A shield full-terrain tunneling simulation test method

Abstract

A shield full-terrain tunneling simulation test method realizes a hydraulic loading intelligent control type model test of shield full-terrain tunneling simulation, can carry out shield construction indoor model test, and carries out research on shield diameter, buried depth, tunneling parameter, construction working condition and the like. The method comprises the following steps: step 1, obtaining soil sample parameters and presetting in an upper computer; step 2, determining a test scheme and presetting in the upper computer to form a system test task; step 3, installing a baffle; step 4, preparing soil samples; step 5, positioning the soil samples; step 6, pressurizing; step 7, shield tunneling; step 8, data acquisition; step 9, test ending; and step 10, pressure releasing and sample dismounting.

Description

Technical Field

[0001] This invention relates to a method for simulating shield tunneling in all terrains, and a hydraulically loaded intelligent control model test bench based on shield tunneling simulation. It is mainly used for indoor model tests simulating shield construction and belongs to the field of tunnel construction engineering technology. Background Technology

[0002] Shield tunneling, as an efficient and safe construction technology, has been widely adopted in subway tunnel construction. To study the impact of shield tunneling on the surrounding environment and the disturbance to buildings, scholars both domestically and internationally commonly use methods such as empirical formulas, analytical methods, theoretical analysis, model testing, and numerical analysis. Because prototype shield tunneling involves complex construction processes and management stages, it lacks repeatability and makes it difficult to obtain definitive research results under single-variable conditions. In contrast, model testing can realistically reproduce the tunnel construction process, possesses a rigorous theoretical foundation, and is simple and easy to implement, resulting in higher reliability of research results. Therefore, model testing is widely used in the fields of geotechnical engineering and underground engineering.

[0003] The selection of tunneling parameters (advance speed, shield diameter) during shield tunneling has a significant impact on the degree of disturbance to the surrounding soil. In actual engineering, these parameters are usually adjusted based on feedback from the construction site, which has a certain lag in risk management and poses safety hazards. However, there are currently few indoor model testing instruments for shield tunneling, making it impossible to know the evolution process of soil disturbance before construction. Therefore, to address the shortcomings of existing technologies, a hydraulically loaded intelligent control model test bench for simulating all-terrain shield tunneling was designed. Summary of the Invention

[0004] The purpose of this invention is to provide a method for simulating shield tunneling in all terrains, enabling intelligent control model testing of shield tunneling with hydraulic loading, conducting indoor model tests of shield construction, and carrying out research on shield diameter, burial depth, tunneling parameters, construction conditions, and other aspects.

[0005] Technical solution:

[0006] A method for simulating shield tunneling across all terrains, characterized by comprising the following steps:

[0007] Step 1: Soil sample parameters are acquired and pre-set in the host computer;

[0008] Step 2: The test plan is determined and pre-loaded into the host computer to form a system test task;

[0009] Step 3: Install the baffle;

[0010] Step 4: Soil sample preparation;

[0011] Step 5: Soil sample location;

[0012] Step 6: Apply pressure;

[0013] Step 7: Shield tunneling;

[0014] Step 8: Data Acquisition;

[0015] Step 9: The experiment is over;

[0016] Step 10: Depressurize and remove samples.

[0017] The intelligent hydraulic loading model test for simulating all-terrain tunneling of a shield tunnel disclosed in this invention has the following advantages:

[0018] (1) This application has the advantage of being able to simulate the entire process of shield tunneling.

[0019] This application focuses on the disturbance effect on the surrounding soil during shield tunneling. Through the tunneling system and loading system 7, the shield tunneling construction and the surrounding soil pressure environment are realistically simulated. Combined with the data collected by the host computer and data acquisition instrument 17, the pressure change value and displacement change value of the soil sample during the entire simulated shield tunneling construction process are obtained, so as to understand the evolution law of soil disturbance during shield construction and reduce construction risks.

[0020] (2) This application has the advantage of enabling research on different tunneling parameters of shield tunnels.

[0021] This application uses a tunneling system controller to control a small motor to rotate an upper rotating rod, which in turn drives the track, thereby rotating a geared rotating rod and advancing it along the toothed grooves of the cutterhead auxiliary rod, thus driving the cutterhead forward. The tunneling system control panel sets and controls the cutterhead's advance speed V1 to simulate the actual tunneling speed V in a shield tunneling project, and controls the electric drill's rotational speed ω1 to simulate the shield machine's rotational speed ω. The diameter D1 of the double-bladed helical rod is selected to simulate the shield machine's diameter D.

[0022]

[0023]

[0024]

[0025] In the formula, n1 is the shield rotation speed similarity ratio, n2 is the shield propulsion speed similarity ratio, and n3 is the shield diameter similarity ratio.

[0026] The simulation of tunneling parameters such as shield diameter, shield advance speed and shield rotation speed during construction was realized, thereby obtaining the spatiotemporal variation law and mechanical response effect of different tunneling parameters on the surrounding soil, providing a reference for the sensitivity analysis of shield tunneling parameters in the future.

[0027] (3) This application has the advantage of being able to simulate shield tunneling at any burial depth.

