Experimental device and method for TBM tunneling and duct piece stress characteristics in active fault zone

Abstract

The invention discloses an active fault zone TBM tunneling and duct piece stress characteristic experimental device and method, and relates to the technical field of tunnel engineering.The active fault zone TBM tunneling and duct piece stress characteristic experimental device comprises a fault model loading system, a TBM tunneling system and a TBM supporting system; the top loading plate and the bottom loading plate are arranged in a central symmetry mode with respect to the axial direction of the excavation centroid, and when the fault trend is perpendicular to the tunneling direction of the TBM tunneling system, the top loading plate and the bottom loading plate are arranged in a central symmetry mode with respect to the radial direction of the excavation centroid. Grouping oil cylinders respectively act on the top loading plate and the bottom loading plate, so that prefabrication of faults with different dip angles in a cross section or a longitudinal section in a fault model loading system is realized; the TBM supporting system is used for supporting the circular excavation boundary after the TBM tunneling system completes tunneling in the fault model loading system; according to the method, scientific support can be provided for TBM rapid tunneling and machine jamming early warning and forecasting of fault fracture zones and active fault zones.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to an active fault zone TBM excavation and segment stress characteristic experimental device and method. Background Art

[0002] The full-face tunnel boring machine (TBM) has been widely used in various tunnel excavation due to its advantages of fast excavation speed, high degree of automation, safety and environmental protection. However, the tunnel route selection is inevitably faced with adverse geology, especially in the mountainous areas in western my country, where many deep and large active faults are developed. TBM excavation often leads to major geological disasters such as tunnel surrounding rock collapse, water and mud inrush, etc., which cause TBM jamming or even burying. TBM excavation faces huge safety risks, which seriously restricts the normal use of TBM. Therefore, it is urgent to study the excavation mechanical response of TBM in the whole process of crossing the fault fracture zone and the jamming problem caused by the deformation and instability of the surrounding rock. At present, there are indoor micro-TBM excavation model test devices that can be used for TBM excavation tests in uniform strata, simple composite strata, and strata with bonded interfaces, such as the micro-TBM excavation model test platform of the State Key Laboratory of Shield and Excavation Technology and the micro-shield excavation model platform of Southwest Jiaotong University. Similar material samples are artificially laid in the model box, and different material interfaces or soft materials with low strength and a certain thickness are used to simulate faults. Therefore, a large number of secondary cracks and fractured damaged rock masses generated in the rock mass on both sides of the fault surface during the compression or tension formation of natural faults are not considered, and these secondary cracks and broken rock masses are often important factors that cause TBM jams. Therefore, it is necessary to propose a physical model test device that can simulate the fracture surface morphology and damaged areas on both sides of the fracture surface produced in the process of shear rupture formation of faults under different stress conditions, and at the same time can carry out TBM excavation. It is used to reveal the technical research on the mechanical response, jamming mechanism and safety control of TBM excavation after the formation and reactivation of fault shear rupture, including the excavation mechanical characteristics of open TBM, single shield TBM and double shield TBM when crossing the fault plane and section crushing zone, and the stress characteristics of support segments. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide an experimental device and method for TBM excavation and segment stress characteristics in an active fault zone. The present invention is suitable for a physical model test system for excavation and support of an open TBM, a single-shield TBM and a double-shield TBM in a fault fracture zone. It can reveal the formation process and failure mechanism of fault shear dislocation under different stress environments, study the full process evolution law of excavation parameters such as thrust and torque of TBM excavation in fractured rock mass on the fault surface and in the fault influence zone, reveal the deformation and failure law of surrounding rock and the jamming mechanism at different fault inclinations and TBM excavation positions, and provide scientific support for rapid excavation and jamming warning and forecast of TBM in fault fracture zones and active fault zones.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an active fault zone TBM excavation and segment stress characteristics experimental device, characterized in that it includes: a fault model loading system, a TBM excavation system and a TBM support system, the fault model loading system includes a fault prefabricated model box, a similar material rock sample is arranged in the fault prefabricated model box, and a top loading plate and a bottom loading plate of different widths and connected in blocks are arranged on the top and bottom of the similar material rock sample. When the fault strikes parallel to the excavation direction of the TBM excavation system, that is, when faults with different inclination angles appear in the excavation cross section, the top loading plate and the bottom loading plate are connected to each other. The arrangement of the loading plates is symmetrical with respect to the axial direction of the excavation centroid. When the fault strikes perpendicular to the excavation direction of the TBM excavation system, that is, when faults with different inclination angles appear in the excavation longitudinal section, the arrangement of the top loading plate and the bottom loading plate is symmetrical with respect to the radial direction of the excavation centroid. The top loading plate and the bottom loading plate are acted on respectively by grouped cylinders, thereby realizing the prefabrication of faults with different inclination angles in the cross section or longitudinal section of the fault model loading system. The TBM support system is used to support the circular excavation boundary after the TBM excavation system completes excavation in the fault model loading system.

