Composite shield test device

Abstract

The application relates to the technical field of shield test, in particular to a composite shield test device, which comprises a stratum simulation module, a shield machine simulation module and a muck improvement module; the stratum simulation module can simulate the stratum environment under actual working conditions; the shield machine simulation module is used for simulating a shield machine; the muck improvement module is connected with the shield machine simulation module and can convey muck improvement additives into the soil bin in the shield machine simulation module. The composite shield test device has the functions of muck improvement, spiral conveyor output, soil bin muck stirring and shield tunneling process simulation, is closer to the movement form and stress condition between the shield machine and the soil body in the actual shield construction process, and has good simulation test effect.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) testing technology, and in particular to a composite TBM testing device. Background Technology

[0002] With the development of underground space construction, the quality requirements for shield tunneling are gradually increasing. Shield tunneling is a dynamic process involving a complex interaction between the machine and the soil. Various uncertainties, such as soil parameters, directly affect the shield-soil interaction process and its mechanical mechanisms. Due to the limitations of the construction environment, it is difficult to directly observe the shield tunneling equipment. Therefore, simulation tests are often used to study the characteristics of shield tunneling machines during underground tunnel construction. This is undoubtedly a scientific, effective, and cost-efficient method. However, current shield tunneling machine simulation test devices have significant discrepancies between simulated and actual working conditions, can only simulate relatively limited conditions, and have poor simulation test results. Summary of the Invention

[0003] The purpose of this invention is to provide a composite shield tunneling test device that can simulate shield tunneling construction under various environmental differences, with good simulation test results, which helps to optimize the adaptability design of shield tunnels to geological conditions.

[0004] A composite shield tunneling test device includes a shield machine simulation module and a soil improvement module. The soil simulation module includes a soil silo, a loading mechanism, and an anti-rotation mechanism. The soil silo is a cylindrical structure open at both ends. The loading mechanism is installed at one axial end of the soil silo and is configured to apply a thrust to the soil within the soil silo. The anti-rotation mechanism is installed inside the soil silo and is configured to prevent the soil from rotating relative to the soil silo. The shield machine simulation module includes a soil chamber, a cutterhead, and a main drive mechanism. The system includes a screw conveyor, a soil bin connected to the end of the soil silo furthest from the loading mechanism to form a closed space, a cutter head located within the closed space and connected to a main drive mechanism located outside the soil bin, the main drive mechanism configured to drive the cutter head to rotate around its own axis, a slag outlet on the side of the soil bin furthest from the soil silo, and an inlet end of the screw conveyor inserted into the soil bin through the slag outlet; a slag improvement module connected to the soil bin, the slag improvement module configured to deliver slag improvement additives into the soil bin.

[0005] Preferably, the system also includes a first base, which comprises a fixed skid frame, a movable skid frame, and a moving drive component. The movable skid frame is slidably mounted on the fixed skid frame, and the moving drive component is configured to drive the movable skid frame to move on the fixed skid frame. The movable skid frame is provided with a reaction support frame and a tilting drive component. The reaction support frame is rotatably mounted on the movable skid frame, and the tilting drive component is configured to drive the reaction support frame to tilt. The soil silo is connected to the reaction support frame.

[0006] Preferably, the loading mechanism includes a thrust piston and a loading drive. The thrust piston is located inside the soil hopper and is in a sealed sliding fit with the soil hopper. The loading drive is mounted on the reaction support frame and is configured to push the thrust piston to reciprocate along the axial direction of the soil hopper.

[0007] Preferably, the anti-rotation mechanism includes an anti-torsion guide post and an anti-rolling part. The anti-torsion guide post is eccentrically disposed at the end of the propulsion piston facing the reaction support frame and extends through the reaction support frame to transition into the reaction support frame. The anti-rolling part is disposed at the end of the propulsion piston facing away from the reaction support frame and can be inserted into the soil to limit and fix the soil. The anti-rolling part is a protrusion that is detachably connected to the propulsion piston.

[0008] Preferably, an airbag is detachably connected to one end face of the propulsion piston facing away from the loading drive.

[0009] Preferably, the main drive mechanism includes a main shaft, a main bearing, a transmission assembly, a first rotary drive assembly, and a sealing seat. The first end of the main shaft passes through the soil chamber and connects to the cutterhead flange of the cutterhead. The main bearing is sleeved on the first end of the main shaft and includes an inner ring, an outer ring, and rollers. The transmission assembly includes a transmission gear and a drive gear. The transmission gear is sleeved on the second end of the main shaft, and the drive gear meshes externally with the transmission gear. The first rotary drive assembly is connected to the drive gear and drives the drive gear to rotate. The sealing seat is sleeved outside the cutterhead flange, forming a sealed space with the main shaft, the cutterhead flange, and the main bearing. The sealing seat includes a mounting ring, a first sealing ring, and a second sealing ring. The mounting ring is mounted on the end face of the outer ring and abuts against the circumferential surface of the cutterhead flange. The first sealing ring is disposed between the mounting ring and the end face of the outer ring, and the second sealing ring is disposed between the mounting ring and the circumferential surface of the cutterhead flange.

[0010] Preferably, the main shaft is connected to a central rotating body.

[0011] Preferably, the screw conveyor includes a second base, an outer cylinder, a variable-amplitude sleeve, a lifting assembly, a screw, a pressure monitoring assembly, and a second rotary drive assembly. The outer cylinder is angle-adjustably mounted on the second base. The outer cylinder has an inlet for the soil to enter, an outlet for the soil to exit, and an injection port connected to the slag improvement module. The inlet is located at one axial end of the outer cylinder, and the outlet is located at the bottom of the outer cylinder on the side away from the inlet. The variable-amplitude sleeve is fitted over the outer cylinder and is configured to connect the outer cylinder to the soil chamber. The lifting assembly is connected to the outer cylinder and is configured to adjust the angle of the outer cylinder. The screw is axially disposed inside the outer cylinder and is composed of multiple detachably connected screw segments. The first end of the screw protrudes from the inlet of the outer cylinder. The pressure monitoring assembly is installed inside the outer cylinder to monitor pressure changes within the outer cylinder. The second rotary drive assembly is detachably connected to the second end of the screw and is configured to drive the screw to rotate.

