A tunnel excavation method for controlling arch crown settlement by reserving rock wall at working face

Abstract

The application discloses a tunnel excavation method for controlling vault settlement by reserving rock wall at a working face, which comprises the following steps: measuring and lofting the working face; dividing the working face of the upper step into sections; excavating two side excavation areas; fixing two half-arch supporting members into the two side excavation areas by using a telescopic arch frame assembling device; installing a narrow space operation device on a cantilever of a cantilever type tunneling machine, installing a cutting head, and excavating an upper excavation area of the rock wall; fixing a top supporting member on the upper excavation area of the rock wall; replacing the cutting head with a drill rod, drilling holes in the upper excavation area of the rock wall, and installing anchor rods; replacing the drill rod with a guniting pipe group, and performing guniting operation; and controlling the cantilever type tunneling machine to excavate the excavation area supported by the rock wall. The narrow space operation device is controlled to move and drill holes in the top wall of the upper excavation area of the rock wall at intervals, and then the anchor rods are inserted into the holes. The application is suitable for the technical field of the construction of the working face of the upper step in the step method of large cross-section tunnels.

Description

Technical Field

[0001] This invention belongs to the technical field of tunnel excavation construction, specifically, it relates to a tunnel excavation method that uses pre-reserved rock walls at the tunnel face to control the settlement of the tunnel arch. Background Technology

[0002] Cantilever tunneling machines are primarily used in industries such as coal mining and other mineral extraction. In recent years, with the construction and development of tunnels and underground engineering, cantilever tunneling machines have been gradually introduced into the field of tunnel construction. They are mainly used in tunnels where blasting is not feasible or in other tunnel projects where vibration control is strictly required. As cantilever tunneling machines are a relatively new type of construction machinery, they are currently mainly used in small-section tunnel projects, and their application in large-section high-speed railway double-track tunnels is still relatively rare.

[0003] When constructing large-section tunnels using a two-stage cantilever tunnel boring machine (TBM), the TBM mechanically breaks the rock by rotating its cutting head to drive the cutting teeth. Compared to drill-and-blast methods, while the vibration generated by the cantilever TBM is less and the disturbance to the surrounding rock is smaller, its single-cycle excavation phase is time-consuming. Excavation of the tunnel face typically takes several hours. During the TBM excavation, tunnel support work cannot be carried out, resulting in the exposed surrounding rock not being supported in a timely manner. This leaves the surrounding rock unsupported for extended periods, which is detrimental to controlling the settlement and deformation of the tunnel arch for large-section, large-span tunnels with Class IV or V soft surrounding rock. Furthermore, after the tunnel arch has developed joints or the extremely fractured surrounding rock has deformed and loosened, the disturbance from mechanical cutting may cause fracturing and spalling, leading to an irregular tunnel cross-section and requiring frequent secondary repairs, greatly increasing the difficulty of support work. Current technology involves excavating the tunnel's circular arch first, followed by initial support construction. Due to the constraints of the front shovel plate of the cantilever tunneling machine, it is difficult to excavate the ring arch first when the cyclic excavation advance is large. In addition, when excavating the ring arch first, the cutting head is a drilling-type cutting excavation, which causes greater disturbance to the surrounding rock and may not be able to guarantee the construction quality of the ring arch. Summary of the Invention

[0004] This invention provides a tunnel excavation method for controlling the settlement of the arch by reserving a rock wall at the tunnel face. This method controls the settlement and deformation of the surrounding rock of the arch during tunnel construction, reduces the assembly time of the steel arch frame inside the tunnel, and can quickly form a steel frame support system.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A tunnel excavation method for controlling arch settlement by reserving a rock wall at the tunnel face includes the following steps:

[0007] Step 1. Surveying and setting out at the tunnel face: Before the cantilever tunneling machine enters the tunnel face for operation, the surveying team first conducts surveying and setting out to mark the tunnel excavation outline and the excavation zone boundaries of the tunnel face.

[0008] Step 2. Divide the upper bench face into four zones for excavation in sequence: the upper rock wall excavation zone, the rock wall support excavation zone, and two side excavation zones. The two side excavation zones are located on the left and right sides of the rock wall support excavation zone, respectively, and the upper rock wall excavation zone is located above the rock wall support excavation zone.

[0009] Step 3: Based on the excavation boundaries marked by the surveying team, the two side excavation areas are excavated sequentially using a cantilever tunneling machine.

[0010] Step 4. After the two side excavation areas are completed, use the telescopic arch frame assembly device to simultaneously extend the two semi-arch support component groups into the two side excavation areas, fix each semi-arch support component in each semi-arch support component group to the perimeter wall of the side excavation area, and anchor the anchor rods in the side excavation area.

[0011] Step 5. After the support work is completed, install the narrow space operation device on the cantilever of the cantilever tunneling machine, and install the cutting head on the narrow space operation device to control the narrow space operation device to carry out excavation work on the upper excavation area of ​​the rock wall.

[0012] Step 6. After the excavation of the upper excavation area of ​​the rock wall is completed, fix multiple top support components to the top wall of the upper excavation area of ​​the rock wall, and connect the two ends of each top support component to the ends of the corresponding semi-arch support component.

[0013] Step 7. Replace the cutting head on the narrow space working device with a drill rod, control the movement of the narrow space working device to make it drill holes at intervals on the top wall of the excavation area above the rock wall, and then insert the anchor rod into the drill hole;

[0014] Step 8. Replace the drill rod on the narrow space working device with a shotcrete pipe assembly, control the operation of the narrow space working device, so that the shotcrete pipe assembly sprays concrete slurry evenly onto the surface of the upper excavation area and the two side excavation areas of the rock wall.

[0015] Step 9. Then control the cantilever tunneling machine to excavate the rock wall support excavation area.

