A reverse-pulling mechanical and artificial freezing combined connecting passage open-cut technology

Abstract

The application discloses a kind of reverse pull machinery and artificial freezing combined connecting passage subsurface excavation process, comprising the following steps: carrying out stratum freezing construction, until the freezing wall is formed in the region of connecting passage proposed excavation and the freezing wall is closed;The proposed excavation region is located in the stratum between adjacent first side tunnel and second side tunnel;On the side tunnel wall of the first side tunnel close to the proposed excavation region and on the side tunnel wall of the second side tunnel close to the proposed excavation region, the excavation contour of the connecting passage is divided respectively.The application significantly improves construction safety and efficiency by the combination of artificial freezing and reverse pull machinery, reduces construction cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground engineering construction. Specifically, it is a kind of connecting passage excavation technology combined with anti-pulling machinery and artificial freezing. BACKGROUND

[0002] There are many challenges in excavating connecting passages in complex strata and water-rich soft soil strata. As an important construction method, freezing method freezes water in soil into ice through artificial refrigeration to form a solid and closed frozen soil ring (frozen wall) to resist water and soil pressure and isolate groundwater, ensuring the safety of the excavation process.

[0003] However, problems such as frozen soil inside the excavation path often occur during the formation of the frozen wall. The reasons for this problem include that the freezing time is too long, resulting in the thickness of the frozen wall entering the inside of the excavation path, and that there is no heat source inside the frozen wall, and the development speed of the frozen wall inside is much faster than the development speed outside; and on the side that has not been excavated, artificial frozen soil continues to freeze, resulting in more frozen soil inside the frozen wall as excavation progresses. Therefore, when the existing freezing construction technology is used for connecting passage construction, there are often difficulties in excavation, increased safety risks, and delays in construction period. Therefore, there is an urgent need for an efficient and safe construction technology to solve the above problems. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to provide a connecting passage excavation technology combined with anti-pulling machinery and artificial freezing, to improve the construction speed and safety of connecting passage construction in water-rich soft soil strata, and to reduce the construction difficulty of connecting passages.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] A connecting passage excavation technology combined with anti-pulling machinery and artificial freezing, comprising the following steps:

[0007] (a) Perform stratum freezing construction until a frozen wall is formed in the proposed excavation area of the connecting passage and the frozen wall is closed; the proposed excavation area is located in the stratum between adjacent first and second side tunnels;

[0008] (b) Divide the excavation contour of the connecting passage on the side tunnel wall of the first side tunnel near the proposed excavation area and on the side tunnel wall of the second side tunnel near the proposed excavation area, respectively;

[0009] (c) Drill a guide hole steel pipe into the proposed excavation area at the center position of the excavation contour in the second side tunnel until the guide hole steel pipe penetrates the proposed excavation area and enters the first side tunnel; the guide hole steel pipe forms a guide hole in the stratum of the proposed excavation area;

[0010] (d) removing the tunnel segments in the first side tunnel within the excavation profile to obtain a back reamer positioning hole; removing the tunnel segments in the second side tunnel within the excavation profile;

[0011] (e) installing a back reamer onto one end of the pilot steel pipe protruding into the first side tunnel, and aligning the back reamer with the back reamer positioning hole, the bit face of the back reamer facing the intended excavation area, the diameter of the back reamer being less than or equal to the diameter of the back reamer positioning hole;

[0012] (f) assembling a back reaming device in the second side tunnel, and connecting the pilot steel pipe with the back reaming device, driving the pilot steel pipe to rotate and the back reamer to cut the intended excavation area by using the back reaming device, and expanding the hole and forming the cross passage; during the back reaming excavation, the support of the cross passage is simultaneously performed.

[0013] The combination of the formation of the frozen wall and the back reaming machine greatly improves the safety and efficiency of the construction of the cross passage. The frozen wall provides stable support to prevent water and sand from gushing, and the back reaming machine operation significantly reduces the manual operation time and labor intensity during construction. In addition, this method effectively avoids the problem of excessive intrusion of the frozen soil wall into the excavation area caused by long-term freezing, ensuring construction efficiency, shortening the freezing period, and reducing costs.

[0014] In step (a) of the above-mentioned back reaming machine combined with artificial freezing cross passage underground excavation process, the inner diameter of the frozen wall after the intersection is smaller than the excavation diameter of the cross passage.

[0015] In step (b) of the above-mentioned back reaming machine combined with artificial freezing cross passage underground excavation process, the diameter of the excavation profile is equal to the excavation diameter of the cross passage.

