A shield full-terrain tunneling simulation hydraulic loading intelligent control type model test bed

Abstract

A shield full-terrain tunneling simulation hydraulic loading intelligent control type model test bench, the whole design is a model box type, the box includes a bearing host, a support baffle, a loading system, a tunneling system, a data acquisition system and a host computer, wherein: the bearing host is located on the linear slide rail and can slide on the slide rail; the loading system can simulate the real stress at the shield excavation position to the maximum extent, realize the simulation of shield tunneling in different buried depths, and provide a test basis for the soil response research of extreme case super deep shield construction; the tunneling system simulates the tunneling process of the shield machine during shield construction; in the data acquisition system, the data acquisition instrument can be connected with the soil pressure cell and the displacement sensor to obtain the displacement and soil pressure changes of the soil during the test; the host computer is connected with the data acquisition instrument to obtain the displacement and mechanical response effect of the soil sample; the host computer is connected with the bearing host, the tunneling system and the loading system, and controls each executing mechanism according to the set test task.

Description

TECHNICAL FIELD

[0001] The present application relates to a shield full-terrain tunneling simulation hydraulic loading intelligent control type model test bench, which is mainly used for simulating indoor model test of shield construction and belongs to the technical field of tunnel construction engineering. BACKGROUND

[0002] As an efficient and safe construction technology, the shield method has been widely promoted in the construction of subway tunnels. In order to study the influence of shield construction on the surrounding environment and buildings, the commonly used research methods by domestic and foreign scholars include empirical formula method, analytical method, theoretical analysis method, model test method, numerical analysis method, etc. Due to the complexity of the construction process and management links involved in the prototype shield construction, it is basically not repeatable, and it is difficult to obtain accurate research results under single variable conditions. The model test can better reproduce the tunnel construction process, has strict theoretical basis and is simple and easy to operate, and the reliability of the research results is also relatively high. Therefore, the model test method is widely used in the fields of geotechnical and underground engineering.

[0003] The selection of tunneling parameters (pushing speed, shield diameter) during shield construction has a great influence on the degree of disturbance of the surrounding soil. In actual engineering, the tunneling parameters are usually adjusted based on the feedback from the construction site, which has a certain lag in risk control and has safety hazards. However, there are few indoor model test instruments for shield tunneling construction at present, so it is impossible to know the development process of soil disturbance before construction. Therefore, in view of the shortcomings of the prior art, a shield full-terrain tunneling simulation hydraulic loading intelligent control type model test bench is designed. SUMMARY

[0004] The present application aims to provide a shield full-terrain tunneling simulation hydraulic loading intelligent control type model test bench, which can perform indoor model test of shield construction and carry out research on shield diameter, burial depth, tunneling parameters, construction conditions, etc.

[0005] Technical scheme:

[0006] A shield full-terrain tunneling simulation hydraulic loading intelligent control type model test bench, characterized in that it is designed as a model box type, and the box includes a bearing host, support baffles, a loading system, a tunneling system, a data acquisition system, and an upper computer, wherein:

[0007] The bearing host is located above the linear slide rail and can slide on the slide rail; and the rear support baffle, the lateral support baffle, and the lower support baffle form a temporary test model box;

[0008] The loading system maximally simulates the real stress at the shield excavation position, realizes the simulation of shield tunneling at different burial depths, and provides a test basis for the research on soil response of ultra-deep shield construction in extreme conditions.

[0009] The tunneling system simulates the tunneling process of a shield machine during shield construction.

[0010] In the data acquisition system, the data acquisition instrument can be connected with the earth pressure cell and the displacement sensor, so as to obtain the displacement of the soil and the change of the earth pressure during the test.

[0011] The host computer is connected with the data acquisition instrument to obtain the space-time variation law and the mechanical response effect of the soil sample; meanwhile, the host computer is connected with the bearing host computer, the tunneling system and the loading system to control each execution mechanism according to the set test task.

[0012] The hydraulic loading intelligent control type model test bench for the shield all-terrain tunneling simulation has the following advantages:

[0013] (1) The device has the advantage of being able to simulate the whole process of shield tunneling construction.

[0014] The device focuses on the disturbance effect of the surrounding soil during shield tunneling construction, and through the tunneling system and the loading system, the shield tunneling construction and the soil pressure environment are simulated, and the pressure change value and the displacement change value of the soil sample during the whole process of simulated shield tunneling construction are obtained by combining the data collected by the host computer and the data acquisition instrument, so as to master the derivation law of soil disturbance during shield construction and reduce the construction risk.

[0015] (2) The device has the advantage of being able to realize the research on different tunneling parameters of the shield.

[0016] The device controls the small motor to rotate the upper rotating rod through the tunneling system controller, drives the track, rotates the gear rotating rod, and advances along the toothed track of the feeding auxiliary rod, and thus drives the feeding device to advance. The advance speed V1 of the feeding device is set through the tunneling system operation panel to simulate the advance speed V in the actual shield engineering, and the rotation speed ω1 of the electric drill is controlled to simulate the rotation speed ω of the shield machine. The diameter D1 of the double-leaf spiral rod is selected to simulate the diameter D of the shield machine.

