Experimental apparatus and methods for simulating the impact of external earthmoving environment on existing tunnels

Abstract

This invention discloses an experimental device for simulating the impact of external soil working environment on existing tunnels. The device includes a central control system, a simulation chamber, and a support frame. The simulation chamber contains a simulated working soil block, within which a simulated tunnel is installed. A limiting frame assembly surrounds the simulated working soil block. A hydraulic hammer is mounted on the support frame, allowing a simulated pipe pile to penetrate the simulated working soil block under the action of the hydraulic hammer. Several pressure and vibration sensors are installed on the outer wall of the simulated tunnel and the limiting frame assembly. The hydraulic hammer, pressure sensors, and vibration sensors are all connected to the central control system. This invention also discloses an experimental method for simulating the impact of external soil working environment on existing tunnels. This invention has a compact structure, can accurately simulate the external soil working environment of tunnels, accurately monitors influencing parameters, is easy to operate, and can analyze the impact of external soil working on the simulated tunnel, providing reasonable suggestions for actual construction.

Description

Technical Field

[0001] This invention relates to the field of earthwork testing technology, specifically to a testing apparatus and method for simulating the impact of external earthwork environments on existing tunnels. Background Technology

[0002] Pile foundations are a type of foundation with high bearing capacity, wide applicability, and a long history. With the continuous construction and development of urban subway systems, the external soil working environment within the subway operating area is constantly impacting existing tunnels, posing a significant safety hazard to subway operations. Current research on such close-contact construction problems largely focuses on numerical simulation methods, and the limited number of field tests is also limited by practical conditions.

[0003] Given the inherent limitations of in-situ tests, model tests, on the other hand, can be tailored and controlled with precise boundary conditions and material properties of piles, soil, and tunnels. This allows for targeted and purposeful studies of pile-soil-tunnel interaction effects, yielding far more extensive data than in-situ tests and enabling the verification of numerical simulations. However, currently, there are few such testing devices on the market that simulate the impact of external soil working environments on existing tunnels. The simulation measures for these environments are often inadequate, lacking accuracy, and are inconvenient to operate, failing to achieve the desired testing objectives. Summary of the Invention

[0004] The purpose of this invention is to provide a test apparatus and method for simulating the impact of external earthwork environment on existing tunnels, so as to solve the above-mentioned defects.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A test device for simulating the impact of external soil working environment on an existing tunnel includes a central control system, a simulation box, and a support frame installed on the outside of the simulation box. The simulation box is a box-shaped body with an open top. A simulated working soil block is placed inside the box-shaped body. A limiting frame assembly is set around the perimeter of the simulated working soil block. The limiting frame assembly is fixed to the box-shaped body by bolts. The limiting frame assembly includes two parallel transverse sliding rods and two longitudinal sliding rods on the same horizontal plane. The two transverse sliding rods and the longitudinal sliding rods intersect each other to form a grid pattern, and both ends of the two longitudinal sliding rods are fixed to the box-shaped body by bolts. The support frame assembly... A hydraulic hammer is mounted on the support frame via longitudinal and transverse screw assemblies. Under the action of the hydraulic hammer, the simulated pipe pile can be vertically driven into the simulated working soil block inside the box-shaped box. The box-shaped box has working holes at its front and rear ends. A simulated tunnel made of PVC or metal is installed in the simulated working soil block, with each end of the simulated tunnel passing through one of the two working holes. Several pressure sensors and vibration sensors are installed on the contact surfaces between the outer wall of the simulated tunnel and the working holes and the simulated working soil block, as well as on the contact surfaces between the simulated working soil block and the limiting frame assembly. The hydraulic hammer, pressure sensors, and vibration sensors are all connected to the central control system.

[0007] Preferably, a lateral limiting baffle and a longitudinal limiting baffle are respectively installed on the inner side of the first lateral sliding rod and the first longitudinal sliding rod, and a plurality of evenly distributed water-permeable holes are provided on the lateral limiting baffle and the longitudinal limiting baffle.