[0016] In step (c) of the above-mentioned back reaming machine combined with artificial freezing cross passage underground excavation process, when drilling into the pilot steel pipe, the pilot steel pipe is drilled in sections, and the adjacent two sections of the pilot steel pipe are connected by threads. Drilling the pilot steel pipe in sections and connecting by threads facilitates long-distance pilot drilling in the limited space of the tunnel, improves the accuracy and safety of the pilot drilling, and the sectional drilling method reduces the risk of pilot deviation. At the same time, the frozen wall has been intersected during the drilling and pilot drilling, and there is no risk of water and sand gushing during the drilling and pilot drilling, which can also reduce the frost heaving pressure inside the cross passage.

[0017] In step (d) of the above-mentioned back reaming machine combined with artificial freezing cross passage underground excavation process, when removing the tunnel segments, a core hole is drilled along the excavation profile on the tunnel segments, and the hole walls of adjacent core holes are in close contact with each other.

[0018] The core hole center of the above-mentioned reverse pulling mechanical and artificial freezing combined connecting channel tunneling process is located on the profile line of the excavation profile.

[0019] The artificial coring method is used to pull out the tunnel segment of the tunnel to be excavated, which can prevent the cutting head from being damaged when the back drilling machine breaks the frozen soil, shorten the reverse pulling time, and further shorten the project, reduce the cost, and improve the benefit. In addition, since the tunnel segment is usually arc-shaped, and the reverse pulling drill bit is generally disc-shaped; if the tunnel segment inside the excavation profile is not pulled out, the outer edge part of the drill bit disc will first contact and rub with the tunnel segment when drilling, while the center part of the drill bit disc is in a state of not being rubbed, and since the tunnel segment is hard, it takes a long time to drill through, which may cause the reverse pulling drill bit to be in an uneven stress state for a long time, and further cause problems such as drill bit deflection, drilling difficulty and the like. The use of the artificial coring method to pull out the tunnel segment can effectively avoid the occurrence of this problem.

[0020] In step (f), the reverse pulling device includes a counterforce support shoe, a hydraulic cylinder, a rotary motor and a leveling support leg; the counterforce support shoe is supported on the tunnel wall outside the excavation profile, the free end of the hydraulic cylinder is fixedly connected with the counterforce support shoe, and the base of the hydraulic cylinder is fixedly connected with the rotary motor; the rotary motor is drivingly connected with the guide hole steel pipe, and the leveling support leg is supported between the rotary motor and the inner bottom wall of the second side tunnel.

[0021] In step (e), a drill bit support pipe is arranged on the bottom surface of the reverse pulling drill bit opposite to the drill bit face; one end of the drill bit support pipe is connected at the center of the bottom surface of the reverse pulling drill bit, and the other end points to the center of the first side tunnel.

[0022] In step (e), after the installation of the reverse pulling drill bit is completed, a support frame and a rotary holding groove are installed in the first side tunnel, the drill bit support pipe is placed in the rotary holding groove, and the support frame is supported between the rotary holding groove and the inner bottom wall of the first side tunnel.

[0023] In step (f), during the reverse pulling excavation process, drill bit support pipes are added to one end of the drill bit support pipe pointing to the center of the first side tunnel in sections, and the adjacent two sections of the drill bit support pipes are threadedly connected. The drill bit support pipe arranged on the bottom surface of the reverse pulling drill bit makes the stress of the reverse pulling drill bit more stable during the reverse pulling process, avoids the deflection or sliding of the reverse pulling drill bit, and improves the construction precision and efficiency.

[0024] The technical scheme of the present application achieves the following beneficial technical effects:

[0025] 1、The excavation process of the connecting channel provided by the present application adopts a mechanized reverse pulling excavation process, which effectively reduces the time of manual excavation, improves the construction efficiency, shortens the freezing period, and further avoids the problems of excessive intrusion of the frozen wall into the interior of the excavation trail and difficulty in excavating the frozen soil caused by long-term freezing. Under the premise of a decrease in the freezing degree of the frozen soil layer, further, the present application provides a mechanized construction method instead of the traditional manual excavation, which avoids the possible personnel injury caused by the falling of frozen soil blocks and reduces the safety risk in the construction process, thereby realizing the dual protection of the construction period and safety.