[0016] Furthermore, when excavating each side excavation area, the cantilever tunneling machine is controlled to horizontally cut a transverse groove from the bottom of the excavation area at the face. The cantilever tunneling machine is then moved forward and positioned, and the cutting is carried out from bottom to top using an S-shaped cutting route, cutting the upper area of ​​the face step by step in a left-right cycle.

[0017] Furthermore, the width of the bottom of the rock wall support excavation area is 20-30% of the tunnel excavation width. The rock wall support excavation area gradually narrows from bottom to top, and the width of the upper part of the rock wall support excavation area is smaller than the width of its bottom, forming a trapezoidal structure.

[0018] Furthermore, the telescopic arch frame assembly device includes two symmetrical telescopic assembly units, with two semi-arched support component groups connected one-to-one with the two telescopic assembly units; the telescopic assembly unit includes a fixed seat mounted on a trolley, a telescopic frame that can extend and retract along the length of the tunnel is mounted on the fixed seat, a telescopic rod that extends and retracts in the same direction as the telescopic frame is mounted on one side of the telescopic frame, and multiple adjustable clamping mechanisms are installed between the telescopic frame and the telescopic rod. The multiple adjustable clamping mechanisms are spaced apart along the extension and retraction direction of the telescopic frame, and each adjustable clamping mechanism clamps the corresponding semi-arched support component.

[0019] Furthermore, the telescopic frame includes a shear frame composed of multiple shear rod groups that are hinged to each other. Two rod-shaped bodies in each shear rod group are hinged to each other through a central hinge shaft. One end of the shear frame is hinged to a fixed base, and a hydraulic cylinder is fixed on the fixed base. The hydraulic cylinder extends along the telescopic direction of the shear frame, and the cylinder rod of the hydraulic cylinder is connected to the central hinge shaft that is close to each other.

[0020] Furthermore, the adjustable clamping mechanism includes a mounting sleeve that is movably fitted outside the telescopic rod. The mounting sleeve is connected to a corresponding central hinge shaft. At least two telescopic members are mounted on the mounting sleeve. An adjustable adapter assembly is mounted on the end of each telescopic member away from the mounting sleeve. A pneumatic gripper or a hydraulic gripper is connected to the adjustable adapter assembly.

[0021] Furthermore, the adjustable adapter assembly includes an assembly base mounted on the telescopic member, an internal threaded sleeve hinged to the assembly base, an adapter screw coaxially threaded to the internal threaded sleeve, and one end of the adapter screw extending toward the semi-arched support member. An adapter seat is rotatably connected to the end of the adapter screw near the semi-arched support member. The pneumatic or hydraulic gripper is detachably connected to the adapter seat. An adjusting screw is threaded to the assembly base, and a hinge seat is rotatably connected to the end of the adjusting screw near the internal threaded sleeve. The hinge seat is hinged to the internal threaded sleeve.

[0022] Furthermore, the confined space operation device includes a multi-angle adjustment mechanism and a rotary clamp respectively connected to both ends of the telescopic boom. The multi-angle adjustment mechanism is detachably connected to the cantilever of the cantilever tunneling machine, and the drill rod, anchor rod or shotcrete pipe assembly is clamped on the rotary clamp.

[0023] Furthermore, the multi-angle adjustment mechanism includes a first motor connected to the cantilever of the cantilever tunneling machine via a motor base, a disc-shaped seat coaxially mounted on the output shaft of the first motor, the disc-shaped seat being coaxially rotatably connected to an annular seat, a second motor mounted on the annular seat, one end of the telescopic arm being fixed to the output shaft of the second motor, and the telescopic arm extending radially along the output shaft of the second motor, and a clutch assembly being constructed between the telescopic arm and the disc-shaped seat.

[0024] Furthermore, the rotary clamp includes a rotary transmission assembly connected to the output shaft of a hydraulic motor. An annular boss is constructed on the rotary transmission assembly, and a plurality of active radial clamping members are uniformly installed on the annular boss along its circumference. The hydraulic motor drives the rotary transmission assembly to rotate the active radial clamping members along the axis of the annular boss.

[0025] The technological advancements achieved by this invention compared to existing technologies, due to the aforementioned structure, lie in the following: This invention primarily optimizes the excavation sequence of the tunnel face during cantilever tunneling machine construction, utilizing the rock mass structure of the tunnel face to control the settlement and deformation of the tunnel arch. Specifically, during single-cycle excavation, a rock wall support excavation area of ​​a certain width is reserved in the middle of the tunnel face. This temporary support helps control the exposed area of ​​the tunnel arch surrounding rock and the unsupported time. After excavation of other parts of the tunnel face is completed, primary support is applied to the surfaces of the other excavated areas. Then, the upper excavation area of ​​the rock wall is excavated and removed, and primary support is applied to the upper surface of the upper excavation area of ​​the rock wall, followed by shotcreting. This creates a relatively solid outer shell on the surfaces of the upper excavation area of ​​the rock wall and the two side excavation areas, solving the problem of convergence, relaxation, deformation, and collapse caused by prolonged unsupported conditions in the tunnel excavation area. This invention, employing a telescopic arch frame assembly device, can simultaneously position two sets of semi-arch support components in two side excavation zones, improving the efficiency of the arrangement, positioning, and installation of the semi-arch support components. This facilitates the fixing of each semi-arch support component to its corresponding position in the tunnel by construction personnel. Furthermore, this invention utilizes a confined space operation device, overcoming the limitation of cantilever tunneling machines in narrow spaces. This device can not only be equipped with a cutting head for excavation but also with extendable drill rods for drilling long holes in confined spaces, thus facilitating the anchoring of extendable anchor rods within the confined space's inner wall. Additionally, the device can be equipped with shotcrete pipe assemblies, enabling uniform shotcrete application to the target area within confined spaces, improving operational mobility and efficiency, and compensating for the limitations of large equipment in confined spaces. In summary, the present invention can effectively control the settlement and deformation of the surrounding rock of the arch during tunnel construction, reduce the assembly time of the steel arch frame inside the tunnel, and quickly form a steel frame support system. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0027] In the attached diagram:

[0028] Figure 1 This is a schematic diagram of the connection between the telescopic arch frame assembly device and the two semi-arch support components in an embodiment of the present invention.