[0012] Preferably, the lifting assembly includes a slide, a support leg, and a bracket. The outer cylinder and the second rotary drive assembly are both fixed on the bracket. The support leg includes a first support leg and a second support leg. The first ends of the first support leg and the second support leg are coaxially hinged to the bottom of the bracket, and the second ends of the first support leg and the second support leg are respectively hinged to two slides provided on the second base. At least one of the two slides can slide on the second base.

[0013] Preferably, the lifting assembly further includes a fastener, and one of the second base and the slide is provided with a plurality of limiting holes at intervals along the sliding direction of the slide, and the other of the second base and the slide is provided with a positioning hole, and the fastener can be inserted into one of the limiting holes and the positioning hole to position the slide.

[0014] The beneficial effects of this invention are as follows: The composite shield tunneling test device of this invention uses a stratum simulation module to simulate the geological environment under actual working conditions and a shield machine simulation module to simulate the shield machine. It integrates functions such as soil improvement, screw conveyor output, soil mixing in the soil chamber, and shield tunneling process simulation, which is closer to the movement and stress conditions between the shield machine and the soil during actual shield construction. The simulation test results obtained by this device can more effectively reflect the characteristics of the actual construction process, such as stratum reshaping, soil cutting and rock breaking, underground obstacle simulation, the structure of the screw conveyor itself, and the influence of improved soil on the soil plug effect. This helps to optimize the adaptability design of the shield to the geology. The stratum simulation module includes an anti-rotation mechanism, which has a wide range of applications and can prevent the soil from rotating or rolling under the action of the cutterhead rotation, making the simulation process closer to the real working conditions and more effectively reflecting the mechanical characteristics of the actual construction process. The simulation test results are good. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the composite shield tunneling test device in an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the separation of the stratum simulation module and the tunnel boring machine simulation module when loading and unloading soil into the soil chamber in an embodiment of the present invention;

[0017] Figure 3 This is a three-dimensional structural diagram of the formation simulation module in an embodiment of the present invention;

[0018] Figure 4 This is a side view of the formation simulation module in an embodiment of the present invention;

[0019] Figure 5 This is a front view of the formation simulation module in this invention.

[0020] Figure 6 This is a rear view of the formation simulation module in an embodiment of the present invention;

[0021] Figure 7 This is a cross-sectional view of the formation simulation module in an embodiment of the present invention;

[0022] Figure 8 This is a cross-sectional view (excluding the tunnel boring machine simulation module) in an embodiment of the present invention;

[0023] Figure 9 yes Figure 7 Enlarged structural diagram at point A in the middle;

[0024] Figure 10 This is a cross-sectional view of the mounting ring in an embodiment of the present invention;

[0025] Figure 11 This is a schematic diagram of the structure of the first rotation drive component in an embodiment of the present invention;

[0026] Figure 12 This is a schematic diagram of the screw conveyor in an embodiment of the present invention.

[0027] In the diagram, 100 is the stratum simulation module; 110 is the first base; 111 is the fixed skid frame; 112 is the movable skid frame; 113 is the column support; 114 is the moving drive component; 120 is the reaction support frame; 130 is the soil silo; 140 is the loading mechanism; 141 is the propulsion piston; 142 is the loading drive component; 150 is the anti-rotation mechanism; 151 is the anti-torsion guide column; 152 is the anti-rolling part; and 160 is the tilting drive component.

[0028] 200. Shield tunneling machine simulation module; 210. Soil chamber; 211. Chamber body; 212. Soil chamber partition; 220. Cutterhead; 221. Cutterhead flange; 230. Main drive mechanism; 231. Main shaft; 232. Main bearing; 2321. Inner ring; 2322. Outer ring; 2322a. Oil injection channel; 2323. Roller; 233. Drive gear; 234. Transmission gear; 235. First rotary drive assembly; 2351. Cutterhead rotary motor; 2352. Diaphragm coupling; 2353. Cutterhead torque sensor; 2354. First reducer; 236. Sealing seat; 2361. Mounting ring; 2361a. Oil injection channel; 2362. First sealing ring; 2363, Second sealing ring; 2364, Third sealing ring; 2365, Fourth sealing ring; 2366, Connecting ring; 240, Screw conveyor; 241, Outer cylinder; 2411, Transparent observation window; 2412, Inlet; 242, Screw; 243, Amplitude sleeve; 244, Lifting assembly; 2441, First support leg; 2442, Second support leg; 2443, Slide table; 2444, Bracket; 245, Second rotary drive assembly; 2451, Screw rotary motor; 2452, Second reducer; 2453, Screw torque sensor; 246, Pressure holding ball valve; 250, Second base; 260, Conveying pipe; 270, Central rotating body. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0030] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0033] Figures 1-12The diagram shows a composite shield tunneling test device proposed in one embodiment of the present invention. The device includes a ground simulation module 100, a shield machine simulation module 200, and a soil improvement module. The ground simulation module 100 simulates the ground environment under actual working conditions and includes a soil hopper 130, a loading mechanism 140, and an anti-rotation mechanism 150. The soil hopper 130 is a cylindrical structure open at both ends. The loading mechanism 140 is installed at one axial end of the soil hopper 130 to apply thrust to the soil within the hopper, simulating the shield machine's propulsion relative to the soil layer. The anti-rotation mechanism 150 is installed inside the soil hopper 130 and configured to prevent the soil from rotating relative to the hopper. The shield machine simulation module 200 simulates the shield machine and includes a soil chamber 210 and a cutterhead 22. 0. The main drive mechanism 230 and the screw conveyor 240 are connected to the soil bin 130 at the end away from the loading mechanism 140 to form a closed space. The cutter head 220 is located in the closed space and is connected to the main drive mechanism 230 located outside the soil bin 210. The cutter head 220 is equipped with cutting blades according to the actual working conditions. The main drive mechanism 230 is configured to drive the cutter head 220 to rotate around its own axis to realize the simulation of soil cutting under real geological conditions. The side of the soil bin 210 away from the soil bin 130 has a slag outlet. The inlet end of the screw conveyor 240 is inserted into the soil bin 210 from the slag outlet. The slag improvement module is connected to the soil bin 210 and is used to improve the slag properties inside the soil bin 210 or in front of the cutter head 220 (the side of the cutter head 220 facing the soil bin 130 is called the front).

