Counter-pull mechanical and artificial freezing combined contact channel underground excavation process

Abstract

The invention discloses a connecting channel underground excavation process combining counter-pulling machinery and artificial freezing, which comprises the following steps of: carrying out stratum freezing construction until freezing walls are formed in a to-be-excavated area of a connecting channel and the freezing walls are intersected into a circle; the to-be-excavated area is located in a stratum between the first side tunnel and the second side tunnel which are adjacent to each other; and excavation contours of the connection channel are divided on the tunnel wall of the side, close to the to-be-excavated area, of the first side tunnel and the tunnel wall of the side, close to the to-be-excavated area, of the second side tunnel correspondingly. Through the combination of manual freezing and counter-pulling machinery, the construction safety and efficiency are remarkably improved, and the construction cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of underground engineering construction, and more specifically to a dark excavation process for a communication channel combining a reverse pulling machine with artificial freezing. Background Art

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

[0003] However, during the formation of the frozen wall, problems such as freezing inside the excavated wasteland often occur. The reasons for this problem include the freezing time being too long, resulting in the thickness of the frozen wall entering the excavated wasteland more, and the absence of a heat source inside the frozen wall, so that the frozen wall develops inward much faster than the external development speed; and on the unexcavated side, the artificial frozen soil continues to freeze, resulting in more frozen soil inside the frozen wall as it is excavated. Therefore, when the existing freezing construction technology is used for the construction of communication channels, there are often problems such as excavation difficulties, increased safety risks, and construction delays. Therefore, an efficient and safe construction technology is urgently needed to solve the above problems. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to provide a connecting channel dark excavation process combining a reverse pulling machine with artificial freezing, so as to improve the construction speed and safety during the construction of the connecting channel in the water-rich soft soil layer and reduce the construction difficulty of the connecting channel.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A communication channel dark excavation process combining a reverse pulling machine with artificial freezing comprises the following steps:

[0007] (a) performing ground freezing construction until a frozen wall is formed in the planned excavation area of ​​the communication channel and the frozen wall is interlocked; the planned excavation area is located in the ground between the adjacent first side tunnel and the second side tunnel;

[0008] (b) dividing the excavation outline of the communication channel on a tunnel wall of the first side tunnel close to the planned excavation area and on a tunnel wall of the second side tunnel close to the planned excavation area respectively;

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

[0010] (d) removing the tunnel segments in the first side tunnel located within the excavation contour to obtain the reverse pull drill bit positioning holes; and removing the tunnel segments in the second side tunnel located within the excavation contour;

[0011] (e) installing a reverse pull drill bit on one end of the guide hole steel pipe extending into the first side tunnel, and aligning the reverse pull drill bit with the reverse pull drill bit positioning hole, with the cutter head of the reverse pull drill bit facing the area to be excavated, and the diameter of the reverse pull drill bit being less than or equal to the diameter of the reverse pull drill bit positioning hole;

[0012] (f) Assemble the back-pull device in the second side tunnel, and connect the guide hole steel pipe to the back-pull device, use the back-pull device to drive the guide hole steel pipe to rotate and pull the back-pull drill bit to cut the area to be excavated, expand the hole and form a connecting channel; during the back-pull excavation process, support the connecting channel simultaneously.

[0013] The combination of frozen wall formation and back-pulling machinery has greatly improved the safety and efficiency of the connection channel construction. The frozen wall provides stable support to prevent water and sand gushing problems, while the back-pulling mechanized operation significantly reduces manual operation time and reduces labor intensity during construction. In addition, this method effectively avoids the problem of excessive intrusion of frozen soil walls into the excavation area caused by long-term freezing, ensuring construction efficiency, shortening the freezing period, and reducing costs.

[0014] In the above-mentioned dark excavation process of the connecting channel combining the reverse pulling machine with artificial freezing, in step (a), the inner diameter of the frozen wall after the circle is smaller than the rough excavation diameter of the connecting channel.

[0015] In the above-mentioned dark excavation process of the connecting channel combining the reverse pulling machine and artificial freezing, in step (b), the diameter of the excavation profile is equal to the excavation rough diameter of the connecting channel.