[0029] Figure 2 This is a front view of the structure connecting the telescopic arch frame assembly device and the two semi-arched support components according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the connection between the telescopic assembly unit and the corresponding semi-arch support component group in the telescopic arch frame assembly device of this invention.

[0031] Figure 4 for Figure 3 A schematic diagram of the structure shown from another angle;

[0032] Figure 5 for Figure 3 Side view of the structure shown;

[0033] Figure 6 This is a schematic diagram of the telescopic rod in the telescopic arch frame assembly device according to an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the adjustable clamping mechanism in the telescopic arch frame assembly device according to an embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the connection between the telescopic component and the adjustable adapter assembly in the adjustable clamping mechanism of this invention.

[0036] Figure 9 This is a schematic diagram of the narrow space operation device according to an embodiment of the present invention;

[0037] Figure 10 This is a schematic diagram of the connection between the telescopic boom and the multi-angle adjustment mechanism in the narrow space operation device according to an embodiment of the present invention;

[0038] Figure 11 for Figure 10 A schematic diagram of the structure shown from another angle;

[0039] Figure 12 This is an axial structural cross-sectional view of the clutch assembly in the multi-angle adjustment mechanism of this invention.

[0040] Figure 13This is a schematic diagram of the rotary clamp in the narrow space operation device according to an embodiment of the present invention;

[0041] Figure 14 This is a schematic diagram of a partially disassembled rotary clamp in a narrow-space working device according to an embodiment of the present invention;

[0042] Figure 15 This is a schematic diagram of the active radial clamping component in the rotary fixture of this invention.

[0043] Figure 16 This is a schematic diagram of the structure of the rotary fixture after removing the active radial clamping component according to an embodiment of the present invention;

[0044] Figure 17 This is an axial structural cross-sectional view of the rotary fixture of the present invention after the active radial clamping component has been removed;

[0045] Figure 18 This is a schematic diagram of the structure of the shotcrete pipe assembly according to an embodiment of the present invention;

[0046] Figure 19 This is a distribution diagram of the four zones on the working face of the upper step according to an embodiment of the present invention;

[0047] Figure 20 This is a path diagram of the excavation of the two side excavation zones in an embodiment of the present invention;

[0048] Figure 21 This is a schematic diagram of the arrangement of anchor bolts on the outer perimeter wall of the tunnel according to an embodiment of the present invention;

[0049] Figure 22 This is a path diagram of the excavation of the rock wall support excavation area according to an embodiment of the present invention.

[0050] Components labeled: 100-Fixed base, 200-Telescopic frame, 201-Rod-shaped body, 202-Middle hinge shaft, 203-End hinge shaft, 204-Hydraulic cylinder, 300-Telescopic rod, 301-Rod head, 302-Plug-in part, 303-Plug-in interface, 400-Adjustable clamping mechanism, 401-Mounting sleeve, 402-Telescopic component, 403-Adjustable adapter assembly, 4031-Assembly base, 4032-Internal threaded sleeve, 4033-Adapter screw, 4034-Adapter base, 4035-First operating handwheel 4036-Adjusting screw, 4037-Second operating handwheel, 500-Semi-arched support component, 501-Slanted mounting edge, 600-Multi-angle adjustment mechanism, 601-First motor, 602-Motor base, 603-Disc-shaped base, 604-Annular base, 605-Adapter plate, 606-Second motor, 607-Clutch assembly, 6071-Central shaft, 6072-Housing shell, 6073-Connecting sleeve, 6074-Piston, 6075-Drive chamber, 6076-First connector tube, 6077-Second connector tube, 6 08-Fixed Sleeve, 609-First Clutch Disc, 610-Second Clutch Disc, 700-Telescopic Arm, 800-Rotary Clamp, 801-Hydraulic Motor, 802-Rotary Transmission Assembly, 8021-Transmission Worm Gear, 8022-Transmission Worm, 8023-Combined Half-Shell, 8024-Worn Gear Half-Shell, 8025-Worn Half-Shell, 803-Annular Boss, 804-Active Radial Clamping Component, 8041-Radial Cylinder, 8042-Base, 8043-Clamping Block, 805-Media Conduction System, 80501 - Assembly ring, 80502 - First annular cavity, 80503 - Second annular cavity, 80504 - First hydraulic pipe, 80505 - Second hydraulic pipe, 80506 - Annular fastener, 80507 - Third annular cavity, 80508 - Fourth annular cavity, 80509 - Third hydraulic pipe, 80510 - Fourth hydraulic pipe, 80511 - First medium channel, 80512 - Second medium channel, 806 - Connecting seat, 807 - Connecting joint, 900 - Main spray pipe, 901 - Spray branch pipe, 902 - Spray nozzle. Detailed Implementation

[0051] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0052] This invention discloses a tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face, such as... Figures 1-22 As shown, it includes the following steps:

[0053] Step 1. Surveying and setting out at the tunnel face: Before the cantilever tunneling machine enters the tunnel face for operation, the surveying team first conducts surveying and setting out to mark the tunnel excavation outline and the excavation zone boundaries of the tunnel face.

[0054] Step 2. Divide the upper bench face into four zones for excavation in sequence: the upper rock wall excavation zone, the rock wall support excavation zone, and two side excavation zones. The two side excavation zones are located on the left and right sides of the rock wall support excavation zone, respectively, and the upper rock wall excavation zone is located above the rock wall support excavation zone.