[0026] 2、In the method provided in the present application, the tunnel segment of the tunnel to be excavated is pulled out by using the manual coring method, which can prevent the cutting head from being damaged when the reverse drilling machine breaks the frozen soil, while shortening the reverse pulling time, thereby shortening the project, reducing the cost, and improving the benefit. In addition, pulling out the tunnel segment can prevent the initial drilling instability and deflection problem caused by the insufficient contact area between the drill bit face of the disc-shaped reverse pulling drill bit and the arc-shaped tunnel segment, and the use of support pipes and hydraulic cylinders and other equipment comprehensively improves the stability, construction precision and efficiency of the reverse pulling reaming. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The schematic diagram of the proposed excavation area position of the subway connecting channel in the embodiment 1 of the present application;

[0028] Figure 2 The schematic diagram of the position relationship between the frozen wall, the inner boundary of the frozen wall and the excavation contour after the stratum freezing construction in the embodiment 1 of the present application;

[0029] Figure 3 The schematic diagram of the excavation contour on the first side tunnel segment in the embodiment 1 of the present application;

[0030] Figure 4 The schematic diagram of the position where the pilot hole penetrates the first side tunnel segment in the embodiment 1 of the present application;

[0031] Figure 5 The schematic diagram of the extension state of the pilot hole steel pipe between the two tunnels in the embodiment 1 of the present application;

[0032] Figure 6 The schematic diagram of the position distribution of the coring hole when removing the tunnel segment along the excavation contour in the embodiment 1 of the present application.

[0033] Figure 7 The schematic diagram of the assembly of the reverse pulling equipment in the embodiment 1 of the present application;

[0034] Figure 8 The schematic diagram of the position of the hydraulic cylinder, the rotary motor and the reverse force support shoe in the second side tunnel in the embodiment 1 of the present application;

[0035] Figure 9 A schematic diagram of the working state of the reverse-pull equipment during the reverse-pull excavation process in Embodiment 1 of the present invention;

[0036] Figure 10 A schematic diagram showing the arrangement of the drill bit, support frame, and rotating bracket in Embodiment 2 of the present invention;

[0037] Figure 11 A schematic diagram of the working state of the reverse-pull equipment during the reverse-pull excavation process in Embodiment 2 of the present invention.

[0038] The reference numerals in the figure are as follows: 1-Guide pipe; 2-Proposed excavation area; 3-Reverse drill bit; 4-Guide hole; 5-Support frame; 6-Rotating support; 7-Reaction support shoe; 8-Hydraulic cylinder; 9-Rotating motor; 10-Leveling support leg; 11-First side tunnel; 1101-First side tunnel segment; 12-Second side tunnel; 1201-Second side tunnel segment; 13-Support structure; 14-Excavation outline; 15-Frozen wall; 16-Inner boundary of frozen wall; 17-Coring hole; 18-Drill bit support pipe. Detailed Implementation

[0039] Example 1

[0040] like Figure 1 As shown, in this embodiment, a tunneling process combining manual freezing and mechanical back-pull is used to excavate a connecting passage (metro connecting passage) between two adjacent subway tunnels. In this embodiment, the two subway tunnels are located at the same depth in the strata.

[0041] In this embodiment, the two adjacent subway tunnels are a first side tunnel 11 and a second side tunnel 12. The tunnel wall of the first side tunnel 11 is composed of a first side tunnel segment 1101, and the tunnel wall of the second side tunnel is composed of a second side tunnel segment 1201.

[0042] In this embodiment, a tunneling technique combining manual freezing and mechanical back-pull is employed to excavate a connecting passage between the first side tunnel 11 and the second side tunnel 12. The planned excavation area 2 of the connecting passage is located in the stratum between the first side tunnel 11 and the second side tunnel 12. The specific steps are as follows:

[0043] 1. Ground freezing construction: Freezing pipes are laid in the area to be excavated 2, and freezing equipment is started to carry out freezing construction until the freezing wall 15 is completed and a stable frozen soil body is formed.

[0044] like Figure 1 and Figure 2 As shown, Figure 2 In the middle, the inner diameter of the frozen wall 15 after the intersection (i.e., the distance between the inner boundaries 16 of the two frozen walls) is smaller than the excavation rough diameter of the connecting passage (the excavation rough diameter is...).Figure 1 The distance between the two excavation profiles 14). The diagonal negative part in the figure represents the part of the frozen wall invading the excavation wasteland. In this embodiment, by controlling the time of the frozen construction, the inside of the excavation wasteland is not completely invaded by the frozen wall when excavating, which can reduce the difficulty of excavation and improve the efficiency of the connection passage excavation.