[0028] During tunnel boring machine (TBM) construction, the tunnel will be subjected to vertical and horizontal pressures σ from the surrounding soil. cz , σ cX , σ cY The loading system of this application controls the hydraulic values ​​of each cylinder via a servo hydraulic power source control panel, and pressurizes the soil sample by pushing the lateral loading plate, upper loading plate, and rear loading plate. The upper loading plate applies a vertical pressure σ. cz Simulate the vertical soil pressure experienced by the tunnel boring machine during tunneling, and determine the horizontal pressure σ applied by the hydraulic cylinder through the lateral loading plate. cX Simulate the horizontal soil pressure experienced by the tunnel boring machine during tunneling, and determine the horizontal pressure σ applied by the hydraulic cylinder through the back loading plate. cY Simulates the horizontal pressure of the soil along the tunneling direction experienced by a tunnel boring machine.

[0029] σ cz =γZ

[0030] σ cX =σ cY =K0σ cz

[0031] In the formula: K0 is the earth lateral pressure coefficient, σ cz K0 represents the vertical pressure on the soil, γ represents the natural unit weight of the soil, and Z represents the actual depth of the tunnel boring machine. K0 and γ were determined by laboratory geotechnical tests before the experiment.

[0032] To simulate the actual ground stress at the shield excavation location to the greatest extent possible, this study simulates shield tunneling at different burial depths, providing an experimental basis for research on soil response during ultra-deep shield tunneling under extreme conditions.

[0033] (4) This application has the advantage of being able to simulate the tunnel boring machine passing over and under existing structures.

[0034] This application, based on the similarity theory of model testing, uses geometric similarity to determine the geometry of the existing structure simulation model and material similarity to select the materials for fabricating the simulation model. It then determines the distance H1 between the existing structure simulation model and the double-bladed auger drill rod, simulating the distance H in actual engineering where a shield tunnel passes over or under an existing structure. Both satisfy the following formula:

[0035]

[0036] In the formula: n4 is the similarity ratio of the spacing between structures.

[0037] By combining the real-time changes in soil pressure and displacement obtained by the host computer and data collector during the test, the impact of soil disturbance on the existing structure during the shield tunneling process is obtained, and the most unfavorable construction conditions with the greatest degree of soil disturbance are known.

[0038] (5) This application has the characteristic of wide applicability.

[0039] This application enables model tests of shield tunneling construction in different soil environments by filling soil samples with different properties. It realizes the simulation of shield tunneling construction without obstacles in all terrains, thereby obtaining the impact effects of shield construction under any geological conditions, and can provide reference opinions for corresponding engineering construction. Attached Figure Description

[0040] Figure 1 This is a cross-sectional view of a hydraulically loaded intelligent control model test bench for all-terrain tunneling simulation.

[0041] Figure 2 yes Figure 1 AA cross-sectional view of the device shown

[0042] Figure 3 yes Figure 1 BB cross-sectional view of the device shown

[0043] Figure 4 yes Figure 1 Front view of the device shown

[0044] Figure 5 yes Figure 1 Left view of the device shown

[0045] Figure 6 yes Figure 1 Right view of the device shown

[0046] Figure 7 This is a schematic diagram of the equipment's tunneling operation.

[0047] Figure 8 yes Figure 7 CC cross-sectional view of the device in its working state.

[0048] Figure 9 This is a schematic diagram of the tunneling system.

[0049] Figure 10 This is a schematic diagram of a lateral support baffle.

[0050] Figure 11 This is a schematic diagram of the rear support baffle.

[0051] Figure 12 This is a schematic diagram of a fixed groove plate.

[0052] Figure 13This is a schematic diagram of the loading system applying pressure along the tunneling direction of the device.

[0053] Figure 14 This is a schematic diagram of the vertical device of the loading system applying pressure in the tunneling direction.

[0054] Figure 15 This is a flowchart of the shield tunneling all-terrain simulation test method of the present invention. Detailed Implementation

[0055] The present invention relates to a hydraulically loaded intelligent control model test bench for simulating all-terrain tunneling of a shield tunnel, comprising the following parts:

[0056] The components include:

[0057] 1 is the host unit, 101 is the linear guide rail, and 102 is the reserved hole;

[0058] 2 is the tunneling system, 201 is the electric drill, 202 is the feed tool, 203 is the feed assist rod, 204 is the tunneling system fixing plate, 205 is the double-blade auger drill rod, 206 is the threaded rod, 207 is the track, 208 is the feed assist rod fixing plate, 209 is the small motor, 210 is the geared rotating rod, 211 is the upper rotating rod, 212 is the tunneling system controller, and 213 is the tunneling system operation panel.

[0059] 3 is the rear support baffle, 301 is the rotatable fixing bolt, and 302 is the nut;

[0060] 4 is a lateral support baffle, 401 is a fixed groove plate, and 402 is a steel upright plate;

[0061] 5 is the lower support baffle;

[0062] 6 represents the handle;

[0063] 7 is the loading system, 701 is the lateral loading plate, 702 is the upper loading plate, 703 is the reaction frame, 704 is the external bearing frame, 705 is the reaction frame support leg, 706 is the rear loading plate, 707 is the servo oil source, 708 is the servo oil source operation panel, 709 is the hydraulic pipeline, and 710 is the oil cylinder.

[0064] 8 indicates an extra-large bolt, and 801 indicates a bolt screw-in rod;

[0065] 9 is a fixed circular plate, and 901 is a threaded pre-drilled hole;

[0066] 13 is a soil sample;

[0067] 15 is a fixing bolt;

[0068] 16 represents a cable;

[0069] 17 is a data acquisition device;

[0070] 18 is an earth pressure cell;

[0071] 19 is a displacement sensor;

[0072] 20 represents the conductor;

[0073] 21 is a simulation model of an existing structure;

[0074] 22 represents the host computer.