[0016] In the above-mentioned dark excavation process for the communication channel combining the reverse pulling machine with artificial freezing, in step (c), when drilling the guide hole steel pipe, the guide hole steel pipe is drilled section by section, and two adjacent sections of the guide hole steel pipe are threadedly connected. The guide hole steel pipe is drilled section by section and connected by threads, which is convenient for long-distance guide hole drilling in the limited space of the tunnel, improves the accuracy and safety of guide hole construction, and the segmented drilling method reduces the risk of guide hole deviation. At the same time, the frozen wall has been circled when drilling the guide hole, and there is no risk of water and sand gushing when drilling the guide hole. At the same time, it can also reduce the frost heave pressure inside the communication channel.

[0017] In the above-mentioned connecting channel dark excavation process combining the reverse pulling machine with artificial freezing, in step (d), when removing the tunnel segment, a circle of core holes is first made on the tunnel segment along the excavation contour, and the walls of adjacent core holes are fitted together.

[0018] In the above-mentioned dark excavation process of the communication channel combining the reverse pulling machine with artificial freezing, the centers of the core holes are all located on the contour line of the excavation contour.

[0019] The use of manual coring to remove the tunnel segments that need to be excavated can prevent the cutter head from being damaged when the raise drill breaks the frozen soil, and shorten the reverse pulling time, thereby shortening the project, reducing costs, and improving efficiency. In addition, since the tunnel segments are usually arc-shaped, and the reverse pull drill bits are generally disc-shaped; if the tunnel segments within the excavation contour are not removed, when the reverse pull drill bit is drilling, the outer edge of the drill bit disc will first contact and rub against the tunnel segments, while the center of the drill bit disc is in a state of no friction. In addition, since the tunnel segments are hard, it takes a long time to drill through, which may cause the reverse pull drill bit to be in an uneven force state for a long time, and further cause problems such as drill bit deflection and drilling construction difficulties. The use of manual coring to remove the tunnel segments can effectively avoid this problem.

[0020] In the above-mentioned connecting channel dark excavation process combining the reverse pulling machinery with artificial freezing, in step (f), the reverse pulling equipment includes a reaction shoe, a hydraulic cylinder, a rotating motor and a leveling leg; wherein the reaction shoe is supported on the tunnel wall outside the excavation contour, the free end of the hydraulic cylinder is fixedly connected to the reaction shoe, and the base of the hydraulic cylinder is fixedly connected to the rotating motor; the rotating motor is drivingly connected to the guide hole steel pipe, and the leveling leg is supported between the rotating motor and the inner bottom wall of the second side tunnel.

[0021] In the above-mentioned connecting channel dark excavation process combining the reverse pull mechanism with artificial freezing, in step (e), a drill bit support tube is arranged on the bottom surface of the reverse pull drill bit opposite to the cutting head surface of the reverse pull drill bit; one end of the drill bit support tube is connected to the center of the bottom surface of the reverse pull drill bit, and the other end points to the center of the first side tunnel.

[0022] In the above-mentioned connecting channel dark excavation process combining the reverse pulling machine with artificial freezing, in step (e), after the reverse pulling drill bit is installed, a support frame and a rotating bracket are installed in the first side tunnel, the drill bit support tube is placed in the rotating bracket, and the support frame is supported between the rotating bracket and the inner bottom wall of the first side tunnel.

[0023] In the above-mentioned dark excavation process of the communication channel combining the reverse pull mechanism with artificial freezing, in step (f), during the reverse pull excavation process, drill bit support tubes are added section by section to the end of the drill bit support tube pointing to the center of the first side tunnel, and two adjacent sections of the drill bit support tubes are threadedly connected. The drill bit support tube is arranged on the bottom surface of the reverse pull drill bit, so that the force on the reverse pull drill bit during the reverse pull process is more stable, avoiding the reverse pull drill bit from deflecting or sliding, and improving the construction accuracy and efficiency.