[0045] 2. Determine the excavation profile and drill into the guide hole steel pipe: According to the excavation wasteland of the connection passage, determine the excavation profile 14 on the first side tunnel segment 1101 and the second side tunnel segment 1201 respectively. Specifically, one excavation profile 14 should be determined on the side tunnel wall of the first side tunnel 11 near the to-be-excavated area 2 (that is, the first side tunnel segment 1101) and the side tunnel wall of the second side tunnel 12 near the to-be-excavated area 2 (that is, the second side tunnel segment 1201), and the diameter of the excavation profile 14 is equal to the excavation wasteland of the connection passage. Then drill into the guide hole steel pipe 1 from the center of the excavation profile 14 on the second side tunnel segment 1201 to the stratum until the guide hole steel pipe 1 penetrates through the to-be-excavated area 2, and drill out from the center of the excavation profile 14 on the first side tunnel segment 1101, that is, the guide hole steel pipe 1 forms a guide hole 4 in the stratum of the to-be-excavated area 2. When drilling into the guide hole steel pipe 1, it should be drilled into section by section, and the adjacent two sections of the guide hole steel pipe 1 are threadedly connected. When drilling into the guide hole steel pipe 1, the frozen wall has already closed, and there will be no water and sand gushing accidents.

[0046] Figure 3 The excavation profile 14 on the first side tunnel segment 1101 is shown in the middle, Figure 4 The position diagram of the guide hole 4 is shown. Figure 5 The extension state diagram of the guide hole steel pipe 1 between the two tunnels is shown. In this embodiment, the guide hole steel pipe 1 extends in the horizontal direction, and the end heads of the two ends of the guide hole steel pipe 1 are located in the first side tunnel 11 and the second side tunnel 12 respectively.

[0047] 3. Remove the tunnel segment: use the artificial coring method to remove the first side tunnel segment 1101 located in the excavation profile 14 to obtain the reverse pulling drill bit positioning hole. Use the same method to remove the second side tunnel segment 1201 located in the excavation profile 14 to expose the to-be-excavated area 2.

[0048] As Figure 6 shown, when removing the tunnel segment at the excavation profile 14, a circle of coring holes 17 is first punched on the tunnel segment along the excavation profile 14 to cut the tunnel segment inside the excavation profile 14 from the tunnel segment outside the excavation profile 14. The centers of the coring holes 17 are located on the profile line of the excavation profile 14, and the hole walls of adjacent coring holes 17 are in close contact with each other.

[0049] The tunnel segment of the tunnel to be excavated is removed by artificial coring, which can prevent the damage of the drill bit when the back drilling machine breaks the frozen soil, shorten the time of back pulling, and further shorten the construction period, reduce the cost, and improve the benefit. Since the tunnel segment is usually arc-shaped and the back pulling drill bit is generally disc-shaped, if the tunnel segment within the excavation contour is not removed, the outer edge of the drill bit disc will first contact and rub against the tunnel segment when the back pulling drill bit drills, while the central part of the drill bit disc is not subjected to friction. Since the tunnel segment is hard, it takes a long time to drill through, which may cause the back pulling drill bit to be in an uneven force state for a long time, and further cause the drill bit to be deflected and the drilling construction to be difficult. The removal of the tunnel segment by artificial coring can effectively avoid this problem.

[0050] In addition, the diameter of the back pulling drill bit 3 is equal to the diameter of the excavation contour of the connecting passage, and is equal to the diameter of the excavation contour. When the first side tunnel segment 1101 is removed by the above method, the diameter (referring to the maximum diameter) of the back pulling drill bit positioning hole is slightly larger than the diameter of the back pulling drill bit 3, and the edge of the back pulling drill bit positioning hole is wavy, that is, only a small part of the tunnel segment remains at the excavation contour 14 on the first side tunnel segment 1101 (i.e. the actual contact position of the back pulling drill bit 3 and the first side tunnel segment). This reduces the contact area between the edge of the back pulling drill bit positioning hole and the back pulling drill bit 3, and reduces the friction therebetween, which is further beneficial to the stability of the back pulling drill bit 3 during drilling, and is beneficial to the rapid progress of the drilling construction.