[0034] The aforementioned composite shield tunneling test device incorporates an anti-rotation mechanism 150 within the simulated strata module. It is applicable to hard rock strata, composite strata with a soft upper layer and a hard lower layer, and soft soil strata. This more closely reflects the movement and stress conditions between the shield machine and the soil during actual shield tunneling construction. The simulation test results obtained using this device can more effectively reflect the characteristics of the actual construction process. Furthermore, the aforementioned composite shield tunneling test device can achieve shield tunneling in various modes, including open-type, semi-earth pressure balance, and earth pressure balance. It integrates functions such as soil improvement, screw conveyor output, soil mixing in the soil chamber, and simulation of the shield tunneling process. It can facilitate research on strata reshaping, soil cutting and rock breaking, underground obstacle simulation, the influence of the screw conveyor's own structure and the improved soil on the soil plug effect, and helps optimize the adaptability design of the shield to the geology, and propose solutions or improvement plans for problems encountered in actual shield tunneling construction.

[0035] To facilitate loading or unloading of materials into or out of the soil silo 130, the stratum simulation module 100 and the tunnel boring machine simulation module 200 can move closer to or further away from each other. Compared to the movable tunnel boring machine simulation module 200, the movement of the stratum simulation module 100 is obviously more convenient (the tunnel boring machine simulation module 200 has a relatively complex structure and large mass). Therefore, the formation simulation module 100 in this embodiment further includes a first base 110, which further includes a fixed skid frame 111 and a movable skid frame 112. A reaction support frame 120 is mounted on the movable skid frame 112, and the soil silo 130 is mounted on the movable skid frame 112 via the reaction support frame 120. The movable skid frame 112 is slidably mounted on the fixed skid frame 111. To achieve automation, a moving drive component 114 is also provided on the first base 110. The fixed end of the moving drive component 114 is connected to the fixed skid frame 111, and the output end of the moving drive component 114 is connected to the movable skid frame 112, enabling it to push the movable skid frame 112 to move on the fixed skid frame 111. Specifically, a slide rail is mounted on the fixed skid frame 111, and the movable skid frame 112 slides along the slide rail under the action of the moving drive component 114. The moving drive component 114 can be a hydraulic cylinder. The tunnel boring machine simulation module 200 also includes a second base 250, on which a support seat is provided for supporting the soil chamber 210.

[0036] Furthermore, the reaction support frame 120 is rotatably mounted on the movable skid frame 112 via the column support 113. During simulated shield tunneling, the soil silo 130 connected to the reaction support frame 120 is horizontally positioned. During material loading or unloading, the end of the soil silo 130 away from the reaction support frame 120 flips upwards, facilitating loading or unloading. Specifically, the flipping of the reaction support frame 120 is achieved by a flipping drive component 160. The flipping drive component 160 can be a rotary motor or a hydraulic cylinder. If a rotary motor is used, its output end is connected to the rotation shaft of the reaction support frame 120. If a hydraulic cylinder is used, one end of the cylinder is hinged to the movable skid frame 112, and the other end is hinged to the reaction support frame 120. In this embodiment, the flipping drive component 160 is a hydraulic cylinder, with two cylinders located on either side of the reaction support frame 120 to achieve stable flipping of the reaction support frame 120.

[0037] The loading mechanism 140 includes a thrust piston 141 and a loading drive 142. The thrust piston 141 is located inside the soil hopper 130 and is in a sealed sliding fit with the soil hopper 130. The loading drive 142 is mounted on the reaction support frame 120 and can push the thrust piston 141 to reciprocate along the axial direction of the soil hopper 130.

[0038] The anti-rotation mechanism 150 includes anti-torsion guide posts 151 and anti-rolling parts 152. The anti-torsion guide posts 151 are eccentrically positioned at the end of the push piston 141 facing the reaction support frame 120 and extend through the reaction support frame 120 for transitional engagement, preventing the push piston 141 from rotating. The anti-rolling parts 152 are positioned at the end of the push piston 141 facing away from the reaction support frame 120, and can engage with the soil to limit and fix the soil, preventing the soil from rolling relative to the push piston 141. For example, four anti-torsion guide posts 151 are provided, connected to the push piston 141 by flanges, and arranged circumferentially on the end face of the push piston 141 to further improve the anti-torsion effect.

[0039] To achieve a seamless connection with the soil, the anti-rollover part 152 can be configured as a strip-shaped groove on the propulsion piston 141. Correspondingly, the soil in the soil hopper 130 facing the propulsion piston 141 has a strip-shaped protrusion that engages with the groove. Alternatively, the anti-rollover part 152 can be configured as a strip-shaped protrusion fixed to the propulsion piston 141, with the soil in the soil hopper 130 facing the propulsion piston 141 having a strip-shaped groove that engages with the protrusion. Clearly, setting a groove in the soil is significantly easier than setting a protrusion. Therefore, in this embodiment, the anti-rollover part 152 is configured as a strip-shaped protrusion and connected to the propulsion piston 141 using detachable connections, including but not limited to screw connections and plug connections. For example, the anti-rollover part 152 is screwed to the propulsion piston 141, and multiple anti-rollover parts 152 are fixed radially to the end face of the propulsion piston 141 facing the simulated tunnel boring machine. It is understandable that the lengths of different anti-roll parts 152 can be the same or different, and no specific restrictions are imposed here.