[0075] The connection methods between the above components are as follows:

[0076] The host unit 1 includes a linear slide rail 101 and a reserved hole 102.

[0077] The host unit 1, located on the linear slide rail 101, can slide on the slide rail. Together with the rear support baffle 3, the lateral support baffle 4, and the lower support baffle 5, it forms a temporary test model box. After the soil sample 13 is compacted in the model box, the baffles are removed, and the sample is pushed into the loading system 7 along the linear slide rail 101.

[0078] The linear guide rail 101 is located below the load-bearing host 1 and is fixed to the outer load-bearing frame 704 of the loading system 7. The load-bearing host 1 pushes the soil sample 13 into the loading system 7 through the linear guide rail 101.

[0079] The reserved hole 102 is located on the main support host 1. During the test, the double-leaf spiral rod 205 passes through it to simulate the tunneling of the shield machine.

[0080] The tunneling system 2 includes an electric drill 201, a cutterhead 202, a cutterhead auxiliary rod 203, a tunneling system fixing plate 204, a double-bladed helical rod 205, a threaded rod 206, a track 207, a cutterhead auxiliary rod fixing plate 208, a small motor 209, a geared rotating rod 210, and an upper rotating rod 211. The tunneling system 2 simulates the tunneling process of a tunnel boring machine (TBM) during shield tunneling construction. The advance speed V1 of the cutterhead 202 simulates the actual advance speed V in a shield tunneling project, the rotational speed ω1 of the electric drill 201 simulates the rotational speed ω of the TBM, and the diameter D1 of the double-bladed helical rod 205 simulates the diameter D of the TBM.

[0081] The electric drill 201 and the feed device 202 are fixed together as a single unit. During the test, the motor speed was set to ω1 through the tunneling system controller 212 to simulate the tunnel boring machine's speed ω. The relationship between the two conforms to the following formula:

[0082]

[0083] In the formula, n1 is the shield tunneling speed similarity ratio.

[0084] The electric drill 201 has a threaded rod 206 at the end. During the test, a double-bladed spiral rod 205 of appropriate diameter is selected and fixed to the electric drill 201 through the threaded rod 206.

[0085] The feed tool 202 is fixed to the electric drill 201, forming a single unit. The feed auxiliary rod 203 passes through the middle of the feed tool 202, meaning the feed tool 202 and the electric drill 201 are attached to the feed auxiliary rod 203. During the test, the feed tool's advance speed is set to V1 via the tunneling system controller 212 to simulate the tunnel boring machine's advance speed V. The relationship between the two is as follows:

[0086]

[0087] In the formula, n2 is the similarity ratio of the shield tunneling speed.

[0088] The feed assist rod 203, fixed to the feed assist rod fixing plate 208 by fixing bolts 15, has a toothed pattern. During tunneling, the tunneling system controller 212 controls the small motor 209 to rotate the upper rotating rod 211, driving the track 207, which in turn rotates the geared rotating rod 210, advancing along the toothed pattern of the feed assist rod 203, and thus driving the feed device 202 forward. The track 207, the geared rotating rod 210, and the upper rotating rod 211 all rotate at the same speed, ω2. Therefore, the advancing speed V1 and ω2 satisfy the following relationship:

[0089] V1=ω2R

[0090] In the formula, R is the diameter of the gear.

[0091] The tunneling system fixing plate 204 is fixed to the host machine 1 by bolts 15. Together with the cutterhead auxiliary rod fixing plate 208, it fixes the entire tunneling system 2 to prevent disturbance during tunneling.

[0092] The double-bladed helical rod 205 has an internal thread at its tail end, allowing it to be fixed to the threaded rod 206 of the motor 201. This ensures that when excavating soil sample 13, the rotational speed of the double-bladed helical rod 205 is the same as the rotational speed of the motor 201, which is ω1. The diameter D1 of the double-bladed helical rod and the shield machine D are related by the following formula:

[0093]

[0094] In the formula, n3 is the similarity ratio of the shield diameter.

[0095] The threaded rod 206 is located at the motor 201 and is an integral part of it. The internal thread at the tail end of the double-lobe helical rod 205 engages with it, allowing the two to be fixed together.

[0096] Track 207 is fitted between upper rotating rod 211 and geared rotating rod 210.

[0097] The feed assist rod fixing plate 208 is fixed to the host machine 1 by bolts 15. Together with the tunneling system fixing plate 204, it fixes the entire tunneling system 2 so that it does not move during tunneling.

[0098] The small motor 209 is fixed above the feed tool 202. During tunneling, the tunneling system controller 212 controls the small motor 209 to work, thereby rotating the upper rotating rod 211.

[0099] A geared rotating rod 210 is located inside the feed tool 202. Its gear meshes with the toothed grooves of the feed auxiliary rod 203. One end of the rotating rod is fixed to the inner wall of the feed tool 202, and the other end extends out of the feed tool 202. During tunneling, the track 207 drives the geared rotating rod 210 to rotate, thereby rotating the gear and causing the feed tool 202 to advance along the feed auxiliary rod 203.

[0100] The upper rotating rod 211 is located inside the small motor 209. During tunneling, the tunneling system controller 212 controls the small motor 209 to work, rotating the upper rotating rod 211, which in turn drives the track 207, thereby rotating the geared rotating rod 210, so that the feed tool 202 advances along the feed auxiliary rod 203.

[0101] The rearward support baffle 3 includes a rotatable fixing bolt 301 and a nut 302.