[0017]

[0018]

[0019]

[0020] In the formula, n1 is the similarity ratio of the shield rotation speed, n2 is the similarity ratio of the shield advance speed, and n3 is the similarity ratio of the shield diameter.

[0021] The simulation of the shield diameter, shield advancing speed and shield rotating speed and other tunneling parameters in the construction process is realized, so that the time-space variation law and mechanical response effect of the surrounding soil under different tunneling parameters during shield construction are obtained, and reference is provided for the sensitivity analysis of shield tunneling parameters in the future.

[0022] (3) The device has the advantage of simulating shield construction at any buried depth.

[0023] During shield construction, the surrounding soil will be subjected to vertical and horizontal pressures σ cz , σ cX , σ cY The loading system of the application controls the hydraulic value of each oil cylinder through the servo oil source servo oil source servo oil source operation panel, and completes the pressure on the soil sample through the pushing lateral loading plate, the upper loading plate and the back loading plate. The upper loading plate applies vertical pressure σ cz The vertical pressure of the soil on the shield tunneling is simulated, and the horizontal pressure σ cX The horizontal pressure of the soil on the shield tunneling is simulated, and the horizontal pressure σ cY The horizontal pressure of the soil on the shield tunneling is simulated, and the horizontal pressure σ

[0024] σ cz = γZ

[0025] σ cX = σ cY = K0σ cz

[0026] In the formula: K0 is the lateral pressure coefficient of soil, σ cz is the vertical pressure of soil, γ is the natural density of soil, and Z is the actual depth of shield construction. K0 and γ are determined by indoor soil test before the test.

[0027] The maximum simulation of the true stress at the shield excavation position is realized, the simulation of shield tunneling at different buried depths is realized, and the test basis for the response research of soil in extreme case of ultra-deep shield construction is provided.

[0028] (4) The device has the advantage of simulating shield overpassing and underpassing existing structures.

[0029] Based on the similarity theory of model test, the geometric shape of the existing structure simulation model is determined according to geometric similarity, and the material of the existing structure simulation model is selected according to material similarity. The distance H1 between the double-spiral drill rod and the existing structure simulation model is determined, the distance H between the shield overpassing and underpassing existing structures in the actual project is simulated, and the two satisfy the following formula:

[0030]

[0031] In the formula: n4 is the similar ratio of the distance between structures.

[0032] Combined with the real-time changes of the pressure and displacement of the soil sample obtained by the host computer and the data collector during the test, the influence process of the soil disturbance on the existing structure during the shield overpassing and underpassing the existing structure is obtained, and the most unfavorable construction condition with the greatest soil disturbance degree is known.

[0033] (5) The device has the characteristics of wide application range.

[0034] The device can carry out shield tunneling construction model tests in different soil layer environments by filling different types of soil samples. It realizes the simulation of full-terrain barrier-free shield tunneling construction, thereby obtaining the influence effect of shield construction under any geological conditions, and can provide reference opinions for corresponding engineering construction. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a hydraulic loading intelligent control type model test bed profile for full-terrain tunneling simulation

[0036] Figure 2 is Figure 1 A-A sectional view of the device shown in

[0037] Figure 3 is Figure 1 B-B sectional view of the device shown in

[0038] Figure 4 is Figure 1 front view of the device shown in

[0039] Figure 5 is Figure 1 left view of the device shown in

[0040] Figure 6 is Figure 1 right view of the device shown in

[0041] Figure 7 is a schematic diagram of the device tunneling work

[0042] Figure 8 is Figure 7 C-C sectional view of the device in working state shown in

[0043] Figure 9 is a schematic diagram of the tunneling system

[0044] Figure 10 is a schematic diagram of the lateral support baffle

[0045] Figure 11 is a schematic diagram of the rear support baffle

[0046] Figure 12is fixed groove plate schematic diagram

[0047] Figure 13 is loading system along the device excavation direction pressure schematic diagram

[0048] Figure 14 is loading system vertical device excavation direction pressure schematic diagram DETAILED DESCRIPTION

[0049] The hydraulic loading intelligent control type model test bench for shield full-terrain excavation simulation of the application, comprises the following parts:

[0050] Each component comprises:

[0051] 1 is a bearing main machine, 101 is a linear slide rail, and 102 is a reserved hole;

[0052] 2 is an excavation system, 201 is an electric drill, 202 is a cutter, 203 is a cutter auxiliary rod, 204 is an excavation system fixing plate, 205 is a double-blade spiral drill rod, 206 is a threaded rod, 207 is a track, 208 is a cutter auxiliary rod fixing plate, 209 is a small motor, 210 is a gear toothed rotating rod, 211 is an upper rotating rod, 212 is an excavation system controller, and 213 is an excavation system operation panel;

[0053] 3 is a rear support baffle, 301 is a rotatable fixed bolt, and 302 is a nut;

[0054] 4 is a lateral support baffle, 401 is a fixed groove plate, and 402 is a steel vertical plate;

[0055] 5 is a lower support baffle;

[0056] 6 is a handle;

[0057] 7 is a loading system, 701 is a lateral loading plate, 702 is an upper loading plate, 703 is a counterforce frame, 704 is an outer bearing frame, 705 is a counterforce frame support foot, 706 is a back loading plate, 707 is a servo oil source, 708 is a servo oil source operation panel, 709 is a hydraulic pipeline, and 710 is an oil cylinder;

[0058] 8 is an oversized bolt, and 801 is a bolt screwing rod;

[0059] 9 is a fixed circular plate, and 901 is a threaded reserved hole;

[0060] 13 is a soil sample;

[0061] 15 is a fixed bolt;

[0062] 16 is a cable;

[0063] 17 is a data acquisition instrument;

[0064] 18 is a earth pressure cell;

[0065] 19 is a displacement sensor;

[0066] 20 is a wire;

[0067] 21 is an existing structure simulation model;

[0068] 22 is a host computer.

