A shield indoor test device and method for simulating various complex strata

Abstract

The application belongs to the technical field of shield test, and provides a shield indoor test device and method for simulating various complex strata. The model box comprises a bottom plate, a first side plate vertically fixed on the bottom plate, a second side plate hinged on the bottom plate, a third side plate hinged on the bottom plate, a fourth side plate hinged on the bottom plate, and a top plate detachably connected with all the side plates. During the test, the shield machine in the shield system excavates the test block through the round hole, and the test block for simulating different complex strata is replaced for multiple times, so that the shield test for various complex strata is completed. The detachable top plate and the hinged arrangement of the three side plates and the bottom plate realize the replacement of different test blocks, and the test can be stopped and the model box can be opened for observation at any time. Meanwhile, the three-layer structure of the standard test block, the test block and the standard test block realizes the precision simulation of the standard stratum, and improves the test precision.

Description

Technical Field

[0001] This invention belongs to the field of shield tunneling testing technology, and in particular relates to a shield tunneling indoor testing device and method for simulating various complex geological formations. Background Technology

[0002] Ultra-large diameter underwater (river) tunnels and urban road tunnels have become important forms of modern transportation. Consequently, ultra-large diameter shield tunnels face challenges such as long-distance excavation, large cross-sectional size effects, and complex geological conditions. This is especially true in complex geological formations with uneven hardness, where the strength variations at the rock-soil interface and the periodic impacts and vibrations exacerbate the problems of cutter wear and abnormal damage. Therefore, conducting indoor shield tunneling tests to simulate on-site conditions can provide valuable reference for the preparation work of actual construction.

[0003] The inventors discovered that current shield tunneling test devices cannot effectively simulate various complex geological formations. Furthermore, after simulating a geological formation, a new geological formation needs to be created within the model box, resulting in long intervals between simulations of different geological formations and affecting test efficiency. Moreover, the phenomena observed in the simulations can only be observed as a whole after the test is completed, and the tunneling phenomena at any point during the test cannot be directly observed. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a shield tunneling indoor testing device and method for simulating various complex geological formations. By setting standard test blocks and test blocks inside a model box with detachable side plates, after each test is completed, only the test blocks need to be replaced to simulate tunneling in various auxiliary geological formations. Furthermore, the test blocks can be opened at any time during tunneling to observe the results, greatly improving the efficiency of shield tunneling indoor testing in various complex geological formations and enhancing the flexibility of observing test phenomena.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a shield tunneling indoor testing device for simulating various complex geological formations, employing the following technical solution:

[0006] An indoor test device for simulating various complex geological formations includes a shield tunneling system and a model box, wherein the model box has circular holes for the tunneling operation of the shield tunneling system;

[0007] The model box includes a base plate, a first side plate vertically fixed to the base plate, a second side plate hinged to the base plate, a third side plate hinged to the base plate, a fourth side plate hinged to the base plate, and a top plate detachably connected to all the side plates; the first side plate has the circular hole.

[0008] Inside the model box, three layers of test blocks are arranged sequentially from the bottom plate to the top plate: a standard test block, a test block, and a standard test block. The test block in the middle is located at the circular hole. The tunnel boring machine in the shield system excavates through the test block through the circular hole. By repeatedly replacing the test blocks that simulate different complex strata, shield tunneling tests on various complex strata are completed.

[0009] Furthermore, the second side plate, the third side plate, and the fourth side plate are all connected to the base plate via multiple hinges.

[0010] Furthermore, the top plate is connected to the second side plate, the third side plate, and the fourth side plate by a plurality of latches.

[0011] Furthermore, wheel rails are provided on the base plate.

[0012] Furthermore, inside the model box, a second standard test block and a fourth standard test block are placed at one end near the bottom plate, and a first standard test block and a third standard test block are placed at one end near the top plate; a first test block is placed between the first standard test block and the second standard test block, and a second test block is placed between the second standard test block and the fourth standard test block.

[0013] Furthermore, the first test block and the second test block simulate different geological structures.

[0014] Furthermore, the tunnel boring machine is equipped with sensors.

[0015] Furthermore, the tunnel boring machine system includes a drive motor, spokes connected to the drive motor via a transmission shaft, and cutters mounted on the spokes.

[0016] Furthermore, the tunnel boring machine system is connected to a tunneling parameter control system.

