Complex environment tunnel safety monitoring and early warning test device

Abstract

The invention discloses a complex environment tunnel safety monitoring and early warning test device which comprises an earth pressure box, channels for simulating excavation are arranged on the two sides of the earth pressure box, jacking devices are arranged on the upper side and the side face of the earth pressure box, the earth pressure box is filled with a test soil body, and an earth pressure sensor and a pore water pressure sensor are arranged in the test soil body. Excavating in the test soil body to form a simulation tunnel, arranging a row of grouting monitoring and reinforcing devices in at least one position direction on the periphery of the simulation tunnel, and distributing the grouting monitoring and reinforcing devices in a zigzag shape through a specific span and a horizontal angle; the grouting monitoring and reinforcing device comprises a split type protection pipe, through holes are formed in pipe sections of the protection pipe, and optical fiber sensors jointly penetrate into all the through holes. The protection pipe is dispersed into a plurality of pipe sections, advance supporting and monitoring of tunnel construction are achieved, and the construction technology is conveniently and reasonably arranged through the test.

Description

Technical Field

[0001] This invention relates to the field of tunnel safety monitoring and testing technology, and in particular to a tunnel safety monitoring and early warning testing device for complex environments. Background Technology

[0002] Tunnel safety monitoring is a technical approach that utilizes sensors, data processing technology, and model building and optimization to monitor and assess the tunnel structure, environment, and operational status in real time. Its main purpose is to identify potential safety hazards within the tunnel and take timely preventative and control measures to ensure the safe operation of the tunnel.

[0003] Advanced reinforcement techniques include diagonal bracing and grouting. However, the stress release mechanism at the excavation face and the stratum deformation mechanism lack theoretical guidance, often leading to the selection of very high safety factors and resulting in waste of reinforcement techniques and quantities. Therefore, it is necessary to conduct model tests on the stress release and stratum deformation response mechanisms at the excavation face of deep-buried tunnels under different advanced reinforcement techniques to select appropriate construction techniques. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a safety monitoring and early warning test device for tunnels in complex environments, thereby solving the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A test device for safety monitoring and early warning of tunnels in complex environments includes an earth pressure chamber, with simulated excavation channels on both sides of the earth pressure chamber, and top pressure devices on the upper and side sides of the earth pressure chamber. The earth pressure chamber is filled with test soil, and earth pressure sensors and pore water pressure sensors are installed in the test soil. A simulated tunnel is formed by excavation in the test soil. A row of grouting monitoring and reinforcement devices is set at at least one position on the periphery of the simulated tunnel. The grouting monitoring and reinforcement devices are distributed in a sawtooth pattern with a specific span and horizontal angle. The grouting monitoring and reinforcement device includes a split protective pipe, with each section of the protective pipe having through holes through which fiber optic sensors are inserted.

[0006] Preferably, a continuous base rod is provided inside the protective pipe, the base rod is coaxially sleeved with and axially slides the grouting pipe, a plug is provided at the end of the grouting pipe, and grout outlet holes are uniformly provided at the front end of the plug.

[0007] Preferably, the outer surface of the plug is provided with an extension hole, and a pressure plate can be pushed out of the extension hole by a spring. One pipe section is provided with a sleeve, and the inner wall of the sleeve is provided with an annular groove. A protruding elastic piece is provided in the annular groove. The adjacent pipe section is provided with a retaining groove, and the elastic piece extends into the retaining groove for limitation. The inner wall of the end of the adjacent pipe section is provided with a strip groove, and the pressure plate can enter the strip groove to push the elastic piece out of the retaining groove.

[0008] Preferably, a chamfer is provided on one side of the pressure plate, and a bevel is provided at one end of the pipe section, with the bevel corresponding to the chamfer.

[0009] Preferably, one end of the protective tube is provided with an annular pull-out groove.

[0010] A test method for safety monitoring and early warning of tunnels in complex environments, which uses the above-mentioned grouting monitoring and reinforcement device to test the reinforcement quality of tunnels, includes the following steps; Preparation work; set process parameters one (spacing A, horizontal angle B) or process parameters two (spacing C, horizontal angle B) for the grouting monitoring and reinforcement device, use computer analysis software such as finite element analysis of tunnel instability, select the optimal parameters, and conduct physical tests on the optimal parameters.

[0011] Step 1: During the geological exploration phase, tunnel samples are taken to determine their physical and mechanical properties, including shear force, strength, and moisture content.