[0102] The rear support baffle 3 has a handle 6 and two rotatable fixing bolts fixed on its left and right sides, respectively. During sample preparation, the rear support baffle 3 is placed above the lower support baffle 5, and the rotatable fixing bolts 301 are engaged in the groove of the fixing groove plate 401 in the side support baffle 4. The nuts 402 are tightened to fix it, thus forming a temporary test model box with the host machine 1, the side support baffle 4 and the lower support baffle 5.

[0103] There are four rotatable fixing bolts 301, two on each side of the rear support baffle 3. During sample preparation, the rotatable fixing bolts 301 are inserted into the grooves of the fixing groove plate 401 in the side support baffle 4, and the nuts 402 are tightened to fix them, so that the host 1, the rear support baffle 3, the side support baffle 4 and the lower support baffle 5 form a temporary test model box.

[0104] Nuts 302, there are four in total, used in conjunction with rotatable fixing bolts 301.

[0105] The lateral support baffle 4 includes a fixed groove plate 401 and a steel upright plate 402.

[0106] There are two lateral support baffles 4, with four steel uprights 402 welded to their backs. The fixing groove plate 401 is fixed to the steel uprights 402 by fixing bolts 15, and two handles 6 are fixed at the top. During sample preparation, the rotatable fixing bolts 301 of the rear support baffle 3 are engaged in the grooves of the fixing groove plate 401 in the lateral support baffle 4, and the nuts 402 are tightened to fix it, thus forming a temporary test model box with the host machine 1, the lateral support baffles 4, and the lower support baffle 5.

[0107] The fixed groove plate 401 is fixed to the steel upright plate 402 on the back of the lateral support baffle 4. During sample preparation, the rotatable fixing bolt 301 of the rear support baffle 3 is inserted into the groove, and the rear support baffle 3 and the lateral support baffle 4 are fixed with the tightening nut 302, thus forming a temporary test model box with the host machine 1 and the lower support baffle 5.

[0108] There are 8 steel upright plates 402 in total. Four plates are welded to the side support baffle 4, and the fixing groove plate 401 is fixed to the steel upright plate 402 by fixing bolts 15.

[0109] The lower support baffle 5 is fixed to the host 1 and cannot be disassembled. During sample preparation, it, together with the host 1, the rear support baffle 3, and the side support baffle 4, forms a temporary test model box.

[0110] There are six handles (6 in total), which are fixed in pairs to the rear support baffle (3) and the two side support baffles (4). This facilitates the assembly and disassembly of the temporary model box.

[0111] The loading system 7 includes a lateral loading plate 701, an upper loading plate 702, a reaction frame 703, an external bearing frame 704, a reaction frame support plate 705, and a rear loading plate 706. The loading plates are pushed by hydraulic cylinders 710 to simulate the real earth pressure environment during shield tunneling. The upper loading plate 702 applies a vertical pressure σ. cz The lateral loading plate 701 and the rear loading plate 706 apply a horizontal pressure σ. cX and σ cY .

[0112] Vertical pressure σ cz Horizontal pressure σ cX and σ cY The setting is based on the following formula.

[0113] σ cz =γZ

[0114] σ cX =σ cY =K0σ cz

[0115] In the formula: K0 is the earth lateral pressure coefficient, σ czσ is the vertical pressure of the soil mass, γ is the natural unit weight of the soil mass, and Z is the actual depth of shield construction. K0 and γ are determined through indoor geotechnical tests before the test.

[0116] There are two lateral loading plates 701, which are respectively located on the left and right sides of the inner ring of the outer bearing frame 704, and each is fixed with a cylinder 710 to apply a horizontal pressure σ to the soil sample 13. cX to simulate the actual horizontal pressure environment of the soil mass during shield construction.

[0117] The upper loading plate 702 has a size slightly smaller than that of the prepared soil sample 13, so that the wire 20 can extend from the gap, enabling the data acquisition instrument 17 to be connected to the earth pressure cell 18 and the displacement sensor 19, thereby obtaining the displacement of the soil mass and the change in soil pressure during the test. It is located on the upper side of the inner ring of the outer bearing frame 704 and is fixed with a cylinder 710 to apply a vertical pressure σ to the soil sample 13. cz to simulate the actual vertical pressure environment of the soil mass during shield construction.

[0118] The reaction frame 703 is connected to the outer bearing frame 703, and there are reaction frame support feet 705 fixed below to ensure the overall stability of the loading system. It is fixed with a cylinder 710 that pushes against the rearward loading plate 706 to apply a horizontal pressure σ to the soil mass 13. cY to simulate the actual horizontal pressure environment of the soil mass in the tunneling direction during shield construction.

[0119] The outer bearing frame 704 is in a "hui" - shaped form, with a reaction frame 703 fixed on the back and connected to the linear slide rail 101 on the front side. There is a cylinder 710 fixed on each of the four sides of the inner ring. The cylinders 710 on the upper side and the left and right sides push against the loading plates to apply pressure to the soil mass, simulating the actual vertical and horizontal pressure environments of the soil mass during shield construction. The cylinder 710 at the bottom pushes against the lower support baffle 5 to prevent damage to the lower support baffle 5 caused by excessive upper load.

[0120] The reaction frame support feet 705 are connected to the reaction frame 703 to ensure the stability of the entire loading system.

[0121] The rearward loading plate 706 is connected to the cylinder 710 at the reaction frame 703. By pushing against the rearward loading plate 706, a horizontal pressure σ is applied to the soil sample 13. cY to simulate the actual earth pressure environment of the soil mass in the tunneling direction during shield construction.

