Large-scale model experiment device and method for excavation, water filling and splitting of high-internal-external-water high-pressure tunnel

Abstract

The invention discloses a large-scale model experiment device and method for excavation and water-filling splitting of a high-internal-external-water high-pressure tunnel. The device comprises an intelligent control excavation supporting telescopic system, an intelligent control excavation load acting system, a barrel-shaped three-way counter-force system, a three-way stress loading system, an inner water pressure control and sealing system, an outer water pressure control system, a temperature control system, a multi-element monitoring information acquisition system and a lining tunnel physical model sample. The barrel-shaped three-way counter-force system takes a counter-force component as a main body, the three-way stress loading system takes a pressurizing component as a main body, and the internal and external water pressure and temperature control system takes a water tunnel seal as a main body to realize sealing and internal water pressure loading to be matched with a water-rich condition applied by a water pipe and a heating plate to adjust the temperature; according to the invention, tunnel multi-mode excavation simulation under three-dimensional stress THM multi-field coupling, water filling and draining lining tunnel operation simulation under high internal and external water pressure, whole-process physical simulation of surrounding rock hydraulic fracturing and monitoring of surrounding rock and lining stress, deformation, internal and external water pressure and seepage multi-element information are realized.

Description

Technical Field

[0001] The invention belongs to the field of geotechnical engineering technology, and specifically is a large-scale model experimental device and method for excavation and water-filling splitting of a high-pressure tunnel with internal and external water. Background Art

[0002] As an important field in infrastructure construction and resource development, geotechnical engineering faces many challenges, including high ground stress, high temperature and high pressure, rock fracture, tunnel water inrush and other problems. It also carries the heavy tasks of underground mining, tunnel construction and geotechnical research. The smooth progress of geotechnical engineering is directly related to the safety, stability and sustainability of the project. There are a large number of structural surfaces and fault zones in the natural rock mass, which greatly change the integrity of the rock mass and affect the stability of the engineering rock mass. These characteristics make the rock mass prone to earthquakes, landslides, rock bursts and other engineering disasters when subjected to high temperature and high water pressure. It causes damage to the construction, casualties, economic losses to the project, etc. Therefore, it is of great significance to study the complex and diverse underground geotechnical and explore new devices.

[0003] On the one hand, geotechnical engineering is often done deep underground, and the existence of groundwater requires underground devices to work under high water pressure. On the other hand, as underground rock engineering continues to expand to deeper depths, the impact of temperature on rock damage is becoming increasingly prominent. Generally speaking, for every 100 meters increase in depth, the rock temperature will increase by 3°C, and at about 5,000 meters underground, the temperature can reach 180°C. Temperature is one of the key factors affecting the deformation and damage of deep hard rock.

[0004] There are often various situations underground, one of which is the rise and fall of groundwater. During the rise and fall of groundwater, the tunnels will repeatedly flow between filling and draining, and when the water pressure is too high, hydraulic fracturing of the rock will occur.

[0005] The current conventional tunnel shield excavation simulation experimental equipment, such as the open shield excavation simulation equipment, is only suitable for stable soil layer construction. When the soil layer stability is poor, other assistance is required. The closed shield excavation simulation equipment cannot be directly observed by personnel.

[0006] In summary, the conventional large-scale physical model experimental devices and methods of tunnels still have the following shortcomings: they cannot effectively simulate the underground high temperature and high water pressure environment, cannot simulate the surrounding rock hydraulic fracturing of high temperature tunnels under three-dimensional stress and water-rich conditions, and cannot simulate the filling and drainage simulation of high temperature water tunnels with internal and external water pressure lining under three-dimensional stress. It is difficult to monitor and collect information such as stress, deformation, temperature, and water pressure, and cannot simulate different excavation methods. Some equipment can simulate high water pressure or high temperature environments, but they have not been able to integrate them and have not been able to achieve intelligent monitoring and information collection.

[0007] In addition, the existing equipment can only provide one way of excavation, which cannot achieve the rock cutting in the simulation project. Therefore, the large-scale physical model experimental equipment and technology of the tunnel should be improved to more realistically simulate the shield-containing The failure mechanism of structural excavation has far-reaching significance for improving the safety and stability of geotechnical engineering.

[0008] Based on this, a system was developed that can simulate intelligent excavation and monitoring under high temperature, high water pressure and multiple coupling conditions. Experimental equipment for collecting stress, deformation, temperature and observing the working conditions and performance of lining and surrounding rock to carry out experiments under high temperature and high water Experimental study on excavation under coupling of multiple conditions such as pressure. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a large-scale model for high internal and external water high pressure tunnel excavation and water filling and splitting The experimental device and method are designed to simulate the excavation under the coupling of multiple conditions such as high temperature and high pressure in the underground and simulate the cofferdam due to water pressure. The hydraulic fracturing and external water pressure damage can be observed, and the failure performance of the lining under high head pressure can be recorded and observed. and its working conditions.

[0010] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a high internal and external water high pressure tunnel excavation water filling The experimental device and method for splitting large-scale models include an intelligent control excavation support expansion system, an intelligent control excavation load action system, a barrel-shaped Three-way reaction force system, three-way stress loading system, internal water pressure control and sealing system, external water pressure control system, temperature control system, multi-element monitoring information collection system, and lining tunnel physical model; the water pressure tunnel model includes: barrel-shaped three-way reaction force system, three-way stress loading system, internal water pressure control and sealing system, external water pressure control system, temperature control system, The drilling rig assembly includes: intelligent excavation support and telescopic system, intelligent excavation load action system, The barrel-shaped three-way reaction system is the main frame of the hydraulic tunnel model. The three-way stress loading system is installed inside the barrel-shaped three-way reaction system. The temperature control system and the lining tunnel physical model are installed in the middle of the three-way stress loading system. The telescopic system is placed in front of the barrel-shaped three-way reaction system, and the intelligent excavation load action system is installed on the intelligent excavation support Above the telescopic system, the multi-dimensional monitoring information collection system and the barrel-shaped three-way reaction force system, three-way stress loading system, and internal water pressure control system are installed. The system and its sealing system, external water pressure control system, and temperature control system are connected and arranged inside the above system, and the oil circuit loading system The system controls the startup of the entire device.

[0011] The three-axis stress loading system includes front and rear bladders, a pressure plate, a hydraulic pillow, a wedge-shaped pressure head, front and rear loading pumps, a vertical Direct loading pump, horizontal loading pump, the front and rear capsules are a square metal plate with a circular hollow in the middle fixed on the model load On the cover plate, the front and rear loading pumps are opposite to the horizontal loading pump and connected to the front and rear bags, which should meet the pressure of the front and rear bags on both sides of the barrel. Force balance loading, when the water injection pressure increases, the stress on the loading model remains unchanged. P w ×S1=(P0+ΔP f )×S2 (1) Where P w is the water injection pressure, S1 is the area of ​​the front and rear capsules, P0 is the initial stress, ΔP f To increase stress, S2 is the contact area between the front and rear bags and the physical model of the lining tunnel. The pressure plate is a metal plate of the same size and shape as the front and rear bags, installed on the inner side of the front and rear bags. The wedge-shaped pressure head is four rectangular metal plates attached to the outside of the heating plate. The hydraulic pillow is four rectangular metal plates attached to the outside of the wedge-shaped pressure head, which can apply pressure to the physical model of the lining tunnel. The vertical loading pump is connected to the upper and lower pieces of the hydraulic pillow, and the horizontal loading pump is connected to both sides of the hydraulic pillow.

[0012] The barrel-shaped three-way reaction force system includes a base, a model bearing cylinder, a model bearing cover plate, and a reaction force pad. The base is a hollow rectangular block in the middle of the prism, and the left and right surfaces of the prism are designed with semicircular holes with the same curvature as the frame. It is installed at the bottom of the entire device and is in continuous arc contact with the model bearing cylinder. The model bearing cylinder is a thick-walled cylinder installed on the base and fits tightly with the base. The wall thickness of the model bearing cylinder is determined as follows:

[0013] Model bearing cylinder Model bearing cylinder wall thickness is determined according to the unfavorable combination of operating conditions and is divided into four working conditions: The water pressure in the tunnel of the first working condition model: The water pressure in the tunnel of the second working condition model acts together with the maximum principal stress of the model: The third working condition model has the water pressure in the tunnel acting together with the second principal stress of the model: The fourth working condition model has the water pressure in the tunnel acting together with the third principal stress of the model: in are the hoop average stress, radial average stress, and axial average stress, respectively. The first principal stress in the cylinder under internal pressure is the hoop stress. r1 is the inner diameter, i.e., the vertical straight-line distance from the center of the model-bearing cylinder to the inner surface. r2 is the outer diameter, i.e., the vertical straight-line distance from the center of the model-bearing cylinder to the outermost surface. r is the vertical straight-line distance from the center of the cylinder to the center of the inner and outer surfaces. P s is the initial water pressure, P p is the reaction force of the loading component, σ g is the tensile stress of the model bearing cover, S g is the area of ​​the model bearing cover plate, h is the length of the model bearing cylinder, σ3 is the length of the model bearing cylinder, σ1 is the first principal stress, σ2 is the second principal stress, σ3 is the third principal stress,

[0014] t is the wall thickness of the model bearing cylinder, where the annular stress is mainly generated by the balance of the tensile stress of the cylindrical steel plate and the water pressure, the radial stress is mainly provided by the normal water pressure and the axial deformation compression during loading, and the tensile stress on both sides is mainly provided by the model bearing cover plates on both sides to prevent rock deformation, the water pressure acting on the model bearing cover plates on both sides, and the axial stress acting on the rock mass.

[0015] The strength judgment criteria for cylinders under the fourth strength criterion are: K is the ratio of the inner and outer diameters, that is, the ratio of the vertical straight line distance from the center of the cylinder to the outermost surface to the vertical straight line distance from the center of the cylinder to the inner surface.

[0016] Substituting the four working conditions into formula (15), we can obtain that t1 is the wall thickness of the model load-bearing cylinder required for working condition 1, t2 is the wall thickness of the model load-bearing cylinder required for working condition 2, t3 is the wall thickness of the model load-bearing cylinder required for working condition 3, and t4 is the wall thickness of the model load-bearing cylinder required for working condition 4.