[0012] Step 2: Based on the physical and mechanical properties of the construction soil measured in Step 1, simulate and prepare test soil. The test soil is filled and compacted in layers in an earth pressure chamber, and earth pressure sensors and pore water pressure sensors are installed.

[0013] Step 3: Excavate a simulated tunnel in the test soil using the mining method or shield tunneling method. Apply uniform or non-uniform loads using a top pressure device. During the excavation process, use a grouting monitoring and reinforcement device for pre-grouting support. The interval span and horizontal angle of the grouting monitoring and reinforcement device are optimized. Record the data from the soil pressure sensor and pore water pressure sensor. Monitor the deformation of the simulated tunnel periphery using a fiber optic sensor.

[0014] Step 4: Analyze the impact of the grouting monitoring and reinforcement device on excavation stability through monitoring data.

[0015] The advantages of this invention are as follows: The tunnel safety monitoring and early warning test device provided by this invention opens a window on the shield of the tunnel boring machine. An installation hole is drilled in the required direction through the window by a directional drill rod. A grouting monitoring and reinforcement device is hydraulically inserted into the installation hole. After the base rod reaches the predetermined depth, the protective pipe is individually withdrawn and pulled outward. The protective pipe is dispersed into several pipe sections. The sinking of one pipe section is monitored by the adjacent pipe sections, thus realizing the advanced support and monitoring of tunnel construction. The process is simulated and tested. The test of this invention facilitates the rational arrangement of construction technology, ensuring safety while improving the efficiency of tunnel construction. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the basic structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the earth pressure box; Figure 3This is a structural schematic diagram of the grouting monitoring and reinforcement device (protective pipe partially cut open). Figure 4 yes Figure 3 Enlarged view of section H in the image; Figure 5 yes Figure 4 A schematic diagram showing the state of the two pipe sections after separation. Figure 6 This is a schematic diagram of the layout of a grouting monitoring and reinforcement device; Figure 7 This is a schematic diagram of another arrangement of the grouting monitoring and reinforcement device.

[0017] In the diagram: 1. Earth pressure box; 11. Top pressure device; 12. Test soil; 13. Simulated tunnel; 10. Karst cave; 2. Pipe section; 211. Pull-out groove; 3. Fiber optic sensor; 4. Base rod; 5. Grouting pipe; 6. Plug; 61. Protruding hole; 62. Pressure plate; 63. Sleeve; 64. Annular groove; 65. Elastic sheet; 66. Slot; 67. Strip groove; 68. Chamfer; 69. Inclined surface. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] like Figures 1 to 7 As shown, the present invention provides a tunnel safety monitoring and early warning test device for complex environments, comprising an earth pressure chamber 1, simulated excavation channels on both sides of the earth pressure chamber 1, a top pressure device 11 on the upper and side sides of the earth pressure chamber 1, test soil 12 filled inside the earth pressure chamber 1, and earth pressure sensors and pore water pressure sensors installed inside the test soil 12. A simulated tunnel 13 is formed by excavation within the test soil 12, and a row of grouting monitoring and reinforcement devices is arranged in at least one position around the simulated tunnel 13. The grouting monitoring and reinforcement devices are distributed in a sawtooth pattern with specific spans and horizontal angles, and the position of the simulated tunnel 13 is as follows: Figure 2 Located at the top 12 o'clock position of the tunnel, this direction is used to create one or more combinations of various geological environments, such as water seepage, buried seepage pipes, karst caves, or local overpressure caused by the bearing piles of the bottom building. All geological environments are achieved through existing technologies. The grouting monitoring and reinforcement device includes a split protective tube. One end of the protective tube is provided with an annular pull-out groove 211. Each section 2 of the protective tube is provided with a through hole. All through holes are connected to a fiber optic sensor 3. The fiber optic sensor 3 is an existing technology and is commonly used for geological subsidence monitoring.