[0040] For composite strata, because the end face of the propulsion piston 141 has high stiffness in contact with the hard rock portion simulating the composite strata, the hard rock is pushed towards the cutterhead 220, while the soft soil portion simulating the composite strata is difficult to advance. To address this, an airbag (not shown in the figure) is installed at the position corresponding to the soft soil on one end face of the anti-roll section 152 of the propulsion piston 141. By pressurizing the airbag, not only can the force imbalance of the propulsion piston 141 be balanced, ensuring the smooth advance of the propulsion piston 141, but also an axial compressive force can be added to the soft soil along the soil hopper 130, thereby forming confining pressure, so that the upper soft soil and the lower rock block advance synchronously. In the actual shield tunneling process, the cutterhead 220 simultaneously cuts the upper soft soil strata and the lower hard rock strata. Understandably, the airbag and the propulsion piston 141 are also detachably connected. When dealing with rock blocks, the airbag can be removed. When dealing with soil in simulated composite strata, the anti-roll part 152 of the propulsion piston 141 corresponding to the soft soil part of the composite strata can be removed and the airbag can be installed on the propulsion piston 141.

[0041] In the actual construction process of shield tunneling, it is often affected by underground confined water. A confined water injection port is also set on the soil material silo 130. Water is injected into the soil material silo 130 through the confined water injection port to simulate confined water, so as to study the impact of confined water on shield tunneling construction.

[0042] The sealing effectiveness between the soil hopper 130 and the propulsion piston 141 is crucial for studying the impact of pressurized water on tunnel boring machine (TBM) construction. The seal between the propulsion piston 141 and the soil hopper 130 is achieved through a lip seal. For example, the propulsion piston 141 has an annular groove circumferentially arranged to accommodate the lip seal. Multiple grooves are spaced apart along the axial direction of the propulsion piston 141, and each groove accommodates one lip seal. The groove is connected to an oil injection port, which is connected to an external oil injection device. Oil is injected into the groove through the oil injection port, causing the lip of the lip seal to deform under hydraulic pressure, thus sealing the lip against the inner wall of the soil hopper 130.

[0043] Furthermore, an elastic, annular sealing ring is connected to one end of the propulsion piston 141 facing away from the reaction force support frame 120. This sealing ring is always in contact with the soil hopper 130. For example, the sealing ring is made of metal and is screwed onto the end face of the piston facing away from the reaction force support frame 120. Its axial cross-section is an arc shape concave towards the piston. After wear, the sealing ring has a certain self-compensation capability due to its elasticity, resulting in a long service life. The sealing ring and the lip seal work together to achieve a double seal between the propulsion piston 141 and the soil hopper 130, providing a good sealing effect.

[0044] Optionally, the soil hopper 130 and the reaction support frame 120 are detachably connected to allow for the replacement of soil hoppers 130 of different lengths, thereby adjusting the propulsion stroke. For example, the soil hopper 130 and the reaction support frame 120 are connected by a flange.

[0045] Depending on the specific testing requirements, the soil silo 130 can be made entirely of transparent acrylic glass for easy observation.

[0046] Since the cutterhead 220 advances smoothly during actual construction, the propulsion piston 141 also needs to ensure smooth movement at all points. Specifically, multiple loading drive components 142 are used to push the propulsion piston 141, and their output ends act evenly on the propulsion piston 141. Hydraulic cylinders can be used, as they can withstand higher working pressures than pneumatic cylinders and are more suitable for simulating heavy-load situations like shield tunneling. In this embodiment, four hydraulic cylinders are provided, connected to the propulsion piston 141 by flanges and arranged in a circumferential array on the end face of the propulsion piston 141.

[0047] refer to Figures 8-11 As shown, the main drive mechanism 230 includes a main shaft 231, a main bearing 232, a drive gear 233, a transmission gear 234, a first rotary drive assembly 235, and a sealing seat 236. The soil hopper 210 includes a hopper body 211 and a soil hopper partition 212. The hopper body 211 is a cylindrical structure with openings at both ends. The soil hopper partition 212 seals the end of the hopper body 211 away from the soil hopper 130. The soil hopper partition 212 has a central hole for the main shaft 231 to pass through and a groove coaxial with the central hole for accommodating the main bearing 232. The first end of the main shaft 231 is provided with a main shaft flange, which can be connected to the cutter head flange 221 of the cutter head 220. The main bearing 232 and the soil hopper partition 212 are sequentially sleeved on the first end of the main shaft 231 from the inside to the outside. Specifically, the main bearing 232 can be selected as three rows. The roller bearing 2323, which is existing technology, includes an inner ring 2321, an outer ring 2322, and a roller 2323. The inner ring 2321 is detachably connected to the main shaft 231 by a hinge bolt, and the outer ring 2322 is detachably connected to the earth chamber partition 212 by a hinge bolt. The transmission gear 234 is sleeved on the second end of the main shaft 231 and keyed to the main shaft 231. The drive gear 233 meshes externally with the transmission gear 234 and is keyed to the output end of the first rotary drive assembly 235. The first rotary drive assembly 235 includes a cutter head rotary motor 2351, which is a variable frequency motor used to drive the drive gear 233 to rotate. The sealing seat 236 is sleeved on the outside of the cutter head flange 221 and forms a sealed space with the main shaft 231, the cutter head flange 221, and the main bearing 232.

[0048] The main drive mechanism 230, through the setting of the sealing seat 236, can prevent slag or other foreign objects from entering between the inner ring 2321 and the outer ring 2322, as well as between the inner ring 2321 and the main shaft 231, thus ensuring the normal rotation of the main shaft 231 and further ensuring the normal operation of the main drive mechanism 230.