[0017] Finally, the wall thickness of the model load-bearing cylinder is determined to be t min =[t1, t2, t3, t4]max Where [σ] is the allowable stress of the material. The wall thickness of the bearing cylinder of the final design model should be multiplied by the safety factor M to consider the safety during operation. That is, the wall thickness of the bearing cylinder of the final design model is Mt min ,

[0018] The model bearing cover is a metal component with a closed internal space and is fixed on a thick-walled cylinder by screws. To calculate the thickness of the model bearing cover, the external force is simplified first, and the direction of the external force that mainly affects the thickness of the model bearing cover is radial. The model bearing cover is regarded as a component composed of multiple small cylinders. One of the cylinders is analyzed separately, and all its parts are subjected to radial external forces. The external force on a single cylinder is regarded as a uniformly distributed load imposed on the single cylinder by the radial average stress. The most unfavorable section position is the point with the maximum bending moment. The bending moment diagram caused by the radial force is drawn for the single cylinder, and the most unfavorable section position is the middle of the single cylinder, which is set as the dangerous B section. Where M yB is the bending moment of the dangerous section B, L is the length of a single cylinder, and the single cylinder with the largest L, i.e. the middle of the model bearing cover plate, is selected as the next analysis.

[0019] The thickness of the model bearing cover is the diameter of a single cylinder and should satisfy: Wherein d is the wall thickness of the model bearing cylinder of the model bearing cover plate, [σ] is the allowable stress, and the reaction pad is an arc-shaped metal block that fits the thick-walled cylinder and fits inside the thick-walled cylinder to provide reaction force support for the device.

[0020] The lined tunnel physical model is installed in the middle of the three-dimensional stress loading system. It is a rectangular rock lined tunnel physical model. The tunnel physical model and the engineering site conditions must maintain similar shapes and sizes, and the corresponding angles are equal, that is, the prototype and the model maintain a certain proportional relationship. The ratio of the prototype and the model is represented by λ, and the cross-sectional size of the model must meet the length ratio: Where L y For the prototype size, L s is the mold size of the tunnel physical model, λ0 is the ratio between the on-site tunnel and the model simulation tunnel, A1 is the cross-sectional area of ​​the on-site tunnel, L1 is the cross-sectional perimeter of the on-site tunnel, A2 is the cross-sectional area of ​​the model simulation tunnel, L2 is the cross-sectional perimeter of the model simulation tunnel,

[0021] The brittleness similarity ratio λ between the tunnel physical model and the original rock is εd Need to meet: Where ε p is the prototype peak strain, ε m is the peak strain of the tunnel physical model;

[0022] Dynamic elastic modulus E d and dynamic Poisson's ratio μd As an important indicator of rock dynamic properties, the dynamic elastic modulus similarity scale Similarity ratio to dynamic Poisson's ratio Satisfy the following formula: Where λ σ is the stress similarity scale; λ ε is the strain similarity scale, strain is a dimensionless physical quantity, then λ ε =1;

[0023] In order to ignore the boundary effect, the edge length a of the physical model of the lined tunnel needs to satisfy the following formula: Where d M The diameter of the physical model of the lined tunnel after drilling is twice the radius of the model simulation tunnel. D2 is the diameter of the model simulation tunnel. The axial dimension of the physical model of the lined tunnel is N times the cross-sectional dimension, N>0.3. The grouting material of the physical model of the lined tunnel must meet the mechanical properties similar to those of the original rock, such as stress, strain, peak residual strength, seepage characteristics, and hydraulic splitting strength. The peak strain and stress of the physical model of the lined tunnel are the same as those of the original rock at the project site, and the seepage coefficient, seepage law, and hydraulic splitting strength are the same as those of the original rock at the project site.

[0024] The temperature control system comprises a heating plate, which is four rectangular metal plates with energized heating wires inside and is attached to the physical model of the lining tunnel.

[0025] The internal water pressure control and its sealing system include an internal water pressure loading pump, an internal water diversion pipe, a filling and drainage valve, end plugs on both sides, a pull rod connecting the end plugs on both sides, an inner hole sealing sleeve, and a sealing loading pump. The pull rod is a metal rod with threads on both sides, which is connected to the end plugs on both sides by threads. The inner hole sealing sleeve is composed of a large cylinder and a small cylinder. The two cylinders are connected in alignment with the center and are installed on the end plugs for sealing to prevent water from overflowing. The end plug is composed of three round cakes with round holes in the middle. The round cake on the side close to the pull rod is also provided with multiple round holes around the middle round hole, which is used to block the outflow of water in the hole and is further fixed by fixing nuts and connecting pull rods with the end plugs on both sides. The internal water pressure loading pump is connected to the external water pressure loading pump on the outside of the water pressure tunnel model. In the internal hole, the two ends of the internal water pressure loading pump are respectively connected to the two ends of the filling and drainage valve. The filling and drainage valve is a control device for controlling the filling and drainage of the internal water pressure system. The sealing loading pump is installed on the right side of the internal and external water pressure loading pumps and is connected to both sides of the water tunnel seal.

[0026] The external water pressure control system includes an external water loading pipe, external water inlet and outlet valves, a connecting pipe, a connecting pipe seal, an inner liner, and an external water pressure loading pump. The external water loading pipe is a spiral water pipe with a one-way hole opened, and the connecting pipe is a right-angle iron pipe. The inner liner is a rock component loaded inside the hole after drilling. The external water inlet and outlet valves are control devices for external water pressure charging and drainage. The connecting pipe seal is a thick cylindrical rubber sleeve at the connection between the connecting pipe and the external water loading pipe. The external water pressure loading pump is connected to the internal water pressure loading pump outside the water pressure tunnel model and connected to the left and right connecting pipes inside the water pressure tunnel model.

[0027] The intelligent control excavation support telescopic system includes a drilling rig base, a guide rail, an x-axis motion block, a trolley motor, a servo motor, a slider, a tray, and a bottom bracket. The drilling rig base is a rectangular steel wire frame, which is composed of a rectangular wire frame connected to a cube wire frame, and then connected to the cube wire frame and the rectangular wire frame to form the bottom of the intelligent control excavation support telescopic system. The guide rail is a groove-shaped long strip track fixed to the base by bolts. The slider is a groove-shaped metal component that fits the size of the guide rail and is installed on the guide rail and connected to the tray by bolts. The support plate is a rectangular steel plate placed on a slider, the x-axis motion block is a circular metal component, in which the parameter of the circular hole is the diameter of the protruding rod of the trolley motor, the x-axis motion block is strung on the trolley motor and the servo motor is installed on the right end of the trolley motor, and the whole composed of the x-axis motion block, the trolley motor and the servo motor is placed in the middle position of the two pairs of sliders under the support plate, and the bottom support is a rectangular steel frame composed of two small rectangular frames. The bearing cylinder is smaller than the base and is fixed on the support plate by bolts.

[0028] The intelligent control excavation load system includes a drill bit, a connecting shaft, a support, a linear bearing, a reaction rod, a tapered roller bearing, a planetary reducer, a hydraulic cylinder, and a pull rod. The drill bit has a variety of different shapes and sizes. The drill bit has a variety of different shapes and sizes. The drill bit diameter should meet the ratio of the current hole diameter of the project to the prototype and model. The connecting shaft is a large thick cylinder and a small thick cylinder. The two cylinders are aligned and connected in the center. It is an intermediate device connecting the drill bit and the planetary reducer. The support is a square steel plate with a round hole in the middle, and a reaction rod insertion hole is provided at each of the four corners of the steel plate. The support provides a working platform for drill excavation. The tapered roller bearing is a radial thrust rolling bearing. It is a circular steel plate with a round hole in the middle and is installed on a planetary reducer. The hydraulic cylinder provides power for the drill bit. Its left end is connected to the planetary reducer through a reaction rod and its right end is installed on the right end support. The pull rod is a stick-shaped metal component used to connect the left and right supports, and the reaction rod is a stick-shaped metal component.

[0029] The multivariate monitoring information acquisition system includes an engineering professional camera, an acoustic emitter, and a multifunctional data monitoring recorder. The engineering professional camera is an instrument placed in the drill hole of the lining tunnel physical model for photographing and recording internal changes. The acoustic emitter is a device that uses sound waves to detect the location and damage of cracks and damage in the lining tunnel physical model and is placed on both sides of the instrument and connected to the lining tunnel physical model through sensor lines. The multifunctional data monitoring recorder includes a water pressure needle for monitoring the water pressure changes of the lining tunnel physical model during the filling and drainage process, and a deformable optical fiber, a pressure needle, a seam measuring needle, a flow needle, a hole pressure needle, and a steel bar needle for monitoring the working conditions of the lining and surrounding rock. The multifunctional data monitoring recorder is arranged in the lining, the hydraulic pillow and the lining The physical model of the tunnel is built between the front and rear capsules and the physical model of the lining tunnel, between the heating plate and the physical model of the lining tunnel, and between the lining and the surrounding rock. The lining of the physical model of the lining tunnel is formed by pouring and curing concrete, and a plurality of annular steel bars are arranged at intervals perpendicular to the longitudinal axis of the pressure tunnel, and a plurality of longitudinal steel bars are arranged at intervals parallel to the longitudinal axis of the pressure tunnel. A crack is preset on the inner wall of the physical model of the lining tunnel, and two monitoring sections AA and BB perpendicular to the axis of the pressure tunnel are selected at intervals along the axial direction of the pressure tunnel. The measuring needles are arranged at the cracks of the monitoring sections containing prefabricated cracks, and the measuring needles span the prefabricated cracks and two are arranged at the prefabricated cracks. The center of the top of the cylindrical body is in the 0° direction, and the measuring needles are arranged in the order of The hole pressure needles are arranged at 0°, 45°, 90°, 135°, 170°, 225°, 270°, and 315° positions of the AA and BB monitoring sections in a clockwise direction. The hole pressure needles on each monitoring section are equidistant from the central axis of the pressure tunnel. The top center of the cylindrical body is the 0° direction. The water pressure needles are arranged on the outer wall of the lining at 0°, 100°, 150°, 225°, and 280° positions of the AA and BB monitoring sections in a clockwise direction. The top center of the cylindrical body is the 0° direction. The water pressure needles are arranged on the lining steel bars at 0°, 30°, 150°, 210°, and 320° positions of the AA and BB monitoring sections in a clockwise direction. Steel bar needle, when pouring the lining, the flow needle is pre-wound into a circle in the lining mold, arranged around the edge, and four circles of the deformed optical fiber are evenly arranged in the mold. The surrounding rock of the lining tunnel physical model is prefabricated by pouring, cutting and grinding the selected rock mass, and four cracks are preset in the surrounding rock. Along the axial direction of the pressure tunnel, a monitoring section 1-1 perpendicular to the axis of the pressure tunnel is set. With the top center as the 0° direction, four cracks are preset at 0°, 90°, 180°, and 270° in a clockwise direction. The top center of the square surrounding rock is the 0° direction, and the pressure needle is arranged inside the surrounding rock at positions of 15°, 75°, 105°, 165°, 195°, 255°, 285°, and 345° in a clockwise direction.The pressure needles are at equal distances from the central axis of the pressure tunnel. The water pressure needles are arranged at the cracks of the prefabricated cracks. The water pressure needles span the prefabricated cracks and are arranged three at each prefabricated crack. When making the surrounding rock, four circles of the deformed optical fiber are evenly arranged in the mold.