[0020] A continuous base rod 4 is installed inside the protective pipe. The base rod 4 serves as the foundation for grouting reinforcement, improving the necessary support capacity (and becoming the lower limit for monitoring) without affecting the settlement monitoring of the outer pipe section 2. The base rod 4 is coaxially fitted with and axially slides the grouting pipe 5. A plug 6 is installed at the end of the grouting pipe 5. Grout outlet holes are evenly distributed at the front end of the plug 6. Grout outlet holes are evenly distributed in the pipe section 2. The grouting pipe 5 is pulled out in sections and paused after being pulled out for a certain distance. Grouting liquid is injected into the soil through the grouting pipe 5, plug 6, and the front pipe section 2. The pipe sections 2 are solidified in the surrounding soil by the grout. Multiple pipe sections 2 achieve the effect of fine monitoring, that is, any pipe section 2 can descend, and the descent range is within the control range of the reinforcement by the base rod 4.

[0021] exist Figure 2 In the process, a window is opened on the shield of the tunnel boring machine, and an installation hole is drilled in the required direction through the window using a directional drill rod. A grouting monitoring and reinforcement device is hydraulically driven into the installation hole. After the base rod 4 reaches the predetermined depth, the protective pipe is individually withdrawn and pulled outwards, dispersing into several pipe sections 2. The sinking of one pipe section 2 is monitored by the adjacent pipe section 2, thus achieving advanced support and monitoring for tunnel construction. Because the span and horizontal angle of the grouting monitoring and reinforcement device have a significant impact on the construction progress (…), Figure 6 and Figure 7 Advanced support requires pausing the tunnel boring machine's excavation, employing large spans and low horizontal angles, resulting in long construction intervals for support. Conversely, it requires frequent shutdowns of the tunnel boring machine, affecting the construction progress. The experiments conducted by this invention facilitate the rational arrangement of construction processes, ensuring safety while improving the efficiency of tunnel construction.

[0022] Specifically, the outer circular surface of the plug 6 is provided with three protruding holes 61. Each protruding hole 61 can be pushed out by a spring through a pressure plate 62. One of the pipe sections 2 is provided with a sleeve 63, and the inner wall of the sleeve 63 is provided with an annular groove 64. The annular groove 64 is provided with a protruding elastic piece 65. The adjacent pipe section 2 is provided with a slot 66. The elastic piece 65 extends into the slot 66 for limitation. The inner wall of the end of the adjacent pipe section 2 is provided with a strip groove 67, and the pressure plate 62 can enter the strip groove 67 to push the elastic piece 65 out of the slot 66. One side of the pressure plate 62 is provided with a chamfer 68, and one end of the pipe section 2 is provided with a bevel 69. The bevel 69 and the chamfer 68 are set to correspond so that after the pipe section 2 stops, the pressure plate 62 retracts into the plug 6. The plug 6 can also be pulled out in the remaining pipe section 2.

[0023] As a method of separating the protective pipe of the grouting monitoring and reinforcement device, the grouting pipe 5 and the plug 6 are pulled outward inside the protective pipe. The plug 6 moves to the sleeve 63 position, the pressure plate 62 pushes outward and enters the strip groove 67, the elastic sheet 65 is pressed into the annular groove 64, and the sleeve 63 is freely separated from the grouting section 2. That is, the subsequent section 2 continues to be pulled outward to form a gap E. The pressure plate 62 presses down on the grouting section 2 to prevent synchronous displacement. Multiple sections 2 are separated in this way without affecting the grouting effect. The formation of the gap E makes the fiber optic sensor 3 like multiple monitors worn at intervals. The monitors monitor individually and in combination, thereby achieving the purpose of fine monitoring.

[0024] This invention discloses a test method for safety monitoring and early warning of tunnels in complex environments, which uses the above-mentioned grouting monitoring and reinforcement device to test the quality of tunnel reinforcement, including the following steps; Preparations; such as Figure 6 and Figure 7 Set either process parameter one (spacing A, horizontal angle B) or process parameter two (spacing C, horizontal angle B) for the grouting monitoring and reinforcement device. Use computer analysis software, such as finite element analysis of tunnel instability, to select the optimal parameters and conduct a physical test on the optimal parameters.

[0025] Step 1: During the geological exploration phase, tunnel samples are taken to determine their physical and mechanical properties, including shear force, strength, and moisture content.

[0026] Step 2: Based on the physical and mechanical properties of the construction soil measured in Step 1, simulate and prepare test soil 12. Test soil 12 is prepared using a mixture of quartz sand, barite powder, gypsum, iron powder, and lubricating oil to prepare different geological conditions (soft soil, sandy soil, or rock). Test soil 12 is filled and compacted in layers in the soil pressure box 1, and soil pressure sensors and pore water pressure sensors are installed.