[0049] The sealing seat 236 includes a mounting ring 2361, a first sealing ring 2362, and a second sealing ring 2363. The mounting ring 2361 is mounted on the end face of the outer ring 2322 and sleeved around the cutter head flange 221, abutting against the circumferential surface of the cutter head flange 221. The first sealing ring 2362 is disposed between the mounting ring 2361 and the end face of the outer ring 2322, and the second sealing ring 2363 is disposed between the mounting ring 2361 and the circumferential surface of the cutter head flange 221, so that a sealing space is formed between the sealing seat 236, the main shaft 231, the main bearing 232, and the cutter head flange 221. Since the cutter head flange 221 rotates relative to the outer ring 2322, a lip seal is selected for the second sealing ring 2363 to compensate for the long-term rotation of the cutter head flange 221. Specifically, a sealing groove is formed on the circumferential surface of the cutterhead flange 221, and the second sealing ring 2363 is placed in the sealing groove. Simultaneously, an oil injection channel 2361a communicating with the sealing groove is formed on the mounting ring 2361 to inject oil into the sealing groove, thereby bringing the lip seal close to the sealing surface. Because the mounting ring 2361 is stationary relative to the outer ring 2322, a general O-ring can be used for the first sealing ring 2362.

[0050] It is understandable that the mounting ring 2361 can also be mounted on the circumferential surface of the cutterhead flange 221 and can rotate relative to the outer ring 2322. In this embodiment, given the large installation space available on the end face of the outer ring 2322, the mounting ring 2361 is detachably connected to the outer ring 2322 using fasteners. Both the outer ring 2322 and the mounting ring 2361 have connecting holes for the fasteners to pass through. Furthermore, the bottom of the groove in the soil chamber partition 212 is also provided with connecting holes. When the mounting ring 2361 is connected to the outer ring 2322, the fasteners can be inserted into the soil chamber partition 212 to connect the outer ring 2322 and the soil chamber 210 together. For example, the axial cross-section of the mounting ring 2361 is L-shaped.

[0051] To prevent slag from entering the groove through the connecting hole and then the main bearing 232, a third sealing ring 2364 is provided on the outer edge of the mounting ring 2361 facing the outer ring 2322. The connecting hole on the mounting ring 2361 is located between the first sealing ring 2362 and the third sealing ring 2364. The oil injection channel 2361a can connect the gap formed by the mounting ring 2361 and the outer ring 2322 in conjunction with the first sealing ring 2362 and the third sealing ring 2364. At this time, the oil in the oil injection channel 2361a can enter the gap to seal the connecting hole.

[0052] Furthermore, the end of the mounting ring 2361 that abuts against the outer ring 2322 extends toward the soil chamber partition 212, and the third sealing ring 2364 is disposed between the mounting ring 2361 and the soil chamber partition 212. Then, the oil injected through the oil injection channel 2361a can enter the gap formed between the outer ring 2322 and the soil chamber partition 212. The outer ring 2322 has an oil injection channel 2361a that connects the circumferential surface of the outer ring 2322 with the space where the roller 2323 is located. The oil can enter the space where the roller 2323 is located through the oil injection channel 2361a from the gap between the outer ring 2322 and the soil chamber partition 212, thus maintaining the lubrication of the main bearing 232.

[0053] To further improve sealing performance, the sealing seat 236 also includes a fourth sealing ring 2365 and a connecting ring 2366. The axial section of the connecting ring 2366 is also L-shaped and is fixed to the end face of the mounting ring 2361 away from the main bearing 232 by bolts. The fourth sealing ring 2365 adopts a tongue seal and is fixed on the connecting ring 2366 to elastically abut against the end face of the cutter disc flange 221 facing away from the main bearing 232.

[0054] The entire sealing seat 236 achieves sealing of the main bearing 232 itself and between the main bearing 232 and the main shaft 231 through a multi-seal structure, with good sealing performance. Moreover, the sealing seat 236 is externally mounted, making it easy to disassemble. When replacing, only the mounting ring 2361 needs to be removed to replace the first sealing ring 2362, the second sealing ring 2363, and the third sealing ring 2364.

[0055] Multiple drive gears 233 are arranged circumferentially along the transmission gear 234. For example, four drive gears 233 can be arranged, and correspondingly, the number of cutter head rotary motors 2351 is also four. In addition to the cutter head rotary motors 2351, the first rotary drive assembly 235 also includes a drive cover plate, a first reducer 2354, and a diaphragm coupling 2352. The drive cover plate is coaxially connected to the soil chamber partition 212. The rotary motors are connected to the drive gears 233 through the first reducer 2354 fixed on the drive cover plate. The drive cover plate is also provided with a gear observation window. By observing the output torque fluctuation of each motor under no-load or load conditions through the gear observation window, the wear of the gears under multi-gear synchronous drive can be observed and judged.

[0056] The drive gear 233 is connected to the output shaft of the first reducer 2354. The input shaft of the first reducer 2354 is connected to the cutter head rotary motor 2351 via a diaphragm coupling 2352, which acts as a vibration damper. The soil chamber partition 212 has four insertion holes corresponding to the output shaft of the first reducer 2354. Output bearings are installed in these holes and fitted onto the output shaft of the first reducer 2354. These output bearings adjust the assembly precision of the drive gear 233 and the transmission gear 234, reducing the off-center load on the drive gear 233, ensuring even force distribution, and further reducing drive vibration. Furthermore, a cutter head torque sensor 2353 is installed between the input shaft of the first reducer 2354 and the cutter head rotary motor 2351. This sensor better monitors the load changes of the drive gear 233, enabling rapid fault detection and repair. It also provides information on the torque changes of the cutter head 220 in different geological formations or after the addition of different soil amendment additives.

[0057] In this embodiment, the main spindle 231 is also connected to a central rotating body 270. The central rotating body 270 is detachably connected to the main spindle 231 by means including but not limited to screw connections. The central rotating body 270 can deliver lubricant to the cutter head 220 to improve the performance of the cutter on the cutter head 220, or it can be connected to the slag improvement module to deliver bentonite improvement agent to improve the slag properties in front of the cutter head 220, which is beneficial to the cutting of the slag. At the same time, more sensors for monitoring the use of the cutter on the cutter head 220 can be arranged on the central rotating body 270 to study the mechanical response of the cutter head 220 with different strata and the adaptability of the thrust and torque of the cutter head 220.

[0058] To accommodate the central rotating body 270, the main shaft 231 is a hollow shaft. The cutter head flange 221 has a through hole for the delivery pipe 260 to pass through. After passing through the main shaft 231, the delivery pipe 260 connects to the cutter head 220 and delivers liquid to the front of the cutter head 220. The delivery pipe 260 is made of wear-resistant material and is used to deliver lubricating fluid or bentonite amendment.