[0030] An installation method and a method for using a large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water, comprising the following steps:

[0031] Step 1: Place the base at the set position, install the thick-walled cylinder on top of the base and fit it tightly with screws, and fix the reaction pad on the inside of the thick-walled cylinder.

[0032] Step 2: Fix the hydraulic pillow horizontally in a square shape on the inside of the reaction pad, install a wedge-shaped pressure head and a multi-function data monitoring recorder on the inside of the hydraulic pillow, and finally install the heating plate on the inside of the wedge-shaped pressure head and install the multi-function data monitoring recorder;

[0033] Step 3: Place the drill base in a suitable position in front of the installed instrument and fix it, install a guide rail on the top of the drill base and fix it with screws, embed the slider in the guide rail, and then fix the support plate to the slider with screws;

[0034] Step 4: Assemble the x-axis motion block, the trolley motor and the servo motor into a complete kit and install it in the middle of the guide rail under the pallet, and then fix the bottom bracket to the pallet with screws;

[0035] Step 5: Install the tapered roller bearing on the planetary reducer and connect the fixed hydraulic cylinder to the right end of the planetary reducer. Install the linear bearing on the reaction rod and string it through the hydraulic cylinder. The left and right supports wrap all the above parts in the middle and the left and right supports are fixedly connected by connecting rods at both ends. Finally, connect the drill bit to the tapered roller bearing through the connecting shaft.

[0036] Step 6: The computer interface is connected to the force sensors, displacement sensors and deformation sensors of each loading cylinder respectively, and the force value and displacement deformation data of the physical model of the lining tunnel in each direction during the experiment are recorded by the computer; at the same time, the sound information of the rock sample experiment is collected in real time by means of acoustic emission and microseismic monitoring;

[0037] Step 7: Install the lining tunnel physical model in the three-dimensional stress loading system, and the various functional metal components are tightly fitted to the lining tunnel physical model;

[0038] Step 8: After the lining tunnel physical model is placed, fit the pressing plate to the front and back of the lining tunnel physical model, and then fit the front and rear capsules tightly to the pressing plate. After ensuring that everything is correct, install the multifunctional data monitoring recorder, cover the model bearing cover plate and fix it with screws;

[0039] Step 9: Start the loading device connected to the heating plate to heat up the physical model of the lined tunnel, and start the internal and external water pressure loading device to fill the external water loading pipe with water and apply water-rich conditions to the rock mass near the external water loading pipe through the one-way hole type external water loading pipe on the external water loading pipe;

[0040] Step 10: After the temperature is raised to the specified temperature, the front and rear and vertical loading devices are started, the front and rear bags begin to apply pressure to the pressure plate, and the pressure is transmitted to the front and rear of the lining tunnel physical model through the pressure plate. The hydraulic pillow begins to apply pressure to the wedge pressure head, and the pressure is transmitted to the heating plate through the wedge pressure head and finally transmitted to the four directions of the lining tunnel physical model through the heating plate;

[0041] Step 11: The pressure exerted by the front and rear bladders and the hydraulic pillow is transmitted to the physical model of the lining tunnel through the metal components. After the preloading is completed, the oil pressure is increased and the physical model of the lining tunnel is formally loaded to the pressure specified by the experiment;

[0042] Step 12: Start the intelligent multi-mode excavation system, the drill bit starts to rotate, and the trolley motor drives the support plate through the slide. The block moves along the X-axis on the guide rail in the direction of the physical model of the lining tunnel. After contact, excavation begins and the stress, deformation and other data during excavation are recorded until the excavation is completed. After the excavation is completed, the motor of the trolley is operated to drive the support plate to move along the X-axis on the guide rail through the slider in the direction away from the physical model of the lining tunnel until the drilling rig leaves the interior of the hydraulic tunnel model.

[0043] Step 13: After the physical model of the lining tunnel is excavated, a professional engineering camera is installed in the excavated hole. Then install the water tunnel seal and start the loading device to fill the internal holes sealed by the water tunnel seal with water to apply internal water pressure to seal it. The force applied by the seal loading satisfies Keep the sealing load greater than the water pressure and open the external water The flow control of the loading water pipe makes the water in the external water loading water pipe flow through the one-way hole opened in the external water loading water pipe to the physical structure of the lining tunnel. The model was subjected to water-rich conditions, and its internal water pressure, deformation, temperature change and stress were recorded. The lining was observed through an engineering camera. Destruction situation;

[0044] Step 14: Fill and drain water step by step into the water hole seal formed by the experimental device to simulate the groundwater pressure. In the working state of pressure loading and unloading, connect the pressure water pump to the joint of the water tunnel seal, and fill the water tunnel seal step by step. During the water filling process, water is continuously added until the lining is damaged. The data at this time is recorded and the water filling is continued until the surrounding rock is hydraulically fractured. This is the end point of the water filling stage, and the data of hydraulic fracturing are recorded. When the step-by-step water filling stage is completed, the water tunnel seal is opened for step-by-step drainage. The water pressure condition during the fine water filling process will be set to the water filling pressure. Pressure gradient, because the water pressure at the water point in the tunnel is generally not less than 0.3MPa, in the working state, it is 1.5 times, so the filling pressure gradient is rounded up. The degree is set to 0.5MPa per level and the water filling pressure increment is set to one tenth of the water filling pressure gradient. The number of water filling steps, the total number of water filling steps, and the total number of filling and drainage steps when the water filling pressure is 0.5MPa are as follows: S total =2×S (26) Where: S1 is the number of steps when the water filling pressure is equal to the set value, S is the total number of water filling steps S total P1 is the total number of steps for filling and draining water; is the set filling pressure, P1 is the design water head of the pressure tunnel, unit is MPa, ΔP is the loading of the step-by-step filling and drainage pressure and unloading amplitude, in MPa;

[0045] Step 15: When filling and draining the water tunnel seal step by step, if no damage occurs at each level or the value does not change, If there is a significant change, the following time can be met to continue to the next step according to the plan. The time for each level of filling, draining, pressurizing or depressurizing Length: Where T K The duration of the Kth stage of filling and draining pressure or depressurization, K is the number of steps of filling and draining step by step; During the step-by-step filling and drainage process, read the pressure display and record the changes in the internal water pressure; During the step-by-step filling and drainage process, the changes in the width of the lining cracks are recorded in real time; during the step-by-step filling and drainage process in the water tunnel seal, The multi-function data monitoring recorder records data and the professional engineering camera records video files. Collect sound information;

[0046] Step 16: During the internal water pressure loading and unloading process, the front and rear bladders are adjusted according to the filling pressure change formula and the drainage pressure change formula. The pressure plate is loaded and unloaded by the formula, and its dynamic pressure adjustment should satisfy the following formula; Ft =P+F1 (28) F=(F t -P) / 2 (29) Where F t The total pressure remains unchanged, F1 is the sum of the pressures on both sides, and F is the pressure on one side; P is the water pressure which satisfies Where S x is the number of water filling steps, S x The x in the The conditions to ensure that the internal water pressure of the physical model of the lining tunnel is coordinated with the external loading pressure and the total pressure remains constant The lower balanced loading is dynamically adjusted with the water pressure inside the surrounding rock so that the overall force of the surrounding rock remains unchanged during the water filling process. Continue to observe and simulate the hydraulic fracturing extending from the hole inside the surrounding rock, and record the pressure and deformation data. Observe and monitor the stress, strain, water content, lining damage audio and video of the physical model of the lining tunnel during the filling and drainage process, the hydraulic fracturing audio and video of the surrounding rock, and the crack width change. Record the stress change, strain, and other changes of the physical model of the lining tunnel during triaxial stress loading and temperature adjustment. Changes are observed, monitored and recorded;

[0047] Step 17: After all the experimental items are completed, start to unload the force, cool down and reduce the oil pressure, save the data and audio and video materials, and finally Finally, check the device condition and complete the experiment. Beneficial effects of the present invention

[0048] Compared with the prior art, the present invention has the following significant advantages: first, it truly simulates the underground environment of high temperature and high water pressure, and subdivides the water pressure into internal water pressure and external water pressure to make the simulated underground environment more realistic, realizes THM multi-field coupled excavation under three-dimensional stress, and multiple conditions can be applied and adjusted separately, which greatly improves the multi-dimensional function of the experiment, and multiple experiments can be carried out separately, that is, a set of equipment can realize the device conditions of multiple experiments, on this basis, it can realize the operation simulation of the lining tunnel under high internal and external water pressure after the lining is applied and the physical simulation of the whole process of hydraulic splitting of the surrounding rock, as well as the multi-information monitoring of the surrounding rock and lining stress, deformation, internal and external water pressure, seepage, cracking, and temperature gradient, and the changes in the inner cavity can be recorded through video data, and secondly, in order to meet the needs and ensure that the device can operate normally, the overall structure thick-walled cylinder is improved, the overall strength is improved, and the operation steps are simplified. The present invention provides practical and feasible hardware conditions for studying multi-factor simulation of underground real rock and soil and excavation under complex environments, which is of great significance to the field of rock mechanics research. Instruction Manual

[0049] Figure 1It is a three-dimensional schematic diagram of the structure of a large-scale model experimental device for excavation, water filling and splitting of a high internal and external water high pressure tunnel according to the present invention;

[0050] Figure 2 It is a front view of a large-scale model experimental device for excavation, water filling and splitting of a high internal and external water high pressure tunnel according to the present invention;

[0051] Figure 3 A top view of a large-scale model experimental device for excavation, water filling and splitting of a high internal and external water high pressure tunnel according to the present invention;

[0052] Figure 4 A three-dimensional schematic diagram of a hydraulic tunnel model of a large-scale model experimental device for excavating and water-filling and splitting a high-pressure tunnel with internal and external water in the present invention;

[0053] Figure 5 A cross-sectional view of a hydraulic tunnel model of a large-scale model experimental device for excavating and water-filling and splitting a high-pressure tunnel with internal and external water according to the present invention;

[0054] Figure 6 It is a front cross-sectional view of a water pressure tunnel model of a large-scale model experimental device for excavating and water-filling and splitting a high-pressure tunnel with internal and external water according to the present invention;

[0055] Figure 7 A three-dimensional schematic diagram of a drilling rig assembly of a large-scale model experimental device for excavating and water-filling and splitting a high-pressure tunnel with internal and external water according to the present invention;

[0056] Figure 8 A cross-sectional view of a drilling rig assembly of a large-scale model experimental device for excavating and water-filling and splitting a high-pressure tunnel with internal and external water according to the present invention;

[0057] Fig. 9 A side cross-sectional view of a drilling rig assembly of a large-scale model experimental device for excavating and water-filling and splitting a high-pressure tunnel with internal and external water according to the present invention;

[0058] Fig.10 It is a schematic diagram of an external water pressure filling device of a large-scale model experimental device for excavation, filling and splitting of a high internal and external water high pressure tunnel according to the present invention;

[0059] Fig.11 A schematic diagram of an internal water pressure filling device of a large-scale model experimental device for excavation, water filling and splitting of a high internal and external water high pressure tunnel according to the present invention;

[0060] Fig.12 A schematic diagram of the monitoring section position of the lining of a large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water in the present invention;

[0061] Fig.13 A schematic diagram of the monitoring section position of the surrounding rock of the large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water in the present invention;

[0062] Fig.14A schematic diagram of the arrangement of monitoring equipment for the surrounding rock 1-1 surface of a large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water according to the present invention;

[0063] Fig.15 It is a schematic diagram of the arrangement position of the steel bar gauge on the AA surface of the lining of the large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water in the present invention;

[0064] Fig.16 A schematic diagram of the arrangement of monitoring equipment for the lining BB surface of a large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water according to the present invention;

[0065] Fig.17 The oil circuit diagram of the large-scale model experimental device for excavation, water filling and splitting of a high internal and external water high pressure tunnel of the present invention;

[0066] Fig.18 It is a schematic diagram of the step-by-step filling and drainage scheme of the hydraulic tunnel model of the present invention.