[0027] Step 3: Excavate a simulated tunnel 13 within the test soil 12 using the mining method or shield tunneling method. Apply uniform or non-uniform loads using the jacking device 11. During the excavation process, use a grouting monitoring and reinforcement device for pre-grouting support. The interval span and horizontal angle of the grouting monitoring and reinforcement device are optimized. Record the data from the soil pressure sensor and pore water pressure sensor. Monitor the deformation of the simulated tunnel 13 through the fiber optic sensor 3.

[0028] Step 4: Analyze the impact of the grouting monitoring and reinforcement device on the excavation stability through monitoring data, and verify the corresponding construction technology for tunnel construction.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A test device for safety monitoring and early warning of tunnels in complex environments, comprising an earth pressure chamber (1), with simulated excavation channels on both sides of the earth pressure chamber (1), a top pressure device (11) on the upper and side sides of the earth pressure chamber (1), and test soil (12) filled inside the earth pressure chamber (1), and an earth pressure sensor and a pore water pressure sensor installed inside the test soil (12), characterized in that: A simulated tunnel (13) was excavated in the test soil (12). A row of grouting monitoring and reinforcement devices was set at at least one location on the periphery of the simulated tunnel (13). The grouting monitoring and reinforcement devices were distributed in a sawtooth pattern with a specific span and horizontal angle. The grouting monitoring and reinforcement device includes a split protective pipe. Each section (2) of the protective pipe is provided with a through hole, and a fiber optic sensor (3) is inserted into all the through holes.

2. The tunnel safety monitoring and early warning test device in a complex environment according to claim 1, characterized in that: The protective pipe is provided with a continuous base rod (4), the base rod (4) is coaxially sleeved with and axially slides the grouting pipe (5), the end of the grouting pipe (5) is provided with a plug (6), and the front end of the plug (6) is provided with uniformly arranged grout outlet holes.

3. The tunnel safety monitoring and early warning test device in a complex environment according to claim 2, characterized in that: The plug (6) has an extension hole (61) on its outer surface. A spring can push out a pressure plate (62) through the extension hole (61). One of the pipe sections (2) is provided with a sleeve (63), and the inner wall of the sleeve (63) is provided with an annular groove (64). A protruding elastic piece (65) is provided in the annular groove (64). The adjacent pipe section (2) is provided with a slot (66). The elastic piece (65) extends into the slot (66) and is limited. The inner wall of the end of the adjacent pipe section (2) is provided with a strip groove (67), and the pressure plate (62) can enter the strip groove (67) to push the elastic piece (65) out of the slot (66).

4. The tunnel safety monitoring and early warning test device in a complex environment according to claim 3, characterized in that: A chamfer (68) is provided on one side of the pressure plate (62), and a bevel (69) is provided at one end of the pipe section (2). The bevel (69) and the chamfer (68) are provided in a corresponding manner.

5. The tunnel safety monitoring and early warning test device in a complex environment according to claim 1, characterized in that: The protective tube is provided with an annular pull-out groove (211) at one end.

6. The tunnel safety monitoring and early warning test device in a complex environment according to claim 1, characterized in that: The method of testing tunnel reinforcement quality using the grouting monitoring and reinforcement device described above. Includes the following steps; Preparation; Set process parameters one or two for the grouting monitoring and reinforcement device, use computer analysis software such as finite element analysis to analyze tunnel instability, select the optimal parameters, and conduct a physical test on the optimal parameters; Step 1: During the geological exploration stage, tunnel samples are taken to determine the physical and mechanical properties of parameters such as shear force, strength, and moisture content. Step 2: Based on the physical and mechanical properties of the construction soil measured in Step 1, simulate and prepare test soil (12). The test soil (12) is filled and compacted in layers in the soil pressure box (1), and soil pressure sensor and pore water pressure sensor are installed. Step 3: Excavate a simulated tunnel (13) in the test soil (12) using the mining method or shield tunneling method. Apply uniform or non-uniform loads using the top pressure device (11). During the excavation process, use the grouting monitoring and reinforcement device for advance grouting support. The interval span and horizontal angle of the grouting monitoring and reinforcement device are selected using the optimal parameters. Record the data of the soil pressure sensor and pore water pressure sensor. Monitor the deformation of the simulated tunnel (13) through the fiber optic sensor (3). Step 4: Analyze the impact of the grouting monitoring and reinforcement device on excavation stability through monitoring data.

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