[0069] Connection between the above components:

[0070] The host computer 1 includes a linear slide rail 101 and a reserved hole 102.

[0071] The host computer 1 is located above the linear slide rail 101 and can slide on the slide rail. Together with the backward 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 pushed into the loading system 7 along the linear slide rail 101.

[0072] The linear slide rail 101 is located below the host computer 1 and is fixed with the outer bearing frame 704 of the loading system 7. The host computer 1 pushes the soil sample 13 into the loading system 7 through the linear slide rail 101.

[0073] The reserved hole 102 is located on the host computer 1 and the double helix rod 205 passes through it during the test to simulate the tunneling of the shield machine.

[0074] The tunneling system 2 includes an electric drill 201, a cutter 202, a cutter auxiliary rod 203, a tunneling system fixing plate 204, a double helix rod 205, a threaded rod 206, a track 207, a cutter auxiliary rod fixing plate 208, a small motor 209, a toothed gear rotating rod 210, and an upper rotating rod 211. The tunneling system 2 simulates the tunneling process of the shield machine during shield construction. The pushing speed V1 of the cutter 202 simulates the pushing speed V in the actual shield project, the rotating speed ω1 of the electric drill 201 simulates the rotating speed ω of the shield machine, and the diameter D1 of the double helix rod 205 simulates the diameter D of the shield machine.

[0075] The electric drill 201 is fixed with the cutter 202 and they are an integral whole. During the test, the motor rotating speed is set to ω1 through the tunneling system controller 212 to simulate the rotating speed ω of the shield machine, and the relationship between them conforms to the following formula:

[0076]

[0077] In the formula, n1 is the shield rotating speed similarity ratio.

[0078] The threaded rod 206 is provided at the end of the electric drill 201, and during the test, the double helix rod 205 with an appropriate diameter is selected to be fixed with the electric drill 201 through the threaded rod 206.

[0079] The feed device 202 is fixed with the electric drill 201 and is an integral whole. The feed auxiliary rod 203 passes through the middle of the feed device 202, that is, the feed device 202 and the electric drill 201 are hung on the feed auxiliary rod 203. During the test, the feed device advancing speed V1 is set by the tunneling system controller 212 to simulate the advancing speed V of the shield machine, and the two are related as follows:

[0080]

[0081] In the formula, n2 is the similarity ratio of the shield advancing speed.

[0082] The feed auxiliary rod 203 is fixed on the feed auxiliary rod fixing plate 208 by the fixing bolt 15 and has a toothed groove. During tunneling, the tunneling system controller 212 controls the small motor 209 to rotate the upper rotating rod 211, drives the track 207, rotates the toothed gear rotating rod 210, and advances along the toothed groove of the feed auxiliary rod 203, thereby driving the feed device 202 to advance. The rotating speeds of the track 207, the toothed gear rotating rod 210, and the upper rotating rod 211 are the same, which is ω2, and the advancing speed V1 and ω2 are related as follows:

[0083] V1=ω2R

[0084] In the formula, R is the gear diameter.

[0085] The tunneling system fixing plate 204 is fixed on the bearing host machine 1 by the bolt 15. Together with the feed auxiliary rod fixing plate 208, it fixes the entire tunneling system 2 so that it does not move during tunneling.

[0086] The double-leaf screw rod 205 has an internal thread at the tail end, which can be fixed with the threaded rod 206 of the electric machine 201, so that the rotating speed of the double-leaf screw rod 205 is consistent with the rotating speed of the electric machine 201, which is ω1. The diameter D1 of the double-leaf screw rod and the diameter D of the shield machine are related as follows:

[0087]

[0088] In the formula, n3 is the similarity ratio of the shield diameter.

[0089] The threaded rod 206 is located in the electric machine 201 and is an integral whole. The internal thread at the tail end of the double-leaf screw rod 205 fits with the threaded rod 206, so that the two can be fixed together.

[0090] The track 207 is sleeved between the upper rotating rod 211 and the toothed gear rotating rod 210.

[0091] The feed auxiliary rod fixing plate 208 is fixed on the bearing host machine 1 by the bolt 15. Together with the tunneling system fixing plate 204, it fixes the entire tunneling system 2 so that it does not move during tunneling.

[0092] Small motor 209, fixed on the cutter 202 above. When digging, digging system controller 212 control small motor 209 work, thus rotating the upper rotating rod 211.

