Annular cutter head, excavation system and excavation method

Abstract

The present invention discloses an annular cutter disc including a cutter holder body and a cutter disc assembly arranged on the cutter holder body; the cutter disc assembly includes an inner cutter disc, an outer cutter disc, a first telescopic member and a second telescopic member; the present invention adopts the form of an inner cutter disc and an outer cutter disc, and the cutter disc can be changed in diameter through the telescopic action of the second telescopic member to achieve graded excavation, and the excavated annular groove can provide space for the pipe segment to enter the rock. The present invention also discloses a tunneling system, and the present invention drives the annular cutter disc to construct underground through a driving body, thereby improving construction efficiency and safety. The present invention also discloses a tunneling method, and the tunneling method of the present invention can be applied to the working conditions when soft soil or soft rock is converted to hard rock formations. The present invention adopts the form of graded excavation, and the outer cutter disc expands the annular groove to the outer diameter of the pipe segment, which is convenient for the pipe segment to sink into the rock to ensure the orderly progress of the construction; concrete and pipe segments are used for sealing and water stopping, creating favorable conditions for subsequent excavation.

Description

Technical Field

[0001] The present invention relates to the field of tunneling, and in particular to an annular cutter head, a tunneling system and a tunneling method. Background Art

[0002] During shaft construction, due to the changeable strata traversed during the vertical excavation process, soft strata on the top and hard strata on the bottom are often encountered. When a sinking shaft boring machine is used for excavation, after entering the medium-weathered rock strata, the rock-breaking efficiency of the pick decreases exponentially as the rock strength increases. At the same time, due to the increased wear of the cutter, the main machine needs to be frequently lifted to replace the cutter, which further reduces the construction efficiency. At the same time, it cannot meet the requirements of the pipe segment entering the rock in the shaft structure design, resulting in a significant reduction in the adaptability of the shaft boring machine. In addition, when the bottom seal encounters a hard rock stratum that exceeds the excavation limit of the equipment or needs to continue to traverse the hard rock stratum, in order to ensure the safety of the well and prevent soil from pouring in from the bottom pipe segment during drainage, causing surface subsidence, the pipe segment needs to be inserted into the rock and embedded.

[0003] In summary, there is an urgent need for an annular cutter head, excavation system and excavation method to solve the problem of how to safely excavate, seal and stop water, and create favorable conditions for the pipe segment to enter the rock when the soft soil or soft rock formation is transformed into the hard rock formation. Summary of the invention

[0004] The purpose of the present invention is to provide an annular cutter head, a tunneling system and a tunneling method to solve the problem of how to safely tunnel, seal and stop water when the soft soil or soft rock formation is transformed into the hard rock formation, and create favorable conditions for the segment to enter the rock. The specific technical solution is as follows:

[0005] A ring-shaped cutter disc comprises a cutter holder body and a cutter disc assembly arranged on the cutter holder body; the cutter disc assembly comprises an inner cutter disc, an outer cutter disc, a first telescopic member and a second telescopic member; both the inner cutter disc and the outer cutter disc are provided with cutting tools for excavation; the two ends of the first telescopic member are respectively connected to the inner cutter disc and the cutter holder body, and the telescopic direction of the first telescopic member is consistent with the excavation direction of the inner cutter disc; the outer cutter disc is movably arranged on the inner cutter disc, and the two ends of the second telescopic member are respectively connected to the outer cutter disc and the inner cutter disc, and the diameter change of the cutter disc is achieved by telescoping the second telescopic member.

[0006] The above technical solution is preferred, wherein the tool holder body comprises a central tube and a tool beam; a plurality of groups of tool beams are fixed on the central tube at equal distances along the circumference of the central tube, and the tool disc assemblies are arranged on the tool beams in a one-to-one correspondence.

[0007] The above technical solution is preferred, wherein a guide cylinder is fixedly provided on the knife beam; the first telescopic member is coaxially arranged in the guide cylinder, and one end of the first telescopic member is hinged to the inner wall of the knife beam or the inner wall of the guide cylinder, and the telescopic end of the first telescopic member is fixedly connected to the inner knife disc.

[0008] Preferably, in the above technical solution, a sealing member is provided between the inner peripheral wall of the guide cylinder and the outer wall of the first telescopic member.

[0009] Preferably, the above technical solution comprises that the cutter disc assembly further comprises a baffle plate arranged on the inner cutter disc, and the baffle plate is used for limiting the position of the outer cutter disc.

[0010] Preferably, the above technical solution comprises the cutter disc assembly further comprising a slurry pump arranged on the inner cutter disc.