[0005] As a further improvement of the present invention, the fault model loading system also includes an L-shaped reaction frame, a side baffle plate arranged on the side and a reaction cover plate arranged on the top. Side loading plates are arranged between the side of the similar material rock sample and the side of the L-shaped reaction frame and the side baffle plate. A horizontal loading cylinder for providing horizontal stress is arranged between the side of the L-shaped reaction frame and the side loading plate. A top vertical loading cylinder for providing vertical stress is arranged between the reaction cover plate and the top loading plate. A bottom vertical loading cylinder for providing vertical bottom stress is arranged between the bottom of the L-shaped reaction frame and the bottom loading plate.

[0006] As a further improvement of the present invention, the TBM excavation system includes a fixed support, a TBM body, a TBM slewing mechanism and a TBM propulsion mechanism arranged on a supporting guide platform, the TBM body includes a cutterhead, a front shield and a rear shield connected to the cutterhead in sequence, and a disc cutter is installed on the cutterhead; the TBM slewing mechanism includes a slewing bearing connected to the cutterhead and passing through the fixed support, and the fixed support is provided with a hydraulic motor for providing slewing torque and a gearbox for controlling different speeds; the TBM propulsion mechanism includes a hydraulic main propulsion cylinder arranged between the fixed support and the TBM support system.

[0007] As a further improvement of the present invention, the TBM support system includes a plurality of segment rings consisting of arc segments and key block segments, the segment rings are connected to the shield tail of the rear shield, and the last ring of segment rings is connected to the hydraulic main propulsion cylinder; the segment rings form longitudinal gaps in the longitudinal axis direction, and annular gaps are formed between adjacent segment rings.

[0008] As a further improvement of the present invention, it also includes a TBM slag discharge system, which includes a slag discharge rocker connected to a fixed bracket, a scraper plate connected to the slag discharge rocker and used for discharging large slag pieces, and a cleaning brush connected to the slag discharge rocker and located behind the scraper plate for discharging fine slag powder particles.

[0009] The present invention also provides an active fault zone TBM excavation and segment stress characteristics experimental method, which is implemented by using the active fault zone TBM excavation and segment stress characteristics experimental device as described above. The experimental method comprises the following steps: Step 1: Adjust the end faces of the bottom vertical loading cylinder to the same level, and then flatten the bottom loading plates in sequence according to the prefabrication requirements of the faults with different inclination angles in the cross section or longitudinal section; according to the positions of the faults with different inclination angles, the bottom loading plates at the fault surfaces are not connected, and the other bottom loading plates are connected as a whole; Step 2, install the side loading plates, then fill and pour the rock samples of similar materials layer by layer until they are level with the top loading plates, and install the top loading plates in sequence. The top loading plates at the fracture surface are not connected, and the other top loading plates are connected; Step 3: Install the top vertical loading cylinder, reaction cover plate, and side baffle plate in sequence to complete the assembly of the fault model loading system; Step 4: The horizontal loading cylinder is uniformly loaded to the target stress according to the set load size, and then the bottom vertical loading cylinder is controlled to retract in groups below the predetermined shear fracture surface to leave movement space for the bottom loading plate, and the positions of other bottom vertical loading cylinders are not adjusted; the top vertical loading cylinder is retracted above the predetermined shear fracture surface to leave movement space for the top loading plate, and the positions of other cylinders are not adjusted; the top vertical loading cylinder is controlled to load in groups according to the displacement loading mode until the sample is broken, and the fault surface and fault fracture zone prefabrication are completed; Step 5: Start the drive motor to rotate the cutterhead through the hydraulic motor, then start the main propulsion cylinder to push the rear shield to make the TBM excavation system move forward to cut similar material rock samples until the cutterhead, the front shield and the rear shield all enter the fault prefabricated model box at a distance less than one ring of segments. During the excavation process, the thrust and torque of the cutterhead are collected in real time, the cutterhead is stopped, the main propulsion cylinder is retracted, and then a ring of segments is installed at the rear shield of the cutterhead. Then, the main propulsion cylinder is extended to push on the newly installed segments; until the excavation reaches the predetermined position behind the fault fracture zone; Step 6: When the TBM excavation system crosses the fault, the bottom vertical loading cylinder and the top vertical loading cylinder that originally caused the fault are continuously loaded in groups using a displacement loading method, so that the upper plate and the lower plate of the fault plane are displaced.