[0093] Gear rotating rod 210, located in the cutter 202, its gear with the toothed profile of the cutter auxiliary rod 203 bite, rotating rod one end fixed in the cutter 202 wall one end of the cutter 202. When digging, the caterpillar 207 drive gear rotating rod 210 rotation, thus rotating the gear, so that the cutter 202 along the cutter auxiliary rod 203 advance.

[0094] Upper rotating rod 211, located in the small motor 209. When digging, digging system controller 212 control small motor 209 work, rotating the upper rotating rod 211, in turn, drive the caterpillar 207, thus rotating the gear rotating rod 210, so that the cutter 202 along the cutter auxiliary rod 203 advance.

[0095] Back support baffle 3, including rotatable fixed bolt 301 and nut 302.

[0096] Back support baffle 3, left and right sides are respectively fixed with a handle 6 and two rotatable fixed bolt. When making sample, the back support plate 3 is placed on the lower support baffle 5, the rotatable fixed bolt 301 is clamped in the recess of the fixed recess plate 401 in the lateral support baffle 4, and the nut 402 is tightened to fix, so as to form a temporary test model box with the bearing host 1, the lateral support baffle 4 and the lower support baffle 5.

[0097] Rotatable fixed bolt 301, a total of four, two on the left and right sides of the back support baffle 3. When making sample, the rotatable fixed bolt 301 is clamped in the recess of the fixed recess plate 401 in the lateral support baffle 4, and the nut 402 is tightened to fix, so as to make the bearing host 1, the back support baffle 3, the lateral support baffle 4 and the lower support baffle 5 form a temporary test model box.

[0098] Nut 302, a total of four, used with the rotatable fixed bolt 301.

[0099] Lateral support baffle 4, including fixed recess plate 401 and steel stand plate 402.

[0100] Lateral support baffle 4, a total of two, four steel stand plates 402 are welded on the back, the fixed recess plate 401 is fixed on the steel stand plate 402 by fixed bolt 15, and two handles 6 are fixed on the upper part. When making sample, the rotatable fixed bolt 301 of the back support baffle 3 is clamped in the recess of the fixed recess plate 401 in the lateral support baffle 4, and the nut 402 is tightened to fix, so as to form a temporary test model box with the bearing host 1, the lateral support baffle 4 and the lower support baffle 5.

[0101] The fixed groove plate 401 is fixed on the steel upright plate 402 at the back of the lateral support baffle 4. During sample preparation, the rotatable fixing bolt 301 of the rear support baffle 3 is clamped in the groove, and the rear support baffle 3 and the lateral support baffle 4 are fixed by tightening the nut 302, thereby forming a temporary test model box together with the bearing host 1 and the lower support baffle 5.

[0102] The steel upright plate 402 has a total of 8 pieces. Every four pieces are welded to the lateral support baffle 4, and the fixed groove plate 401 is fixed to the steel upright plate 402 by the fixing bolt 15.

[0103] The lower support baffle 5 is fixed to the bearing host 1 and cannot be disassembled. During sample preparation, it forms a temporary test model box together with the bearing host 1, the rear support baffle 3, and the lateral support baffle 4.

[0104] The handle 6 has a total of six, which are fixed on the rear support baffle 3 and two lateral support baffles 4 respectively. It is convenient for the assembly and disassembly of the temporary model box.

[0105] The loading system 7 includes a lateral loading plate 701, an upper loading plate 702, a counterforce frame 703, an outer bearing frame 704, a counterforce frame support plate 705, and a back loading plate 706. The loading plates are pushed by oil cylinders 710 to simulate the actual soil pressure environment during shield construction. The upper loading plate 702 applies vertical pressure σ cz , the lateral loading plate 701 and the back loading plate 706 apply horizontal pressure σ cX and σ cY .

[0106] The vertical pressure σ cz , the horizontal pressure σ cX and σ cY are set according to the following formula.

[0107] σ cz = γZ

[0108] σ cX = σ cY = K0σ cz

[0109] In the formula: K0 is the lateral pressure coefficient of soil, σ cz is the vertical pressure of soil, γ is the natural density of soil, and Z is the actual depth of shield construction. K0 and γ are determined by indoor soil test before the test

[0110] The lateral loading plate 701 has a total of two, which are located on the left and right sides of the inner ring of the outer bearing frame 704, and each is fixed with an oil cylinder 710 to apply horizontal pressure σ cX to the soil sample 13 to simulate the actual horizontal pressure environment of the soil during shield construction.

[0111] The upper loading plate 702 is slightly smaller than the size of the prepared soil sample 13, so that the lead wire 20 can be extended from the gap, so that the data acquisition instrument 17 can be connected with the soil pressure cell 18 and the displacement sensor 19, so as to obtain the displacement and soil pressure change of the soil body during the test. The oil cylinder 710 is fixed on the upper side of the inner ring of the outer bearing frame 704, and vertical pressure σ is applied to the soil sample 13 cz , simulating the real environment of vertical pressure of soil body in shield construction.

[0112] The counterforce frame 703 is connected with the outer bearing frame 703, and the counterforce frame support foot 705 is fixed below to ensure the overall stability of the loading system. An oil cylinder 710 is fixed, and the horizontal pushing back loading plate 706 is pushed, so as to apply horizontal pressure σ to the soil body 13 cY , simulating the real environment of horizontal soil pressure in the tunneling direction of soil body in shield construction.