[0067] Among them, 1-thick-walled cylinder, 2-reaction pad, 3-hydraulic pillow, 4-wedge-shaped pressure head, 5-heating plate, 6-model bearing cover plate, 7-front and rear capsules, 8-pressure plate, 9-external water loading water pipe, 10-water tunnel sealing, 101-end plug, 102-filling and drainage valve, 103-both end plugs connecting rod, 104-inner hole sealing sleeve, 105-fixing nut, 11-base, 12-lining, 13-lining tunnel physical model, 14-drill bit, 15-connecting shaft, 16-slider, 17-linear bearing, 18-tapered roller bearing, 19-bottom bracket, 20-drilling rig base, 21-guide rail left, 22-trolley motor, 2 3-servo motor, 24-right guide rail, 25-X-axis motion block, 26-hydraulic cylinder, 27-support plate, 28-connecting rods for plugging the ends of the drilling rig, 29-behind the support, 30-planetary reducer, 31-front of the support, 32-reaction stick, 33-cylinder cover, 34-acoustic emission, 35-multi-function data monitoring recorder, 36-engineering professional camera, 37-deformed optical fiber, 38-water pressure needle, 39-hole pressure needle, 40-rebar needle, 41-seam measuring needle, 42-connecting pipe, 43-external water inlet and outlet valves, 44-connecting pipe seal, 45-filling and drainage valve, 46-internal water diversion pipe, 47-pressure needle, 48-flow needle. DETAILED DESCRIPTION

[0068] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0069] In order to achieve the above object, the present invention adopts the following technical solution:

[0070] A large-scale model experimental device for high internal and external water high pressure tunnel excavation and water filling and splitting, including an intelligent control excavation support expansion and contraction system, an intelligent control excavation load action system, a barrel-shaped three-way reaction force system, a three-way stress loading system, an internal water pressure control and its sealing system, an external water pressure control system, a temperature control system, a multi-dimensional monitoring information collection system, and a 13-lined tunnel physical model; the water pressure tunnel model includes a barrel-shaped three-way reaction force system, a three-way stress loading system, an internal water pressure control and its sealing system, an external water pressure control system, a temperature control system, a multi-dimensional monitoring information collection system, and a drilling rig assembly including an intelligent control excavation support expansion and contraction system. The main frame of the hydraulic tunnel model is the barrel-shaped three-way reaction force system, the three-way stress The loading system is installed inside the barrel-shaped three-way reaction system, and the temperature control system is installed in close contact with the 13-lined tunnel physical model. The intelligent excavation support telescopic system is placed in the middle of the three-way stress loading system and in front of the barrel-shaped three-way reaction force system. The excavation load action system is installed above the intelligent excavation support telescopic system, and the multi-dimensional monitoring information collection system is connected with the barrel-shaped three-way reflective force system, three-way stress loading system, internal water pressure control and sealing system, external water pressure control system, temperature control system Connected and arranged inside the above systems, the oil circuit loading system controls the startup of the entire device.

[0071] The three-axis stress loading system includes 7-front and rear capsules, 8-pressure plates, 3-hydraulic pillows, 4-wedge pressure heads, and the 7- The front and rear bladders are a square metal plate with a circular hollow in the middle fixed on the 6-model load-bearing cover and connected to the horizontal loading pump. The vertical loading pump on the right side is connected to the pressure balance loading of the 7-front and rear bags on both sides of the barrel, ensuring loading when the water injection pressure increases. The stress on the model remains unchanged. P w ×S1=(P0+ΔP f )×S2 (1) Where P w is the water injection pressure, S1 is the area of ​​the front and rear capsules, P0 is the initial stress, ΔP f To increase stress, S2 is the front The contact area between the rear capsule and the lining tunnel physical model, the 8-pressure plate is a metal plate with the same size and shape as the 7-front and rear capsules. Installed on the inside of the front and rear capsules 7, the wedge-shaped pressure head is four rectangular metal plates attached to the outside of the heating plate 5, the 3-hydraulic pillow Four rectangular metal plates are attached to the 4-wedge-shaped pressure head to apply pressure to the 13-lined tunnel physical model and to the front and rear Loading pump connected.

[0072] The barrel-shaped three-way reaction force system includes 11-base, 1-model bearing cylinder, 6-model bearing cover plate, 2-reaction force The base 11 is a hollow rectangular block in the middle of the prism, and the left and right sides of the prism are designed with semicircular holes with the same curvature as the frame. The metal component supporting all parts is installed at the bottom of the device. The 1-model bearing cylinder is a thick-walled cylinder installed at 11-base fits tightly with 11-base and should satisfy the following formula

[0073] The determination of the wall thickness of the model load-bearing cylinder is divided into four working conditions: The water pressure in the tunnel of the first working condition model: The water pressure in the tunnel of the second working condition model acts together with the maximum principal stress of the model: The third working condition model has the water pressure in the tunnel acting together with the second principal stress of the model: The fourth working condition model has the water pressure in the tunnel acting together with the third principal stress of the model: in σ r p , σ z p are the hoop average stress, radial average stress, and axial average stress, respectively. The first principal stress in the cylinder under internal pressure is the hoop stress. r1 is the inner diameter, i.e., the vertical straight-line distance from the center of the model-bearing cylinder to the inner surface. r2 is the outer diameter, i.e., the vertical straight-line distance from the center of the model-bearing cylinder to the outermost surface. r is the vertical straight-line distance from the center of the cylinder to the center of the inner and outer surfaces. P s is the initial water pressure, P p is the reaction force of the loading component, σ g is the tensile stress of the model bearing cover, S g is the area of ​​the model bearing cover, h is the length of the model bearing cylinder, σ1 is the first principal stress, σ2 is the second principal stress, σ3 is the third principal stress,

[0074] t is the wall thickness of the model bearing cylinder, where the annular stress is mainly generated by the balance of the tensile stress of the cylindrical steel plate and the water pressure, the radial stress is mainly provided by the normal water pressure and the axial deformation compression during loading, and the tensile stress on both sides is mainly provided by the model bearing cover plates on both sides to prevent rock deformation, the water pressure acting on the model bearing cover plates on both sides, and the axial stress acting on the rock mass.

[0075] The strength judgment criteria for cylinders under the fourth strength criterion are: K is the ratio of the inner and outer diameters, that is, the ratio of the vertical straight line distance from the center of the cylinder to the outermost surface to the vertical straight line distance from the center of the cylinder to the inner surface.

[0076] Substituting the four working conditions into the above formula, we can obtain that t1 is the wall thickness of the model load-bearing cylinder required for working condition 1, t2 is the wall thickness of the model load-bearing cylinder required for working condition 2, t3 is the wall thickness of the model load-bearing cylinder required for working condition 3, and t4 is the wall thickness of the model load-bearing cylinder required for working condition 4. Make sure that the minimum wall thickness of the model load-bearing cylinder is not less than the maximum wall thickness of the model load-bearing cylinder calculated under the above four working conditions: t min ≥[t1, t2, t3, t4] max

[0077] Where [σ] is the allowable stress of the material. The wall thickness of the bearing cylinder of the final design model should be multiplied by the safety factor M to consider the safety during operation. That is, the wall thickness of the bearing cylinder of the final design model is Mt min ,

[0078] The 6-model load-bearing cover plate is a metal component with a closed internal space and is fixed on the 1-thick-walled cylinder by screws. To calculate the thickness of the 6-model load-bearing cover plate, the external force is simplified first, and the direction of the external force that mainly affects the thickness of the 6-model load-bearing cover plate is radial. The 6-model load-bearing cover plate is regarded as a component composed of multiple small cylinders. One of the cylinders is analyzed separately, and all its parts are subjected to radial external forces. The external force on a single cylinder is regarded as a uniformly distributed load imposed by the radial average stress on the single cylinder. The most unfavorable section position is the point where the bending moment is maximum. The bending moment diagram caused by the radial force is drawn for the single cylinder, and the most unfavorable section position is the middle of the single cylinder, which is set as the dangerous B section. Where M yB is the bending moment of the dangerous section B, L is the length of a single cylinder, and the single cylinder with the largest L, i.e. the middle of the 6-model bearing cover plate, is selected as the next analysis. The thickness of the model bearing cover is the diameter of a single cylinder, which should satisfy Wherein d is the wall thickness of the model bearing cylinder of the model bearing cover plate, [σ] is the allowable stress, and the 2-reaction pad is an arc-shaped metal block fitted to the 1-thick-walled cylinder and fitted inside the 1-thick-walled cylinder to provide reaction force support for the device.

[0079] The 13-lined tunnel physical model is installed in the middle of the three-dimensional stress loading system. It is a rectangular rock 13-lined tunnel physical model. The tunnel physical model and the engineering site conditions must maintain similar shapes and sizes, and the corresponding angles are equal, that is, the prototype and the model maintain a certain proportional relationship. The ratio of the prototype and the model is represented by λ, and the cross-sectional size of the model must meet the length ratio: Where L y For the prototype size, L s is the mold size of the tunnel physical model, λ0 is the ratio between the on-site tunnel and the model simulation tunnel, A1 is the cross-sectional area of ​​the on-site tunnel, L1 is the cross-sectional perimeter of the on-site tunnel, A2 is the cross-sectional area of ​​the model simulation tunnel, L2 is the cross-sectional perimeter of the model simulation tunnel,

[0080] The brittleness similarity ratio λ between the tunnel physical model and the original rock is εd Need to meet: Where ε p is the prototype peak strain, ε m is the peak strain of the tunnel physical model;

[0081] Dynamic elastic modulus E d and dynamic Poisson's ratio μ d As an important indicator of rock dynamic properties, the dynamic elastic modulus similarity scale Similarity ratio to dynamic Poisson's ratio Satisfy the following formula: Where λ σ is the stress similarity scale; λ ε is the strain similarity scale, strain is a dimensionless physical quantity, then λ ε =1;

[0082] In order to ignore the boundary effect, the edge length a of the physical model of the lined tunnel needs to satisfy the following formula: Where d Mis the hole diameter of the 13-lined tunnel physical model after drilling, which is twice the radius of the model simulated tunnel, D2 is the diameter of the model simulated tunnel, and the grouting material of the 13-lined tunnel physical model must meet the mechanical properties similar to those of the original rock, such as stress, strain, peak residual strength, seepage characteristics, and hydraulic splitting strength. The peak strain and stress of the 13-lined tunnel physical model are the same as those of the original rock at the project site, and the seepage coefficient, seepage law, and hydraulic splitting strength are the same as those of the original rock at the project site;

[0083] The temperature control system includes a heating plate, wherein the heating plate 5 is four rectangular metal plates with energized heating wires inside and is attached to the lining tunnel physical model 13.