[0024] The technical solution of the present invention achieves the following beneficial technical effects:

[0025] 1. The underground excavation process for the communication channel provided by the present invention adopts a mechanized reverse-pull excavation process, which effectively reduces the time of manual excavation, improves construction efficiency, shortens the freezing period, and further avoids the problem of excessive intrusion of the frozen wall into the excavated wasteland and difficulty in excavating frozen soil caused by long-term freezing; on the premise that the freezing degree of the frozen soil layer decreases, further, the mechanized construction method provided by the present invention replaces the traditional manual excavation, avoids personal injury caused by the falling of frozen soil blocks, reduces the safety risks in the construction process, and thus achieves dual protection of construction period and safety.

[0026] 2. In the method provided in the present invention, the tunnel segments to be excavated are pulled out by artificial coring, which can prevent the cutter head from being damaged when the reverse drilling machine breaks the frozen soil, and shorten the reverse pulling time, thereby shortening the project, reducing costs, and improving benefits. In addition, pulling out the tunnel segments can prevent the initial drilling instability and deflection caused by the insufficient contact area between the drill bit face of the disc-shaped reverse pulling drill bit and the arc-shaped tunnel segments. In addition, the use of equipment such as support pipes and hydraulic cylinders comprehensively improves the stability, construction accuracy and efficiency of reverse pulling and expanding holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the location of the proposed excavation area of ​​the subway communication channel in Example 1 of the present invention;

[0028] Figure 2 Schematic diagram of the positional relationship between the frozen wall, the inner boundary of the frozen wall and the excavation outline after ground freezing construction in Example 1 of the present invention;

[0029] Figure 3 A schematic diagram of the excavation profile on the first side tunnel segment in Example 1 of the present invention;

[0030] Figure 4 A schematic diagram of the position of the pilot hole penetrating the first side tunnel segment in Example 1 of the present invention;

[0031] Figure 5 A schematic diagram of the guide hole steel pipe extending between two tunnels in Example 1 of the present invention;

[0032] Figure 6 Schematic diagram of the position distribution of core holes when removing tunnel segments along the excavation contour in Example 1 of the present invention.

[0033] Figure 7 Schematic diagram of the assembly of the reverse pulling device in Example 1 of the present invention;

[0034] Figure 8 Schematic diagram of the positions of the hydraulic cylinder, the rotary motor and the reaction force support shoe in the second side tunnel in Example 1 of the present invention;

[0035] Fig. 9 A schematic diagram of the working state of the back-pull device during the back-pull excavation process in Example 1 of the present invention;

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

[0037] Fig.11 A schematic diagram of the working state of the reverse pulling device during the reverse pulling excavation process in Example 2 of the present invention.

[0038] The reference numerals in the figure are represented as follows: 1-guide hole steel pipe; 2-intended excavation area; 3-reverse pull drill bit; 4-guide hole; 5-support frame; 6-rotating bracket; 7-reaction support shoe; 8-hydraulic cylinder; 9-rotating motor; 10-leveling leg; 11-first side tunnel; 1101-first side tunnel segment; 12-second side tunnel; 1201-second side tunnel segment; 13-support structure; 14-excavation contour; 15-frozen wall; 16-inner boundary of frozen wall; 17-coring hole; 18-drill bit support pipe. DETAILED DESCRIPTION

[0039] Example 1

[0040] like Figure 1 As shown, in this embodiment, a dark excavation process combining artificial freezing and reverse pulling machinery is adopted to carry out dark excavation of a communication channel (subway communication channel) between two adjacent subway tunnels. In this embodiment, the two subway tunnels are located at the same depth in the stratum.

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

[0042] In this embodiment, a dark excavation process combining artificial freezing and reverse pulling machinery is used to dark excavate a communication channel between the first side tunnel 11 and the second side tunnel 12. The proposed excavation area 2 of the communication channel 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: Arrange freezing pipes in the planned excavation area 2, start the freezing equipment to carry out freezing construction until the freezing wall 15 is connected and a stable frozen soil body is formed.

[0044] like Figure 1 and Figure 2 As shown, Figure 2 In the embodiment, the inner diameter of the frozen wall 15 after the circle (i.e., the distance between the inner boundaries 16 of the two frozen walls) is smaller than the excavation diameter of the connecting channel (i.e., the excavation diameter is Figure 1 The negative part of the oblique line in the figure represents the part where the frozen wall invades the excavated waste path. In this embodiment, by controlling the freezing construction time, the inside of the excavated waste path is not completely invaded by the frozen wall during excavation, which can reduce the difficulty of excavation and improve the excavation efficiency of the communication channel.

