual needs.

[0046] Reference Figure 1 The seepage water pressure loading module 500 also includes a water pressure sensor 550, which is arranged on the pipeline between the high-pressure water pipe 530, the water tank 510 and the first gas storage 540. A water stop valve 531 is arranged at the connection end between the high-pressure water pipe 530 and the water tank 510, and a rubber piston 532 is arranged at the outlet end of the high-pressure water pipe 530. The working condition of the water stop valve 531 is judged according to the water pressure sensor 550. If the water pressure required by the experiment is reached, the water stop valve 531 can be closed, thereby ensuring the stability of the water pressure in the cracks of the rock sample.

[0047] There are two water pressure sensors 550 , which are respectively arranged on the high pressure water pipe 530 and the pipeline between the water tank 510 and the first gas storage 540 . The water stop valve 531 is arranged at the interface between the high pressure water pipe 530 and the water tank 510 .

[0048] The working process of the seepage water pressure loading module 500 is as follows: the first launch valve 541 is opened, and the first gas storage tank 540 is connected to the right end face of the water tank 510, so that the pressure at the right end of the water-isolating piston 520 is greater than that at the left end, thereby pushing the water-isolating piston 520 to move to the left, thereby applying seepage water pressure to the rock sample, and then achieving the seepage water pressure required for the experiment. During the experiment, you can choose whether to close the water stop valve according to the value of the water pressure sensor 550, so that the water pressure can be maintained at a specific size without changing.

[0049] The seepage water pressure loading module 500 can provide the required water pressure. The water stop valve is closed according to the water pressure. The water stop valve has a specific switch. The high-pressure water pipe 530 can resist sufficient water pressure without affecting the experiment during the experiment. The rubber piston 532 can ensure the sealing performance well and has ductility. When the high-pressure water pipe is inserted, it can firmly seal the outside of the mouth.

[0050] The seepage water pressure loading module 500 uses a gas emission valve and a water tank containing a water cavity to provide power to apply seepage water pressure to the rock sample. It can freely adjust the size of the seepage water pressure, cooperate with the test, form an independent system, and facilitate the analysis of subsequent data.

[0051] This device can set a stable confining pressure, that is, in the absence of disturbance, the relationship between crack penetration and water pressure can be found by changing the size of the seepage water pressure, or by setting a stable seepage water pressure, applying different stresses through the jack, oil injection port and impact disturbance, creating different stress states, so as to find out whether the crack penetration is related to the surrounding rock disturbance.

[0052] Reference Figure 2 , the impact force module 800 is used to apply impact disturbance to the rock sample. The impact force module 800 includes a second gas storage tank 810, an impact part 820 and a sleeve 830. The outlet of the second gas storage tank 810 is provided with a second launch valve 811. One end of the sleeve 830 is connected to the outlet of the second gas storage tank 810, and the other end of the sleeve 830 is connected to the sealing fixture assembly 400. The impact part 820 is arranged in the sleeve 830. The control system 700 is connected to the second launch valve 811. By controlling the second launch valve 811 to open or close, the impact part 820 applies impact disturbance to the rock sample. Specifically, the impact part 820 includes a striker 821 and an incident rod 822. The striker 821 is located between the outlet of the second gas storage tank 810 and the front end of the incident rod 822.

[0053] The impact force application module 800 is a force application system similar to the Hopkinson bar. It applies an instantaneous impact force to the impact body 821, and the impact body 821 acts on the incident rod 822 through the sleeve. The incident rod 822 hits the minimum principal stress surface of the rock sample through the sleeve to simulate the impact load, thereby achieving the impact disturbance caused by blasting excavation to the surrounding rock mass, resulting in the penetration of the cracks in the rock mass.

[0054] Specifically, after the impact force module 800 receives the relevant instructions, the second launch valve 811 is opened, the second gas storage 810 is connected to the inside of the sleeve 830, and the gas in the second gas storage 810 is ejected so that the impact body 821 carries energy to rush toward the incident rod 822, and the incident rod 822 hits the rock sample through the smooth sleeve 830, so as to simulate the impact stress caused to the surrounding rock by the disturbance during tunnel excavation. Under the action of the impact stress, the cracks in the rock sample are further developed, resulting in the penetration of the cracks.

[0055] Of course, it is easy to understand that the impact force application module 800 includes a spring and an impact part, and by controlling the spring to reset, the impact part applies impact disturbance to the rock sample. The spring can be a high-strength spring, so that the impact block can hit the incident rod at a high speed.

[0056] The impact force module 800 can well simulate the impact of disturbance on the surrounding rock mass caused by blasting and excavation, and observe the development of cracks.

[0057] The crack development monitoring module 600 includes a crack detector 610 and a probe 620. The probe 620 is used to detect rock samples and can be positioned according to actual detection requirements. The probe 620 is connected to the crack detector 610. The crack detector 610 can capture the layout of cracks inside the rock sample through the probe 620.