[0017] To achieve the above objectives, in a second aspect, the present invention also provides a method for simulating indoor shield tunneling tests of various complex geological formations, employing the following technical solution:

[0018] A method for simulating indoor shield tunneling tests of various complex geological formations, employing the indoor shield tunneling test apparatus for simulating various complex geological formations as described in the first aspect, comprising:

[0019] The tunnel boring machine in the shield tunneling system excavates the test block through the circular hole. By repeatedly replacing the test block to simulate different complex strata, shield tunneling tests on various complex strata are completed.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The model box in this invention includes a base plate, a first side plate vertically fixed to the base plate, a second side plate hinged to the base plate, a third side plate hinged to the base plate, a fourth side plate hinged to the base plate, and a top plate detachably connected to all the side plates. A circular hole is formed on the first side plate. Inside the model box, three layers of test blocks—a standard test block, a test block, and a standard test block—are arranged sequentially from the base plate to the top plate. The test block in the middle is located at the circular hole. During the test, the tunnel boring machine (TBM) in the shield system excavates through the circular hole to excavate the test block. By repeatedly replacing the test blocks simulating different complex geological formations, TBM tests on various complex geological formations are completed. The detachable top plate and the hinged connection between the three side plates and the base plate allow for the replacement of different test blocks, and the test can be stopped and the model box opened for observation at any time. Simultaneously, the three-layer structure of the standard test block, test block, and standard test block achieves accurate simulation of standard geological formations, improving test accuracy.

[0022] In this invention, the first test block and the second test block simulate different geological structures, and tunneling simulation tests of two different geological formations can be completed in sequence, thereby improving efficiency.

[0023] This invention simulates various complex geological formations by replacing detachable model boxes and combined test blocks, which can greatly reduce the length of the simulated geological formations in the indoor test of shield tunneling. While simulating shield tunneling in various complex geological formations, it can avoid the risk of shield tunneling deviating from the tunneling line due to excessively long simulated geological formations in the indoor test. Attached Figure Description

[0024] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0025] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the model box cover being removed in Embodiment 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the side panel of the model box in Embodiment 1 of the present invention being opened;

[0028] Figure 4 This is a side view of the model box in Embodiment 1 of the present invention;

[0029] Figure 5 This is a top view of the model box in Embodiment 1 of the present invention;

[0030] Figure 6 This is a bottom view of the model box in Embodiment 1 of the present invention;

[0031] The components include: 1. Model box; 11. First side plate; 12. Second side plate; 13. Third side plate; 14. Fourth side plate; 15. Top plate; 16. Bottom plate; 17. Lock; 18. Hinge; 19. Wheel and rail; 2. Stratum simulation system; 21. First standard test block; 22. Second standard test block; 23. Third standard test block; 24. Fourth standard test block; 25. First test test block; 26. Second test test block; 3. Shield tunneling system; 31. Drive motor; 32. Spokes; 33. Cutting tools; 34. Drive shaft; 35. Conveyor belt; 36. Slag box; 4. Tunneling parameter control system; 41. Control platform; 42. Signal connection system; 5. Monitoring system; 51. Sensor; 52. Monitoring terminal. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0034] Example 1:

[0035] Research on the size effect of ultra-large diameter shield tunnels is still in the exploratory stage. In particular, due to limitations such as cutter wear and damage, the tunneling efficiency of shield tunnels in composite strata is low, severely restricting the progress of engineering projects. Effective solutions to these problems include improving the material of the cutterhead, improving the production process of the cutter ring, innovating structural dimensions, and optimizing the coordinated deployment of cutter groups. However, the essential premise is to clarify the stress changes of the cutterhead in strata with strength differences, such as soil-rock composite strata, under the influence of the geometric size effect of ultra-large diameter shield tunnels, and the vibration and impact damage mechanism of the cutterhead under varying loads. Therefore, it is urgent to conduct systematic and in-depth research on the rock-breaking mechanism, cutter damage mechanism, and prediction and control methods for ultra-large diameter shield tunnels traversing long distances and complex strata.

[0036] To address the problems of low efficiency in simulating different geological formations using current shield tunneling testing devices, and the inability to directly observe tunneling phenomena at any given moment during the test, such as... Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a shield tunneling indoor test device for simulating various complex geological formations, including a shield tunneling system 3 and a model box 1. The model box 1 has a circular hole for the shield tunneling system 3 to tunnel. It can be understood that the diameter of the circular hole should be slightly larger than the diameter of the shield machine.

[0037] The model box 1 includes a base plate 16, a first side plate 11 vertically fixed to the base plate 16, a second side plate 12 hinged to the base plate 16, a third side plate 13 hinged to the base plate 16, a fourth side plate 14 hinged to the base plate 16, and a top plate 15 detachably connected to all the side plates; the first side plate 11 has the circular hole.