[0113] The outer bearing frame 704 is "h" shaped, the back is fixed with the counterforce frame 703, and the front side is connected with the linear slide rail 101. An oil cylinder 710 is fixed on each of the four sides of the inner ring, and the oil cylinders 710 on the upper side and the left and right sides push the loading plate to apply pressure to the soil body, simulating the real vertical and horizontal pressure environment of the soil body in shield construction. The oil cylinder 710 at the bottom pushes the lower support baffle 5 to avoid excessive load above and damage to the lower support baffle 5.

[0114] The counterforce frame support foot 705 is connected with the counterforce frame 703 to ensure the stability of the entire loading system.

[0115] The rear loading plate 706 is connected with the oil cylinder 710 at the counterforce frame 703, and the horizontal pushing back loading plate 706 is pushed to apply horizontal pressure σ to the soil sample 13 cY , simulating the real environment of soil pressure in the tunneling direction of soil body in shield construction.

[0116] The super large bolt 8 is located on the left and right sides of the bearing host 1. After the bearing host 1 and the soil sample 13 are pushed into the outer bearing frame 704 along the linear slide rail 101, the super large bolt 8 is pushed into the threaded reserved hole 901 of the fixed circular plate 9, and the bolt screwing rod 801 is screwed, and the fixing of the bearing host 1 and the outer bearing frame 704 is completed.

[0117] The bolt screwing rod 801 is located at the end of the super large bolt 8. After the super large bolt 8 is pushed into the threaded reserved hole 901 of the fixed circular plate 9, the bolt screwing rod 801 is rotated to complete the fixing of the bearing host 1 and the outer bearing frame 704.

[0118] Two fixed circular plates 9 are fixed on the left and right sides of the outer bearing frame 704 by fixing bolts 15. The threaded reserved holes 901 in the center of the circular plates are mapped with the super large bolts 8, so that the super large bolts 8 can pass through the threaded reserved holes 901 to complete the fixation of the bearing host 1 and the outer bearing frame 704.

[0119] The threaded reserved holes 901 are located in the center of the fixed circular plate and are mapped with the positions of the super large bolts 8.

[0120] The servo oil source 707 provides hydraulic oil to each oil cylinder through the hydraulic pipeline 709.

[0121] The servo oil source operation panel 708 controls the pressure of each oil cylinder 710, that is, the pressure value of each loading plate when the loading system is loaded.

[0122] The hydraulic pipeline 709 has five pipes, four of which 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, and one is located inside the counterforce frame 703 and is connected to the oil cylinder 710 of the counterforce frame 703, which transports the hydraulic oil distributed by the servo oil source 707 to each oil cylinder 710.

[0123] The oil cylinder 710 has five cylinders, four of which are fixed on the four sides of the inner ring of the outer bearing frame 704 by fixing bolts 15, and one is fixed on the counterforce frame 703 by fixing bolts 15. The servo oil source operation panel 708 is operated to control the pressure of the oil cylinder 710 pushing the loading plate to the soil, simulating the vertical and horizontal pressure environment of the soil in the shield construction process.

[0124] The soil sample 13 is selected from the same soil as the actual engineering soil parameter to simulate the shield construction environment.

[0125] The tunneling system controller 212 is connected to the tunneling system 2 through the cable 16. During tunneling, the tunneling control system 14 controls the small motor 209 to rotate the upper rotating rod 211, drives the crawler 207 to rotate, and then drives the gear rotating rod 210 to rotate, and pushes along the toothed track of the cutting auxiliary rod 203, and drives the cutter 202 to advance, simulating the tunneling of the shield in the soil.

[0126] The tunneling system operation panel 213 controls the advancing speed V1 of the cutter 202 to simulate the advancing speed V of the shield in the actual engineering, controls the rotating speed ω1 of the electric drill 201 to simulate the rotating speed ∈ of the shield machine, and controls the diameter D1 of the double-leaf screw rod 205 to simulate the diameter D of the shield machine.

[0127] Fixing bolt 15, fixing effect. The feed auxiliary rod 203 is fixed on the feed auxiliary rod fixing plate 208, the feed auxiliary rod fixing plate 208 is fixed on the tunneling system fixing plate 204, the tunneling system fixing plate 204 is fixed on the bearing main machine 1, the fixed groove plate 401 is fixed on the steel vertical plate 402, the fixed circular plate 9 is fixed on the outer bearing frame 704, the oil cylinder 710 is fixed on the outer bearing frame 704 inner ring four sides, and the oil cylinder 710 is fixed on the counterforce frame 703.

[0128] Cable 16, connecting the tunneling system controller 212 and the tunneling system 2.

[0129] Data acquisition instrument 17, connected with soil pressure cell 18, displacement sensor 19 and host computer 22 through wire 20.

[0130] Soil pressure cell 18, connected with data acquisition instrument 20 through wire 20, buried in soil sample 13 in advance during the soil sample burying stage, and used for monitoring the pressure change value of soil sample 13 during the test.

[0131] Displacement sensor 19, connected with data acquisition instrument 20 through wire 20, buried in soil sample 13 in advance during the soil sample burying stage, and used for monitoring the displacement change value of soil sample 13 during the test.