[0059] refer to Figure 12As shown, the screw conveyor 240 includes a lifting assembly 244, an outer cylinder 241, a screw 242, a second rotary drive assembly 245, and a pressure monitoring assembly. The outer cylinder 241 is angle-adjustably mounted on the second base 250 via the lifting assembly 244, which is used to adjust the angle of the outer cylinder 241. The outer cylinder 241 has an inlet for soil entry and an outlet for soil discharge. The inlet is located at one axial end of the outer cylinder 241, and the outlet is located at the bottom of the outer cylinder 241 on the side away from the inlet, and a pressure-holding ball valve 246 is installed at the outlet. The pressure monitoring assembly is installed inside the outer cylinder 241 to monitor pressure changes within the outer cylinder 241. The screw 242 moves along the outer cylinder 241... A screw 242 is axially inserted inside the outer cylinder 241. Its first end extends from the inlet of the outer cylinder 241 and through the slag outlet into the soil chamber 210. Its second end extends out of the outer cylinder 241 and is detachably connected to a second rotary drive assembly 245 fixed at the end of the outer cylinder 241 away from the inlet. The second rotary drive assembly 245 is configured to drive the screw 242 to rotate and includes a screw rotary motor 2451, which is also a variable frequency motor. The effect of the screw 242's rotation speed on the pressure-holding capacity of the simulated shield tunnel screw conveyor 240 can be determined by adjusting the speed of the screw rotary motor 2451. A second reducer 2452 is also connected between the screw rotary motor 2451 and the screw 242. Furthermore, the screw 242 is composed of multiple screw segments detachably connected using methods including, but not limited to, key connections.

[0060] The aforementioned screw conveyor 240 has an adjustable outer cylinder 241 relative to the second base 250. During the test, the inclination angle of the outer cylinder 241 was adjusted from small to large. By observing the changes in the readings of the pressure monitoring component during the operation of the screw conveyor 240, the minimum inclination angle at which the screw conveyor 240 can form an effective "soil plug effect" under this geological environment can be obtained, at which point the conveying capacity is strongest. By replacing different screw sections on the screw 242 (in descending order of pitch), and observing the operation of the cutter head 220... The change in the reading of the pressure monitoring component can be used to obtain the maximum pitch at which the screw conveyor 240 can form an effective "soil plug effect" under the geological environment. The screw 242 is designed to be composed of multiple detachable screw segments, and only one segment needs to be replaced each time. This reduces the testing cost of the screw conveyor 240 compared to replacing the entire screw 242. Moreover, the screw segments located at different positions in the screw 242 can be replaced to determine the impact of screw segments with the same pitch at different positions on the pressure holding capacity of the screw conveyor 240.

[0061] The pressure monitoring component includes multiple pressure sensors spaced apart along the axial direction of the outer cylinder 241. The pressure measured by the pressure sensors can be linearly fitted, and the higher the consistency, the better the pressure holding capability.

[0062] To achieve a fixed connection between the screw conveyor 240 and the earth chamber 210, refer to Figure 1 As shown, the screw conveyor 240 also includes a variable-amplitude sleeve 243, which is fitted onto the outer cylinder 241. A first flange and a second flange are respectively installed at both ends of the sleeve. The first flange connects to the mounting flange on the outer cylinder 241, and the second flange is a non-circular flange that can be screwed onto the earth chamber partition 212. The variable-amplitude sleeve 243 is replaced according to the adjustment angle of the outer cylinder 241. It is necessary to ensure that when the variable-amplitude sleeve 243 is fitted onto the outer cylinder 241, the first flange is parallel to the mounting flange on the outer cylinder 241, and the second flange is parallel to the earth chamber partition 212 (i.e., in a vertical position).

[0063] The lifting assembly 244 is located on the side of the outer cylinder 241 away from the luffing sleeve 243. The lifting assembly 244 can be a hydraulic cylinder. The two ends of the hydraulic cylinder are respectively hinged to the outer cylinder 241 and the second base 250. The angle of the outer cylinder 241 can be adjusted by the extension and retraction of the hydraulic cylinder.

[0064] In this embodiment, the lifting assembly 244 includes a slide 2443, support legs, and a bracket 2444. The outer cylinder 241 and the second rotary drive assembly 245 are both fixed on the bracket 2444. There are two support legs, including a first support leg 2441 and a second support leg 2442. The first ends of the first support leg 2441 and the second support leg 2442 are coaxially hinged to the bottom of the bracket 2444. The second ends of the first support leg 2441 and the second support leg 2442 are respectively hinged to two slides 2443 provided on the second base 250. At least one of the two slides 2443 can slide on the second base 250. As one of the slides 2443 moves, the included angle between the first support leg 2441 and the second support leg 2442 connected to the slide 2443 will change, and the height of the connection point between the outer cylinder 241 and the bracket 2444 will naturally change.

[0065] The first leg 2441, the second leg 2442, and the second base 250 can form a stable triangular structure, which can significantly improve the support stability of the outer cylinder 241 compared to using a hydraulic cylinder to adjust the height of the outer cylinder 241.

[0066] Furthermore, since both slides 2443 can slide on the second base 250, when one slide 2443 slides on the second base 250, under the transmission action of the support leg, the other slide 2443 can move in the opposite direction to the first slide 2443. It is understood that in this embodiment, the sliding direction of the two slides 2443 relative to the second base 250 does not affect the adjustment of the height of the outer cylinder 241. They can be spaced apart along the projection direction of the outer cylinder 241 on the second base 250, or along a direction perpendicular to the projection direction of the outer cylinder 241 on the second base 250, or along other directions.

[0067] Meanwhile, the screw conveyor 240 also includes a limiting component, which includes a locked state that restricts the movement of the slide 2443 and an unlocked state that does not restrict the movement of the slide 2443. In the locked state, the limiting component can limit the angle of the outer cylinder 241 to prevent it from changing angle during the operation of the simulated shield screw conveyor 240.