[0051] 4. Installing the back pulling drill bit: installing the back pulling drill bit 3 in the first side tunnel 11. The back pulling drill bit 3 is installed at the end of the guide hole steel pipe 1 extending into the first side tunnel 11, and the back pulling drill bit 3 is aligned with the back pulling drill bit positioning hole. The drill bit face of the back pulling drill bit 3 on which the drill bit is installed faces the area to be excavated 2, and the bottom surface opposite to the drill bit face faces the center of the first side tunnel 11.

[0052] 5. Assembling the back pulling equipment: the back pulling equipment includes a rotary motor 9, a hydraulic oil cylinder 8, a back pulling support shoe 7, and a leveling support leg 10. After the back pulling drill bit 3 is installed, the back pulling equipment is assembled in the second side tunnel 12. Specifically, the back pulling support shoe 7 is supported on the tunnel wall outside the excavation contour 14, the free end of the hydraulic oil cylinder 8 is fixedly connected with the back pulling support shoe 7, and the base of the hydraulic oil cylinder 8 is fixedly connected with the rotary motor 9; the rotary motor 9 is drivingly connected with the guide hole steel pipe 1. The leveling support leg 10 is supported between the rotary motor 9 and the inner bottom wall of the second side tunnel 12, so as to ensure that the rotary motor 9 does not shift in the working state, and to keep the rotary motor 9 coaxial with the guide hole steel pipe 1 and the back pulling drill bit 3. As shown in Figure 7 and Figure 8 .

[0053] 6. Reverse Pull Excavation: Driven by the rotary motor 9 and the transmission action of the guide pipe 1, the reverse pull drill bit 3 performs reverse pull excavation along the direction from the first side tunnel 11 to the second side tunnel 12. The reverse pull drill bit 3 rotates and cuts the frozen strata, enlarging the guide hole 4 into a subway connecting passage. Figure 9 As shown, during the reverse excavation process, the hydraulic cylinder 8 applies a force pointing to the left in the diagram to the reaction shoe support, causing the reaction shoe 7 to make close contact with the tunnel inner wall (i.e., the second tunnel segment 1201 surrounding the excavation outline 14), providing stable support. Simultaneously, the hydraulic cylinder 8 also applies a force pointing to the right in the diagram to the rotary motor 9, further causing the rotary motor to pull the reverse drill bit to the right through the guide steel pipe, ensuring the reverse drill bit is in close contact with the ground and improving the excavation effect. The construction of the support structure 13 is carried out simultaneously during the reverse excavation process, ultimately forming the subway connecting passage.

[0054] Example 2

[0055] In this embodiment, a combined manual freezing and reverse-pull mechanical excavation technique is used to excavate a subway connecting passage between two adjacent subway tunnels. The main difference between this embodiment and Embodiment 1 is that in this embodiment, a drill bit support pipe 18 is provided on the bottom surface of the reverse-pull drill bit 3; one end of the drill bit support pipe 18 is connected to the center of the bottom surface of the reverse-pull drill bit 3, and the other end points towards the center of the first side tunnel 11. After the reverse-pull drill bit 3 is installed, a support frame 5 and a rotating bracket 6 are installed into the first side tunnel 11.

[0056] like Figure 10 As shown, when installing the support frame 5 and the rotating tray 6, the drill bit support pipe 18 is placed in the rotating tray 6, and the support frame 5 is supported between the rotating tray 6 and the inner bottom wall of the first side tunnel 11.

[0057] like Figure 11 As shown in this embodiment, during the reverse-pull excavation process, drill bit support pipes 18 are added section by section to the end of the drill bit support pipe 18 pointing towards the center of the first side tunnel 11, with adjacent sections of the drill bit support pipe 18 connected by threads. As the reverse-pull drill bit 3 moves continuously to the right in the figure, the drill bit support pipe 18 extends continuously to the left, always supported by the rotating bracket 6. This helps the reverse-pull drill bit maintain positional stability in both the horizontal and vertical directions, and through the support frame 5, the reverse-pull drill bit can maintain stability in its height position. This design can improve the stability of the reverse-pull drill bit 3 during drilling.

[0058] Obviously, the above embodiments are only examples for clearly illustrating the present application and are not intended to limit the present application. Based on the above description, one of ordinary skill in the art can make other different forms of changes or modifications. Here, it is not necessary or possible to enumerate all the embodiments. The obvious changes or modifications derived from the above should be covered in the protection scope of the present application.