[0011] A tunneling system comprises a driving body and the annular cutter disc; the annular cutter disc is arranged on the driving body, and the driving body is used to drive the annular cutter disc to work.

[0012] A tunneling method adopts the tunneling system, and the specific steps are as follows:

[0013] Step S1: The driving body drives the annular cutter disc to rotate;

[0014] Step S2: The first telescopic member of the annular cutter disc drives the inner cutter disc to extend downward, and the inner cutter disc cuts an annular groove on the tunnel face. When the annular groove reaches a specified depth H1, the first telescopic member retracts;

[0015] Step S3: the second telescopic member drives the outer cutter disc to extend, so that the cutting diameter of the annular cutter disc increases; the first telescopic member drives the inner cutter disc and the outer cutter disc to dig downward to a specified depth H2, and after the annular groove is expanded, the second telescopic member drives the outer cutter disc to retract, and the first telescopic member drives the inner cutter disc and the outer cutter disc to retract;

[0016] Step S4: the pipe segment is sunk and inserted into the rock and soil;

[0017] Step S5: pouring concrete in the annular groove to seal and stop water;

[0018] Step S6: Continue excavating the tunnel face until the construction is completed.

[0019] The above technical solution is preferably that in step S6, the drilling and blasting method is used to continue excavating the tunnel face.

[0020] The above technical solution is preferably that in step S6, before excavating the tunnel face, the underground mud is first pumped out of the well.

[0021] The application of the technical solution of the present invention has the following beneficial effects:

[0022] (1) The annular cutter disc of the present invention comprises a cutter holder body and a cutter disc assembly arranged on the cutter holder body; the cutter disc assembly comprises an inner cutter disc, an outer cutter disc, a first telescopic member and a second telescopic member; the first telescopic member of the present invention provides a force for the inner cutter disc and the outer cutter disc to dig downward, and the present invention adopts the form of an inner cutter disc and an outer cutter disc, and the cutter disc can be changed in diameter through the telescopic action of the second telescopic member to achieve graded excavation and reduce the driving power requirement. At the same time, the annular cutter disc of the present invention is particularly suitable for upper soft and lower hard strata and when the groundwater level is high, the excavated annular groove can provide space for the pipe segment to enter the rock, which is convenient for sealing and water stopping, and improves the safety factor of construction. In addition, both the inner cutter disc and the outer cutter disc have the ability to cut annular grooves under hard rock conditions. Compared with full-section excavation, the excavation amount is reduced, which can save excavation construction costs.

[0023] (2) The tool holder body of the present invention includes a central tube and a tool beam; the tool disc assembly of the present invention is arranged in a one-to-one correspondence with the tool beam, and the construction efficiency is improved by arranging multiple sets of tool disc assemblies.

[0024] (3) The guide cylinder of the present invention facilitates guiding the extension and retraction of the first telescopic member to ensure stability during excavation.

[0025] (4) The sealing member of the present invention can ensure that the annular cutter head of the present invention can be constructed underwater, that is, the annular cutter head of the present invention is suitable for water-rich formations and has good practicality.

[0026] (5) The baffle plate and the inner cutter disc of the present invention can play a role of resisting and limiting when the outer cutter disc is excavating downward. It should be noted that in the present invention, the inner cutter disc provides a supporting reaction force for the outer cutter disc on its rotation path, and the baffle plate provides a vertical supporting reaction force when the outer cutter disc is excavating, so as to ensure the stability of the structure. In addition, in the present invention, when the outer cutter disc is excavating, the second telescopic member is not subjected to force, the structure is more stable, and the service life of the second telescopic member can be significantly improved.

[0027] (6) The main function of the slurry pump of the present invention is to pump the slurry from the bottom of the well to the surface of the well, so as to facilitate the orderly excavation work of the annular cutter disc.

[0028] (7) The present invention also discloses a tunneling system, including a driving body and the annular cutter disc; the annular cutter disc is arranged on the driving body. The present invention drives the annular cutter disc to work underground through the driving body, without the need for personnel to go down the well for operation, thereby improving construction efficiency and safety.

[0029] (8) The present invention also discloses a tunneling method, which adopts the tunneling system, and specifically includes steps S1 to S6. The tunneling method of the present invention can be applied to the working conditions when soft soil or soft rock is converted to hard rock strata. The present invention adopts the form of graded excavation to reduce the driving power requirement, that is, firstly, an inner cutter disc is used to cut an annular groove, and an outer cutter disc is used to expand the annular groove. The outer cutter disc expands the annular groove to the outer diameter of the pipe segment, which is convenient for the pipe segment to sink into the rock, so as to avoid the soil layer from pouring in from the bottom pipe segment, causing surface settlement, so as to ensure the orderly progress of the construction; after the annular groove is cut out, concrete and pipe segments are used to seal and stop water, so as to create favorable conditions for subsequent excavation. The favorable conditions here specifically refer to: a. The sudden surge weak points in the boundary range of rock and soft soil are blocked by the embedded pipe segments, thereby reducing the sudden surge risk; b. Concrete is poured into the annular groove to embed the pipe segment with the rock stratum, further ensuring the stability and sealing of the pipe segment; c. After the poured concrete solidifies, it is convenient to remove the mud in the well.