[0010] The beneficial effects of the present invention are: 1. The present invention can carry out conventional shear box shear dislocation tests on large-scale physical models, including shear tests under different shear distribution loads, shear rates and normal stresses, which can reveal the tensile shear formation mechanism and failure mode of fractures under different shear stress states. The fracture surface and the damage area near the fracture surface can better simulate the natural failure mechanism of fault planes or fault fracture zones with different inclination angles.

[0011] 2. The indoor micro-TBM excavation and support tests based on the present invention in stable fault zones and activated fault zones can reveal the thrust and torque variation patterns of TBM excavation under fault geological conditions with different inclination angles and dips, clarify the stress characteristics of the cutterhead, shield and segments under different fault inclination angles, and provide technical guidance for excavation construction and optimal design of segments for TBMs crossing complex faults and broken zones. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A cross-sectional view of a fault model loading system in an embodiment of the present invention; Figure 2 It is a longitudinal cross-sectional view of a fault model loading system in an embodiment of the present invention; Figure 3 A schematic diagram of a method for configuring a loading plate and a cylinder for prefabricating faults at different inclination angles in a cross section according to an embodiment of the present invention; Figure 4A schematic diagram of a method for configuring a loading plate and a cylinder for prefabricating faults at different inclination angles in a longitudinal section according to an embodiment of the present invention; Figure 5 It is a schematic diagram of TBM excavation and fault activation displacement after fault prefabrication in the cross section in an embodiment of the present invention; Figure 6 It is a schematic diagram of TBM excavation and fault activation and dislocation after prefabrication of the fault in the longitudinal section in an embodiment of the present invention. DETAILED DESCRIPTION

[0013] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0014] Example:

[0015] An experimental device for TBM excavation and segment stress characteristics in an active fault zone, comprising: a fault prefabricated model box, a TBM excavation system, a TBM slag discharge system and a TBM support system. The fault prefabricated model box is used to make similar material samples. Grouped cylinders are used to apply confining pressure around the similar material samples to produce specific shear fracture surfaces as faults or fault zones. The TBM machine and the TBM support system are arranged outside the front end face of the fault prefabricated model box, and the cutter head rotation axis coincides with the axis of the front and rear end faces of the model box to ensure that the whole machine excavates along the center position. The support segment is located at the tail of the rear shield of the micro-TBM. After the TBM excavation is completed, the segment can be cyclically supported by the jacking of the hydraulic main propulsion cylinder located behind the segment.

[0016] The fault prefabrication model box includes a reaction frame with detachable top and side plates, a bottom vertical loading cylinder, a horizontal loading cylinder, and a top vertical loading cylinder connected to the reaction frame. The left side loading plate, right side loading plate, top loading plate, and bottom loading plate are used to provide uniform surface force for the specimen. The top loading plate and bottom loading plate of different lengths and connected in blocks are centrally symmetrical about the excavation centroid, and the prefabrication of faults with different inclination angles can be achieved through group control of the cylinders.

[0017] The micro TBM excavation system includes a support and guide platform for enabling the micro TBM to move forward and backward along the excavation path, a fixed bracket connected to the support and guide platform for providing reaction force for the hydraulic main propulsion cylinder, a circular cutterhead with a disc cutter installed, a front shield connected to the cutterhead, a rear shield connected to the front shield, a hydraulic main propulsion cylinder for providing thrust for the cutter to break rocks, a hydraulic motor and gearbox installed on the fixed bracket for providing rotational torque and speed of the cutterhead, and a slewing bearing connected to the cutterhead and passing through the fixed bracket.

[0018] The micro-TBM mucking system includes a mucking rocker connected to a fixed bracket and located inside the segment, rear shield and front shield; a scraper plate adjacent to the front end of the mucking rocker at the bottom of the cutterhead and used to discharge large rock cuttings; and a cleaning brush located behind the scraper plate for cleaning small-size debris and rock powder. The scraped cuttings are accumulated near the hydraulic main propulsion cylinder and are cleaned manually.

[0019] The micro-TBM support system mainly includes arc segments with similar proportions to real engineering segments and closed-loop key segments. The looped segments are located between the tail of the micro-TBM rear shield and the hydraulic main propulsion cylinder.