[0038] Inside the model box 1, three layers of test blocks are arranged in reverse order from the bottom plate 16 to the top plate 15: a standard test block, a test block, and a standard test block. The test block in the middle is located at the circular hole. The tunnel boring machine in the shield system 3 tunnels through the circular hole to excavate the test block. By replacing the test blocks that simulate different complex strata multiple times, shield tunneling tests on various complex strata are completed.

[0039] Specifically, the detachable top plate 15 and the hinged connection between the three side plates and the bottom plate 16 enable the replacement of different test blocks, and allow the test to be stopped and the model box 1 to be opened for observation at any time; at the same time, the three-layer structure of standard test block, test block and standard test block enables accurate simulation of standard strata and improves the test accuracy.

[0040] Optionally, the standard test block can be a 200mm*150mm*150mm concrete test block; the test block can be a test block simulating various complex geological strata, which is prefabricated in advance through indoor testing, and its size is the same as the standard test block. The test blocks can be prefabricated according to different needs, including but not limited to test blocks that are soft on top and hard on the bottom, test blocks with boulders, and test blocks with cavities, etc.

[0041] In this embodiment, optionally, the first side plate 11 can be vertically fixed to the base plate 16 by welding or other methods; the second side plate 12, the third side plate 13, and the fourth side plate 14 can all be connected to the base plate 16 by multiple hinges 18. The top plate 15 is connected to the second side plate 12, the third side plate 13, and the fourth side plate 14 by multiple latches 17. The hinges 18 can be hinged hinges, and the latches 17 can be implemented using conventional technology, which will not be described in detail here.

[0042] The base plate 16 is provided with wheel rails 19.

[0043] like Figure 1As shown, optionally, in the model box 1, a second standard test block 22 and a fourth standard test block 24 are placed at one end near the bottom plate 16, and a first standard test block 21 and a third standard test block 23 are placed at one end near the top plate 15; a first test block 25 is placed between the first standard test block 21 and the second standard test block 22, and a second test block 26 is placed between the second standard test block 22 and the fourth standard test block 24.

[0044] Optionally, the first test block 35 and the second test block 36 simulate different geological structures.

[0045] The tunnel boring machine is equipped with sensors 51. Specifically, the sensors 51 may include various monitoring equipment, which are connected to monitoring terminals. Specifically, the device in this embodiment also includes a monitoring system 5, which is equipped with various monitoring devices, including but not limited to devices for monitoring cutter wear and soil pressure monitoring devices, based on the data to be monitored. The sensors are connected to monitoring terminals 52.

[0046] In this embodiment, to study the influence of tunneling parameters and cutterhead wear in complex strata, the installed monitoring elements may include a magnetic flux change sensing device, a temperature sensing device, and a thrust monitoring device installed on the cutterhead. The magnetic flux change sensing device monitors the real-time wear value of the cutterhead, the temperature sensing device monitors the temperature change of the cutterhead, and the thrust monitoring device monitors the thrust exerted by the cutterhead on the rock and soil surface. The monitoring terminal stores the monitoring data generated during the tunneling process.

[0047] The tunnel boring machine (TBM) system 3 includes a drive motor 31, spokes 32 connected to the drive motor 31 via a transmission shaft 34, and cutters 33 mounted on the spokes 32. The power drive of the TBM system 3 originates from the drive motor 31. The TBM system 3 also includes a muck removal system, which includes a conveyor belt 35 and a muck container 36. The conveyor belt 35 is used to transport the muck generated by the TBM cutters cutting test blocks, and the muck container 36 is used to store the transported muck. The transmission shaft 34 can be a threaded steel shaft or similar structure. One end of the threaded steel shaft passes through the container and connects to the cutterhead formed by the spokes, and the other end is connected to the drive motor 31.

[0048] Of course, the shield tunneling system 3 also includes a braking device that can perform certain braking movements before and after the entire system to achieve tunneling motion; or, one end of the threaded steel shaft passes through the housing and is connected to the cutterhead, and the other end is connected to the drive motor 31. The rotation of the drive motor 31 drives the cutterhead to rotate through the threaded steel shaft, and provides thrust to the cutterhead through the threaded steel shaft.

[0049] The tunnel boring machine system 3 is connected to a tunneling parameter control system 4. The tunneling parameter control system 4 includes a control platform 41 and a signal connection system 42. The control platform 41 controls the drive motor 31 through the signal connection system 42, controls the tunneling parameters, and controls the rotational speed and thrust of the tunnel boring machine cutterhead.