[0068] The limiting components can be fasteners. One of the second base 250 and the slide 2443 has multiple limiting holes spaced apart along the sliding direction of the slide 2443, while the other has a positioning hole. Fasteners can be inserted into the positioning hole and one of the limiting holes to limit the movement of the slide 2443. The fasteners can be bolts or pins. By adjusting the position of the limiting hole into which the fastener is inserted, the position of the slide 2443 on the second base 250 can be adjusted. It is understood that the number of limiting holes is the same as the number of luffing sleeves 243, with each limiting hole corresponding to one luffing sleeve 243 for connection to the simulated earth chamber 210.

[0069] The outer cylinder 241 is also provided with multiple injection ports 2412 for injecting slag modification materials such as bentonite, foam, and polymer. The injection ports 2412 can be connected to the slag modification module to cooperate with the pressure sensor to establish an effective evaluation of the improvement effect of the same modification material on different adverse strata or the improvement effect of different modification materials on the same strata. This provides technical guidance for the pressure holding characteristics of the screw conveyor 240 in earth pressure shield construction, especially in water-rich strata. In this embodiment, the screw conveyor 240 also includes a pore water pressure gauge.

[0070] To allow for a direct view of the soil transfer inside the screw conveyor 240, a transparent observation window 2411 is provided on the outer cylinder 241. Specifically, the transparent observation window 2411 can be located on the side of the outer cylinder 241 near the luffing sleeve 243.

[0071] A screw torque sensor 2452 is also installed between the reducer and the screw 242. If the torque measured by the screw torque sensor 2452 suddenly fluctuates and decreases, it indicates that the screw conveyor 240 is unstable in maintaining pressure.

[0072] The slag improvement module comprises an air compressor, a foam generator, storage tanks, various pipeline pumps, and transport pipelines. Multiple storage tanks are provided, storing foaming agent, air, bentonite slurry, polymer, and water respectively. After the foaming agent and water are mixed in the foam generator, the air compressor injects compressed air into the foam generator, causing the mixture to expand and produce foam. The foam and bentonite slurry are then injected into the screw conveyor 240 through the transport pipeline via inlet 2412 to improve the slag. In case of water pockets or gushing, the polymer can be pumped into the screw conveyor 240 to improve the slag. By adjusting the dosage of compressed air, foam, and bentonite additives through the pipeline pumps, the ratio of slag improvement additives can be freely adjusted and controlled to simulate slag improvement and achieve excellent slag improvement results.

[0073] When using the above-mentioned composite shield tunneling test device to simulate shield tunneling construction, the test soil must first be prepared according to the strata to be simulated. The simulated strata include soft soil strata, hard rock strata, and composite strata.

[0074] If the test soil is a rock block simulating hard rock, the rock block needs to be processed into a cylindrical geometry consistent with the radial cross-section of the soil hopper 130, and then grooved to cooperate with the anti-rollover part 152 to ensure that the torque exerted on the rock block by the cutterhead 220 during rock breaking does not cause it to rotate. If the test soil is soft soil simulating soft soil strata, and the strata themselves do not have cohesion or do not have self-stability after initial consolidation, after applying load to establish initial confining pressure and unloading, add a layer of cohesive soil or apply a layer of adhesive to the end face of the soft soil away from the propulsion piston 141 to make it self-stability after reversal and prevent the soft soil from rotating. When the soil falls from the soil hopper 130 for testing, the cutterhead 220 needs to first cut off the cohesive soil or the part coated with adhesive before data acquisition. If the test soil is soft soil and rock blocks simulating a composite stratum, the soft soil part does not have self-stability. After being loaded into the soil hopper, a layer of cohesive soil or a layer of adhesive needs to be added. In addition, the anti-roll part 152 of the upper part of the push piston 141 corresponding to the soft soil needs to be replaced with an air bladder, and air or liquid needs to be injected into the air bladder to make the confining pressure on the entire test soil consistent with the confining pressure of the simulated stratum depth, while ensuring that the soft soil and rock blocks can be pushed synchronously by the push piston 141.

[0075] When the test soil is loaded into the soil silo 130, the position and angle of the soil silo 130 are adjusted by the flipping drive 160 and the loading drive 142 so that the opening of the end away from the reaction support frame 120 faces upward. After the test soil is filled into the soil silo 130, a load is applied to the test soil according to the simulated geological environment (such as the depth of the shield tunnel), and a preliminary confining pressure is established. Then the load is unloaded, and the soil silo 130 is flipped and moved to connect the soil silo 210 and close the opening of the soil silo 130.

[0076] Based on the selected mode (open type, semi-earth pressure balance type, earth pressure balance type), the initial cutterhead speed, the advance piston speed, the initial speed of the screw conveyor, and the soil chamber pressure are set. This pushes the advance piston and rotates the cutterhead, thereby simulating functions such as shield tunneling, bolt conveyor soil discharge, and soil mixing in the soil chamber. At the same time, by adding soil improvement additives to the soil chamber through the soil improvement module, the impact of the soil improvement additives on tunneling parameters (cutterhead torque, tunneling efficiency) and the pressure holding capacity of the screw conveyor can be observed when facing different strata. By adjusting the angle of the screw conveyor or replacing the screw section on the screw, the impact of the screw conveyor's own structure on the pressure holding capacity and soil discharge efficiency can be observed, providing a theoretical basis for actual shield construction.