[0045] 2. Determine the excavation profile and drill into the pilot hole steel pipe: According to the rough excavation diameter of the communication channel, determine the excavation profile 14 on the first side tunnel segment 1101 and the second side tunnel segment 1201 respectively. Specifically, an excavation profile 14 should be determined on the tunnel wall of the first side tunnel 11 close to the planned excavation area 2 (that is, the first side tunnel segment 1101) and on the tunnel wall of the second side tunnel 12 close to the planned excavation area 2 (that is, the second side tunnel segment 1201), and the diameter of the excavation profile 14 is equal to the rough excavation diameter of the communication channel. Then, drill into the pilot hole steel pipe 1 from the center of the excavation profile 14 on the second side tunnel segment 1201 into the stratum until the pilot hole steel pipe 1 passes through the planned excavation area 2 and is drilled out from the center of the excavation profile 14 on the first side tunnel segment 1101, and the pilot hole steel pipe 1 forms a pilot hole 4 in the stratum of the planned excavation area 2. When drilling into the pilot hole steel pipe 1, it should be drilled section by section, and the two adjacent sections of the pilot hole steel pipe 1 are threadedly connected. When drilling into the pilot hole steel pipe 1, the frozen wall has been circled, 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 FIG. Figure 4 Schematic diagram of the position of the guide hole 4. Figure 5 It is a schematic diagram of the extension state of the guide hole steel pipe 1 between the two tunnels. In this embodiment, the guide hole steel pipe 1 extends in the horizontal direction, and the ends of the guide hole steel pipe 1 are respectively located in the first side tunnel 11 and the second side tunnel 12.

[0047] 3. Removing tunnel segments: Using manual coring, remove the first side tunnel segment 1101 located within the excavation profile 14 to obtain the reverse pull drill bit positioning hole. Using the same method, remove the second side tunnel segment 1201 located within the excavation profile 14 to expose the planned excavation area 2.

[0048] like Figure 6 As shown, when removing the tunnel segment at the excavation profile 14, a circle of core holes 17 are first made 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 core holes 17 are all located on the contour line of the excavation profile 14, and the walls of adjacent core holes 17 fit each other.

[0049] The use of manual coring to remove the tunnel segments that need to be excavated can prevent the cutter head from being damaged when the raise drill breaks the frozen soil, and shorten the reverse pulling time, thereby shortening the construction period, reducing costs, and improving efficiency. Since the tunnel segments are usually arc-shaped, and the reverse pull drill bits are generally disc-shaped; if the tunnel segments within the excavation contour are not removed, when the reverse pull drill bit is drilling, the outer edge of the drill bit disc will first contact and rub against the tunnel segments, while the center of the drill bit disc is in a state of no friction. In addition, since the tunnel segments are hard, it takes a long time to drill through, which may cause the reverse pull drill bit to be in an uneven force state for a long time, and further cause problems such as drill bit deflection and drilling construction difficulties. The use of manual coring to remove the tunnel segments can effectively avoid this problem.

[0050] In addition, the diameter of the back-pull drill bit 3 is equal to the rough diameter to be excavated of the communication channel, and is equal to the diameter of the excavation profile. When the first side tunnel segment 1101 is removed by the above method, the diameter (referring to the maximum diameter) of the obtained back-pull drill bit positioning hole is slightly larger than the diameter of the back-pull drill bit 3, and the edge of the back-pull drill bit positioning hole is wavy, that is, only a very small part of the tunnel segment remains at the excavation profile 14 on the first side tunnel segment 1101 (that is, the actual contact position between the back-pull drill bit 3 and the first side tunnel segment). This reduces the contact area between the edge of the back-pull drill bit positioning hole and the back-pull drill bit 3, reduces the friction between the two, and further helps the back-pull drill bit 3 to remain stable during the drilling process, and is conducive to the rapid progress of the drilling construction.