[0058] This rock fracture penetration device that simulates the tunnel excavation process, through the closed integrity of the rock sample and the setting of the pressure chamber, that is, under a true triaxial stress state, combined with impact disturbance, can simulate the natural rock stress state, find the influencing factors of rock seepage fracture penetration, find the relationship between seepage fractures and seepage water pressure, rock stress state, and impact disturbance, and provide data support for tunnel excavation.

[0059] The control system 700 is connected to the crack detector 610, the seepage water pressure loading module 500 and the impact force module 800. The control system is a computer terminal, which can control the seepage water pressure loading module 500 and the impact force module 800, and can derive the stress state of the rock sample, the impact stress under which the incident rod 822 rushes to the rock sample, the development of the cracks, that is, the layout of the cracks and whether the cracks are through.

[0060] This device is used to study whether the cracks in the rock are connected. Through this, the reasons for their formation can be found. It has strong research value and can ensure the safety of workers during construction. It can be used to improve the stability and safety of tunnel construction. It can find the relationship between seepage water pressure, surrounding rock disturbance and crack development, and independently realize the inconvenience of seepage water pressure by changing the stress state, especially the impact stress, and use the crack development monitoring module 600 to find the law.

[0061] A testing method adopts the rock crack penetration device in the process of simulating tunnel excavation described in the first aspect of the embodiment, including: preparing a rock sample, manufacturing a sealing fixture assembly according to the size of the rock sample, mechanically processing the rock sample to form an artificial rock sample crack, and cleaning it with alcohol to coat the minimum stress surface of the rock sample with silicone rubber; adjusting the vertical jack and the horizontal jack so that the rock sample is placed in the center and assembling the rock sample joint; controlling the seepage water pressure loading module through the control system to provide water pressure to the rock sample cracks in the rock sample, controlling the vertical jack through the control system to apply vertical stress to the rock sample, controlling the horizontal jack through the control system to apply horizontal stress to the rock sample, controlling the oil filling port through the control system to apply oil pressure, thereby simulating the natural stress state, controlling the impact force module through the control system to apply impact disturbance to the rock sample, and the crack development monitoring module to detect the extension of the rock sample crack and send information to the control system.

[0062] In a specific embodiment, first, prepare the rock, and prepare the rock sample cracks as described above, clean the material with alcohol, glue the upper cover plate 410 and the lower cover plate 420 first, and then seal the gap with silicone rubber, place the sealing plate 450 between the left pressure plate 430, the right pressure plate 440 and the rock sample, and seal the sealing plate 450 with silicone rubber, place four sealing strips between the upper cover plate 410, the lower cover plate 420 and the left pressure plate 430 and the right pressure plate 440 to ensure deformation, and finally seal the upper cover plate 410, the lower cover plate 420 and the left pressure plate 430 and the right pressure plate 440. The small stress surface is coated with silicone rubber to ensure that no cracks appear and to ensure the sealing of the rock sample. The control system, i.e., the computer terminal, controls the gas in the first gas storage 540 to push the water-blocking piston 520 forward after passing through the first launch valve 541. The thrust generated by the water-blocking piston 520 will be converted into water pressure in the crack to achieve the simulation of the seepage water pressure. The working condition of the water-stop valve 531 is judged according to the water pressure sensor 550. If the water pressure required by the experiment is reached, the water-stop valve 531 can be closed to ensure the stability of the water pressure in the crack of the rock sample. A vertical jack is adjusted to a position where the rock sample can be horizontally aligned with the rock sample joint, and then the rock sample is placed on it to ensure stability. The remaining jacks are slowly adjusted so that the rock sample is at the center of each force. After the seepage water pressure is replenished, oil pressure can be applied from the oil filling port. The oil filling port 110 is controlled by the computer terminal. Under the action of the jack, the rock sample is given vertical and horizontal forces. At this time, the rock sample is in a simulated true triaxial stress state. The oil pressure and the jack are both controlled by the computer to achieve independent stress application. The gas in the second gas storage 810 is ejected through the second launch valve 811 so that the impact body 821 carries energy and rushes toward the incident rod 822. The incident rod 822 hits the rock sample through the smooth sleeve 830, so as to simulate the impact stress caused to the surrounding rock by the disturbance during tunnel excavation. Under the action of the impact stress, the cracks in the rock sample are further developed, resulting in the penetration of the cracks. The crack detector 610 can capture the layout of the cracks inside the rock sample through the probe 620. The computer terminal can derive the stress state of the rock sample, the impact stress under which the incident rod 822 rushes toward the rock sample, and the development of the cracks, that is, whether the crack layout is through, so as to achieve the experimental purpose.