[0055] Step 3: Based on the excavation boundaries marked by the surveying team, the two side excavation areas are excavated sequentially using a cantilever tunneling machine.

[0056] Step 4. After the two side excavation areas are completed, a central rock wall is formed at the rock wall support excavation area. The telescopic arch frame assembly device is used to simultaneously extend the two semi-arch support component groups into the two side excavation areas, and each semi-arch support component 500 in each semi-arch support component group is fixed to the perimeter wall of the side excavation area, and the anchor rod is anchored in the side excavation area.

[0057] Step 5. After the support work is completed, install the narrow space operation device on the cantilever of the cantilever tunneling machine, and install the cutting head on the narrow space operation device to control the narrow space operation device to carry out excavation work on the upper excavation area of ​​the rock wall.

[0058] Step 6. After the excavation of the upper excavation area of ​​the rock wall is completed, fix multiple top support components to the top wall of the upper excavation area of ​​the rock wall, and connect the two ends of each top support component to the end of the corresponding semi-arch support component 500; construct an inclined mounting edge 501 at one end of each semi-arch support component 500 near the top support component, and construct overlapping edges that are adapted to the inclined mounting edge 501 at both ends of each top support component. The overlapping edges and the inclined mounting edge 501 are assembled together, and the top support component and the semi-arch support component 500 can be fixed by means of rivets, welding, etc.

[0059] Step 7. Replace the cutting head on the narrow space working device with a drill rod, control the movement of the narrow space working device to make it drill holes at intervals on the top wall of the excavation area above the rock wall, and then insert the anchor rod into the drill hole;

[0060] Step 8. Replace the drill rod on the narrow space working device with a shotcrete pipe assembly, control the operation of the narrow space working device, so that the shotcrete pipe assembly sprays concrete slurry evenly onto the surface of the upper excavation area and the two side excavation areas of the rock wall.

[0061] Step 9. Next, control the cantilever tunneling machine to excavate the middle rock wall of the rock wall support excavation area. Operate the cantilever tunneling machine to cut from the bottom of the middle rock wall upwards, using an S-shaped cutting route, and cut the middle rock wall step by step upwards in a left-right cycle.

[0062] The working principle and advantages of this invention are as follows: This invention mainly optimizes the excavation sequence of the tunnel face during cantilever tunneling machine construction, and utilizes the rock mass structure of the tunnel face to control the settlement and deformation of the tunnel arch. Specifically, during single-cycle excavation, a rock wall support excavation area of ​​a certain width is reserved in the middle of the tunnel face. Through the temporary support of the reserved rock wall support excavation area, the exposed area of ​​the surrounding rock of the tunnel arch and the unsupported time are controlled. After the excavation of other parts of the tunnel face is completed, the surface of the other excavated parts is first provided with primary support, and then the upper excavation area of ​​the rock wall is excavated and removed. Primary support is then provided on the upper surface of the upper excavation area of ​​the rock wall, and shotcreting is carried out. This forms a relatively solid outer shell 6072 on the surface of the upper excavation area of ​​the rock wall and the two side excavation areas, solving the problem of convergence relaxation deformation and collapse caused by the surrounding rock of the tunnel excavation area being in an unsupported state for a long time. This invention, by employing a telescopic arch frame assembly device, can simultaneously position two sets of semi-arch support components to two side excavation zones in one go, improving the efficiency of the arrangement, positioning, and installation of the semi-arch support components 500, and facilitating the fixing of each semi-arch support component 500 to the corresponding position in the tunnel by construction personnel. This invention, by employing a confined space operation device, overcomes the limitation of cantilever tunneling machines being unable to perform excavation operations in confined spaces. Furthermore, the confined space operation device can not only be equipped with a cutting head for excavation operations but also with extendable drill rods for drilling long holes in confined spaces, thus facilitating the anchoring of extendable anchor rods within the inner wall of the confined space. Additionally, the confined space operation device can be equipped with shotcrete pipe assemblies to achieve uniform shotcrete application to the target area surface within confined spaces, improving operational mobility and efficiency, and compensating for the inability of large equipment to operate in confined spaces. In summary, the present invention can effectively control the settlement and deformation of the surrounding rock of the arch during tunnel construction, reduce the assembly time of the steel arch frame inside the tunnel, and quickly form a steel frame support system.

[0063] As a preferred embodiment of the present invention, such as Figure 20 As shown, during excavation of each side excavation area, the cantilever tunneling machine (TBM) horizontally cuts a transverse groove from the bottom of the excavation area at the tunnel face. The TBM is then moved forward and positioned, and cutting begins from the bottom upwards in an S-shaped pattern, cyclically cutting the upper part of the tunnel face. During the rock-breaking process, the falling rock fragments are transferred by the shovel section to a rear transport vehicle and then removed from the tunnel by a muck truck. After the initial excavation according to the design outline, the TBM undergoes a secondary trimming process to ensure the final cross-section matches the design. When the TBM encounters harder rock during construction, it can prioritize cutting along the rock strata or fracture zones, with the remaining portion handled separately using a hydraulic breaker. This reduces the difficulty of the TBM operation and minimizes the consumption of cutting teeth.

[0064] As a preferred embodiment of the present invention, such as Figure 19 As shown, the width of the bottom of the rock wall support excavation area is 20-30% of the tunnel excavation width. The rock wall support excavation area gradually narrows from bottom to top, with the upper part being narrower than the bottom, forming a trapezoidal structure. The width of the rock wall support excavation area is dynamically adjusted according to the tunnel face rock conditions and construction conditions to ensure the stability of the central rock wall. In this embodiment, the upper step excavation width is approximately 15m, and the bottom width of the rock wall support excavation area can be set to 3-4m. A certain slope is formed on both sides of the central rock wall to further ensure its stability. The height of the upper excavation area of ​​the rock wall is set to 1.5m.