[0122] There are two extra - large bolts 8, which are respectively located on the left and right sides of the loading main body 1. After the loading main body 1 and the soil sample 13 are pushed into the outer bearing frame 704 along the linear slide rail 101 to complete the positioning of the soil mass. The extra - large bolts 8 are pushed into the threaded reserved holes 901 of the fixed circular plate 9, and the bolt screw rod 801 is tightened to complete the fixation of the loading main body 1 and the outer bearing frame 704.

[0123] The bolt screw-in rod 801 is located at the end of the oversized bolt 8. After the oversized bolt 8 is pushed into the threaded pre-drilled hole 901 of the fixing circular plate 9, the bolt screw-in rod 801 is rotated to complete the fixing of the main support 1 and the outer support frame 704.

[0124] Two circular plates 9 are fixed to the left and right sides of the outer load-bearing frame 704 respectively by fixing bolts 15. The threaded pre-drilled hole 901 in the center of the circular plate corresponds to the oversized bolt 8, so that the oversized bolt 8 can pass through the threaded pre-drilled hole 901 to complete the fixation of the load-bearing host 1 to the outer load-bearing frame 704.

[0125] The threaded pre-drilled hole 901 is located at the center of the fixed circular plate and corresponds to the position of the oversized bolt 8.

[0126] The servo oil source 707 supplies hydraulic oil to each cylinder through the hydraulic pipeline 709.

[0127] The servo hydraulic power control panel 708 controls the pressure of each hydraulic cylinder 710, i.e., the pressure value of each loading plate when the loading system is loading.

[0128] There are five hydraulic lines 709 in total. Four of them are located inside the four sides of the outer bearing frame 704 and are connected to the four oil cylinders in the inner ring of the outer bearing frame 704 respectively. One line is located inside the reaction frame 703 and is connected to the oil cylinder 710 of the reaction frame 703, which delivers the hydraulic oil distributed by the servo oil source 707 to each oil cylinder 710.

[0129] There are five hydraulic cylinders 710 in total. Four are fixed to the four sides of the inner ring of the outer bearing frame 704 by fixing bolts 15, and one is fixed to the reaction frame 703 by fixing bolt 15. The servo hydraulic power control panel 708 controls the pressure of each hydraulic cylinder 710 pushing the loading plate onto the soil, simulating the vertical and horizontal pressure environment of the soil during shield tunneling.

[0130] Soil sample 13 was selected, using soil with the same geotechnical parameters as the actual project, to realistically simulate the tunnel boring machine (TBM) construction environment.

[0131] The tunneling system controller 212 is connected to the tunneling system 2 via cable 16. During tunneling, the tunneling control system 14 controls the small motor 209 to rotate the upper rotating rod 211, which drives the track 207, thereby rotating the geared rotating rod 210 and advancing along the toothed pattern of the cutterhead auxiliary rod 203, thereby driving the cutterhead 202 to advance, simulating the tunneling of a shield in the soil.

[0132] The tunneling system operation panel 213 controls the advance speed V1 of the cutterhead 202 to simulate the advance speed V in the actual shield tunneling project, controls the rotation speed ω1 of the electric drill 201 to simulate the rotation speed ω of the shield machine, and controls the diameter D1 of the double-bladed spiral rod 205 to simulate the diameter D of the shield machine.

[0133] Fixed bolt 15 serves a fixing function. The feed assist rod 203 is fixed to the feed assist rod fixing plate 208, the feed assist rod fixing plate 208 is fixed to the tunneling system fixing plate 204, the tunneling system fixing plate 204 is fixed to the bearing host 1, the fixing groove plate 401 is fixed to the steel vertical plate 402, the fixing circular plate 9 is fixed to the outer bearing frame 704, the hydraulic cylinder 710 is fixed to the four sides of the inner ring of the outer bearing frame 704, and the hydraulic cylinder 710 is fixed to the reaction frame 703.

[0134] Cable 16 connects the tunneling system controller 212 and the tunneling system 2.

[0135] The data acquisition instrument 17 is connected to the earth pressure box 18, the displacement sensor 19 and the host computer 22 via wires 20.

[0136] Earth pressure cell 18 is connected to data acquisition instrument 20 via wire 20. It is pre-installed in soil sample 13 during the soil sample 13 installation stage to monitor the pressure change value of soil sample 13 during the test.

[0137] The displacement sensor 19 is connected to the data acquisition instrument 20 via the wire 20. It is pre-installed in the soil sample during the soil sample 13 installation stage to monitor the displacement change of the soil sample 13 during the test.

[0138] The conductor 20 connects the earth pressure cell 18, the displacement sensor 19, and the data acquisition instrument 17.

[0139] The existing structure simulation model 21 simulates existing structures encountered during shield tunneling, such as existing tunnels and underground pipelines. The distance H1 between the model and the double-blade auger drill rod 205 simulates the distance H between the shield tunneling machine and existing structures in actual engineering. Both satisfy the following formula:

[0140]

[0141] In the formula: n4 is the similarity ratio of the spacing between structures.

[0142] The host computer 22 is connected to the data acquisition instrument 17 via wire 20. During the test, the host computer 22 controls the data acquisition instrument 17 to collect the displacement and pressure change values ​​of the soil sample 13 and displays and processes them on the host computer 22, thereby obtaining the spatiotemporal variation law of the displacement of the soil sample 13 and its mechanical response effect. At the same time, the host computer 22 is connected to the control equipment of the host machine 1 (not shown in the figure), the control equipment of the tunneling system 2 (i.e., the tunneling system controller 211), and the control equipment of the loading system 7 (not shown in the figure) to control the various actuators according to the set test tasks.