[0008] Preferably, a second horizontal sliding rod and a second vertical sliding rod are respectively provided below the first horizontal sliding rod and the first vertical sliding rod. Both the first horizontal sliding rod and the second horizontal sliding rod are provided with strip-shaped adjustment holes. The first vertical sliding rod and the second vertical sliding rod pass through the strip-shaped adjustment holes of the first horizontal sliding rod and the second horizontal sliding rod, respectively. The ends of the second horizontal sliding rod and the second vertical sliding rod are provided with connecting rods and are respectively connected and fixed to the first horizontal sliding rod and the first vertical sliding rod.

[0009] Preferably, both the transverse sliding rod and the longitudinal sliding rod are vertically provided with a fixing rod at their ends, and the fixing rod is provided with a threaded fixing hole, and the bolt passes through the threaded fixing hole of the fixing rod; a limiting fixing groove is provided on the outer wall of the box-shaped box, and a plastic anti-slip layer is provided in the limiting fixing groove, and the front end of the bolt engages with the plastic anti-slip layer of the limiting fixing groove.

[0010] Preferably, an opening-shaped corridor space is formed between the inner wall of the box-shaped container and the simulated working soil block, and the opening-shaped corridor space is filled with water to a certain depth.

[0011] Preferably, the longitudinal lead screw device and the transverse lead screw device each include a longitudinal lead screw and a transverse lead screw, and the longitudinal lead screw and the transverse lead screw are controlled to rotate by a motor; two longitudinal lead screws are provided and are respectively installed on the support frames on the front and rear sides of the box-shaped housing, and each longitudinal lead screw is provided with two ball bearing sliding bases; two transverse lead screws are provided, and their two ends are respectively fixedly installed on the ball bearing sliding bases of the two longitudinal lead screws; each of the two transverse lead screws is provided with a ball bearing sliding base, and a hydraulic hammer mounting rod is provided between the two ball bearing sliding bases, and the hydraulic hammer device is installed on the hydraulic hammer mounting rod.

[0012] Preferably, the hydraulic hammer device includes a hydraulic hammer capable of vertical hammering via hydraulic control. A limit module is provided under the hydraulic hammer mounting rod below the hydraulic hammer device. A vertically oriented limit groove is provided on the front end face of the limit module, and the hydraulic hammer is placed in the limit groove. Two opposing limit claws are installed under the limit module. The limit claws are controlled by a motor and a central control system to perform tightening and loosening operations. The simulated pipe pile is vertically placed between the two limit claws and within the limit groove.

[0013] Preferably, the central control system is equipped with a display screen, through which the data from the pressure sensor and vibration sensor can be displayed.

[0014] Preferably, a test method for simulating the impact of external earthmoving environments on existing tunnels includes the following steps:

[0015] S1. Excavate the actual geotextile layer or a similar geotextile layer where the tunnel is located, excavate a certain slightly larger square earth block, remove the loose soil around it affected by the excavation, and retain a certain square earth block to form a simulated working earth block; or analyze the composition and compaction of the actual geotextile layer where the tunnel is located, and then use soil of various components to mix and mechanically compress them to make a simulated working earth block.

[0016] S2. Loosen the bolts of the limiting frame assembly, slide both horizontal sliding rods and both vertical sliding rods outward, and then place the simulated working soil block obtained in step S in the center of the box-shaped box.

[0017] S3. Install several pressure sensors and vibration sensors on the inner sides of the first transverse sliding rod and the first longitudinal sliding rod. Then slide both the first transverse sliding rod and the two first longitudinal sliding rods inward, so that the transverse limiting baffle and the longitudinal limiting baffle are tightly attached to the perimeter of the simulated working soil block, and make the pressure sensors and vibration sensors installed on the inner sides of the first transverse sliding rod and the first longitudinal sliding rod contact the simulated working soil block. Then tighten the bolts on the first transverse sliding rod and the first longitudinal sliding rod to fix the limiting frame assembly to the simulated working soil block.

[0018] S4. Water of a certain depth is injected into the arch-shaped corridor space formed between the inner wall of the box and the simulated working soil block, and the simulated working soil block is soaked for a certain period of time to simulate the environment of the simulated working soil block being affected by groundwater.

[0019] S5. The simulated working soil block is excavated through the working hole of the box-shaped box and the mechanical working device, and then PVC or metal pipes are embedded to form a simulated tunnel; at the same time, several pressure sensors and vibration sensors are installed on the contact surface between the simulated tunnel and the simulated working soil block and the contact surface between the simulated tunnel and the working hole, so as to realize the simulation of the tunnel excavation under real conditions.