[0065] As a preferred embodiment of the present invention, such as Figures 1-8 As shown, the telescopic arch frame assembly device includes two symmetrically arranged telescopic assembly units, and two sets of semi-arched support component groups are connected to the two telescopic assembly units one-to-one. Each telescopic assembly unit includes a fixed base 100, a telescopic frame 200, a telescopic rod 300, and multiple adjustable clamping mechanisms 400. The fixed base 100 is mounted on a trolley, the telescopic frame 200 is mounted on the fixed base 100, and the telescopic frame 200 can extend and retract along the length of the tunnel. The telescopic rod 300 is mounted on one side of the telescopic frame 200, and its two ends are connected to the two ends of the telescopic frame 200 one-to-one. The extension and retraction direction of the telescopic rod 300 is the same as that of the telescopic frame 200. In this embodiment, multiple adjustable clamping mechanisms 400 are installed between the telescopic frame 200 and the telescopic rod 300. These adjustable clamping mechanisms 400 are spaced apart along the extension and retraction direction of the telescopic frame 200, and each adjustable clamping mechanism 400 clamps the corresponding semi-arched support component 500. Before assembling the semi-arched support components 500 onto the telescopic arch frame assembly device, the telescopic frames 200 of the two telescopic assembly units are controlled to be in a fully retracted state. Then, each semi-arched support component 500 is assembled onto its corresponding adjustable clamping mechanism 400. After completion, the telescopic frames 200 are gradually extended, ensuring that the spacing between adjacent semi-arched support components 500 reaches a predetermined value, and that these semi-arched support components 500 are evenly distributed along the length of the tunnel, covering the inner wall of the side excavation area. Then, each semi-arched support component 500 is fixed to the inner wall of the side excavation area. This embodiment, by employing the telescopic frames 200 and multiple adjustable clamping mechanisms 400 to adjust the position and spacing of the semi-arched support components 500, improves the efficiency of construction operations and ensures that the semi-arched support components 500 can effectively provide main support for the inner wall of the side excavation area.

[0066] As a preferred embodiment of the present invention, such as Figure 5As shown, the telescopic frame 200 includes a shear frame composed of multiple shearing rod groups hinged together. Two rod-shaped bodies 201 in each shearing rod group are hinged together via a central hinge shaft 202. The ends of adjacent rod-shaped bodies 201 in two adjacent shearing rod groups are hinged together via end hinge shafts 203. In this embodiment, one end of the shear frame is hinged to a fixed base 100. A hydraulic cylinder 204 is fixed to the fixed base 100. The hydraulic cylinder 204 extends along the telescopic direction of the shear frame, and its cylinder rod is connected to the adjacent central hinge shafts 202. In this embodiment, by controlling the movement of the hydraulic cylinder 204, the shear frame is driven to telescopically extend along the length of the tunnel. Figure 6 As shown, the telescopic rod 300 includes two opposing rod heads 301. The ends of these two rod heads 301 that are far apart from each other are connected to the two ends of the shearing frame. Multiple insertion portions 302 are constructed at the ends of the two rod heads 301 that are close to each other. These insertion portions 302 are evenly arranged circumferentially along the rod heads 301, and each insertion portion 302 extends along the telescopic direction of the shearing frame. An insertion interface 303 is formed between adjacent insertion portions 302. The insertion portions 302 on the two rod heads 301 are movably inserted into the corresponding insertion interfaces 303. When the shearing frame telescopically extends or retracts, the telescopic rod 300 also telescopically extends or retracts accordingly, and the radial length of the telescopic rod 300 does not change, so that the adjustable clamping mechanism 400 can slide smoothly on the telescopic rod 300.

[0067] As a preferred embodiment of the present invention, such as Figure 7 , Figure 8As shown, the adjustable clamping mechanism 400 includes a mounting sleeve 401, multiple telescopic members 402, and an adjustable adapter assembly 403 equal in number to the telescopic members 402. The telescopic members 402 are generally hydraulic or pneumatic cylinders. The mounting sleeve 401 is movably fitted onto the telescopic rod 300, and is fixedly connected to a corresponding central hinge shaft 202; that is, the number of central hinge shafts 202 between adjacent mounting sleeves 401 is the same. There are at least two telescopic members 402, all mounted on the mounting sleeve 401. Each adjustable adapter assembly 403 is mounted on the end of the corresponding telescopic member 402 furthest from the mounting sleeve 401. Each adjustable adapter assembly 403 is connected to a pneumatic or hydraulic gripper, which clamps the corresponding portion of the semi-arched support member 500. In this embodiment, by controlling the telescopic frame 200 to extend and retract, the distance between the central hinge shafts 202 gradually increases, thereby causing the central hinge shafts 202 to drive the mounting sleeve 401 to move along the length of the telescopic rod 300. In this way, the mounting sleeve 401 drives the adjustable adapter 403 to move through the telescopic component 402, thereby achieving the purpose of adjusting the distance between the semi-arched support components 500. The adjustable adapter assembly 403 in this embodiment includes a mounting base 4031, an internal threaded sleeve 4032, an adapter screw 4033, an adapter seat 4034, an adjusting screw 4036, and a hinge seat. The mounting base 4031 is installed on the end of the telescopic member 402 away from the mounting sleeve 401. The internal threaded sleeve 4032 is hinged to the mounting base 4031. The adapter screw 4033 is coaxially threaded with the internal threaded sleeve 4032, and one end of the adapter screw extends toward the semi-arched support member 500. The adapter seat 4034 is rotatably connected to the end of the adapter screw near the semi-arched support member 500. A pneumatic gripper or a hydraulic gripper is detachably connected to the adapter seat 4034. A first operating handwheel 4035 is installed at the other end of the adapter screw. In this embodiment, the adjusting screw 4036 is threadedly connected to the mounting base 4031, and the hinge seat is rotatably connected to one end of the adjusting screw 4036 near the internal threaded sleeve 4032. The hinge seat is hinged to the internal threaded sleeve 4032, and a second operating handwheel 4037 is mounted on the other end of the adjusting screw 4036. In this embodiment, by controlling at least one of the following: the extension and retraction of the telescopic member 402, the connection position of the adapter screw 4033 and the internal threaded sleeve 4032, and the connection angle between the adjusting screw 4036 and the internal threaded sleeve 4032, the pneumatic or hydraulic grippers are clamped at the corresponding positions of the semi-arched support member 500, ensuring that the semi-arched support member 500 remains stable and does not tilt or shift during position adjustment and fixation to the tunnel wall.