[0020] Figure 1 and Figure 2 They are the cross-sectional and longitudinal sections of the fault model loading system, respectively.

[0021] The fault model loading system includes a bottom L-shaped reaction frame 1 for providing confining pressure of a rock sample of similar material, a horizontal loading cylinder 2 connected to the inner side of the L-shaped reaction frame 1 for providing horizontal stress, a top vertical loading cylinder 4 connected to a reaction cover plate 3 for providing vertical stress, and a bottom vertical loading cylinder 5 connected to the bottom of the L-shaped reaction frame 1 for providing vertical bottom stress. The reaction cover plate 3 and a detachable side baffle 39 are both connected to the L-shaped reaction frame 1 by bolts, and all cylinders can be loaded individually or in groups. The left side loading plate 6 and the right side loading plate 7 connected to the two sides of the similar material rock sample 36, the multiple spliced ​​top loading plates 8, 9, 10, 11 and 12 connected to the top surface of the similar material rock sample 36, and the multiple spliced ​​bottom loading plates 13, 14, 15, 16 and 17 connected to the bottom surface of the similar material rock sample 36, wherein the detachable top loading plates and bottom loading plates are centrally symmetrical about the centroid of the circular tunnel excavation boundary 18. All different detachable loading plates are used to make faults with different inclination angles. The front baffle 19 and the rear baffle 20 connected to the similar material rock sample 36 and with excavated holes are used to provide front and rear constraints of the similar material rock sample 36 respectively.

[0022] The micro-TBM excavation system includes a support guide platform 21 for supporting the micro-TBM excavation and support system, and the micro-TBM body includes a cutter head 22, a front shield 23, a rear shield 24, and a disc cutter 25 installed on the cutter head 22. The micro-TBM slewing mechanism includes a slewing bearing 26 connected to the cutter head 22 and passing through a fixed bracket 29, a hydraulic motor 27 for providing slewing torque, and a gearbox 28 for controlling different speeds. The hydraulic motor 27 and the gearbox 28 are both installed on the fixed bracket 29. The propulsion mechanism of the micro-TBM includes a hydraulic main propulsion cylinder 30 connected to the fixed bracket 29, and the other end of the hydraulic main propulsion cylinder 30 is connected to a segment ring 32 containing a segment annular joint 41.

[0023] The micro-TBM slag discharge system includes a micro-TBM slag discharge mechanism including a slag discharge rocker 33 connected to a fixed bracket 29, a slag scraper 34 connected to the slag discharge rocker 33 and used to discharge large slag flakes, and a cleaning brush 35 connected to the slag discharge rocker 33 and located behind the slag scraper 34 and used to discharge slag powder and fine particles.

[0024] The micro-TBM support system includes a segment ring 32 composed of an arc segment 31 and a key block segment 42 and connected to the shield tail of the rear shield 24, and the last segment ring is connected to the hydraulic main propulsion cylinder 30. The segment ring 32 forms a longitudinal gap 40 in the longitudinal axis direction, and an annular gap 41 is formed between the segment rings 32.

[0025] This embodiment also provides a method for prefabricating a fault fracture zone and testing the excavation performance of a micro-TBM. The physical model sample can prefabricate two types of faults with different occurrences. One type is that the fault strike is parallel to the excavation direction of the micro-TBM, that is, faults with different dips appear in the excavation cross section. The other type is that the fault strike is perpendicular to the excavation direction of the micro-TBM, that is, faults with different dips appear in the excavation longitudinal section. Figure 3 and Figure 4 The schematic diagrams are respectively the loading plate and the cylinder configuration method for prefabricating faults with different inclination angles in the cross section and the longitudinal section. The following is a detailed description of the prefabrication method of faults with different inclination angles in the cross section.

[0026] Continue to refer Figure 3 , Step 1, adjust the upper end surface of the bottom vertical loading cylinder 5 to the same level, and then lay the bottom loading plates 13-17 in sequence. According to the fault positions with different inclination angles, the bottom loading plates at specific fault surfaces are not connected, and other bottom loading plates are connected by bolts.