[0084] The internal water pressure control and sealing system include an internal water pressure loading pump, 46-internal water diversion pipe, 45-filling and drainage valve, 101-end plugs on both sides, 103-end plug connecting rods, 104-inner hole sealing sleeve, and a sealing loading pump. The end plug connecting rod 101 is a metal rod with threads on both sides and is connected to the end plugs 101 through threads. The inner hole sealing sleeve 104 is composed of a large cylinder and a small cylinder. The two cylinders are connected in an aligned center and are used for sealing to prevent water from overflowing and is installed on the end plugs. The 101-end plug connecting rod is a metal rod with threads on both sides and is connected to the end plugs 101 through threads. The inner hole sealing sleeve 104 is composed of a large cylinder and a small cylinder. The two cylinders are connected in an aligned center and are used for sealing to prevent water from overflowing and is installed on the end plugs. The plug is composed of three round cakes with a round hole in the middle. The round cake on the side close to the pull rod is also provided with multiple round holes around the middle round hole, which is used to block the water outflow in the hole and is further fixed by the pull rod connected to the plugs on both sides through fixing nuts. The internal water pressure loading pump and the external water pressure loading pump are connected to the outside of the water pressure tunnel model. In the internal hole, the two ends of the internal water pressure loading pump are respectively connected to the two ends of the 45-filling and drainage valve. The 45-filling and drainage valve is a control device for controlling the filling and drainage of the internal water pressure system. The sealed loading pump is installed on the right side of the internal and external water pressure loading pumps and is connected to both sides of the water tunnel seal.

[0085] The external water pressure control system includes 9-external water loading water pipe, 43-external water inlet and outlet valves, 42-connecting pipe, 44-connecting pipe seal, 12-lining, and external water pressure loading pump. The 9-external water loading water pipe is a spiral water pipe with a one-way hole, the 42-connecting pipe is a right-angle iron pipe, the 12-lining is a rock component loaded inside the hole after drilling, the 43-external water inlet and outlet valves are a control device for external water pressure charging and drainage, the connecting pipe seal is a thick cylindrical rubber sleeve at the connection between the connecting pipe and the external water loading water pipe, the external water pressure loading pump is connected to the internal water pressure loading pump outside the water pressure tunnel model, and is connected to the left and right connecting pipes inside the water pressure tunnel model.

[0086] The intelligent control excavation support telescopic system includes 20-drilling rig base, 24-guide rail, 25-x-axis motion block, 22-trolley motor, 23-servo motor, 16-slider, 27-tray, 19-bottom bracket, the 20-drilling rig base is a steel wire frame composed of a rectangular wire frame connected to a cube wire frame and then connected to the cube wire frame and the rectangular wire frame to form the bottom part of the intelligent control excavation support telescopic system, the 24-guide rail is a groove-shaped long strip track fixed to the base by bolts, and the 16-slider is a groove-shaped metal component that fits the size of the guide rail and is installed on the guide rail by screws. The nail is connected to the 27-support plate, and the 27-support plate is a rectangular iron plate placed on the 16-slider. The 25-x-axis motion block is a circular metal component in which the circular hole parameter is the diameter of the protruding rod of the trolley motor. The x-axis motion block is strung on the 22-trolley motor and the 23-servo motor is installed on the right end of the 22-trolley motor. This whole is placed in the middle position of the two pairs of 16-sliders under the 27-support plate. The 19-bottom support is a rectangular steel frame composed of two small rectangular frames. The 1-thick-walled cylinder is smaller than the 20-drilling rig base and is fixed on the 27-support plate by screws.

[0087] The intelligent control excavation load action system includes 14-drill bit, 15-connecting shaft, 29-support, 17-linear bearing, 32-reaction rod, 18-tapered roller bearing, 30-planetary reducer, 26-hydraulic cylinder, 28-connecting rods at both ends of the drilling rig. The 14-drill bit has a variety of different shapes and sizes. The drill bit diameter should meet the ratio of the current hole diameter of the project to the prototype and model. The 15-connecting shaft is a large thick cylinder and a small thick cylinder. The center alignment connection of the two cylinders is an intermediate device connecting the 14-drill bit and the 30-planetary reducer. The 29-support is a square steel plate A circular hole is provided in the middle, and a reaction rod insertion hole is provided at each corner of the steel plate. The 29-support provides a working platform for the 14-drill excavation. The 18-tapered roller bearing is a radial thrust rolling bearing. It is a circular steel plate with a circular hole in the middle and is installed on the 30-planetary reducer. The 26-hydraulic cylinder provides power for the 14-drill. Its left end is connected to the 30-planetary reducer through the 32-reaction rod, and the right end is installed on the right end 29-support. The 103-side end plug connecting rods are stick-shaped metal components used to connect the left and right 29-supports, and the 32-reaction rods are stick-shaped metal components.

[0088] The multivariate monitoring information acquisition system includes 36-engineering professional cameras, 34-acoustic emitters, and multifunctional data monitoring recorders. The 36-engineering professional cameras are instruments placed in the drilled holes of the 13-lining tunnel physical model for photographing and recording internal changes. The 34-acoustic emitters are devices that use sound waves to detect the locations and conditions of cracks and damage in the 13-lining tunnel physical model. The devices are placed on both sides of the instrument and are connected to the 13-lining tunnel physical model through sensor lines. The multifunctional data monitoring recorder includes 38-water pressure needles for monitoring the changes in water pressure of the lining tunnel physical model during the filling and drainage process, and 37-deformable optical fibers, 47-pressure needles, 41-seam measuring needles, and 48-flow meters for monitoring the working conditions of the lining and surrounding rock. The multifunctional data monitoring recorder is arranged in the lining, between the hydraulic pillow and the physical model of the lining tunnel, between the front and rear capsules and the physical model of the lining tunnel, between the heating plate and the physical model of the lining tunnel, and between the lining and the surrounding rock. The lining of the physical model of the lining tunnel is formed by pouring and curing concrete, in which a plurality of annular steel bars are arranged at intervals perpendicular to the longitudinal axis of the pressure tunnel, and a plurality of longitudinal steel bars are arranged at intervals parallel to the longitudinal axis of the pressure tunnel. A crack is preset on the inner wall of the physical model of the lining tunnel, and two monitoring sections AA and BB perpendicular to the axis of the pressure tunnel are selected at intervals along the axial direction of the pressure tunnel. The 41-seam measuring needle is arranged in the monitoring section containing the prefabricated crack. The cracks are located at the center of the top of the cylindrical body, the 41-seam measuring needle spans the prefabricated cracks and two are arranged at the prefabricated cracks, the top center of the cylindrical body is in the 0° direction, and the 39-hole pressure needle is arranged at 0°, 45°, 90°, 135°, 170°, 225°, 270°, and 315° positions of the AA and BB monitoring sections in a clockwise direction, and the hole pressure needles on each monitoring section are equidistant from the central axis of the pressure tunnel, the top center of the cylindrical body is in the 0° direction, and the 38-water pressure needle is arranged on the outer wall of the lining at 0°, 100°, 150°, 225°, and 280° positions of the AA and BB monitoring sections in a clockwise direction, respectively. The 40-steel needles are arranged on the lining steel bars at positions of 0°, 30°, 150°, 210°, and 320° of the AA and BB monitoring sections in a clockwise direction. When casting the lining, the flow needle is pre-wound into a circle in the lining mold, and a circle is arranged around the edge, and four circles of the 37-deformed optical fiber are evenly arranged in the mold. The surrounding rock of the physical model of the lining tunnel is prefabricated by casting, cutting, and grinding of the selected rock mass, and four cracks are preset in the surrounding rock. Along the axial direction of the pressure tunnel, a monitoring section 1-1 perpendicular to the axis of the pressure tunnel is set, with the top center as the 0° direction, and four cracks are preset at 0°, 90°, 180°, and 270° in a clockwise direction, respectively, and the top center of the square surrounding rock is the 0° direction.The 47-pressure needles are arranged inside the surrounding rock at the positions of 15°, 75°, 105°, 165°, 195°, 255°, 285°, and 345° in the clockwise direction. The 47-pressure needles are at equal distances from the central axis of the pressure tunnel. The 38-water pressure needles are arranged at the cracks of the prefabricated cracks. The 38-water pressure needles span the prefabricated cracks and three are arranged at each prefabricated crack. When making the surrounding rock, four circles of the 37-deformed optical fibers are evenly arranged in the mold.