[0068] As a preferred embodiment of the present invention, such as Figures 9-17As shown, the confined space operation device includes a telescopic boom 700, a multi-angle adjustment mechanism 600, and a rotary clamp 800. The multi-angle adjustment mechanism 600 and the rotary clamp 800 are respectively connected to both ends of the telescopic boom 700. The multi-angle adjustment mechanism 600 is detachably connected to the cantilever of the cantilever tunneling machine. The drill rod, anchor rod, or shotcrete pipe assembly is clamped on the rotary clamp 800. The telescopic boom 700 is generally a hydraulic cylinder. In this embodiment, by controlling the movement of the multi-angle adjustment mechanism 600, it drives the telescopic boom 700 to adjust the position and angle of the rotary clamp 800. Controlling the movement of the telescopic boom 700 drives the rotary clamp 800 to extend into the confined space. Controlling the movement of the rotary clamp 800 drives the drill rod, anchor rod, or shotcrete pipe assembly to rotate, thereby performing drilling, anchoring, or shotcrete operations. During the process of inserting the anchor rod into the borehole, the rotation of the rotary clamp 800 can be discontinued.

[0069] As a preferred embodiment of the present invention, such as Figures 10-12As shown, the multi-angle adjustment mechanism 600 includes a first motor 601, a disc-shaped seat 603, an annular seat 604, a second motor 606, and a clutch assembly 607. The first motor 601 is connected to the cantilever of the cantilever tunneling machine via a motor mount 602, and is also connected to the annular seat 604 via two adapter plates 605. The disc-shaped seat 603 is coaxially mounted on the output shaft of the first motor 601 and is coaxially rotatably connected to the annular seat 604. The second motor 606 is mounted on the annular seat 604, and a fixing sleeve 608 is fixed to one end of the telescopic arm 700. This fixing sleeve 608 is fixedly mounted on the output shaft of the second motor 606, and the telescopic arm 700 extends radially along the output shaft of the second motor 606. The clutch assembly 607 is constructed between the telescopic arm 700 and the disc-shaped seat 603, and is used to lock the corresponding positions of the telescopic arm 700 and the disc-shaped seat 603. The clutch assembly 607 of this embodiment includes a central shaft 6071, a connecting sleeve 6073, a first clutch disc 609, and a second clutch disc 610. One end of the central shaft 6071 is coaxially rotatably connected to one end of the output shaft of the second motor 606. A housing 6072 is fixed outside the central shaft 6071 and is fixedly connected to a disc-shaped seat 603. The connecting sleeve 6073 is fitted outside the central shaft 6071 and is movably connected to the central shaft 6071. A piston 6074 is coaxially fixed at one axial end of the connecting sleeve 6073. The piston 6074 extends into the housing 6072 and divides the inner cavity of the housing 6072 into two drive chambers 6075. The second clutch disc 610 is coaxially fixed at the other end of the connecting sleeve 6073, and the first clutch disc 609 is coaxially fixed at one end of the fixing sleeve 608 near the connecting sleeve 6073. A first connector pipe 6076 and a second connector pipe 6077 are installed on the outer casing 6072, and the first connector pipe 6076 and the second connector pipe 6077 are connected to two drive chambers 6075 one by one. The working principle and advantages of this embodiment are as follows: In this embodiment, hydraulic oil is introduced into one drive chamber 6075, and the hydraulic oil in the other drive chamber 6075 is discharged, causing the piston 6074 to move axially along the central axis 6071, and then driving the second clutch disc 610 to move closer to or away from the first clutch disc 609 through the connecting sleeve 6073. When the first clutch disc 609 and the second clutch disc 610 are engaged, the telescopic arm 700 and the disc seat 603 are locked. When the first clutch disc 609 and the second clutch disc 610 are disengaged, the second motor 606 can be controlled to drive the telescopic arm 700 to rotate along the output shaft of the second motor 606, thereby achieving the purpose of vertical angle adjustment. After the adjustment is completed, the first clutch disc 609 and the second clutch disc 610 are controlled to engage again. In this embodiment, the first motor 601 can be controlled to drive the disc seat 603 to rotate by a predetermined angle, thereby causing the disc seat 603 to drive the rotary clamp 800 to rotate circumferentially along the annular seat 604 via the telescopic arm 700.Therefore, this embodiment can control the operation of the first motor 601 and / or the second motor 606 to achieve the purpose of adjusting the rotary clamp 800 at multiple angles, thereby adapting to drilling, anchoring and shotcreting operations at different positions.