[0063] This test method can simulate rock samples under true triaxial stress state, so as to realize the crack penetration caused by impact disturbance during tunnel excavation, as well as the law of crack development and seepage water pressure. The influence law of impact disturbance when the rock sample cracks penetrate can be found to ensure the safety of tunnel excavation personnel.

[0064] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A device for simulating rock crack penetration during tunnel excavation, characterized in that: include: A pressure test box, wherein the top of the pressure test box is provided with an oil filling port, and the bottom of the pressure test box is provided with an oil outlet; Vertical jacks arranged in pairs, arranged oppositely on the bottom and top surfaces of the pressure test box; The transverse jacks are arranged in pairs and are arranged on opposite sides of the pressure test box. The vertical jack and the transverse jack are arranged in the pressure test box through a sealing sleeve. A seepage water pressure loading module is used to provide water pressure to the rock sample fissures of the rock sample. The seepage water pressure loading module includes a water tank, a water-isolating piston, a high-pressure water pipe and a first gas storage device. The high-pressure water pipe connects the rock sample fissures with the water tank. The water-isolating piston is arranged in the water tank. The water-isolating piston can move along the water tank. One end of the first gas storage device is connected to the water tank. A first launch valve is arranged at the outlet of the first gas storage device. The water-isolating piston moves by controlling the first launch valve to be opened or closed. A sealing fixture assembly is clamped by the vertical jack and the horizontal jack, the sealing fixture assembly includes a sealing cavity for placing a rock sample, the rock sample is provided with a rock sample crack, the sealing fixture assembly includes an upper cover plate, a lower cover plate, a left pressure plate, a right pressure plate and two side plates, a sealing plate is placed between the left pressure plate and the right pressure plate and the rock sample, the sealing plate and the rock sample are sealed and adhered by silicone rubber, and the high-pressure water pipe connects the rock sample crack with the water tank through the left pressure plate or the right pressure plate; An impact force application module, used for applying impact disturbance to the rock sample; A crack development monitoring module, comprising a crack detector and a probe, wherein the probe is used to detect the rock sample, and the probe is connected to the crack detector; A control system is connected with the crack detector, the seepage water pressure loading module and the impact force application module.

2. The rock crack penetration device for simulating tunnel excavation according to claim 1, characterized in that: The seepage water pressure loading module also includes a water pressure sensor, which is arranged on a pipeline between the high-pressure water pipe, the water tank and the first gas storage device.

3. The rock crack penetration device for simulating tunnel excavation according to claim 1, characterized in that: The water tank is a rectangular parallelepiped, a water stop valve is provided at the connection end between the high-pressure water pipe and the water tank, and a rubber piston is provided at the outlet end of the high-pressure water pipe.

4. The rock crack penetration device for simulating tunnel excavation according to claim 1, characterized in that: Sealing strips are arranged between the upper cover plate, the lower cover plate, the left pressure-bearing plate and the right pressure-bearing plate.

5. The rock crack penetration device for simulating tunnel excavation according to claim 1, characterized in that: The impact force application module includes a second gas reservoir, an impact part and a sleeve. The outlet of the second gas reservoir is provided with a second launch valve. One end of the sleeve is connected to the outlet of the second gas reservoir, and the other end of the sleeve is connected to the sealing clamp assembly. The impact part is arranged in the sleeve, and the control system is connected to the second launch valve. By controlling the second launch valve to open or close, the impact part applies impact disturbance to the rock sample.

6. The rock crack penetration device for simulating tunnel excavation according to claim 5, characterized in that: The impact part includes a striker and an incident rod, wherein the striker is located between the second gas storage outlet and the front end of the incident rod.

7. The rock crack penetration device for simulating tunnel excavation according to claim 1, characterized in that: The impact force application module includes a spring and an impact part. By controlling the spring, the impact part applies impact disturbance to the rock sample.

8. A test method, using the rock crack penetration device for simulating tunnel excavation as claimed in any one of claims 1 to 7, characterized in that: include: Prepare a rock sample, manufacture the sealing fixture assembly according to the size of the rock sample, mechanically process the rock sample to form an artificial rock sample crack, clean it with alcohol, and coat the minimum stress surface of the rock sample with silicone rubber; Adjusting the vertical jack and the horizontal jack so that the rock sample is placed in the center and assembling the rock sample joint; The control system controls the seepage water pressure loading module to provide water pressure to the rock sample cracks in the rock sample, The control system controls the vertical jack to apply vertical stress to the rock sample, and the control system controls the transverse jack to apply transverse stress to the rock sample. The control system controls the oil injection port to apply oil pressure, thereby simulating a natural stress state. The control system controls the impact force application module to apply impact disturbance to the rock sample, and the crack development monitoring module detects the extension of the rock sample cracks and sends the information to the control system.

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