[0143] The design and usage of the above-mentioned platform of the present invention (e.g.) Figure 15 (Flowchart shown):

[0144] Step 1: Soil parameters are acquired and pre-set in the host computer 22.

[0145] Soil sample 13 from the construction site was selected for indoor geotechnical testing to obtain the natural unit weight γ and the soil lateral pressure coefficient K0 required for developing the test plan.

[0146] Step 2: The test plan is determined and pre-set in the host computer 22 to form a system test task.

[0147] Step 2.1. Determine the tunneling parameters of tunneling system 2:

[0148] The advance speed V1 of the cutterhead 202 is determined to simulate the actual advance speed V in a tunnel boring machine (TBM) project. The rotational speed ω1 of the electric drill 201 is determined to simulate the rotational speed ω of the TBM. The determined tunneling parameters V1 and ω1 are input into the tunneling system operation panel 213. The diameter D1 of the double-bladed auger 205 is selected to simulate the diameter D of the TBM. Alternatively, these parameters can be preset in the host computer 22, which is connected to the tunneling system control equipment.

[0149] Step 2.2. Determine the loading pressure of the loading system 7: Based on the actual burial depth and the natural unit weight γ and soil lateral pressure coefficient K0 of the soil sample 13 obtained in Step 1, input the data into the servo hydraulic power supply operation panel 708 (or input it into the host computer 22, which is connected to the control equipment of the loading system 7) to determine the magnitude of the surrounding soil pressure during shield tunneling. The hydraulic cylinder 710 applies vertical pressure σ through the upper loading plate 702. c Simulating the vertical soil pressure experienced by the tunnel boring machine during tunneling, the horizontal pressure σ applied by the hydraulic cylinder 710 through the lateral loading plate 701 was determined. cX Simulating the horizontal soil pressure experienced by the tunnel boring machine, it was determined that the hydraulic cylinder 710 applies the horizontal pressure σ through the back-loading plate 706. cY Simulates the horizontal pressure exerted by the soil along the tunneling direction on the tunnel boring machine;

[0150] Step 2.3. Determine the material, size, and spacing of the existing structure simulation model 21 and pre-place it on the host computer 22: Based on the geometric similarity theory and material similarity theory of model tests, determine the geometry and material of the existing structure simulation model 21 to simulate the existing structures encountered during shield tunneling; based on the distance between the shield and the structure in the actual project, determine the distance H1 between the shield and the double-blade spiral drill rod 205 to simulate the distance between the shield and the existing structure in the actual project.

[0151] Step 2.4. Determine the deployment plan for the monitoring equipment and pre-install it on the host computer 22:

[0152] Determine the installation locations of the earth pressure cell 18 and the displacement sensor 19 in the soil sample 13.

[0153]

[0154]

[0155]

[0156] σ cz =Z

[0157] σ cX =σ cY =K0σ cz

[0158]

[0159] In the formula, n1 is the shield rotation speed similarity ratio, n2 is the shield advance speed similarity ratio, n3 is the shield diameter similarity ratio, and n4 is the structure spacing similarity ratio.

[0160] Step 3: Install the baffle.

[0161] Pull the load-bearing host 1 out along the linear slide rail 101, place the rear support baffle 3 and the lateral support baffle 4 on the lower support baffle 5, and then insert the four rotatable fixing bolts 301 of the rear support baffle 3 into the corresponding fixing groove plates 401 on the steel upright plate 402 on the back of the lateral support baffle 4, and finally tighten the nuts 302 to fix it. At this time, the load-bearing host 1, the rear support baffle 3, the lateral support baffle 4 and the lower support baffle 5 constitute a temporary test model box. In order to prevent the soil from sticking to the support baffles, apply oil to the surfaces of the rear support baffle 3, the lateral support baffle 4 and the lower support baffle 5 and wrap them with plastic wrap to eliminate the influence.

[0162] Step 4: Soil sample preparation.

[0163] The host unit 1, rear support baffle 3, lateral support baffle 4, and lower support baffle 5 form a temporary test model box with internal dimensions of 500mm × 500mm × 500mm. The soil is compacted in layers, and the actual height of the filled soil sample 13 is 530mm, with the excess 30mm representing the compression consolidation allowance. The surface is smoothed, and the elevation and flatness are checked. Simultaneously with the layered filling, according to the test plan, a simulated model 21 of the existing structure, an earth pressure cell 18, and a displacement sensor 19 are installed at the corresponding locations. The data collector 18 is connected to the earth pressure cell 18 and the displacement sensor 19 using wires 20.

[0164] Step 5: Soil sample location.

[0165] After the soil sample is prepared, remove all support baffles. Loosen the nut 302 to disengage the rotatable fixing bolt 301 in the rear support baffle 3 from the fixing groove 401 in the side support baffle 4, thereby removing the rear support baffle 3 and the side support baffle 4. Then, push the load-bearing host 1 and the soil sample 13 into the loading system 7 along the linear slide rail 101. Align the oversized bolt 8 with the threaded pre-drilled hole 901 in the fixing circular plate 9, tighten the bolt screw-in rod 801, and complete the positioning.

[0166] Step 6: Apply pressure.