[0132] Wire 20, connecting soil pressure cell 18, displacement sensor 19 and data acquisition instrument 17.

[0133] Existing structure simulation model 21, simulating existing structures encountered during shield construction, such as existing tunnels, pipelines and the like, and the distance H1 between the double-leaf spiral drill rod 205, simulating the distance H between the shield and the existing structure in the actual project, both satisfying the following formula:

[0134]

[0135] In the formula, n4 is the similar ratio of the structure distance.

[0136] Host computer 22, connected with data acquisition instrument 17 through wire 20. During the test period, the host computer 22 controls the data acquisition instrument 17 to collect the displacement change value and the pressure change value of the soil sample 13 and displays and processes them in the host computer 22, so as to obtain the displacement space-time change rule and the mechanical response effect of the soil sample 13. At the same time, the host computer 22 is connected with the control equipment (not shown in the figure) of the bearing main machine 1, the control equipment (i.e. tunneling system controller 211) of the tunneling system 2 and the control equipment (not shown in the figure) of the loading system 7, and controls each execution mechanism according to the set test task.

[0137] The design and use mode of the platform are as follows:

[0138] Step 1, obtain the soil parameters and preset them in the host computer 22.

[0139] Select the soil sample 13 at the construction site, and conduct indoor soil test to obtain the natural specific gravity γ and the soil lateral pressure coefficient K0 required for formulating the test scheme.

[0140] The test scheme of step 2 is preset in the upper computer 22 to form the system test task.

[0141] Step 2.1. Determine the tunneling parameters of the tunneling system 2:

[0142] Determine the advancing speed V1 of the cutter 202 to simulate the advancing speed V of the shield in actual engineering, and determine the rotating speed ∈1 of the electric drill 201 to simulate the rotating speed ∈ of the shield machine. The determined tunneling parameters V1 and ∈1 are input into the tunneling system operation panel 213. Select the diameter D1 of the double-leaf screw rod 205 to simulate the diameter D of the shield machine. Or input through the upper computer 22 which is preset and connected with the control device of the tunneling system.

[0143] Step 2.2. Determine the loading pressure of the loading system 7: according to the actual buried depth and the natural specific gravity γ and the soil lateral pressure coefficient K0 of the soil sample 13 obtained in step 1, input the servo oil source operation panel 708 (or input through the upper computer 22 which is preset and connected with the control device of the loading system 7), so as to determine the size of the earth pressure around the shield tunneling construction. The oil cylinder 710 applies vertical pressure σ cz Simulate the vertical pressure of the soil body when the shield is tunneling, and determine that the oil cylinder 710 applies horizontal pressure σ cX Simulate the horizontal pressure of the soil body when the shield is tunneling, and determine that the oil cylinder 710 applies horizontal pressure σ cY Simulate the horizontal pressure of the soil body along the tunneling direction when the shield is tunneling;

[0144] Step 2.3. Determine the material, size and spacing of the existing structure simulation model 21, and preset in the upper computer 22: according to the geometric similarity theory and material similarity theory of model test, determine the geometric shape and material of the made existing structure simulation model 21 to simulate the existing structure encountered in the shield construction process; according to the spacing between the shield and the structure in the actual engineering, determine the spacing H1 of the double-leaf screw drill rod 205 to simulate the spacing of the shield overpassing and underpassing the existing structure in the actual engineering;

[0145] Step 2.4. Determine the layout scheme of the monitoring equipment, and preset in the upper computer 22:

[0146] Determine the embedding position of the soil pressure cell 18 and the displacement sensor 19 in the soil sample 13.

[0147]

[0148]

[0149]

[0150] σ cz = Z

[0151] σ cX = σ cY = K0σ cz

[0152]

[0153] wherein n1 is a similarity ratio of the shield rotating speed, n2 is a similarity ratio of the shield advancing speed, n3 is a similarity ratio of the shield diameter, and n4 is a similarity ratio of the structure spacing.

[0154] Step 3: installing the baffle.

[0155] The bearing host 1 is pulled out along the linear slide rail 101, the rearward supporting baffle 3 and the lateral supporting baffle 4 are placed on the lower supporting baffle 5, then the four rotatable fixing bolts 301 in the rearward supporting baffle 3 are respectively clamped in the corresponding fixing groove plates 401 on the back steel upright plates 402 of the lateral supporting baffle 4, and finally the nuts 302 are tightened for fixation. At this time, the bearing host 1, the rearward supporting baffle 3, the lateral supporting baffle 4 and the lower supporting baffle 5 constitute a temporary test model box. In order to prevent the soil from sticking to the supporting baffles, the surfaces of the rearward supporting baffle 3, the lateral supporting baffle 4 and the lower supporting baffle 5 are smeared with oil and wrapped with plastic wrap to eliminate the influence.

[0156] Step 4: soil sample preparation.

[0157] The bearing host 1, the rearward supporting baffle 3, the lateral supporting baffle 4 and the lower supporting baffle 5 constitute a temporary test model box, with an internal size of 500mm x 500mm x 500mm. The actual filling soil sample 13 has a height of 530mm, with an extra 30mm as a compression consolidation allowance. The height and flatness are leveled and inspected. While the soil is filled layer by layer, the existing structure simulation model 21, the earth pressure cell 18 and the displacement sensor 19 are buried at the corresponding positions according to the test scheme, and the data collection instrument 18 is connected to the earth pressure cell 18 and the displacement sensor 19 through the wire 20.