[0030] (9) After sealing and water stopping, the method of the present invention uses the drilling and blasting method to continue excavation, which can effectively construct hard rock geology and avoid the wear of the tool caused by the use of tool excavation construction in hard rock geology.

[0031] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] In the attached picture:

[0034] Figure 1 is a schematic diagram of the driving body in this embodiment using a cutting device for excavation;

[0035] Figure 2 is a schematic diagram of the driving body in this embodiment using an annular cutter disc for excavation (illustrating excavation using a first cutting diameter);

[0036] Figure 3 is a schematic diagram of the driving body in this embodiment using an annular cutter disc for excavation (illustrating excavation using a second cutting diameter);

[0037] Figure 4 is a schematic diagram of the annular groove after the diameter expansion is completed and filled with concrete in this embodiment;

[0038] Figure 5 is a schematic structural diagram of the annular cutter disc in this embodiment;

[0039] Figure 6 yes Figure 5 Schematic diagram of top view;

[0040] Figure 7 yes Figure 5 A schematic diagram of a cutter head assembly in FIG.

[0041] Figure 8 yes Figure 5 Schematic diagram of the outer cutter disc switching cutting diameter (showing the top view);

[0042] Among them, 1. tool holder body; 1.1. center tube; 1.2. tool beam; 1.3. reinforcement beam; 2. cutter disc assembly; 2.1. inner cutter disc; 2.2. outer cutter disc; 2.3. first telescopic member; 2.4. second telescopic member; 2.5. baffle; 3. tool; 4. guide tube; 5. slurry pump; 6. driving body; 7. pipe segment; 8. cutting equipment; 9. concrete; D1. first cutting diameter; D2. second cutting diameter. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0044] Example:

[0045] An annular cutter disc comprises a cutter holder body 1 and a cutter disc assembly 2 arranged on the cutter holder body 1. Figures 5 to 8 As shown, the details are as follows;

[0046] The tool holder body 1 of this embodiment is the bearing structure of the tool disc assembly 2. Figure 5 and Figure 6 As shown, specifically:

[0047] The tool holder body 1 includes a central tube 1.1 and a tool beam 1.2; the upper end surface of the central tube 1.1 is connected to the driving body 6 by high-strength bolts; the number of tool beams 1.2 is arranged in multiple groups, and the multiple groups of tool beams 1.2 in this embodiment are fixed (for example, welded) on the outer peripheral wall of the central tube 1.1 at equal intervals along the circumference of the central tube 1.1; the number of tool beams 1.2 is illustrated in this embodiment as 6 groups, and the tool beams 1.2 are arranged one-to-one with the tool disc assembly 2, that is, the tool disc assembly 2 in this embodiment is also arranged in 6 groups.

[0048] The knife beam 1.2 is a steel plate welded structure, the upper end of the knife beam 1.2 is fixed on the central tube 1.1, and the lower end of the knife beam 1.2 is used to install the knife disc assembly 2.

[0049] Regarding the tool holder body 1, preferably, the tool holder body 1 of this embodiment further includes a reinforcing beam 1.3, and a plurality of groups of reinforcing beams 1.3 are connected between two circumferentially adjacent groups of tool beams 1.2 to ensure the strength of the overall structure, that is, to ensure that the tool beams 1.2 are not deformed.

[0050] The cutter disc assembly 2 comprises an inner cutter disc 2.1, an outer cutter disc 2.2, a first telescopic member 2.3 and a second telescopic member 2.4 (the first telescopic member and the second telescopic member are both telescopic cylinders);

[0051] like Figure 5 As shown, a guide cylinder 4 is fixedly provided inside the lower end of the cutter beam 1.2, a first telescopic member 2.3 is coaxially arranged in the guide cylinder 4, and the upper end of the first telescopic member 2.3 is hinged to the inner wall of the cutter beam 1.2 or the inner wall of the guide cylinder 4, the lower end (telescopic end) of the first telescopic member 2.3 is fixedly connected to the inner cutter disc 2.1, and the telescopic direction of the first telescopic member 2.3 is consistent with the excavation direction. In this embodiment, due to the vertical shaft construction, the telescopic direction of the first telescopic member 2.3 and the excavation direction are both vertical.