[0027] In the second step, bolts are used to install the left side loading plate 6 and the adjacent bottom loading plate 17, and bolts are used to connect the right side loading plate 7 and the bottom loading plate 13. The front baffle 19 and the rear baffle 20 can be connected to the side loading plate 7 and the bottom loading plate 13 by bolts using transparent high-strength tempered glass of a certain thickness, thereby forming a model box body closed on all sides. Then, similar materials are slowly filled and compacted layer by layer until they reach the top surface of the model box, and the top loading plates 8, 9, 10, 11 and 12 are installed in sequence. The top loading plates are not connected at the set fracture surface position, and other positions are connected by bolts. For example Figure 3 In the 60° fault plane 37 in the middle cross section, no connection is used at the bottom loading plates 15 and 16, and no connection is used at the top loading plates 10 and 11.

[0028] Step 3: Install the reaction cover plate 3 with the top vertical loading cylinder 4 and the side baffle 39 to complete the assembly of the fault model box.

[0029] In step 4, the horizontal loading cylinder 2 is uniformly loaded to the target stress according to the set load size, and then the bottom vertical cylinder 5 below the predetermined shear fracture surface is retracted to leave movement space for the loading plate, and the positions of other bottom vertical cylinders are not adjusted. The top vertical loading cylinder 4 above the specific fault fracture surface is loaded according to the displacement loading mode until the sample breaks, at which time the fault surface and fault fracture zone are prefabricated. During the loading process of the top vertical loading cylinder 4, relative sliding occurs between the left side loading plate 6 and the horizontal loading cylinder 2. Therefore, a ball contact is set at the end of the horizontal loading cylinder 2 to reduce the end friction resistance.

[0030] Continue to refer Figure 2 and Figure 3 After the fault models of different occurrences are completed, the micro-TBM excavation and support process is carried out. Step 1, start the hydraulic motor 27, drive the cutter head 22 to rotate through the slewing bearing 26, and then start the hydraulic main propulsion cylinder 30 to push the rear shield 24 to make the whole machine move forward to cut the model sample, until the cutter head 22, the front shield 23 and the rear shield 24 all enter the model sample at a distance slightly less than one ring of segments. The thrust and torque of the cutter head during the excavation process will be collected in real time. Step 2, stop the rotation of the cutter head 22, retract the hydraulic main propulsion cylinder 30, and then install a ring of segments at the tail of the rear shield 24, and continue to extend the hydraulic main propulsion cylinder 30 to push on the newly installed segments. Step 3, repeat steps 1 and 2 until the excavation reaches the predetermined position behind the fault fracture zone.

[0031] In view of the fault activation after excavation, when the micro-TBM crosses the fault, the loading cylinder that originally broke is continuously loaded by displacement loading, so that the upper and lower plates of the fault plane are displaced. Figure 5 and Figure 6 The relative sliding distance generated by the fault plane squeezes the TBM cutterhead 22, front shield 23, rear shield 24 and segment ring 32, which may cause a machine jam in severe cases, thereby revealing the mechanical properties of the TBM and segments in the activated fault.

[0032] The fault model loading prefabrication method and TBM excavation performance test for the case where the strike of the fault with different inclination angles is perpendicular to the excavation direction are similar to the above steps. In order to observe the fault rupture morphology in the longitudinal section, the front baffle 19 and the rear baffle 20 can be replaced with steel plates with holes, and the side baffle 39 can be made of high-strength transparent tempered glass material to observe the damage characteristics of the fault in the longitudinal section.

[0033] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An experimental device for TBM excavation and segment stress characteristics in active fault zones, characterized in that: include: A fault model loading system, a TBM excavation system and a TBM support system, wherein the fault model loading system comprises a prefabricated fault model box, wherein a rock sample of similar material is arranged in the prefabricated fault model box, and a top loading plate and a bottom loading plate of different widths and connected in blocks are arranged at the top and bottom of the rock sample of similar material. When the fault strikes parallel to the excavation direction of the TBM excavation system, that is, when faults of different inclination angles appear in the excavation cross section, the arrangement of the top loading plate and the bottom loading plate is centrally symmetrical with respect to the axial direction of the excavation centroid. When the fault strikes perpendicular to the excavation direction of the TBM excavation system, that is, when faults with different inclination angles appear in the excavation longitudinal section, the arrangement of the top loading plate and the bottom loading plate is centrally symmetrical in the radial direction of the excavation centroid, and the top loading plate and the bottom loading plate are acted on by grouped cylinders respectively, thereby realizing the prefabrication of faults with different inclination angles in the cross section or longitudinal section of the fault model loading system; the TBM support system is used to support the circular excavation boundary after the TBM excavation system completes excavation in the fault model loading system.