[0158] Step 5: soil sample positioning.

[0159] After the soil sample is prepared, the supports are removed. The nut 302 is loosened, the rotatable fixing bolt 301 in the rear support 3 is separated from the fixing groove 401 in the lateral support 4, and the rear support 3 and the lateral support 4 are removed. The main machine 1 and the soil sample 13 are pushed into the loading system 7 along the linear slide rail 101. The oversized bolt 8 is aligned with the threaded reserved hole 901 in the fixed disc 9, the bolt is screwed into the rod 801, and the positioning is completed.

[0160] Step 6: Pressurization.

[0161] As shown in Figure 13 and Figure 14 , the vertical pressure σ cz , the horizontal pressure σ cX , and σ cY of the soil body are determined according to the test scheme. The hydraulic value of each oil cylinder 710 is controlled through the servo oil source operation panel 708 on the servo oil source 707, the soil sample 13 is pressurized by pushing the lateral loading plate 701, the upper loading plate 702, and the back loading plate 706. At the same time, the lower support 5 is pushed by the oil cylinder 710 to avoid excessive soil pressure on the upper part of the device.

[0162] Step 7: Shield tunneling.

[0163] According to the test scheme, the double-leaf auger rod 205 with a suitable diameter D1 is selected and fixed on the electric drill 201 through the threaded rod 206. As shown in Figure 9 , the upper rotating rod 211 is rotated by operating the tunneling system controller 212 to control the small motor 209, which drives the crawler 207, thereby rotating the gear rotating rod 210 and advancing along the toothed trace of the feed auxiliary rod 203, and thus driving the feed device 202 to advance. The advancing speed V1 of the feed device 202 is set through the tunneling system operation panel 213 to simulate the advancing speed V of the shield in actual engineering, and the rotating speed ω1 of the electric drill 201 is set to simulate the rotating speed ω of the shield machine.

[0164] Step 8: Data acquisition.

[0165] As shown in Figure 7 and Figure 8 , during the test, the data acquisition instrument 17 is controlled by the upper computer 22 to acquire the soil pressure change value and the soil displacement change value in the soil sample 13 in real time, and the change values are displayed on the upper computer 22.

[0166] Step 9: End of test.

[0167] After the test is completed, as shown in Figure 9 , the main machine 1 and the soil sample 13 are pushed into the loading system 7 along the linear slide rail 101. The oversized bolt 8 is aligned with the threaded reserved hole 901 in the fixed disc 9, the bolt is screwed into the rod 801, and the positioning is completed.As shown in FIG. 8, the operation of the excavation system controller 212 stops the electric drill 201 from working, while controlling the small motor 209 to rotate the upper rotating rod 211, drive the crawler 207, rotate the gear rotating rod 210, and push along the toothed trace of the feeding auxiliary rod 203, thereby driving the cutter 202 to exit the soil sample 13 backward.

[0168] Step 10: pressure relief and sample removal.

[0169] As shown in FIG. 8, the operation of the excavation system controller 212 stops the electric drill 201 from working, while controlling the small motor 209 to rotate the upper rotating rod 211, drive the crawler 207, rotate the gear rotating rod 210, and push along the toothed trace of the feeding auxiliary rod 203, thereby driving the cutter 202 to exit the soil sample 13 backward. Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 8 As shown in FIG. 8, the operation of the excavation system controller 212 stops the electric drill 201 from working, while controlling the small motor 209 to rotate the upper rotating rod 211, drive the crawler 207, rotate the gear rotating rod 210, and push along the toothed trace of the feeding auxiliary rod 203, thereby driving the cutter 202 to exit the soil sample 13 backward.

[0170] Steps (1)-(10) are repeated, different diameters D1 of the double-leaf spiral drill rod 205 are selected to realize the research on different shield diameters; different rotation speeds ω1 and pushing speeds V1 of the excavation system are selected to realize the research on different shield excavation parameters; different soil pressures σ cz , σ cX , and σ cY of the loading system are selected to realize the research on different shield depths; different intervals H1 are selected to realize the research on the shield crossing under different interval existing structures; and different soil samples are selected to realize the research on the influence of soil layer parameters on shield excavation.​​​​​