[0020] S6. Connect the pressure sensors and vibration sensors installed on the inner sides of the transverse sliding rod 1 and the longitudinal sliding rod 1, as well as on the outer wall of the simulated tunnel, to the central control system.

[0021] S7. The longitudinal and transverse screw devices are controlled by a motor, and the position of the hydraulic hammer device is adjusted. Then, the hydraulic hammer device is used to drive the simulated pipe pile into the predetermined position of the simulated working soil block. The data of various pressure sensors and vibration sensors during the simulated pipe pile driving operation are displayed on the central control system and the display screen installed on it. By analyzing these data, the impact of the simulated external soil working environment on the existing tunnel can be obtained, thus completing the entire process of the test on the impact of the simulated external soil working environment on the existing tunnel.

[0022] The beneficial effects of this invention are as follows:

[0023] This invention discloses an experimental device and method for simulating the impact of external soil working environments on existing tunnels. A limiting frame assembly is installed around the perimeter of the simulated working soil block to limit and fix its stability. A simulated pipe pile is vertically driven into the simulated working soil block within a box-shaped enclosure using a hydraulic hammer, simulating the commonly used hammer-driven pile driving operation in reality, achieving a high degree of simulation accuracy. Several pressure and vibration sensors installed on the outer wall of the simulated tunnel and at the limiting frame assembly monitor the pressure and vibration parameters experienced by the simulated tunnel and the periphery of the simulated working soil block during the pile driving operation, enabling the analysis of the impact on the simulated tunnel. This invention provides an experimental device for simulating the impact of external soil working environments on existing tunnels. The device is compact, highly accurate in simulating the external soil working environment of the tunnel, and provides accurate monitoring of impact parameters. The experimental method is simple and convenient to operate. This invention can analyze the impact of external soil working on the simulated tunnel, providing reasonable suggestions for actual construction. Attached Figure Description

[0024] Figure 1 : A schematic diagram of the overall structure of the experimental device for simulating the impact of external earthwork environment on existing tunnels according to the present invention;

[0025] Figure 2 : Figure 1 Schematic diagram of the structure at point A in the middle;

[0026] Figure 3 : Figure 1 Schematic diagram of the structure at point B;

[0027] Figure 4 : Figure 1 Schematic diagram of the structure at point C. Detailed Implementation

[0028] Combined with appendix Figure 1-4 The specific embodiments of the present invention are described below:

[0029] like Figure 1-4 As shown, a test device for simulating the impact of external earthwork operation environment on existing tunnels includes a central control system, a simulation box 1, and a support frame 2 installed on the outside of the simulation box 1.

[0030] The simulation box 1 is a box-shaped container 11 with an open top. Inside the box-shaped container 11, there is a simulated working soil block 3. The simulated working soil block 3 can be derived from the actual environment of the tunnel. That is, the actual soil layer or a similar soil layer (including a simple soil layer, a mud-sand layer, or a gravel layer, etc.) of the tunnel is excavated, and a soil block of a certain size is excavated. The loose soil around it affected by the excavation is removed, and a soil block of a certain size is retained to form the simulated working soil block 3. Alternatively, the simulated working soil block 3 can be made by analyzing the composition and compaction of the actual soil layer of the tunnel, and then using the various components to mix and compress them.