Claims

1. A tunnel excavation process combining mechanical anti-pull and manual freezing, characterized in that, Includes the following steps: (a) Ground freezing construction is carried out until a frozen wall (15) is formed in the proposed excavation area (2) of the connecting passage and the frozen walls (15) are encircled; the proposed excavation area (2) is located in the stratum between the adjacent first side tunnel (11) and the second side tunnel (12); (b) The excavation outline (14) of the connecting passage is delineated on the tunnel wall of the first side tunnel (11) near the proposed excavation area (2) and on the tunnel wall of the second side tunnel (12) near the proposed excavation area (2). (c) Drill a guide pipe (1) into the proposed excavation area (2) at the center of the excavation outline (14) in the second side tunnel (12) until the guide pipe (1) penetrates the proposed excavation area (2) and enters the first side tunnel (11); the guide pipe (1) forms a guide hole (4) in the stratum of the proposed excavation area (2); (d) Cut off the tunnel segment located within the excavation profile (14) in the first side tunnel (11) to obtain the reverse drill bit positioning hole; remove the tunnel segment located within the excavation profile (14) in the second side tunnel (12); (e) Install the reverse pull drill bit (3) onto one end of the guide hole steel pipe (1) that extends into the first side tunnel (11), and align the reverse pull drill bit (3) with the reverse pull drill bit positioning hole, with the cutting edge of the reverse pull drill bit (3) facing the area to be excavated (2), and the diameter of the reverse pull drill bit (3) being less than or equal to the diameter of the reverse pull drill bit positioning hole; (f) Assemble the reverse pull device in the second side tunnel (12) and connect the guide hole steel pipe (1) to the reverse pull device. Use the reverse pull device to drive the guide hole steel pipe (1) to rotate and pull the reverse pull drill bit (3) to cut the area to be excavated (2), expand the hole and form a connecting passage. During the reverse excavation process, the support for the connecting passage is carried out simultaneously; In step (d), when removing the tunnel segment, first drill a ring of core holes (17) along the excavation outline (14) on the tunnel segment, with the walls of adjacent core holes (17) fitting together. In step (e), a drill bit support tube (18) is provided on the bottom surface of the reverse pull drill bit (3) which is opposite to the cutting face of the reverse pull drill bit (3); one end of the drill bit support tube (18) is connected to the center of the bottom surface of the reverse pull drill bit (3), and the other end points to the center of the first side tunnel (11). In step (e), after the reverse pull drill bit (3) is installed, a support frame (5) and a rotating tray (6) are installed in the first side tunnel (11), the drill bit support pipe (18) is placed in the rotating tray (6), and the support frame (5) is supported between the rotating tray (6) and the inner bottom wall of the first side tunnel (11).

2. The underground excavation process for connecting passages combining mechanical anti-pull and manual freezing as described in claim 1, characterized in that, In step (a), the inner diameter of the frozen wall (15) after the loop is smaller than the excavation diameter of the connecting channel.

3. The underground excavation process for connecting passages combining mechanical anti-pull and manual freezing as described in claim 1, characterized in that, In step (b), the diameter of the excavation profile (14) is equal to the excavation rough diameter of the connecting passage.

4. The underground excavation process for connecting passages combining mechanical anti-tensioning and manual freezing as described in claim 3, characterized in that, In step (c), when drilling the guide pipe (1), the guide pipe (1) is drilled section by section, and adjacent sections of the guide pipe (1) are threaded together.

5. The underground excavation process for connecting passages combining mechanical anti-pull and manual freezing as described in claim 1, characterized in that, The center of each core hole (17) is located on the outline of the excavation profile (14).

6. The underground excavation process for connecting passages combining mechanical anti-pull and manual freezing as described in claim 3, characterized in that, In step (f), the counter-pull device includes a counter-force support shoe (7), a hydraulic cylinder (8), a rotary motor (9), and a leveling support leg (10); wherein, the counter-force support shoe (7) is supported on the tunnel wall outside the excavation profile (14), the free end of the hydraulic cylinder (8) is fixedly connected to the counter-force support shoe (7), and the base of the hydraulic cylinder (8) is fixedly connected to the rotary motor (9); the rotary motor (9) is driven to the guide hole steel pipe (1), and the leveling support leg (10) is supported between the rotary motor (9) and the inner bottom wall of the second side tunnel (12).

7. The tunnel excavation process combining mechanical anti-tensioning and manual freezing as described in claim 1, characterized in that, In step (f), during the reverse excavation process, drill bit support pipes (18) are added section by section to the end of the drill bit support pipe (18) pointing towards the center of the first side tunnel (11), and adjacent sections of the drill bit support pipe (18) are threaded together.

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