[0051] 4. Install the reverse pull drill bit: Install the reverse pull drill bit 3 in the first side tunnel 11. Install the reverse pull drill bit 3 at one end of the pilot hole steel pipe 1 extending into the first side tunnel 11, and align the reverse pull drill bit 3 with the reverse pull drill bit positioning hole. The cutter head surface of the reverse pull drill bit 3 with the cutter head facing the area to be excavated 2, and the bottom surface opposite to the cutter head surface facing the center of the first side tunnel 11.

[0052] 5. Assemble the reverse pulling device: The reverse pulling device includes a rotating motor 9, a hydraulic cylinder 8, a reaction shoe 7 and a leveling leg 10. After the reverse pulling drill bit 3 is installed, assemble the reverse pulling device in the second side tunnel 12. Specifically, the reaction 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 reaction shoe 7, the base of the hydraulic cylinder 8 is fixedly connected to the rotating motor 9; the rotating motor 9 is drivingly connected to the guide hole steel pipe 1. The leveling leg 10 is supported between the rotating motor 9 and the inner bottom wall of the second side tunnel 12 to ensure that the rotating motor 9 does not shift in the working state and to keep the rotating motor 9 coaxial with the guide hole steel pipe 1 and the reverse pulling drill bit 3. Figure 7 and Figure 8 shown.

[0053] 6. Reverse excavation: Under the driving action of the rotating motor 9 and the transmission action of the guide hole steel pipe 1, the reverse drill bit 3 performs reverse excavation along the direction from the first side tunnel 11 to the second side tunnel 12. The reverse drill bit 3 rotates to cut the frozen stratum and expand the guide hole 4 into a subway communication channel. Fig. 9 As shown, during the back-pull excavation process, the hydraulic cylinder 8 applies a force pointing to the left side of the figure to the back-pull shoe support, so that the back-pull shoe 7 is in close contact with the inner wall of the tunnel (i.e., the second side tunnel segment 1201 outside the excavation profile 14) to provide stable support; at the same time, the hydraulic cylinder 8 also applies a force pointing to the right side of the figure to the rotating motor 9, which further causes the rotating motor to tighten the back-pull drill bit to the right through the guide hole steel pipe, so that the back-pull drill bit is in close contact with the stratum, improving the excavation effect. During the back-pull excavation process, the construction of the support structure 13 is carried out simultaneously, and finally a subway communication channel is formed.

[0054] Example 2

[0055] In this embodiment, a dark excavation process combining artificial freezing and reverse pull machinery is adopted to conduct dark excavation of a subway communication channel between two adjacent subway tunnels. The main difference between this embodiment and embodiment 1 is that in this embodiment, a drill support tube 18 is provided on the bottom surface of the reverse pull drill bit 3; one end of the drill 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. After the reverse pull drill bit 3 is installed, the support frame 5 and the rotating bracket 6 are installed in the first side tunnel 11.

[0056] like Fig.10 As shown, when the support frame 5 and the rotating bracket 6 are installed, the drill support tube 18 is placed in the rotating bracket 6 to support the support frame 5 between the rotating bracket 6 and the inner bottom wall of the first side tunnel 11 .

[0057] like Fig.11 As shown, in this embodiment, during the reverse excavation process, drill bit support tubes 18 are added section by section to the end of the drill bit support tube 18 pointing to the center of the first side tunnel 11, and two adjacent sections of the drill bit support tubes 18 are threadedly connected. As the reverse pull drill bit 3 continues to move toward the right side in the figure, the drill bit support tube 18 continues to extend toward the left side and is always supported by the rotating bracket 6, which is conducive to the reverse pull drill bit to maintain a stable position in the horizontal and vertical directions, and through the support of the support frame 5, the reverse pull drill bit can maintain a stable height position. Such a design can improve the stability of the reverse pull drill bit 3 during drilling.