[0031] A limiting frame assembly 4 is installed around the perimeter of the simulated soil block 3. The limiting frame assembly 4 is fixed to the box-shaped housing 11 by bolts 44. The limiting frame assembly 4 includes two parallel horizontal sliding rods 41 and two vertical sliding rods 46 on the same horizontal plane. The two horizontal sliding rods 41 and the vertical sliding rods 46 intersect each other to form a grid shape, and both ends of the two are fixed to the box-shaped housing 11 by bolts 44. A horizontal limiting baffle 45 and a vertical limiting baffle 48 are respectively installed on the inner side of the horizontal sliding rods 41 and the vertical sliding rods 46. The horizontal limiting baffle 45 and the vertical limiting baffle 48 are each provided with several evenly distributed permeable holes. Below the first horizontal sliding rod 41 and the first vertical sliding rod 46, there are second horizontal sliding rods 42 and 47 respectively. Both the first horizontal sliding rod 41 and the second horizontal sliding rod 42 are provided with strip-shaped adjustment holes 412. The first vertical sliding rod 46 and the second vertical sliding rod 47 pass through the strip-shaped adjustment holes 412 of the first horizontal sliding rod 41 and the second horizontal sliding rod 42 respectively. The ends of the second horizontal sliding rod 42 and the second vertical sliding rod 47 are provided with connecting support rods 411 and are respectively connected and fixed to the first horizontal sliding rod 41 and the first vertical sliding rod 46. Both the transverse sliding rod 41 and the longitudinal sliding rod 46 have a vertically fixed rod 43 at their ends. The fixed rod 43 has a threaded fixing hole, and the bolt 44 passes through the threaded fixing hole of the fixed rod 43. The outer wall of the box-shaped housing 11 has a limiting fixing groove 13, which has a plastic anti-slip layer. The front end of the bolt 44 engages with the plastic anti-slip layer of the limiting fixing groove 13. By sliding and adjusting the two transverse sliding rods 41 and the longitudinal sliding rod 46 in a cross manner, the simulated working soil block 3 can be easily installed into the box-shaped housing 11. It can also realize the pressure and limitation of the transverse limiting baffle 45 and the longitudinal limiting baffle 48 on the simulated working soil block 3, ensuring the stability of the simulated working soil block 3 during the test.

[0032] The inner wall of the box-shaped container 11 forms an opening-shaped corridor space 10 between it and the simulated working soil block 3. The opening-shaped corridor space 10 is filled with water of a certain depth. By adjusting the depth of the water filling in the opening-shaped corridor space 10 and the immersion time of the simulated working soil block 3 in water, the environment affected by groundwater on the simulated working soil block 3 can be simulated.

[0033] The box-shaped housing 11 has working holes 12 at its front and rear ends. A simulated tunnel 5, made of PVC or metal, is installed inside the simulated working soil block 3, with each end of the simulated tunnel 5 penetrating through one of the two working holes 12. In actual operation, firstly, the working holes 12 of the box-shaped housing 11 and related mechanical devices are used to excavate the simulated working soil block 3. Then, PVC or metal pipes are inserted to form the simulated tunnel 5, thus simulating the tunnel excavation process in real-world conditions.

[0034] A hydraulic hammer device 6 is mounted on the support frame 2 via longitudinal and transverse screw assemblies. The simulated pipe pile 8, under the action of the hydraulic hammer device 6, can vertically penetrate into the simulated working soil block 3 within the box-shaped housing 11. The longitudinal and transverse screw assemblies each include a longitudinal screw 22 and a transverse screw 24, respectively. The longitudinal screw 22 and transverse screw 24 are rotated by motors. Two longitudinal screws 22 are provided and mounted on the support frame 2 on the front and rear sides of the box-shaped housing 11, respectively. Each longitudinal screw 22 is equipped with two ball bearing sliding bases 23. Two transverse screws 24 are provided, with their ends fixedly mounted on the ball bearing sliding bases 23 of the two longitudinal screws 22. Two transverse screws 24 are equipped with ball bearing sliding bases 25, and a hydraulic hammer mounting rod 26 is positioned between the two ball bearing sliding bases 25. The hydraulic hammer device 6 is mounted on the hydraulic hammer mounting rod 26. The hydraulic hammer device 6 includes a hydraulic hammer 61, which can perform vertical hammering through hydraulic control. A limit module 7 is provided under the hydraulic hammer mounting rod 26 below the hydraulic hammer device 6. A vertical limit groove 71 is provided on the front end face of the limit module 7, and the hydraulic hammer 61 is placed in the limit groove 71. Two oppositely arranged limit claws 72 are installed under the limit module 7. The limit claws 72 are controlled by a motor and a central control system to perform loosening and locking operations. The simulated pipe pile 8 is vertically placed between the two limit claws 72 and in the limit groove 71.

[0035] Several pressure and vibration sensors are installed on the contact surfaces between the outer wall of the simulated tunnel 5 and the working hole 12 and the simulated working soil block 3, as well as on the contact surface between the simulated working soil block 3 and the limiting frame assembly 4. The hydraulic hammer device 6, pressure sensors, and vibration sensors are all connected to the central control system. The central control system is equipped with a display screen, which displays the data from the pressure and vibration sensors. The pressure and vibration effects on the simulated tunnel 5 during pile driving can be monitored through the central control system and the display screen.