[0089] A method for installing and using a large-scale model experimental device for high internal and external water high pressure tunnel excavation and water filling and splitting, comprising the following steps:

[0090] Step 1: Place the 11-base at the set position, install the 1-thick-walled cylinder on the top of the 11-base and fit it tightly with screws, and fix the 2-reaction pad on the inside of the 1-thick-walled cylinder;

[0091] Step 2: Fix the 3-hydraulic pillow horizontally in a square shape on the inside of the 2-reaction pad, install the wedge-shaped pressure head and the multi-function data monitoring recorder on the inside of the 3-hydraulic pillow, and finally install the 5-heating plate on the inside of the wedge-shaped pressure head and the multi-function data monitoring recorder;

[0092] Step 3: Place the 14-drill bit 11-base in a suitable position in front of the installed instrument and fix it, install the 21-guide rail on the 14-drill bit 11-base and fix it with screws, embed the 16-slider in the 21-guide rail, and then fix the 27-support plate to the 16-slider with screws;

[0093] Step 4: Assemble the 25-X-axis motion block, 22-trolley motor and 23-servo motor into a complete kit and install it in the middle of the 21-guide rail under the 27-pallet, and then fix the 19-bottom bracket to the 27-pallet with screws;

[0094] Step 5: Install the 18-tapered roller bearing on the 30-planetary reducer and connect and fix the 26-hydraulic cylinder on the right end of the 30-planetary reducer, install the 17-linear bearing on the 32-reaction rod and string it through the 26-hydraulic cylinder, the left and right 29-supports wrap all the above parts in the middle and the left and right 29-supports are fixedly connected by the 103-side end plugs and connecting rods, and finally connect the 14-drill bit to the 18-tapered roller bearing through the 15-connecting shaft;

[0095] Step 6: The computer interface is connected to the force sensors, displacement sensors and deformation sensors of each loading cylinder respectively, and the force value and displacement deformation data of the lining tunnel physical model in each direction during the experiment are recorded by the computer; at the same time, the sound information of the rock sample experiment is collected in real time by means of 34-acoustic emission and microseismic monitoring;

[0096] Step 7: Install the 13-lined tunnel physical model in the three-dimensional stress loading system, and the various functional metal components are tightly fitted and finally firmly fitted with the 13-lined tunnel physical model;

[0097] Step 8: After placing the 13-lined tunnel physical model, fit the 8-pressing plate to the front and back of the 13-lined tunnel physical model, and then fit the 7-front and rear capsules tightly to the 8-pressing plate. After ensuring that everything is correct, install the multi-function data monitoring recorder, cover the 6-model bearing cover plate, and fix it with screws;

[0098] Step 9: Start the loading device connected to the 5-heating plate to heat up the 13-lined tunnel physical model, and start the internal and external water pressure loading device to fill the 9-external water loading pipe with water and apply a water-rich condition to the 13-lined tunnel physical model through the rock mass near the one-way hole type external water loading pipe on the external water loading pipe;

[0099] Step 10: After the temperature is raised to the specified temperature, the front and rear and vertical loading devices are started, 7-front and rear bags begin to apply pressure to 8-pressing plate, and the pressure is transmitted to the front and rear of 13-lining tunnel physical model through 8-pressing plate, 3-hydraulic pillow begins to apply pressure to the wedge pressure head, and the pressure is transmitted to 5-heating plate through the wedge pressure head and finally transmitted to 13-lining tunnel physical model in four directions of up, down, left and right through 5-heating plate;

[0100] Step 11: The pressure applied by 7-front and rear bags and 3-hydraulic pillow is transmitted to 13-lining tunnel physical model through metal components to complete preloading. When the preloading is completed, the oil pressure is increased to formally load the 13-lining tunnel physical model to the pressure specified by the experiment;

[0101] Step 12: Start the intelligent control multi-mode excavation system, 14-drill bit starts to rotate, 22-trolley motor drives 27-support plate to move along the X-axis on 21-guide rail through 16-slider toward 13-lining tunnel physical model, and excavation starts after contact and records stress, deformation and other data during excavation until the excavation is completed. After the excavation is completed, the trolley motor is operated to drive the support plate to move along the X-axis on the guide rail through the slider away from the lining tunnel physical model until the drilling rig leaves the inside of the hydraulic tunnel model;

[0102] Step 13: After the 13-lined tunnel physical model is excavated, a professional engineering camera is installed in the excavated hole, and then the 10-water tunnel seal is installed and the loading device is started to fill the internal hole sealed by the 10-water tunnel seal with water to apply internal water pressure to it. The force applied by the sealing load meets When the water is filled for the first time, the maximum internal water pressure is 0.05MPa, that is, the entire process of the first water filling must meet P 密>0.05Mpa, the maximum water pressure in the second water filling is 0.1Mpa, that is, the whole process of the second water filling must meet P 密 >0.1Mpa and so on until the last step of water filling, the maximum internal water pressure is 1.5Mpa, that is, the whole process of the last water filling must meet P 密 >1.5Mpa; The sealing loading force is greater than the water pressure, and the flow control of the 9-external water loading water pipe is opened to fill the 9-external water loading water pipe with water through the one-way hole opened in the 9-external water loading water pipe to apply a water-rich condition to the 13-lining tunnel physical model, record its internal water pressure, deformation, temperature change and stress, and observe the lining damage through an engineering professional camera;

[0103] Step 14: Fill and drain water step by step into the 10-water tunnel seal formed by the experimental device to simulate the groundwater pressure and the internal water pressure loading and unloading working state. Connect the pressure pump to the joint of the 10-water tunnel seal, and fill the 10-water tunnel seal with water step by step. During the filling process, fill water until the lining is damaged, record the data at this time, and continue to fill water until the surrounding rock hydraulic fracturing occurs. This is the end point of the water filling stage. Record the data of hydraulic fracturing. When the step-by-step water filling stage is over, open the water tunnel seal to drain water step by step. For the water pressure conditions of lining damage and hydraulic fracturing during the fine water filling process, the water filling pressure gradient will be set. Because the water pressure at the water point in the tunnel is generally not less than 0.3MPa, it is 1.5 times in the working state, so the water filling pressure gradient is rounded to 0.5MPa per level and the water filling pressure increment is set to one tenth of the water filling pressure gradient. When the step-by-step water filling stage is completed, the 10-water hole seal is opened for step-by-step drainage. The number of water filling steps, the total number of water filling steps, and the total number of filling and drainage steps when the water filling pressure is 0.5Mpa are as follows: S total =2×S (26) Where: S1 is the number of steps when the water filling pressure is equal to 0.5Mpa, S is the total number of water filling steps, S total is the total number of steps for filling and draining water, P1 is the filling pressure of 0.5Mpa, P t is the design water head of the pressure tunnel, in MPa, with a value of 1.5 MPa; ΔP is the loading and unloading amplitude of the step-by-step filling and drainage pressure, in MPa, with a value of 0.05 MPa;

[0104] Step 15: When filling and draining the 10-water tunnel seal step by step, if no damage occurs at each level or the value does not change significantly, the following time can be met and the next step can be carried out according to the plan; The duration of each stage of filling, draining, pressurizing or depressurizing is: Where: T K is the duration of the K-th level of filling and drainage pressurization or depressurization, and K is the number of steps of step-by-step filling and drainage; during the step-by-step filling and drainage process in the 10-water tunnel seal, read the pressure display number and record the change of the internal water pressure; during the step-by-step filling and drainage process in the 10-water tunnel seal, record the change of the lining crack width in real time; during the step-by-step filling and drainage process in the 10-water tunnel seal, During the water process, the multi-function data monitoring recorder records the data and the 36-engineering professional camera records the video files. Item, 34-Acoustic emission instrument collects sound information;

[0105] Step 16: During the internal water pressure loading and unloading process, 7-front and rear bladders cooperate with the water filling pressure change formula and drainage pressure Force change formula: The 8-pressure plate is loaded and unloaded by pressure, and its dynamic pressure adjustment should satisfy the following formula: F t =P+F1 (28) F=(F t -P) / 2 (29) Where F t The total pressure remains unchanged, F1 is the sum of the pressures on both sides, and F is the pressure on one side; P is the water pressure which satisfies Where S x is the number of water filling steps, S x The x in the Ensure that the internal water pressure of the lining tunnel physical model is coordinated with the external loading pressure and that the load is balanced under the condition that the total pressure remains unchanged. The water pressure inside the surrounding rock is dynamically adjusted so that the overall force of the surrounding rock is maintained during the water filling process. The hydraulic fracturing extending from the hole inside the simulated surrounding rock is observed and the pressure and deformation data are recorded. Stress, strain, water content, lining damage audio and video of the physical model of the lined tunnel during water flow, and hydraulic splitting audio and video of the surrounding rock The crack width changes were monitored and recorded, and the stress changes of the lining tunnel physical model during triaxial stress loading and temperature adjustment were compared. Observe, monitor and record chemical and strain changes;

[0106] Step 17: After all the experimental items are completed, the force is released, the temperature is lowered, and the oil pressure is reduced. The data and audio and video materials are saved. Finally, check the device and complete the experiment.

[0107] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Scope of protection of the invention: Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the invention shall be included in the scope of protection of the invention.