[0050] 1. Model box; 11. First side plate; 12. Second side plate; 13. Third side plate; 14. Fourth side plate; 15. Top plate; 16. Bottom plate; 17. Lock; 18. Hinge; 19. Wheel and rail; 2. Stratum simulation system; 21. First standard test block; 22. Second standard test block; 23. Third standard test block; 24. Fourth standard test block; 25. First test test block; 26. Second test test block; 3. Shield tunneling system; 31. Drive motor; 32. Spokes; 33. Cutting tools; 34. Drive shaft; 35. Conveyor belt; 36. Slag box; 4. Tunneling parameter control system; 41. Control platform; 42. Signal connection system; 5. Monitoring system; 51. Sensor; 52. Monitoring terminal.

[0051] One working principle or process of the device in this embodiment is as follows:

[0052] S1. Assemble the test device; the shield machine in the shield system 3 is required to pass through the first side plate 11 with a circular hole and contact the test block;

[0053] S2. The drive system and drive connection device drive the cutterhead to rotate and provide thrust, enabling the tunnel boring machine to excavate test blocks simulating complex strata; the tunneling parameter control system 4 controls the drive system, thereby controlling the tunneling parameters; the muck removal system transports the muck generated during the tunneling process; and the monitoring system monitors and records the required data.

[0054] S3. When the tunnel boring machine completes the excavation of the first simulated test block, turn off the drive system, open the model box, take out the standard test block above the first simulated test block, and after taking off the first simulated test block and the standard test block below, turn off the braking device on the wheel rail on the bottom panel, drag the bottom panel to the location of the first simulated test block in the opposite direction of the excavation direction, and place the standard test block and the new simulated test block.

[0055] When the braking device mounted on the base plate is to be closed, the operation can be completed through an electrically controlled gate;

[0056] S4. After assembling the model box, repeat steps S2 and S3.

[0057] The experimental apparatus provided in this embodiment can simulate the tunneling of tunnel boring machines (TBMs) in various complex geological formations, such as composite formations with soft upper layers and hard lower layers, formations containing boulders, and formations containing karst caves. Simultaneously, by using combined test blocks to simulate the tunneling strata, the actual working conditions of TBM tunneling can be better simulated. The simulation of various complex geological formations through the replacement of detachable model boxes and combined test blocks significantly reduces the length of the simulated geological formations in indoor TBM testing. This allows the experimental apparatus and method disclosed in this invention to avoid the risk of the TBM deviating from its tunneling path due to excessively long simulated geological formations while simulating TBM tunneling in various complex geological formations. Experiments using the experimental apparatus of this embodiment can reveal the rock-breaking mechanism and damage mechanism of the cutterhead when the TBM tunnels through various complex geological formations, providing indoor experimental ideas for addressing the abnormal damage to TBM cutterheads caused by impact effects in complex geological formations.

[0058] Example 2:

[0059] This embodiment provides a simulated indoor shield tunneling test for various complex geological formations, further explaining and supplementing the apparatus in Embodiment 1. Specifically:

[0060] Actual working condition design needs to consider factors such as cutterhead size and cutter selection. The cutterhead size corresponds to the excavation face diameter D1 of the tunnel boring machine (TBM). The burial depth of the TBM is generally between 2.6D1 and 4.2D1 (D1 is the excavation face diameter of the model TBM). Furthermore, due to differences in the overburden layers, the earth pressure at the tunnel excavation site will vary. These issues can be addressed by taking on-site samples of the overburden strata under actual working conditions, obtaining the earth pressure at the tunnel excavation site through indoor tests, and then adjusting the overburden earth pressure using a pressure machine acting on the top panel to simulate the earth pressure at the TBM excavation site under different tunnel depths and overburden conditions. In this optimal embodiment, the tunnel depth is between 3.2D1 and 4.4D1, and the calculated earth pressure is between 83 kPa and 206 kPa. The earth pressure calculation range is calculated using the above method, taking into account various complex strata through which the tunnel passes. Through the excavation of test blocks 25, 26, and 27, the simulation of the tunnel passing through various complex strata is completed.

[0061] Optionally, the model box 1 has dimensions of 620mm*470mm*470mm, with 22 ring-shaped steel strands for the latches; 13 stainless steel hinges; the diameter D2 of the circular hole is 120mm, slightly larger than the diameter D1 of the tunnel boring machine, to facilitate the tunneling of the machine; the bottom plate 16 is equipped with a fixed wheel rail 19; the top plate 15 and the side plates are connected by latches 17, the side plates are connected to each other by latches 17, and the side plates and the bottom plate 16 are connected by hinges.