[0036] A test method for simulating the impact of external earthmoving environments on existing tunnels includes the following steps:

[0037] S1. Excavate the actual geotextile layer or a similar geotextile layer where the tunnel is located, excavate a certain slightly larger square earth block, remove the loose soil around it affected by the excavation, and retain a certain square earth block to form a simulated working earth block 3; or analyze the composition and compaction of the actual geotextile layer where the tunnel is located, and then use soil of each component to mix and mechanically compress to make a simulated working earth block 3.

[0038] S2. Loosen the bolt 44 of the limiting frame assembly 4, slide the two transverse sliding rods 41 and the two longitudinal sliding rods 46 outward, and then place the simulated working soil block 3 obtained in step S1 in the center of the box-shaped box 11.

[0039] S3. Install several pressure sensors and vibration sensors on the inner surfaces of the transverse sliding rod 41 and the longitudinal sliding rod 46. Then slide both transverse sliding rods 41 and both longitudinal sliding rods 46 inward, so that the transverse limiting baffle 45 and the longitudinal limiting baffle 48 are tightly attached to the perimeter of the simulated working soil block 3, and make the pressure sensors and vibration sensors installed on the inner surfaces of the transverse sliding rods 41 and the longitudinal sliding rod 46 contact the simulated working soil block 3. Then tighten the bolts 44 on the transverse sliding rods 41 and the longitudinal sliding rod 46 to fix the limiting frame assembly 4 to the simulated working soil block 3.

[0040] S4. Water of a certain depth is injected into the opening-shaped corridor space 10 formed between the inner wall of the box-shaped box 11 and the simulated working soil block 3, and the simulated working soil block 3 is soaked for a certain period of time to simulate the environment of the simulated working soil block 3 being affected by groundwater.

[0041] S5. The simulated working soil block 3 is excavated through the working hole 12 of the box-shaped box 11 and the mechanical working device, and then a PVC or metal pipe is embedded to form a simulated tunnel 5. At the same time, several pressure sensors and vibration sensors are installed on the contact surface between the outer wall of the simulated tunnel 5 and the simulated working soil block 3 and the contact surface between the outer wall of the simulated tunnel 5 and the working hole 12, so as to realize the simulation of the tunnel excavation under real conditions.

[0042] S6. Connect the pressure sensors and vibration sensors installed on the inner sides of the transverse sliding rod 41 and the longitudinal sliding rod 46, as well as on the outer wall of the simulated tunnel 5, to the central control system.

[0043] S7. The longitudinal and transverse lead screw devices are controlled by a motor to adjust the position of the hydraulic hammer device 6. Then, the hydraulic hammer device 6 is used to drive the simulated pipe pile 8 into the predetermined position of the simulated working soil block 3. The data of various pressure sensors and vibration sensors during the driving of the simulated pipe pile 8 are displayed on the central control system and the display screen installed on it. By analyzing these data, the impact of the simulated external soil working environment on the existing tunnel can be obtained, thus completing the entire process of the test on the impact of the simulated external soil working environment on the existing tunnel.

[0044] This invention discloses an experimental device for simulating the impact of external soil working environment on existing tunnels. A limiting frame assembly 4 is installed around the perimeter of the simulated working soil block 3 to limit and fix its stability. A simulated pipe pile 8 is vertically driven into the simulated working soil block 3 within a box-shaped housing 11 using a hydraulic hammer device 6, simulating the commonly used hammer-driven pile driving operation in reality, achieving a high degree of simulation accuracy. Several pressure and vibration sensors installed on the outer wall of the simulated tunnel 5 and at the limiting frame assembly 4 monitor the pressure and vibration parameters experienced by the simulated tunnel 5 and the periphery of the simulated working soil block 3 during the pile driving operation, enabling the analysis of the impact of the simulated tunnel 5.

[0045] This invention discloses a test apparatus for simulating the impact of external soil working environment on existing tunnels. The apparatus is compact and capable of accurately simulating the external soil working environment of the tunnel, with precise monitoring of impact parameters. The test method of this invention is simple and convenient to operate. Furthermore, this invention can analyze the impact of external soil working on the simulated tunnel, providing reasonable suggestions for actual construction.