2. The active fault zone TBM excavation and segment stress characteristics experimental device according to claim 1 is characterized in that: The fault model loading system also includes an L-shaped reaction frame, a side baffle plate arranged on the side and a reaction cover plate arranged on the top. Side loading plates are arranged between the side of the similar material rock sample and the side of the L-shaped reaction frame and the side baffle plate. A horizontal loading cylinder for providing horizontal stress is arranged between the side of the L-shaped reaction frame and the side loading plate. A top vertical loading cylinder for providing vertical stress is arranged between the reaction cover plate and the top loading plate. A bottom vertical loading cylinder for providing vertical bottom stress is arranged between the bottom of the L-shaped reaction frame and the bottom loading plate.

3. The active fault zone TBM excavation and segment stress characteristics experimental device according to claim 2 is characterized in that: The TBM excavation system includes a fixed support, a TBM body, a TBM slewing mechanism and a TBM propulsion mechanism arranged on a supporting guide platform. The TBM body includes a cutterhead, a front shield and a rear shield connected to the cutterhead in sequence, and a disc cutter is installed on the cutterhead; the TBM slewing mechanism includes a slewing bearing connected to the cutterhead and passing through the fixed support, and the fixed support is provided with a hydraulic motor for providing slewing torque and a gearbox for controlling different speeds; the TBM propulsion mechanism includes a hydraulic main propulsion cylinder arranged between the fixed support and the TBM support system.

4. The active fault zone TBM excavation and segment stress characteristics experimental device according to claim 3 is characterized in that: The TBM support system includes a plurality of segment rings consisting of arc segments and key block segments, wherein the segment rings are connected to the shield tail of the rear shield, and the last segment ring is connected to the hydraulic main propulsion cylinder; the segment rings form longitudinal gaps in the longitudinal axis direction, and annular gaps are formed between adjacent segment rings.

5. The active fault zone TBM excavation and segment stress characteristics experimental device according to claim 3 or 4, characterized in that: It also includes a TBM slag discharge system, which includes a slag discharge rocker connected to a fixed bracket, a scraper plate connected to the slag discharge rocker and used to discharge large slag pieces, and a cleaning brush connected to the slag discharge rocker and located behind the scraper plate for discharging fine slag powder particles.

6. An experimental method for TBM excavation and segment stress characteristics in active fault zones, characterized in that: The active fault zone TBM excavation and segment stress characteristics experimental device as claimed in claim 4 or 5 is used to implement the experimental method, which comprises the following steps: Step 1: Adjust the end faces of the bottom vertical loading cylinder to the same level, and then flatten the bottom loading plates in sequence according to the prefabrication requirements of the faults with different inclination angles in the cross section or longitudinal section; according to the positions of the faults with different inclination angles, the bottom loading plates at the fault surfaces are not connected, and the other bottom loading plates are connected as a whole; Step 2, install the side loading plates, then fill and pour the rock samples of similar materials layer by layer until they are level with the top loading plates, and install the top loading plates in sequence. The top loading plates at the fracture surface are not connected, and the other top loading plates are connected; Step 3: Install the top vertical loading cylinder, reaction cover plate, and side baffle plate in sequence to complete the assembly of the fault model loading system; Step 4: The horizontal loading cylinder is uniformly loaded to the target stress according to the set load size, and then the bottom vertical loading cylinder is controlled to retract in groups below the predetermined shear fracture surface to leave movement space for the bottom loading plate, and the positions of other bottom vertical loading cylinders are not adjusted; the top vertical loading cylinder is retracted above the predetermined shear fracture surface to leave movement space for the top loading plate, and the positions of other cylinders are not adjusted; the top vertical loading cylinder is controlled to load in groups according to the displacement loading mode until the sample is broken, and the fault surface and fault fracture zone prefabrication are completed; Step 5: Start the drive motor to rotate the cutterhead through the hydraulic motor, then start the main propulsion cylinder to push the rear shield to make the TBM excavation system move forward to cut similar material rock samples until the cutterhead, the front shield and the rear shield all enter the fault prefabricated model box at a distance less than one ring of segments. During the excavation process, the thrust and torque of the cutterhead are collected in real time, the cutterhead is stopped, the main propulsion cylinder is retracted, and then a ring of segments is installed at the rear shield of the cutterhead. Then, the main propulsion cylinder is extended to push on the newly installed segments; until the excavation reaches the predetermined position behind the fault fracture zone; Step 6: When the TBM excavation system crosses the fault, the bottom vertical loading cylinder and the top vertical loading cylinder that originally caused the fault are continuously loaded in groups using a displacement loading method, so that the upper plate and the lower plate of the fault plane are displaced.

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