[0167] like Figure 13 and Figure 14 As shown, based on the test plan, the vertical pressure σ on the soil is determined. cz Horizontal pressure σ cX and σ cY The hydraulic pressure of each cylinder 710 is controlled by the servo hydraulic power source operation panel 708 on the servo hydraulic power source 707. The pressure on the soil sample 13 is achieved by pushing the lateral loading plate 701, the upper loading plate 702, and the rear loading plate 706. At the same time, the cylinder 710 pushes the lower support baffle 5 to prevent excessive soil pressure from damaging the device.

[0168] Step 7: Shield tunneling.

[0169] According to the test plan, a double-bladed auger drill rod 205 with a suitable diameter D1 was selected and fixed to the electric drill 201 via a threaded rod 206. Figure 9 As shown, the tunneling system controller 212 controls the small motor 209 to rotate the upper rotating rod 211, which drives the track 207, thereby rotating the geared rotating rod 210 and advancing it along the toothed groove of the cutter advance auxiliary rod 203, thus driving the cutter advance device 202 to advance. The tunneling system operation panel 213 sets and controls the advance speed V1 of the cutter advance device 202 to simulate the advance speed V in the actual shield tunneling project, and controls the rotation speed ω1 of the electric drill 201 to simulate the rotation speed ω of the shield machine.

[0170] Step 8: Data Acquisition.

[0171] like Figure 7 and Figure 8 As shown, during the experiment, the host computer 22 controls the data acquisition instrument 17 to collect the soil pressure change value and soil displacement change value in the soil sample 13 in real time, and displays the change value on the host computer 22.

[0172] Step 9: The experiment is now complete.

[0173] After the experiment, if Figure 9As shown, the operation of the tunneling system controller 212 shuts down the electric drill 201 to stop working, and at the same time controls the small motor 209 to rotate the upper rotating rod 211, which drives the track 207, thereby rotating the geared rotating rod 210 and advancing along the toothed pattern of the feed auxiliary rod 203, thereby driving the feeder 202 to retreat from the soil sample 13.

[0174] Step 10: Depressurize and remove samples.

[0175] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 , Figure 8 As shown, the pressure of each cylinder 710 is controlled by the servo oil source operation panel 708; the bolt screwing rod 801 is rotated to separate the oversized bolt 8 from the threaded pre-drilled hole 901 in the fixed circular plate 9, and then the entire bearing host 1 is pulled out along the linear slide rail 101. The soil unloading is completed, the sample is dismantled, and the equipment is cleaned and maintained.

[0176] Repeat steps (1) to (10), selecting double-bladed spiral drill rods 205 with different diameters D1 to study different shield diameters; selecting different rotational speeds ω1 and propulsion speeds V1 of the tunneling system to study different shield tunneling parameters; selecting different earth pressures σ of the loading system. cz , σ cX , σ cY To achieve the study of different shield tunneling depths; to achieve the study of shield tunneling passing over and under existing structures with different spacings by selecting different spacings H1; and to achieve the study of the influence of soil layer parameters on shield tunneling by selecting different soil samples.

Claims

1. A method for simulating shield tunneling across all terrains. Its characteristics include the following steps: Step 1: Obtain soil sample (13) parameters and pre-set them in the host computer (22); Step 2: The test plan is determined and pre-set in the host computer (22) to form a system test task; Step 3: Install the baffle; Step 4: Soil sample preparation; Step 5: Soil sample location; Step 6: Apply pressure; Step 7: Tunneling; Step 8: Data Acquisition; Step 9: The experiment is over; Step 10: Depressurize and remove samples; Step 2: The test plan is determined and pre-set in the host computer (22) to form a system test task; Step 2.

1. Determine the tunneling parameters of the tunneling system (2): The feed speed V1 of the cutterhead (202) is determined to simulate the actual feed speed V in a tunnel boring machine (TBM) project, and the rotational speed of the electric drill (201) is determined.

1. Simulated rotational speed of tunnel boring machine The diameter D1 of the double-bladed auger drill rod (205) is selected to simulate the diameter D of the tunnel boring machine. The determined tunneling parameters V1, Input 1 and D1 into the tunneling system operation panel (213); or input them into the host computer (22), which is connected to the tunneling system control equipment. Step 2.

2. Determine the loading pressure of the loading system (7): Based on the actual burial depth and the natural unit weight of the soil sample (13) obtained in Step 1. and earth lateral pressure coefficient Input the servo oil source operation panel (708) or input the preset in the host computer (22). The host computer (22) is connected to the control equipment of the loading system (7) to determine the magnitude of the surrounding soil pressure during shield tunneling. The oil cylinder (710) applies vertical pressure through the upper loading plate (702). The vertical pressure of the soil sample (13) during shield tunneling was simulated to determine the horizontal pressure applied by the hydraulic cylinder (710) through the lateral loading plate (701). The horizontal pressure of the soil sample (13) during the tunnel boring machine was simulated to determine the horizontal pressure applied by the hydraulic cylinder (710) through the back loading plate (706). The horizontal pressure of soil sample (13) along the tunneling direction was simulated during shield tunneling. Step 2.

3. Determine the material, size, and spacing of the existing structure simulation model (21) and pre-place it on the host computer (22): Based on the geometric similarity theory and material similarity theory of model tests, determine the geometry and material of the existing structure simulation model (21) to simulate the existing structures encountered during shield tunneling; based on the actual distance between the shield and the structure in the project, determine the distance between the shield and the double-bladed spiral drill rod (205). This simulates the spacing between shield tunnels passing over and under existing structures in actual engineering projects. Step 2.