Claims

1. A large-scale model experimental device for excavation and water-filling and splitting of high-pressure tunnels, characterized in that: The device includes an intelligent control excavation support telescopic system, an intelligent control excavation load action system, a barrel-shaped three-way reaction system, a three-way stress loading system, an internal water pressure control and its sealing system, an external water pressure control system, a temperature control system, a multi-dimensional monitoring information collection system, and a lining tunnel physical model; the water pressure tunnel model includes a barrel-shaped three-way reaction system, a three-way stress loading system, an internal water pressure control and its sealing system, an external water pressure control system, a temperature control system, and a multi-dimensional monitoring information collection system; the drilling rig assembly includes an intelligent control excavation support telescopic system, an intelligent control excavation load action system, and a barrel-shaped three-way reaction system for water pressure The main frame of the tunnel model, the three-dimensional stress loading system is installed inside the barrel-shaped three-dimensional reaction system, the temperature control system and the lining tunnel physical model are installed in the middle of the three-dimensional stress loading system, the intelligent control excavation support telescopic system is placed in front of the barrel-shaped three-dimensional reaction system, the intelligent control excavation load action system is installed above the intelligent control excavation support telescopic system, the multi-element monitoring information acquisition system is connected with the barrel-shaped three-dimensional reaction system, the three-dimensional stress loading system, the internal water pressure control and its sealing system, the external water pressure control system, and the temperature control system and arranged inside the above systems, and the oil circuit loading system controls the start of the entire device; The three-dimensional stress loading system includes front and rear bladders, a pressure plate, a hydraulic pillow, and a wedge-shaped pressure head. The front and rear bladders are square metal plates with a circular hollow in the middle, which are fixed on the model bearing cover plate and connected to the vertical loading pump on the right side of the horizontal loading pump. It should meet the pressure balance loading of the front and rear bladders on both sides of the barrel, and ensure that the stress on the loading model remains unchanged when the water injection pressure increases: P w ×S1=(P0+ΔP f )×S2 (1) Where P w is the water injection pressure, S1 is the area of ​​the front and rear capsules, P0 is the initial stress, ΔP f To increase stress, S2 is the contact area between the front and rear bladders and the physical model of the lining tunnel. The pressure plate is a metal plate of the same size and shape as the front and rear bladders installed inside the front and rear bladders. The wedge-shaped pressure head is four rectangular metal plates attached to the outside of the heating plate. The hydraulic pillow is four rectangular metal plates attached to the outside of the wedge-shaped pressure head. It can apply pressure to the physical model of the lining tunnel and is connected to the front and rear loading pumps. The barrel-shaped three-way reaction force system includes a base, a model bearing cylinder, a model bearing cover plate, and a reaction force pad. The base is a hollow rectangular block in the middle of the prism, and the left and right surfaces of the prism are designed with semicircular holes with the same curvature as the frame. It is installed at the bottom of the entire device and is in continuous arc contact with the model bearing cylinder. The model bearing cylinder is a thick-walled cylinder installed on the base and fits tightly with the base. The wall thickness of the model bearing cylinder is determined as follows: The wall thickness of the model load-bearing cylinder is determined according to the unfavorable combination of operating conditions and divided into four operating conditions; The water pressure in the tunnel of the first working condition model: The water pressure in the tunnel of the second working condition model acts together with the maximum principal stress of the model: The third working condition model has the water pressure in the tunnel acting together with the second principal stress of the model: The fourth working condition model has the water pressure in the tunnel acting together with the third principal stress of the model: in σ r p , σ z p are the hoop average stress, radial average stress, and axial average stress, respectively. The first principal stress in the cylinder under internal pressure is the hoop stress. r1 is the inner diameter, i.e., the vertical straight-line distance from the center of the model-bearing cylinder to the inner surface. r2 is the outer diameter, i.e., the vertical straight-line distance from the center of the model-bearing cylinder to the outermost surface. r is the vertical straight-line distance from the center of the cylinder to the center of the inner and outer surfaces. P s is the initial water pressure, P p is the reaction force of the loading component, σ g is the tensile stress of the model bearing cover, S g is the area of ​​the model bearing cover plate, h is the length of the model bearing cylinder, σ1 is the first principal stress, σ2 is the second principal stress, and σ3 is the third principal stress; t is the wall thickness of the model bearing cylinder, where the annular stress is mainly generated by the balance of the tensile stress of the cylindrical steel plate and the water pressure, the radial stress is mainly provided by the normal water pressure and the axial deformation compression during loading, and the tensile stress on both sides is mainly provided by the model bearing cover plates on both sides to prevent rock deformation, the water pressure acting on the model bearing cover plates on both sides, and the axial stress acting on the rock mass; The strength criterion for the model load-bearing cylinder is: K is the ratio of the inner and outer diameters, that is, the vertical straight line distance from the center of the cylinder to the outermost surface is divided by the vertical straight line distance from the center of the cylinder to the inner surface; Substitute the stress states of the four working conditions into formula (16) to obtain the model load-bearing cylinder wall thickness corresponding to the four working conditions: t1 is the model load-bearing cylinder wall thickness required for working condition 1, t2 is the model load-bearing cylinder wall thickness required for working condition 2, t3 is the model load-bearing cylinder wall thickness required for working condition 3, and t4 is the model load-bearing cylinder wall thickness required for working condition 4; Make sure that the minimum value of the model load-bearing cylinder wall thickness is not less than the maximum value of the model load-bearing cylinder wall thickness calculated under the above four working conditions: t min ≥[t1、t2、t3、t4] max Where [σ] is the allowable stress of the material. The wall thickness of the final design model bearing cylinder should be multiplied by the safety factor M to consider the safety during operation. That is, the wall thickness of the final model bearing cylinder design model bearing cylinder is Mt min ; The model bearing cover plate is a metal component with a closed internal space and is fixed on a thick-walled cylinder by bolts. To calculate the thickness of the model bearing cover plate, the external force is first simplified, and the direction of the external force that mainly affects the thickness of the model bearing cover plate is radial. The cover plate is regarded as a component composed of multiple small cylinders. One of the cylinders is analyzed separately, and all parts are subjected to radial external forces. The external force on a single cylinder is regarded as a uniformly distributed load imposed on the single cylinder by the radial average stress. The most unfavorable section position is the position with the maximum bending moment. The bending moment diagram caused by the radial force is drawn for the single cylinder, and the most unfavorable section position is the middle of the single cylinder, which is set as the dangerous B section. In the formula is the bending moment of the dangerous section B, L is the length of a single cylinder, and the single cylinder with the largest L, i.e. the middle of the model load-bearing cover plate, is selected as the next analysis according to the most unfavorable condition; The wall thickness of the model bearing cover plate model bearing cylinder is the diameter of a single cylinder and should satisfy: Where d is the thickness of the bottom of the model bearing cover plate, [σ] is the allowable stress. The reaction pad is an arc-shaped metal block that fits the model bearing cylinder and fits inside the model bearing cylinder to provide reaction force support for the device; The lined tunnel physical model is installed in the middle of the three-dimensional stress loading system. It is a rectangular rock lined tunnel physical model. The tunnel physical model and the engineering site conditions must maintain similar shapes and sizes, and the corresponding angles are equal, that is, the prototype and the model maintain a certain proportional relationship. The scale of the prototype and the model is represented by λ. The cross-sectional size of the lined tunnel physical model must meet the length scale: Where L y For the prototype size, L s is the mold size of the tunnel physical model, λ0 is the ratio between the on-site tunnel and the model simulation tunnel, A1 is the cross-sectional area of ​​the on-site tunnel, L1 is the cross-sectional perimeter of the on-site tunnel, A2 is the cross-sectional area of ​​the model simulation tunnel, and L2 is the cross-sectional perimeter of the model simulation tunnel; The brittleness similarity ratio λ between the tunnel physical model and the original rock is εd Need to meet: Where ε p is the prototype peak strain, ε m is the peak strain of the tunnel physical model; Dynamic elastic modulus E d and dynamic Poisson's ratio μ d As an important indicator of rock dynamic properties, the dynamic elastic modulus similarity scale Similarity ratio to dynamic Poisson's ratio Satisfy the following formula: Where λ σ is the stress similarity scale; λ ε is the strain similarity scale, strain is a dimensionless physical quantity, then λ ε =1; In order to ignore the boundary effect, the cross-sectional edge length a of the physical model of the lined tunnel must satisfy the following formula: Where d M is the diameter of the physical model of the lined tunnel after drilling, D2 is the diameter of the model simulated tunnel, the axial dimension of the physical model of the lined tunnel is N times the cross-sectional dimension, N>0.3; the grouting material of the physical model of the lined tunnel must meet the mechanical properties similar to those of the original rock, such as stress, strain, peak residual strength, seepage characteristics, and hydraulic fracturing strength. The peak strain and stress of the physical model of the lined tunnel are the same as those of the original rock at the project site, and the seepage coefficient, seepage law and hydraulic fracturing strength are the same as those of the original rock at the project site.

2. A large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water according to claim 1, characterized in that: The temperature control system comprises a heating plate, which is four rectangular metal plates with energized heating wires inside and is attached to the physical model of the lining tunnel.

3. A large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water according to claim 1, characterized in that: The internal water pressure control and its sealing system include an internal water pressure loading pump, an internal water diversion pipe, a filling and drainage valve, end plugs on both sides, a pull rod connecting the end plugs on both sides, an inner hole sealing sleeve, and a sealing loading pump. The pull rod is a metal rod with threads on both sides, which is connected to the end plugs on both sides by threads. The inner hole sealing sleeve is composed of a large cylinder and a small cylinder. The two cylinders are connected in alignment with the center and are installed on the end plugs for sealing to prevent water from overflowing. The end plug is composed of three round cakes with round holes in the middle. The round cake on the side close to the pull rod is also provided with multiple round holes around the middle round hole, which is used to block the outflow of water in the hole and is further fixed by fixing nuts and connecting pull rods with the end plugs on both sides. The internal water pressure loading pump is connected to the external water pressure loading pump on the outside of the water pressure tunnel model. In the internal hole, the two ends of the internal water pressure loading pump are respectively connected to the two ends of the filling and drainage valve. The filling and drainage valve is a control device for controlling the filling and drainage of the internal water pressure system. The sealing loading pump is installed on the right side of the internal and external water pressure loading pumps and is connected to both sides of the water tunnel seal.

4. A large-scale model experimental device for excavation and water-filling and splitting of a high internal and external water pressure tunnel according to claim 1, characterized in that: The external water pressure control system includes an external water loading pipe, external water inlet and outlet valves, a connecting pipe, a connecting pipe seal, an inner liner, and an external water pressure loading pump. The external water loading pipe is a spiral water pipe with a one-way hole opened, and the connecting pipe is a right-angle iron pipe. The inner liner is a rock component loaded inside the hole after drilling. The external water inlet and outlet valves are control devices for external water pressure charging and drainage. The connecting pipe seal is a thick cylindrical rubber sleeve at the connection between the connecting pipe and the external water loading pipe. The external water pressure loading pump is connected to the internal water pressure loading pump outside the water pressure tunnel model and connected to the left and right connecting pipes inside the water pressure tunnel model.

5. The large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water according to claim 1 is characterized by: The intelligent control excavation support telescopic system includes a drilling rig base, a guide rail, an x-axis motion block, a trolley motor, a servo motor, a slider, a tray, and a bottom bracket. The drilling rig base is a rectangular steel wire frame, which is composed of a rectangular wire frame connected to a cube wire frame, and then connected to the cube wire frame and the rectangular wire frame to form the bottom part of the intelligent control excavation support telescopic system. The guide rail is a groove-shaped long strip track fixed to the base by bolts. The slider is a groove-shaped metal component that fits the size of the guide rail and is installed on the guide rail through bolts and the bracket. The support plate is a rectangular steel plate placed on a slider, the x-axis motion block is a circular metal component, in which the parameter of the circular hole is the diameter of the extension rod of the trolley motor, the x-axis motion block is strung on the trolley motor and the servo motor is installed on the right end of the trolley motor, and the whole composed of the x-axis motion block, the trolley motor and the servo motor is placed in the middle position of the two pairs of sliders under the support plate, and the bottom support is a rectangular steel frame composed of two small rectangular frames. The bearing cylinder is smaller than the base and is fixed on the support plate by bolts.

6. A large-scale model experimental device for excavation and water-filling and splitting of a high-pressure tunnel with internal and external water according to claim 1, characterized in that: The intelligent control excavation load system includes a drill bit, a connecting shaft, a support, a linear bearing, a reaction rod, a tapered roller bearing, a planetary reducer, a hydraulic cylinder, and a pull rod. The drill bit has a variety of different shapes and sizes. The drill bit has a variety of different shapes and sizes. The drill bit diameter should meet the ratio of the current hole diameter of the project to the prototype and model. The connecting shaft is a large thick cylinder and a small thick cylinder. The two cylinders are aligned and connected in the center. It is an intermediate device connecting the drill bit and the planetary reducer. The support is a square steel plate with a round hole in the middle, and a reaction rod insertion hole is provided at each of the four corners of the steel plate. The support provides a working platform for drill excavation. The tapered roller bearing is a radial thrust rolling bearing. It is a circular steel plate with a round hole in the middle and is installed on a planetary reducer. The hydraulic cylinder provides power for the drill bit. Its left end is connected to the planetary reducer through a reaction rod and its right end is installed on the right end support. The pull rod is a stick-shaped metal component used to connect the left and right supports, and the reaction rod is a stick-shaped metal component.