[0070] As a preferred embodiment of the present invention, such as Figures 13-17 As shown, the rotary clamp 800 includes a hydraulic motor 801, a rotary transmission assembly 802, an annular boss 803, and multiple active radial clamping members 804. The rotary transmission assembly 802 is connected to the telescopic arm 700. The output shaft of the hydraulic motor 801 is connected to the rotary transmission assembly 802. The annular boss 803 is constructed on the rotary transmission assembly 802, and the multiple active radial clamping members 804 are mounted on the annular boss 803, and these active radial clamping members 804 are evenly arranged along the circumference of the annular boss 803. In this embodiment, the hydraulic motor 801 drives the rotary transmission assembly 802 to rotate, causing the rotary transmission assembly 802 to drive the annular boss 803 to rotate. During the rotation of the annular boss 803, the active radial clamping members 804 rotate along the axis of the annular boss 803. This embodiment controls the movement of all active radial clamping members 804, ensuring that corresponding parts of the drill rod, anchor rod, or shotcrete assembly are clamped between these active radial clamping members 804, and that the axis of the drill rod, anchor rod, or shotcrete assembly coincides with the axis of the annular boss 803, thereby facilitating drilling, anchoring, or shotcreting. Furthermore, the drill rod and anchor rod are generally designed as multi-section detachable components, allowing for adjustments in length as needed to facilitate drilling or anchoring operations in confined spaces. During drilling or anchoring operations, the cantilever of the tunnel boring machine is controlled to move vertically, gradually extending the drill rod or anchor rod; once one section of the drill rod or anchor rod has been fully extended, another section is connected.

[0071] As a preferred embodiment of the present invention, such as Figure 14As shown, the rotary transmission assembly 802 includes a transmission worm gear 8021 and a transmission worm 8022, which are connected in a transmission manner. A combined half-shell 8023 is provided at the portion of the transmission worm gear 8021 and the transmission worm 8022 that are close to each other. At the ends of the transmission worm gear 8021 and the transmission worm 8022 that are far apart from each other, worm gear half-shell 8024 and worm half-shell 8025 are respectively provided. The worm gear half-shell 8024 and worm half-shell 8025 are detachably connected to the corresponding ends of the combined half-shell 8023. The output shaft of the hydraulic motor 801 is coaxially connected to one axial end of the transmission worm 8022. The annular boss 803 is coaxially fixedly connected to the transmission worm gear 8021. A connecting joint 807 is constructed on the worm gear half-shell 8024, and this connecting joint 807 is detachably connected to one end of the telescopic arm 700. In this embodiment, the transmission worm 8022 is driven to rotate, which in turn drives the transmission worm wheel 8021 to rotate. The transmission worm wheel 8021 drives multiple active radial clamping members 804 to rotate along the axis of the transmission worm wheel 8021 via the annular boss 803.

[0072] As a preferred embodiment of the present invention, such as Figures 15-17As shown, the active radial clamping member 804 includes a radial cylinder 8041. Multiple connecting seats 806 are spaced circumferentially on the annular boss 803. The radial cylinder 8041 is fixedly mounted on the corresponding connecting seat 806. A base base 8042 is fixed to the end of the cylinder rod of the radial cylinder 8041. A clamping block 8043 is detachably connected to the base base 8042, allowing for the replacement of different types of clamping blocks 8043 depending on the component being clamped. In this embodiment, all radial cylinders 8041 are connected to a medium conduction system 805, which is constructed within the rotary transmission assembly 802. Specifically, the medium conduction system 805 includes an assembly ring 80501 coaxially rotatably mounted on an annular boss 803. The assembly ring 80501 and the annular boss 803 form mutually independent first annular cavities 80502 and 80503. A first hydraulic pipe 80504 and a second hydraulic pipe 80505 are constructed on the assembly ring 80501. The first hydraulic pipe 80504 and the second hydraulic pipe 80505 are connected to the first annular cavities 80502 and 80503 respectively. The first hydraulic pipe 80504 is connected to one end of the cylinder body of each radial cylinder 8041, and the second hydraulic pipe 80505 is connected to the other end of the cylinder body of each radial cylinder 8041. An annular seat 80506 is coaxially rotatably connected to the end of the transmission worm gear 8021 away from the annular boss 803. The annular seat 80506 and the transmission worm gear 8021 form independent third annular cavities 80507 and 80508. A third hydraulic pipe 80509 and a fourth hydraulic pipe 80510 are constructed on the annular seat 80506, communicating with the third annular cavity 80507 and the fourth annular cavity 80508 respectively. A first medium channel 80511 and a second medium channel 80512 are provided within the transmission worm gear 8021. The first medium channel 80511 connects the first annular cavity 80502 and the third annular cavity 80507, and the second medium channel 80512 connects the second annular cavity 80503 and the fourth annular cavity 80508. In this embodiment, hydraulic oil is introduced into the third hydraulic pipe 80509 or the fourth hydraulic pipe 80510, and the hydraulic oil is discharged from the fourth hydraulic pipe 80510 or the third hydraulic pipe 80509, so that the hydraulic oil drives the radial cylinders 8041 to move and clamp the drill rod, anchor rod or shotcrete pipe assembly.

[0073] As a preferred embodiment of the present invention, such as Figure 18As shown, the shotcrete assembly includes a main shotcrete pipe 900, which is held by a rotary clamp 800. Multiple shotcrete branch pipes 901 are connected to the main shotcrete pipe 900 at intervals along its circumference. Multiple shotcrete nozzles 902 are connected to each shotcrete branch pipe 901 at intervals along its length. During the rotation of the main shotcrete pipe 900, the shotcrete branch pipes 901 rotate along the axis of the main shotcrete pipe 900, thereby achieving uniform and thorough shotcrete application by the shotcrete nozzles 902.