4. Determine the deployment plan for the monitoring equipment and pre-install it on the host computer (22): Determine the installation locations of the earth pressure cell (18) and displacement sensor (19) in the soil sample (13); In the formula For the similarity ratio of shield tunneling speed, For the similarity ratio of shield tunneling speed, For the similarity ratio of shield diameter, The similarity ratio of the spacing between structures. This refers to the actual depth of the tunnel boring machine (TBM). This refers to the spacing between shield tunnels passing over and under existing structures in actual engineering projects.

2. The test method as described in claim 1, characterized in that, Step 1: Soil sample (13) parameters are obtained and pre-set in the host computer (22); Soil samples (13) were selected from the construction site for indoor geotechnical testing to obtain the natural unit weight of soil samples (13) required for developing the test plan. Earth lateral pressure coefficient .

3. The test method as described in claim 1, characterized in that, Step 3: Install the baffle; Pull out the host machine (1) along the linear slide rail (101), place the rear support baffle (3) and the side support baffle (4) on the lower support baffle (5), and then insert the four rotatable fixing bolts (301) in the rear support baffle (3) into the corresponding fixing groove plates (401) on the steel upright plate (402) on the back of the side support baffle (4), and finally tighten the nuts (302) to fix it; at this time, the host machine (1), the rear support baffle (3), the side support baffle (4) and the lower support baffle (5) constitute a temporary test model box; in order to prevent the soil sample (13) from sticking to each support baffle, apply oil to the surface of the rear support baffle (3), the side support baffle (4) and the lower support baffle (5) and wrap them with plastic wrap to eliminate the influence.

4. The test method as described in claim 1, characterized in that, Step 4: Soil sample preparation; The host (1), rear support baffle (3), side support baffle (4) and lower support baffle (5) form a temporary test model box with internal dimensions of 500mm×500mm×500mm. The soil is compacted in layers. The actual filling soil sample (13) height is 530mm, with an extra 30mm for compression consolidation. The soil is smoothed and the elevation and flatness are checked. While filling the soil in layers, according to the test plan, the existing structure simulation model (21), earth pressure cell (18) and displacement sensor (19) are buried at the corresponding positions. The data acquisition instrument (17) is connected to the earth pressure cell (18) and displacement sensor (19) respectively with wires (20).

5. The test method as described in claim 1, characterized in that, Step 6: Apply pressure; According to the test plan, the vertical pressure applied to the soil sample (13) by the upper loading plate (702) was determined. Horizontal pressure is applied by the lateral loading plate (701). And apply horizontal pressure through the back loading plate (706) The hydraulic values ​​of each cylinder (710) are controlled by the servo oil source operation panel (708) on the servo oil source (707). The pressure on the soil sample (13) is completed by pushing the lateral loading plate (701), the upper loading plate (702), and the back loading plate (706). At the same time, the cylinder (710) pushes the lower support baffle (5) to avoid excessive soil pressure on the upper part and damage to the device.

6. The test method as described in claim 1, characterized in that, Step 7: Shield tunneling; According to the test plan, a double-bladed spiral drill rod (205) with a suitable diameter D1 was selected and fixed to the electric drill (201) via a threaded rod (206). The tunneling system controller (212) was used to control the small motor (209) to rotate the upper rotating rod (211), which in turn drove the track (207), thereby rotating the geared rotating rod (210) and advancing along the toothed pattern of the feed auxiliary rod (203), thereby driving the feeder (202) to advance. The advance speed V1 of the feeder (202) was set and controlled through the tunneling system operation panel (213) to simulate the advance speed V in the actual shield tunneling project, and the rotation speed of the electric drill (201) was controlled.

1. Simulated rotational speed of tunnel boring machine .

7. The test method as described in claim 1, characterized in that, Step 8: Data Acquisition; During the experiment, the host computer (22) controls the data acquisition instrument (17) to collect the soil pressure change value and the displacement change value of the soil sample (13) in real time, and displays the change value on the host computer (22).

8. The test method as described in claim 1, characterized in that, Step 9: The experiment is over; After the test, the tunneling system controller (212) was turned off and the electric drill (201) was stopped. At the same time, the small motor (209) was controlled to rotate the upper rotating rod (211), which drove the track (207), thereby rotating the geared rotating rod (210) and advancing along the toothed pattern of the feed auxiliary rod (203), thereby driving the feeder (202) to exit the soil sample (13) backward.

9. The test method as described in claim 1, characterized in that, Step 10: Depressurize and remove samples; The pressure of each cylinder (710) is controlled by the servo oil source operation panel (708); the bolt screw rod (801) is rotated to separate the oversized bolt (8) from the threaded pre-drilled hole (901) in the fixed circular plate (9), and then the entire bearing host (1) is pulled out along the linear slide rail (101) to complete the soil unloading and sample removal and to clean and maintain the equipment. Repeat steps (1) to (10) and select different diameters. The double-bladed spiral drill rod (205) was used to study different shield diameters; different rotational speeds of the tunneling system were selected.

1. The propulsion speed V1 is used to study different shield tunneling parameters; the vertical pressure applied by the loading system through the upper loading plate (702) is selected. Horizontal pressure is applied by the lateral loading plate (701). And apply horizontal pressure through the back loading plate (706) To achieve research on different shield tunneling depths; Select different spacing This study aims to investigate the impact of shield tunneling on existing structures with different spacings as it passes over and under them; and to study the influence of soil parameters on shield tunneling by selecting different soil samples.

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