7. The large-scale model experimental device for excavation and water-filling and splitting of a high internal and external water pressure tunnel according to claim 1 is characterized by: The multivariate monitoring information acquisition system includes an engineering professional camera, an acoustic emitter, and a multifunctional data monitoring recorder. The engineering professional camera is an instrument placed in the drill hole of the lining tunnel physical model for photographing and recording internal changes. The acoustic emitter is a device that uses sound waves to detect the location and damage of cracks and damage in the lining tunnel physical model and is placed on both sides of the instrument and connected to the lining tunnel physical model through sensor lines. The multifunctional data monitoring recorder includes a water pressure needle for monitoring the water pressure changes of the lining tunnel physical model during the filling and drainage process, and a deformable optical fiber, a pressure needle, a seam measuring needle, a flow needle, a hole pressure needle, and a steel bar needle for monitoring the working conditions of the lining and surrounding rock. The multifunctional data monitoring recorder is arranged in the lining, the hydraulic pillow and the lining The physical model of the tunnel is built between the front and rear capsules and the physical model of the lining tunnel, between the heating plate and the physical model of the lining tunnel, and between the lining and the surrounding rock. The lining of the physical model of the lining tunnel is formed by pouring and curing concrete, and a plurality of annular steel bars are arranged at intervals perpendicular to the longitudinal axis of the pressure tunnel, and a plurality of longitudinal steel bars are arranged at intervals parallel to the longitudinal axis of the pressure tunnel. A crack is preset on the inner wall of the physical model of the lining tunnel, and two monitoring sections AA and BB perpendicular to the axis of the pressure tunnel are selected at intervals along the axial direction of the pressure tunnel. The measuring needles are arranged at the cracks of the monitoring sections containing prefabricated cracks, and the measuring needles span the prefabricated cracks and two are arranged at the prefabricated cracks. The center of the top of the cylindrical body is in the 0° direction, and the measuring needles are arranged in the order of The hole pressure needles are arranged at 0°, 45°, 90°, 135°, 170°, 225°, 270°, and 315° positions of the AA and BB monitoring sections in a clockwise direction. The hole pressure needles on each monitoring section are equidistant from the central axis of the pressure tunnel. The top center of the cylindrical body is the 0° direction. The water pressure needles are arranged on the outer wall of the lining at 0°, 100°, 150°, 225°, and 280° positions of the AA and BB monitoring sections in a clockwise direction. The top center of the cylindrical body is the 0° direction. The water pressure needles are arranged on the lining steel bars at 0°, 30°, 150°, 210°, and 320° positions of the AA and BB monitoring sections in a clockwise direction. Steel bar needle, when pouring the lining, the flow needle is pre-wound into a circle in the lining mold, arranged around the edge, and four circles of the deformed optical fiber are evenly arranged in the mold. The surrounding rock of the lining tunnel physical model is prefabricated by pouring, cutting and grinding the selected rock mass, and four cracks are preset in the surrounding rock. Along the axial direction of the pressure tunnel, a monitoring section 1-1 perpendicular to the axis of the pressure tunnel is set. With the top center as the 0° direction, four cracks are preset at 0°, 90°, 180°, and 270° in a clockwise direction. The top center of the square surrounding rock is the 0° direction, and the pressure needle is arranged inside the surrounding rock at positions of 15°, 75°, 105°, 165°, 195°, 255°, 285°, and 345° in a clockwise direction.The pressure needles are at equal distances from the central axis of the pressure tunnel. The water pressure needles are arranged at the cracks of the prefabricated cracks. The water pressure needles span the prefabricated cracks and are arranged three at each prefabricated crack. When making the surrounding rock, four circles of the deformed optical fiber are evenly arranged in the mold.

8. The method for using the large-scale model experimental device for high internal and external water pressure tunnel excavation and water filling and splitting according to claims 1 to 7 is characterized in that: The steps include: Step 1: Place the base at the set position, install the model bearing cylinder on top of the base and fit it tightly with bolts, and fix the reaction pad on the inside of the model bearing cylinder. Step 2: Fix the hydraulic pillow horizontally in a square shape on the inside of the reaction pad, install a wedge-shaped pressure head and a multi-function data monitoring recorder on the inside of the hydraulic pillow, and finally install the heating plate on the inside of the wedge-shaped pressure head and install the multi-function data monitoring recorder; Step 3: Place the drill base in a suitable position in front of the installed instrument and fix it, install a guide rail on the top of the drill base and fix it with bolts, embed the slider in the guide rail, and then fix the support plate to the slider with bolts; Step 4: Assemble the x-axis motion block, the trolley motor and the servo motor into a complete kit and install it in the middle of the guide rail under the pallet, and then fix the bottom bracket to the pallet with bolts; Step 5: Install the tapered roller bearing on the planetary reducer and connect the fixed hydraulic cylinder to the right end of the planetary reducer. Install the linear bearing on the reaction rod and string it through the hydraulic cylinder. The left and right supports wrap all the above parts in the middle and the left and right supports are fixedly connected by a tie rod. Finally, connect the drill bit to the tapered roller bearing through the connecting shaft. Step 6: The computer interface is connected to the force sensors, displacement sensors and deformation sensors of each loading cylinder respectively, and the force value and displacement deformation data of the physical model of the lining tunnel in each direction during the experiment are recorded by the computer; at the same time, the sound information of the rock sample experiment is collected in real time by means of acoustic emission and microseismic monitoring; Step 7: Install the physical model of the lined tunnel in the three-dimensional stress loading system, and the various functional metal components are tightly fitted to the physical model of the lined tunnel; Step 8: After the lining tunnel physical model is placed, fit the pressure plate to the front and back of the lining tunnel physical model, and then fit the front and rear bags tightly to the pressure plate. After ensuring that there is no error, install the multifunctional data monitoring recorder, cover the model bearing cover plate and fix it with bolts; Step 9: Start the loading device connected to the heating plate to heat up the physical model of the lined tunnel, and start the internal and external water pressure loading devices to fill the water pipe with water and apply water-rich conditions to the rock mass near the one-way hole water pipe on the water pipe; Step 10: After the temperature is raised to the specified temperature, the front and rear and vertical loading devices are started, the front and rear bags begin to apply pressure to the pressure plate, and the pressure is transmitted to the front and rear of the lining tunnel physical model through the pressure plate. The hydraulic pillow begins to apply pressure to the wedge pressure head, and the pressure is transmitted to the heating plate through the wedge pressure head and finally transmitted to the four directions of the lining tunnel physical model through the heating plate; Step 11: The pressure applied by the front and rear bags and the hydraulic pillow is transmitted to the physical model of the lining tunnel through the metal components to complete the preloading. When the preloading is completed, the oil pressure is increased to formally load the physical model of the lining tunnel to the pressure specified by the experiment; Step 12: Start the intelligent control multi-mode excavation system, the drill bit starts to rotate, the trolley motor drives the support plate to move along the X-axis on the guide rail through the slider toward the lining tunnel physical model, and excavation starts after contact and records the stress, deformation and other data during excavation until the excavation is completed. After the excavation is completed, the trolley motor is operated to drive the support plate to move along the X-axis on the guide rail through the slider away from the lining tunnel physical model until the drilling rig leaves the inside of the hydraulic tunnel model; Step 13: After the physical model of the lining tunnel is excavated, a professional engineering camera is installed in the excavated hole, and then the water tunnel seal is installed and the loading device is started to fill the internal hole sealed by the water tunnel seal with water to apply internal water pressure to it. The force applied by the sealing load meets Keep the sealing loading force greater than the water pressure, and open the flow control of the water pipe to fill the water pipe with water through the one-way hole opened in the water pipe to apply water-rich conditions to the physical model of the lining tunnel, record its internal water pressure, deformation, temperature change and stress, and observe the lining damage through a professional engineering camera; Step 14: Fill and drain water step by step into the water tunnel seal formed by the experimental device to simulate the groundwater pressure and the internal water pressure loading and unloading working state. Connect the pressure pump to the joint of the water tunnel seal to fill the water tunnel seal step by step. During the filling process, fill water until the lining is damaged. Record the data at this time and continue to fill water until the surrounding rock hydraulic fracturing occurs. This is the end point of the water filling stage. Record the data of hydraulic fracturing. When the step-by-step water filling stage is over, open the water tunnel seal to drain water step by step. For the water pressure conditions of lining damage and hydraulic fracturing during the fine water filling process, the water filling pressure gradient will be set. Because the water pressure at the water point in the tunnel is generally not less than 0.3MPa, it is 1.5 times in the working state. Then round it up and set the water filling pressure gradient to 0.5MPa per level and set the water filling pressure increment each time to one tenth of the water filling pressure gradient. The number of water filling steps, the total number of water filling steps, and the total number of filling and drainage steps when the water filling pressure is 0.5MPa are as follows: S total =2×S (26) Where: S1 is the number of steps when the water filling pressure is equal to the set value, S is the total number of water filling steps S total is the total number of filling and drainage steps; P1 is the set value of the filling pressure, P1 is the design water head of the pressure tunnel, unit MPa, ΔP is the loading and unloading amplitude of the step-by-step filling and drainage pressure, unit MPa; Step 15: When filling and draining the water tunnel seal step by step, if there is no damage at each level or the value does not change significantly, the following time can be met to continue to the next step according to the plan. The duration of each level of filling and draining pressurization or depressurization is: Where T k is the duration of pressurization or depressurization of the Kth level of filling and drainage, and K is the number of steps of filling and drainage step by step; during the step-by-step filling and drainage process in the water tunnel seal, the pressure indication number is read and the change of internal water pressure is recorded; during the step-by-step filling and drainage process in the water tunnel seal, the change of lining crack width is recorded in real time; during the step-by-step filling and drainage process in the water tunnel seal, the multi-function data monitoring recorder performs data recording and monitoring, and the professional engineering camera shoots and records video files, and the acoustic emission instrument collects sound information; Step 16: During the internal water pressure loading and unloading process, the front and rear bags load and unload the pressure plate according to the water filling pressure change formula and the drainage pressure change formula. The dynamic pressure adjustment should satisfy the following formula: F t =P+F1 (28) F=(F t -P) / 2 (29) Where F t The total pressure remains unchanged, F1 is the sum of the pressures on both sides, and F is the pressure on one side; P is the water pressure which satisfies Where S x is the number of water filling steps, S x The x in the figure represents the number of times to ensure that the internal water pressure of the physical model of the lining tunnel is coordinated with the external loading pressure and to maintain dynamic adjustment of the balanced loading and the water pressure inside the surrounding rock under the condition that the total pressure remains unchanged, so that the overall stress of the surrounding rock remains unchanged during the water filling process. Continue to observe the hydraulic splitting extending from the hole inside the simulated surrounding rock, and record the pressure and deformation data. During the filling and drainage process, the stress, strain, water content, lining damage audio and video, hydraulic splitting audio and video of the physical model of the lining tunnel are observed and monitored, and the crack width changes are recorded. The stress changes and strain changes of the physical model of the lining tunnel during the three-dimensional stress loading and temperature adjustment are observed, monitored and recorded. Step 17: After all experimental items are completed, start to unload the force, reduce the temperature and oil pressure, save the data and audio and video materials, and finally check the device status to complete the experiment.

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