[0062] Test blocks simulating complex geological formations can be prepared based on soil samples from the actual construction area or similar material tests. The test blocks are prefabricated through on-site sampling or similar material tests. The tunnel boring machine traverses three types of complex geological formations: soft upper layer and hard lower layer, hard upper layer and sandy gravel lower layer, and hard granite layer.

[0063] Optionally, the tunnel boring machine (TBM) has a cylindrical overall shape with a 100mm cutterhead. The cutterhead is a multi-plate type, consisting of three multi-plates 32 and cutters 33 mounted on the multi-plates 32. The multi-plates 32 are machined from steel plates, and the cutters 33 are machined from carbon alloy. The cutterhead is connected to a drive motor 31 via a threaded steel shaft. The drive connection uses a threaded steel shaft, and the propulsion and rotation of the cutterhead are achieved by a guide rail, the threaded steel shaft, the drive motor, and its gears. The tunneling speed of the TBM is determined by the cutterhead's rotational speed and the jacking force. The cutterhead's rotational speed and thrust are connected to the motor via the threaded steel shaft, with the motor providing the rotation and thrust. The lower part of the TBM also includes a muck removal system, which consists of a conveyor track 35 and a muck box 36. The muck track 35 is used to remove muck blocks generated by the rear-transmitted cutterhead cutting through the rock and soil surface, and the muck box 36 is used to store the muck blocks.

[0064] The tunneling parameter control system 4 includes a control platform 41 and a signal connection system 42. The control platform 41 controls the rotation and thrust of the drive motor 31 through the signal connection system 42, thereby controlling the speed and thrust of the tunnel boring machine cutterhead; the signal connection system 42 may include signal connection lines, etc.

[0065] Example 3:

[0066] This embodiment provides a method for simulating indoor shield tunneling tests with multiple complex geological formations. It employs the indoor shield tunneling test apparatus for simulating multiple complex geological formations as described in Embodiment 1, including:

[0067] The tunnel boring machine in the shield tunneling system excavates the test block through the circular hole. By repeatedly replacing the test block to simulate different complex strata, shield tunneling tests on various complex strata are completed.

[0068] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A shield indoor test device for simulating a plurality of complex strata, characterized in that, The shield system and a model box are included, and a round hole for tunneling work of the shield system is formed on the model box; The model box comprises a bottom plate, a first side plate vertically fixed on the bottom plate, a second side plate hingedly connected to the bottom plate, a third side plate hingedly connected to the bottom plate, a fourth side plate hingedly connected to the bottom plate, and a top plate detachably connected to all the side plates; the round hole is formed on the first side plate; Three layers of test blocks, i.e. a standard test block, a test test block and a standard test block, are sequentially arranged in the model box from the bottom plate to the top plate in reverse; the test test block in the middle is located at the round hole; the shield machine in the shield system tunnels the test test block through the round hole, and different test test blocks simulating different complex strata are replaced for multiple times to complete shield test on multiple complex strata; The second side plate, the third side plate and the fourth side plate are connected to the bottom plate through multiple hinges; the top plate is connected to the second side plate, the third side plate and the fourth side plate through multiple locks respectively; the test test block is prefabricated in advance through indoor test, and has the same size as the standard test block; In the model box, a second standard test block and a fourth standard test block are placed at one end close to the bottom plate, and a first standard test block and a third standard test block are placed at one end close to the top plate; a first test test block is placed between the first standard test block and the second standard test block, and a second test test block is placed between the second standard test block and the fourth standard test block.

2. The shield indoor test device for simulating various complex strata according to claim 1, wherein, A wheel track is arranged on the bottom plate.

3. The shield indoor test device for simulating various complex strata according to claim 1, wherein, The first test test block and the second test test block simulate different stratum structures.

4. The shield indoor test device for simulating various complex strata according to claim 1, characterized in that, A sensor is arranged on the shield machine.

5. The shield indoor test device for simulating various complex strata according to claim 1, characterized in that, The shield system comprises a driving motor, a spoke connected to the driving motor through a transmission shaft, and a cutter arranged on the spoke.

6. The shield indoor test device for simulating various complex strata according to claim 1, characterized in that, The shield system is connected with a tunneling parameter control system.

7. A method for simulating a plurality of complex ground formations in a shield indoor test, characterized in that, The shield indoor test device for simulating multiple complex strata comprises the shield system and the model box. The shield machine in the shield system tunnels the test test block through the round hole, and different test test blocks simulating different complex strata are replaced for multiple times to complete shield test on multiple complex strata.

Images