[0077] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A composite shield tunneling test device, comprising a stratum simulation module (100), a shield tunneling machine simulation module (200), and a slag improvement module, characterized in that: The stratum simulation module (100) includes a soil silo (130), a loading mechanism (140), and an anti-rotation mechanism (150). The soil silo (130) is configured as a cylindrical structure with openings at both ends. The loading mechanism (140) is installed at one axial end of the soil silo (130) and is configured to apply a thrust to the soil inside the soil silo (130). The anti-rotation mechanism (150) is installed inside the soil silo (130) and is configured to prevent the soil from rotating relative to the soil silo (130). The tunnel boring machine simulation module (200) includes a soil chamber (210), a cutterhead (220), a main drive mechanism (230), and a screw conveyor (240). The soil chamber (210) can be connected to the end of the soil silo (130) away from the loading mechanism (140) to form a closed space. The cutterhead (220) is located in the closed space and connected to the main drive mechanism (230) located outside the soil chamber (210). The main drive mechanism (230) is configured to drive the cutterhead (220) to rotate around its own axis. The side of the soil chamber (210) away from the soil silo (130) has a slag outlet. The inlet end of the screw conveyor (240) is inserted into the soil chamber (210) from the slag outlet. The slag improvement module is connected to the soil silo (210), and the slag improvement module is configured to deliver slag improvement additives into the soil silo (210). It also includes a first base (110), which includes a fixed skid frame (111), a movable skid frame (112), and a moving drive (114). The movable skid frame (112) is slidably disposed on the fixed skid frame (111). The moving drive (114) is configured to drive the movable skid frame (112) to move on the fixed skid frame (111). The movable skid frame (112) is provided with a reaction support frame (120) and a flipping drive (160). The reaction support frame (120) is rotatably disposed on the movable skid frame (112). The flipping drive (160) is configured to drive the reaction support frame (120) to flip. The soil silo (130) is connected to the reaction support frame (120). The loading mechanism (140) includes a thrust piston (141) and a loading drive (142). The thrust piston (141) is located inside the soil hopper (130) and is in a sealed sliding fit with the soil hopper (130). The loading drive (142) is mounted on the reaction support frame (120). The loading drive (142) is configured to push the thrust piston (141) to reciprocate along the axial direction of the soil hopper (130). The anti-rotation mechanism (150) includes an anti-torsion guide post (151) and an anti-rolling part (152). The anti-torsion guide post (151) is eccentrically located at one end of the push piston (141) facing the reaction support frame (120) and extends through the reaction support frame (120) to transition into the reaction support frame (120). The anti-rolling part (152) is located at one end of the push piston (141) facing away from the reaction support frame (120) and can be inserted into the soil to limit and fix the soil. The anti-rolling part (152) is a protrusion that is detachably connected to the push piston (141).

2. The composite shield tunneling test device according to claim 1, characterized in that, An airbag is detachably connected to one end face of the thrust piston (141) facing away from the loading drive (142).

3. The composite shield tunneling test device according to claim 1, characterized in that, The main drive mechanism (230) includes: The main shaft (231) has its first end inserted into the soil chamber (210) and connected to the cutterhead flange (221) of the cutterhead (220); The main bearing (232) is sleeved on the first end of the main shaft (231) and includes an inner ring (2321), an outer ring (2322) and a roller (2323). The transmission assembly includes a transmission gear (234) and a drive gear (233), wherein the transmission gear (234) is sleeved on the second end of the main shaft (231), and the drive gear (233) meshes externally with the transmission gear (234); The first rotary drive assembly (235) is connected to the drive gear (233) and drives the drive gear (233) to rotate; A sealing seat (236) is fitted over the cutter head flange (221) and forms a sealing space with the main shaft (231), the cutter head flange (221) and the main bearing (232). The sealing seat (236) includes a mounting ring (2361), a first sealing ring (2362) and a second sealing ring (2363). The mounting ring (2361) is mounted on the end face of the outer ring (2322) and abuts against the circumferential surface of the cutter head flange (221). The first sealing ring (2362) is disposed between the mounting ring (2361) and the end face of the outer ring (2322). The second sealing ring (2363) is disposed between the mounting ring (2361) and the circumferential surface of the cutter head flange (221).

4. The composite shield tunneling test device according to claim 3, characterized in that, The main shaft (231) is connected to a central rotating body.

5. The composite shield tunneling test device according to claim 1, characterized in that, The tunnel boring machine simulation module (200) also includes a second base (250), and the screw conveyor (240) includes: The outer cylinder (241) is installed on the second base (250) at an adjustable angle. The outer cylinder (241) has an inlet for the soil to enter, an outlet for the soil to exit, and an injection port (2412) connected to the slag improvement module. The inlet is located at one axial end of the outer cylinder (241), and the outlet is located at the bottom of the outer cylinder (241) on the side away from the inlet. A variable amplitude sleeve (243) is sleeved outside the outer cylinder (241), and the variable amplitude sleeve (243) is configured to connect the outer cylinder (241) and the earth chamber (210). A lifting assembly (244) is connected to the outer cylinder (241), and the lifting assembly (244) is configured to adjust the angle of the outer cylinder (241); A screw (242) is axially disposed inside the outer cylinder (241) along the outer cylinder (241). The screw (242) is detachably connected from multiple screw segments. The first end of the screw (242) protrudes from the inlet of the outer cylinder (241). A pressure monitoring component is installed inside the outer cylinder (241) to monitor pressure changes within the outer cylinder (241); A second rotary drive assembly (245) is detachably connected to the second end of the screw (242), and the second rotary drive assembly (245) is configured to drive the screw (242) to rotate.

6. The composite shield tunneling test device according to claim 5, characterized in that, The lifting assembly (244) includes a slide (2443), legs, and a bracket (2444). The outer cylinder (241) and the second rotary drive assembly (245) are both fixed on the bracket (2444). The legs include a first leg (2441) and a second leg (2442). The first ends of the first leg (2441) and the second leg (2442) are coaxially hinged to the bottom of the bracket (2444). The second ends of the first leg (2441) and the second leg (2442) are respectively hinged to two slides (2443) provided on the second base (250). At least one of the two slides (2443) can slide on the second base (250).

7. The composite shield tunneling test device according to claim 6, characterized in that, The lifting assembly (244) further includes a fastener. One of the second base (250) and the slide (2443) is provided with a plurality of limiting holes at intervals along the sliding direction of the slide (2443). The other of the second base (250) and the slide (2443) is provided with a positioning hole. The fastener can be inserted into one of the limiting holes and the positioning hole to position the slide (2443).

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