[0046] The invention has been described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the invention, or the direct application of the inventive concept and technical solution to other situations without modification, is within the protection scope of the invention.

Claims

1. A test apparatus for simulating the impact of external earthmoving environments on existing tunnels, characterized in that, The system includes a central control system, a simulation box (1), and a support frame (2) installed on the outside of the simulation box (1). The simulation box (1) is a box-shaped body (11) with an open top. A simulated working soil block (3) is set inside the box-shaped body (11). A limit frame assembly (4) is set around the simulated working soil block (3). The limit frame assembly (4) is fixed to the box-shaped body (11) by bolts (44). The limit frame assembly (4) includes two horizontal sliding rods (41) and two vertical sliding rods (46) that are parallel to each other and on the same horizontal plane. The two horizontal sliding rods (41) and the two vertical sliding rods (46) intersect each other to form a grid shape, and both ends of the two are fixed to the box-shaped body (11) by bolts (44). The support frame (2) has a central control system, a simulation box (1), and a support frame (2) installed on the outside of the simulation box (1). A hydraulic hammer device (6) is installed through the longitudinal screw device and the transverse screw device. The simulated pipe pile (8) can be vertically penetrated into the simulated working soil block (3) in the box-shaped box (11) under the action of the hydraulic hammer device (6). The box-shaped box (11) is provided with working holes (12) at the front and rear ends. The simulated working soil block (3) is equipped with a simulated tunnel (5) made of PVC or metal material. The two ends of the simulated tunnel (5) pass through the two working holes (12) respectively. Several pressure sensors and vibration sensors are provided on the contact surface between the outer wall of the simulated tunnel (5) and the working hole (12) and the simulated working soil block (3), as well as on the contact surface between the simulated working soil block (3) and the limiting frame assembly (4). The hydraulic hammer device (6), pressure sensors, and vibration sensors are all connected to the central control system. The inner sides of the first transverse sliding rod (41) and the first longitudinal sliding rod (46) are respectively equipped with a transverse limiting baffle (45) and a longitudinal limiting baffle (48). The transverse limiting baffle (45) and the longitudinal limiting baffle (48) are each provided with a number of evenly distributed water-permeable holes. The second transverse sliding rod (42) and the second longitudinal sliding rod (47) are respectively provided below the first transverse sliding rod (41) and the first longitudinal sliding rod (46). The first transverse sliding rod (41) and the second transverse sliding rod (42) are each provided with a strip-shaped adjustment hole (412). The first longitudinal sliding rod (46) and the second longitudinal sliding rod (47) pass through the strip-shaped adjustment hole (412) of the first transverse sliding rod (41) and the second transverse sliding rod (42). The ends of the second transverse sliding rod (42) and the second longitudinal sliding rod (47) are each provided with a connecting support rod (411) and are respectively connected and fixed to the first transverse sliding rod (41) and the first longitudinal sliding rod (46). The central control system is equipped with a display screen, through which data from the pressure sensor and vibration sensor can be displayed.

2. The experimental apparatus for simulating the impact of external earthmoving environment on existing tunnels according to claim 1, characterized in that, The ends of the first horizontal sliding rod (41) and the first vertical sliding rod (46) are each provided with a fixed rod (43). The fixed rod (43) is provided with a threaded fixing hole, and the first bolt (44) passes through the threaded fixing hole of the fixed rod (43). The outer wall of the box-shaped box (11) is provided with a limiting fixing groove (13), and a plastic anti-slip layer is provided in the limiting fixing groove (13). The front end of the first bolt (44) is engaged with the plastic anti-slip layer of the limiting fixing groove (13).

3. The experimental apparatus for simulating the impact of external earthmoving environment on existing tunnels according to claim 2, characterized in that, The inner wall of the box-shaped container (11) and the simulated working soil block (3) form a mouth-shaped corridor space (10), which is filled with water of a certain depth.