[0058] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A dark excavation process for a communication channel combining a reverse pulling machine with artificial freezing, characterized in that: The following steps are involved: (a) performing ground freezing construction until a frozen wall (15) is formed in the planned excavation area (2) of the communication channel and the frozen wall (15) is intertwined; the planned excavation area (2) is located in the ground between the adjacent first side tunnel (11) and the second side tunnel (12); (b) dividing the excavation outline (14) of the communication channel on the tunnel wall of the first side tunnel (11) close to the planned excavation area (2) and on the tunnel wall of the second side tunnel (12) close to the planned excavation area (2); (c) drilling a pilot hole steel pipe (1) into the proposed excavation area (2) at the center position of the excavation profile (14) in the second side tunnel (12), until the pilot hole steel pipe (1) passes through the proposed excavation area (2) and enters the first side tunnel (11); the pilot hole steel pipe (1) forms a pilot hole (4) in the stratum of the proposed excavation area (2); (d) removing the tunnel segments in the first side tunnel (11) that are located within the excavation profile (14) to obtain a reverse pull drill bit positioning hole; and removing the tunnel segments in the second side tunnel (12) that are located within the excavation profile (14); (e) installing a reverse pull drill bit (3) on one end of the guide hole steel pipe (1) extending into the first side tunnel (11), and aligning the reverse pull drill bit (3) with the reverse pull drill bit positioning hole, with the blade surface 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) assembling a back-pull device in the second side tunnel (12), connecting the guide hole steel pipe (1) to the back-pull device, and using the back-pull device to drive the guide hole steel pipe (1) to rotate and pull the back-pull drill bit (3) to cut the area to be excavated (2), expand the hole and form a communication channel; During the reverse excavation process, the communication channel is supported simultaneously.

2. The dark excavation process for the communication channel combining the reverse pulling machine and artificial freezing according to claim 1 is characterized in that: In step (a), the inner diameter of the frozen wall (15) after the circle is formed is smaller than the rough excavation diameter of the communication channel.

3. The dark excavation process for the communication channel combining the reverse pulling machine and artificial freezing according to claim 1 is characterized in that: In step (b), the diameter of the excavation profile (14) is equal to the excavation rough diameter of the communication channel.

4. The dark excavation process for the communication channel combining the reverse pulling machine and artificial freezing according to claim 3 is characterized in that: In step (c), when drilling into the guide hole steel pipe (1), the guide hole steel pipe (1) is drilled section by section, and two adjacent sections of the guide hole steel pipe (1) are threadedly connected.

5. The dark excavation process for the communication channel combining the reverse pulling machine and artificial freezing according to claim 4 is characterized in that: In step (d), when removing the tunnel segment, a circle of core holes (17) is firstly made on the tunnel segment along the excavation contour (14), and the walls of adjacent core holes (17) are fitted together.

6. The dark excavation process for the communication channel combining the reverse pulling machine and artificial freezing according to claim 5 is characterized in that: The centers of the core holes (17) are all located on the contour line of the excavation contour (14).

7. The dark excavation process for the communication channel combining the reverse pulling machine and artificial freezing according to claim 3 is characterized in that: In step (f), the counter-pulling device includes a reaction shoe (7), a hydraulic cylinder (8), a rotating motor (9) and a leveling leg (10); wherein the reaction 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 reaction shoe (7), and the base of the hydraulic cylinder (8) is fixedly connected to the rotating motor (9); the rotating motor (9) is drivingly connected to the guide hole steel pipe (1), and the leveling leg (10) is supported between the rotating motor (9) and the inner bottom wall of the second side tunnel (12).

8. The dark excavation process for connecting channels combining a reverse pulling machine with artificial freezing according to claim 1 is characterized in that: In step (e), a drill bit support tube (18) is provided on the bottom surface of the reverse pull drill bit (3) opposite to the cutting head surface 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).

9. The dark excavation process for connecting channels combining a reverse pulling machine with artificial freezing according to claim 8 is characterized in that: In step (e), after the reverse pull drill bit (3) is installed, a support frame (5) and a rotating bracket (6) are installed in the first side tunnel (11), the drill bit support tube (18) is placed in the rotating bracket (6), and the support frame (5) is supported between the rotating bracket (6) and the inner bottom wall of the first side tunnel (11).

10. The dark excavation process for connecting channels combining a reverse pulling machine with artificial freezing according to claim 9 is characterized in that: In step (f), during the reverse excavation process, drill bit support tubes (18) are added section by section to the end of the drill bit support tube (18) pointing to the center of the first side tunnel (11), and two adjacent sections of the drill bit support tube (18) are threadedly connected.

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