[0074] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., 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 tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face, characterized in that, Includes the following steps: Step 1. Surveying and setting out at the tunnel face: Before the cantilever tunneling machine enters the tunnel face for operation, the surveying team first conducts surveying and setting out to mark the tunnel excavation outline and the excavation zone boundaries of the tunnel face. Step 2. Divide the upper bench face into four zones for excavation in sequence: the upper rock wall excavation zone, the rock wall support excavation zone, and two side excavation zones. The two side excavation zones are located on the left and right sides of the rock wall support excavation zone, respectively, and the upper rock wall excavation zone is located above the rock wall support excavation zone. Step 3: Based on the excavation boundaries marked by the surveying team, the two side excavation areas are excavated sequentially using a cantilever tunneling machine. Step 4. After the two side excavation areas are completed, use the telescopic arch frame assembly device to simultaneously extend the two semi-arch support component groups into the two side excavation areas, fix each semi-arch support component in each semi-arch support component group to the perimeter wall of the side excavation area, and anchor the anchor rods in the side excavation area. Step 5. After the support work is completed, install the narrow space operation device on the cantilever of the cantilever tunneling machine, and install the cutting head on the narrow space operation device to control the narrow space operation device to carry out excavation work on the upper excavation area of ​​the rock wall. Step 6. After the excavation of the upper excavation area of ​​the rock wall is completed, fix multiple top support components to the top wall of the upper excavation area of ​​the rock wall, and connect the two ends of each top support component to the ends of the corresponding semi-arch support component. Step 7. Replace the cutting head on the narrow space working device with a drill rod, control the movement of the narrow space working device to make it drill holes at intervals on the top wall of the excavation area above the rock wall, and then insert the anchor rod into the drill hole; Step 8. Replace the drill rod on the narrow space working device with a shotcrete pipe assembly, control the operation of the narrow space working device, so that the shotcrete pipe assembly sprays concrete slurry evenly onto the surface of the upper excavation area and the two side excavation areas of the rock wall. Step 9. Then control the cantilever tunneling machine to excavate the rock wall support excavation area.

2. The tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face according to claim 1, characterized in that: When excavating each side excavation area, the cantilever tunneling machine is controlled to horizontally cut a transverse groove from the bottom of the excavation area at the face. The cantilever tunneling machine is then moved forward and positioned, and the cutting is carried out from bottom to top in an S-shaped cutting route, cutting the upper area of ​​the face step by step in a left-right cycle.

3. The tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face according to claim 1, characterized in that: The bottom width of the rock wall support excavation area is 20-30% of the tunnel excavation width. The rock wall support excavation area gradually narrows from bottom to top, and the width of the upper part of the rock wall support excavation area is smaller than the width of its bottom, forming a trapezoidal structure.

4. The tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face according to claim 1, characterized in that: The telescopic arch frame assembly device includes two symmetrical telescopic assembly units, with two semi-arched support component groups connected one-to-one with the two telescopic assembly units. Each telescopic assembly unit includes a fixed seat mounted on a trolley, a telescopic frame that can extend and retract along the length of the tunnel mounted on the fixed seat, a telescopic rod that extends and retracts in the same direction as the telescopic frame mounted on one side of the telescopic frame, and multiple adjustable clamping mechanisms installed between the telescopic frame and the telescopic rod. The multiple adjustable clamping mechanisms are spaced apart along the extension and retraction direction of the telescopic frame, and each adjustable clamping mechanism clamps the corresponding semi-arched support component.

5. A tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face according to claim 4, characterized in that: The telescopic frame includes a shear frame composed of multiple shear rod groups that are hinged to each other. Two rod-shaped bodies in each shear rod group are hinged to each other through a central hinge shaft. One end of the shear frame is hinged to a fixed base, and a hydraulic cylinder is fixed on the fixed base. The hydraulic cylinder extends along the telescopic direction of the shear frame, and the cylinder rod of the hydraulic cylinder is connected to the central hinge shaft that is close to each other.

6. A tunnel excavation method for controlling arch settlement by reserving a rock wall at the tunnel face according to claim 5, characterized in that: The adjustable clamping mechanism includes a mounting sleeve that is movably fitted onto the telescopic rod. The mounting sleeve is connected to a corresponding central hinge shaft. At least two telescopic components are mounted on the mounting sleeve. An adjustable adapter assembly is mounted on the end of each telescopic component away from the mounting sleeve. A pneumatic gripper or a hydraulic gripper is connected to the adjustable adapter assembly.

7. A tunnel excavation method for controlling arch settlement by reserving a rock wall at the tunnel face according to claim 6, characterized in that: The adjustable adapter assembly includes an assembly base mounted on the telescopic component, an internal threaded sleeve hinged to the assembly base, an adapter screw coaxially threaded to the internal threaded sleeve, and one end of the adapter screw extending toward the semi-arched support component. An adapter seat is rotatably connected to the end of the adapter screw near the semi-arched support component. A pneumatic or hydraulic gripper is detachably connected to the adapter seat. An adjusting screw is threaded to the assembly base, and a hinge seat is rotatably connected to the end of the adjusting screw near the internal threaded sleeve. The hinge seat is hinged to the internal threaded sleeve.

8. The tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face according to claim 1, characterized in that: The confined space operation device includes a multi-angle adjustment mechanism and a rotary clamp connected to both ends of the telescopic boom. The multi-angle adjustment mechanism is detachably connected to the cantilever of the cantilever tunneling machine, and the drill rod, anchor rod or shotcrete pipe assembly is clamped on the rotary clamp.

9. A tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face according to claim 8, characterized in that: The multi-angle adjustment mechanism includes a first motor connected to the cantilever of the cantilever tunneling machine via a motor base, a disc-shaped seat coaxially mounted on the output shaft of the first motor, the disc-shaped seat being coaxially rotatably connected to an annular seat, a second motor mounted on the annular seat, one end of the telescopic arm being fixed to the output shaft of the second motor, and the telescopic arm extending radially along the output shaft of the second motor, and a clutch assembly being constructed between the telescopic arm and the disc-shaped seat.

10. A tunnel excavation method for controlling arch settlement by reserving rock walls at the tunnel face according to claim 8, characterized in that: The rotary clamp includes a rotary transmission assembly connected to the output shaft of a hydraulic motor. An annular boss is constructed on the rotary transmission assembly, and multiple active radial clamping members are uniformly installed on the annular boss along its circumference. The hydraulic motor drives the rotary transmission assembly to rotate the active radial clamping members along the axis of the annular boss.

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