[0052] The function of the guide cylinder 4 is to provide guidance when the first telescopic member 2.3 is extended or retracted to ensure the stability of the structure. In this embodiment, a seal (such as a sealing ring, which is not indicated in this embodiment) is provided between the inner circumferential wall of the guide cylinder 4 and the outer circumferential wall of the first telescopic member 2.3, and the seal is located at the opening position at the lower end of the guide cylinder 4.

[0053] The inner cutter disc 2.1 and the outer cutter disc 2.2 are both provided with a plurality of sets of cutters 3, and the specific types and models of the cutters 3 can be selected according to the actual situation. For example, when excavation or cutting is required, the cutters 3 are preferably roller cutters. In case of a soil layer, a set of scrapers can be arranged on the inner cutter disc 2.1 for standby use.

[0054] like Figure 7 and Figure 8 As shown, the outer cutter disc 2.2 is hinged on the side wall of the inner cutter disc 2.1, and the two ends of the second telescopic member 2.4 are respectively hinged to the side wall of the outer cutter disc 2.2 and the side wall of the inner cutter disc 2.1, and the telescopic direction of the second telescopic member 2.4 is perpendicular to the telescopic direction of the first telescopic member 2.3. The second telescopic member 2.4 drives the outer cutter disc 2.2 to rotate to the outside of the inner cutter disc 2.1 (i.e., horizontally away from the center point of the center tube 1.1) or rotates the outer cutter disc 2.2 back to the inside of the inner cutter disc 2.1, thereby realizing the diameter-changing function of the annular cutter disc (i.e., realizing the change of cutting diameter).

[0055] like Figure 7 and Figure 8 As shown, in this embodiment, the cutting diameter of the plurality of inner cutter discs 2.1 during rotation is defined as the first cutting diameter (i.e. Figure 2When the outer cutter disc 2.2 rotates to the outside of the inner cutter disc 2.1, the cutting diameter of the plurality of sets of outer cutter discs 2.2 during rotation is defined as the second cutting diameter (i.e. Figure 3 D2), the second cutting diameter is greater than the first cutting diameter, that is, the cutting diameter of the annular cutter disc becomes larger at this time; and when the outer cutter disc 2.2 is rotated to retract the inner side of the inner cutter disc 2.1, the cutting diameters of the multiple groups of outer cutter discs 2.2 are smaller than the first cutting diameter, that is, by rotating the outer cutter disc 2.2, the annular cutter disc can be converted between the first cutting diameter and the second cutting diameter, that is, the diameter change is achieved. Figure 8 (a) shows that the outer cutter disc 2.2 is not extended. Figure 8 (b) shows the outer cutter disc 2.2 after being extended.

[0056] In this embodiment, the second cutting diameter is equal to the outer diameter of the shaft segment 7, and an annular groove whose outer diameter matches the segment 7 can be cut to facilitate the installation of the segment 7; considering the actual construction situation, the second cutting diameter can also be 2-10 cm larger than the outer diameter of the shaft segment 7.

[0057] like Figure 7 As shown, the cutter disc assembly 2 in this embodiment is preferred, and the cutter disc assembly 2 also includes a baffle 2.5 fixed on the side wall of the inner cutter disc 2.1. In the excavation direction (vertical), the baffle 2.5 is located at the upper end of the outer cutter disc 2.2 (i.e., the side away from the tunnel face). The function of the baffle 2.5 is to limit the outer cutter disc 2.2 when the outer cutter disc 2.2 is excavating downward, that is, the baffle provides a vertical support reaction force for the outer cutter disc 2.2, and the side wall of the inner cutter disc 2.1 provides a support reaction force on the rotation path of the outer cutter disc 2.2, thereby ensuring that the outer cutter disc 2.2 can excavate downward smoothly.

[0058] The cutter disc assembly 2 in this embodiment is preferred, and the cutter disc assembly 2 also includes a slurry pump 5 fixedly arranged on the inner cutter disc 2.1. The number of the slurry pumps 5 is selected according to actual conditions. The slurry pumps 5 are used to transport impurities such as debris generated during construction to outside the well.

[0059] This embodiment also discloses a tunneling system, which includes a driving body 6 and the annular cutter head. Figure 2 and Figure 3 As shown; the driving body 6 is supported in the shaft, the tool holder body 1 of the annular cutter disc (specifically the center tube 1.1) is connected to the driving body 6, and the driving body 6 drives the tool holder body 1 to rotate, that is, the driving body 6 provides the power for rotation and excavation.