Claims

1. A shield full-terrain tunneling simulation hydraulic loading intelligent control model test bed, characterized in that, The whole is designed as a model box type, the box includes a bearing host (1), support baffle, loading system (7), tunneling system (2), data acquisition system, host computer (22), wherein: The bearing host (1) is located on the linear slide rail (101) and can slide on the slide rail; with the backward support baffle (3), the lateral support baffle (4) and the lower support baffle (5) to form a temporary test model box; The loading system (7) maximizes the simulation of the real stress at the shield excavation position, realizes the simulation of different buried depth shield tunneling, and provides a test basis for the research of soil response of extreme case of ultra-deep shield construction; The tunneling system (2) simulates the tunneling process of the shield machine during shield construction; In the data acquisition system, the data acquisition instrument (17) can be connected with the soil pressure cell (18) and the displacement sensor (19), so as to obtain the displacement and soil pressure change of the soil during the test; The host computer (22) is connected with the data acquisition instrument (17) to obtain the displacement and mechanical response effect of the soil sample (13); at the same time, the host computer (22) is connected with the bearing host (1), the tunneling system (2) and the loading system (7) to control each execution mechanism according to the set test task; The loading system (7) controls the hydraulic value of each oil cylinder (710) through the servo oil source operation panel (708) on the servo oil source (707), pushes the lateral loading plate (701), the upper loading plate (702), and the back loading plate (706) to complete the pressurization of the soil sample (13); the upper loading plate (702) applies vertical pressure The oil cylinder (710) applies horizontal pressure through the lateral loading plate (701) by simulating the vertical pressure of the soil body when the shield is excavated The oil cylinder (710) applies horizontal pressure through the back loading plate (706) by simulating the horizontal pressure of the soil body when the shield is excavated The oil cylinder (710) applies horizontal pressure along the excavation direction by simulating the horizontal pressure of the soil body along the excavation direction when the shield is excavated In the formula: is the lateral pressure coefficient of soil, is the vertical pressure of soil, is the horizontal pressure of soil, is the horizontal pressure of soil along the tunneling direction; is the natural specific gravity of soil, and Z is the actual depth of shield construction; and determined by indoor geotechnical test before the test; Side loading plates (701), two in total, one on each side of the inner ring of the outer bearing frame (704), each fixed with an oil cylinder (710) to apply horizontal pressure to the soil sample (13) , simulating the real horizontal pressure environment of the soil during shield construction; The oil cylinder (710) is fixed on the upper side of the outer load frame (704) inner ring, and applies vertical pressure to the soil sample (13) , simulating the real environment of vertical pressure of soil body in shield construction; Counterforce frame (703) is connected with outer bearing frame (704), and counterforce frame support foot (705) is fixed below to ensure overall stability of loading system (7); oil cylinder (710) is fixed, pushes back loading plate (706), and horizontal pressure is applied to soil sample (13) , simulate the real environment of horizontal soil pressure in the direction of soil excavation of shield construction The outer bearing frame (704) is "H" shaped, the back is fixed with a counterforce frame (703), the front side is connected with the linear slide rail (101); the inner ring is fixed with an oil cylinder (710) on each side, the oil cylinder on the upper side and the left and right sides pushes the loading plate to apply pressure to the soil, simulating the vertical and horizontal real pressure environment of the soil during shield construction; The back loading plate (706) is connected with the oil cylinder (710) at the counterforce frame (703), and the horizontal pressure is applied to the soil sample (13) by pushing the back loading plate (706) , and the real environment of the soil pressure in the tunneling direction of the soil body in the shield construction is simulated.

2. The model test bed of claim 1, wherein Further, the counterforce frame support foot (705) is connected with the counterforce frame (703) to ensure the stability of the whole loading system (7).

3. The model test stand of claim 1, wherein The tunneling system controller (212) controls the small motor (209) to rotate the upper rotating rod (211), drives the caterpillar belt (207), rotates the gear rotating rod (210), and pushes along the toothed trace of the feeding auxiliary rod (203), and thus drives the feeding device (202) to push; the pushing speed V1 of the feeding device (202) is set through the tunneling system operation panel (213) to simulate the pushing speed V in the actual engineering of the shield, and the rotating speed of the electric drill (201) is controlled 1The rotating speed of the simulated shield machine .

4. The model test bed of claim 3, wherein Further, the tunneling system (2): The diameter D1 of the double-leaf screw rod (205) is selected to simulate the diameter D of the shield machine; wherein is the similarity ratio of the shield rotation speed, is the similarity ratio of the shield advancing speed, is the similarity ratio of the shield diameter, the simulation of the tunneling parameters of the shield diameter, the shield advancing speed and the shield rotation speed in the construction process is realized, so as to obtain the space-time variation law and the mechanical response effect of the displacement of the surrounding soil under different tunneling parameters in the shield construction, and provide a reference for the sensitivity analysis of the shield tunneling parameters in the future.

5. The model test stand of claim 1, wherein Further, the tunneling system (2), the data acquisition instrument (17) and the host computer (22): The tunneling system (2) and the host computer (22) are connected with the data acquisition instrument (17), so as to obtain the pressure change value and displacement change value of the soil sample (13) during the whole process of simulated shield tunneling, master the derivation law of soil disturbance in shield construction process, and reduce the construction risk.

6. The model test stand of claim 1, wherein Further, a simulation model (21) of the existing structure is provided; the distance between the double helical screw (205) and the existing structure is set by the host computer (22) , and the distance H between the shield and the existing structure in the actual project is simulated, and both satisfy the following formula: In the formula: is the ratio of the distance between structures. Combined with the real-time change value of the soil sample (13) pressure and displacement obtained by the data acquisition instrument (17) and the host computer (22) during the test process, the influence process of the existing structure disturbed by the soil sample (13) during the shield overpass and underpass of the existing structure is obtained, the most unfavorable construction condition of the soil sample (13) disturbance is known, and the construction risk is reduced.

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