4. The experimental apparatus for simulating the impact of external earthmoving environment on existing tunnels according to claim 3, characterized in that, The longitudinal screw device and the transverse screw device each include a longitudinal screw (22) and a transverse screw (24), and the longitudinal screw (22) and the transverse screw (24) are rotated by a motor respectively; there are two longitudinal screws (22) and they are respectively installed on the support frame (2) on the front and rear sides of the box-shaped housing (11), and each longitudinal screw (22) is provided with two ball sliding bases (23); there are two transverse screws (24), and their two ends are respectively fixedly installed on the ball sliding bases (23) of the two longitudinal screws (22); each of the two transverse screws (24) is provided with a ball sliding base (25), and a hydraulic hammer mounting rod (26) is provided between the two ball sliding bases (25), and the hydraulic hammer device (6) is installed on the hydraulic hammer mounting rod (26).

5. The experimental apparatus for simulating the impact of external earthmoving environment on existing tunnels according to claim 4, characterized in that, The hydraulic hammer device (6) includes a hydraulic hammer (61), which can be hydraulically controlled to hammer vertically. A limit module (7) is provided under the hydraulic hammer mounting rod (26) below the hydraulic hammer device (6). A vertical limit groove (71) is provided on the front end face of the limit module (7), and the hydraulic hammer (61) is placed in the limit groove (71). Two oppositely arranged limit claws (72) are installed under the limit module (7). The limit claws (72) are controlled by a motor and a central control system to perform tightening and loosening operations. The simulated pipe pile (8) is vertically placed between the two limit claws (72) and in the limit groove (71).

6. The test method of the test apparatus for simulating the impact of external earthmoving environment on existing tunnels according to claim 5, characterized in that, Includes the following steps: S1. Excavate the actual soil layer or similar soil layer where the tunnel is located in reality, excavate a certain slightly larger square earth block, remove the loose soil around it affected by the excavation, and retain a certain square earth block to form a simulated working earth block (3); or analyze the composition and compaction of the actual soil layer where the tunnel is located, and then use the soil of each component to mix and mechanically compress to make a simulated working earth block (3). S2. Loosen the bolt (44) of the limiting frame assembly (4), slide the two transverse sliding rods (41) and the two longitudinal sliding rods (46) outward, and place the simulated working soil block (3) obtained in step S1 in the center of the box-shaped box (11). S3. Install several pressure sensors and vibration sensors on the inner sides of the transverse sliding rod (41) and the longitudinal sliding rod (46). Then slide the two transverse sliding rods (41) and the two longitudinal sliding rods (46) inward, and make the transverse limiting baffle (45) and the longitudinal limiting baffle (48) tightly adhere to the periphery of the simulated working soil block (3). Make the pressure sensors and vibration sensors installed on the inner sides of the transverse sliding rod (41) and the longitudinal sliding rod (46) contact the simulated working soil block (3). Then tighten the bolts (44) on the transverse sliding rod (41) and the longitudinal sliding rod (46) to fix the limiting frame assembly (4) to the simulated working soil block (3). S4. A certain depth of water is injected into the opening-shaped corridor space (10) formed between the inner wall of the box-shaped box (11) and the simulated working soil block (3) and the simulated working soil block (3) is soaked for a certain period of time to realize the simulation of the environment of the simulated working soil block (3) affected by groundwater. S5. The simulated working soil block (3) is excavated through the working hole (12) of the box-shaped box (11) and the mechanical working device, and then a simulated tunnel (5) is made by embedding PVC or metal pipes. At the same time, several pressure sensors and vibration sensors are installed on the contact surface between the outer wall of the simulated tunnel (5) and the simulated working soil block (3) and the contact surface between the outer wall of the simulated tunnel (5) and the working hole (12), so as to realize the simulation of the tunnel excavation situation in reality. S6. Connect the pressure sensor and vibration sensor installed on the inner side of the transverse sliding rod (41) and the longitudinal sliding rod (46) and the outer wall of the simulated tunnel (5) to the central control system. S7. The longitudinal screw device and the transverse screw device are controlled by the motor, and the position of the hydraulic hammer device (6) is adjusted. Then, the simulated pipe pile (8) is hammered into the predetermined position of the simulated working soil block (3) by the hydraulic hammer device (6). Then, the data of each pressure sensor and vibration sensor during the pile driving operation of the simulated pipe pile (8) are displayed on the central control system and the display screen installed on it. By analyzing these data, the influence of the simulated external soil working environment on the existing tunnel can be obtained, thus completing the entire process of the test of the influence of the simulated external soil working environment on the existing tunnel.

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