[0060] This embodiment also discloses a tunneling method, which uses the tunneling system.

[0061] like Figure 1As shown, before the excavation method of this embodiment is performed, the driving body 6 of the excavation system uses a cutting device 8 to excavate in the soft soil layer. The specific cutting device 8 refers to the prior art;

[0062] When encountering hard rock formation or super-hard rock formation, the cutting device 8 is removed, and the annular cutter head in this embodiment is installed on the driving body 6 of the tunneling system, and then the tunneling system is lowered, and the annular cutter head excavates the annular groove. The specific steps are as follows:

[0063] Step S1: Figure 2 As shown, the driving body 6 reaches the designated working position in the shaft, and the driving body 6 drives the annular cutter disc to rotate, thereby rotating the multiple groups of inner cutter discs 2.1. At this time, the outer cutter disc 2.2 does not extend, that is, the first cutting diameter D1 is used to cut the annular groove;

[0064] Step S2: The first telescopic member 2.3 of the annular cutter disc drives the inner cutter disc 2.1 to extend downward. As the inner cutter disc 2.1 rotates, the inner cutter disc 2.1 cuts an annular groove on the tunnel face. When the annular groove is cut to a specified depth H1, the first telescopic member 2.3 stops extending and retracts, driving the inner cutter disc 2.1 to lift upward.

[0065] Step S3: The annular groove excavated in step S2 is expanded outward to the outside of the installation diameter of the pipe segment 7 by the outer cutter head 2.2, as follows:

[0066] Switching cutting diameter: the second telescopic member 2.4 extends, thereby driving the outer cutter disc 2.2 to rotate to the outside of the inner cutter disc 2.1, and the cutting diameter of the annular cutter disc increases (i.e. switches to the second cutting diameter D2);

[0067] Ring groove expansion: Figure 3 As shown, the first telescopic member 2.3 begins to extend, that is, after the first telescopic member 2.3 drives the inner cutter head 2.1 and the outer cutter head 2.2 to dig downward to a specified depth H2 (H2≤H1), the first telescopic member 2.3 stops extending;

[0068] The inner cutter disc 2.1 and the outer cutter disc 2.2 are retracted: the second telescopic member 2.4 drives the outer cutter disc 2.2 to retract to the inner side of the inner cutter disc 2.1, and the cutting diameter of the annular cutter disc is reduced (i.e., switched to the first cutting diameter D1), and then the first telescopic member 2.3 is retracted, thereby driving the inner cutter disc 2.1 and the outer cutter disc 2.2 to be lifted up;

[0069] In this step S3, due to the downward excavation of the outer cutter head 2.2, the annular groove excavated in step S2 can be expanded outward to meet the diameter requirement for the installation of the pipe segment 7.

[0070] Step S4: the pipe segment is sunk and inserted into the rock and soil, and the tunneling system sinks along with the pipe segment. At this point, one tunneling cycle is completed.

[0071] Then, steps S1 to S4 are repeated to satisfy the transition construction of the tunneling system (specifically the annular cutter head) from the soft soil layer to the hard soil layer, and then the next step is carried out;

[0072] Step S5: Concrete 9 is poured in the annular groove excavated by the above-mentioned multiple excavation cycles to seal and stop water, so as to reduce the risk of water seepage, and then the underground mud is finally pumped out of the well, and the underground equipment (including the excavation system and other equipment) is lifted up and recovered, preparing for the next excavation construction;

[0073] Step S6: After the sealing and water stopping in step S5 is completed, the tunnel face is continued to be excavated, preferably by using the drilling and blasting method (until the excavation of the hard rock formation section is completed). In this embodiment, the tunnel face is continued to be excavated here, including the part of the center of the annular groove where no concrete is poured and the part of the annular groove where concrete is poured. That is to say, the size of the excavation diameter can be selected when continuing to excavate according to the actual design requirements; through steps S1 to S6, the conversion from soft soil layer to hard soil layer can be effectively handled;

[0074] It should be noted that: since the central area of ​​the annular groove is not excavated when the segment sinks, the total distance of the segment sinking multiple times is not greater than the vertical safety distance from the central area of ​​the annular groove to the annular cutter disc (specifically the center tube) to avoid the annular cutter disc colliding with the central area of ​​the annular groove when sinking.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tunneling method, characterized in that: A tunneling system is used, the tunneling system comprising a driving body (6) and an annular cutter disc, the annular cutter disc is arranged on the driving body (6), and the driving body (6) is used to drive the annular cutter disc to work; The annular cutter disc comprises a cutter holder body (1) and a cutter disc assembly (2) arranged on the cutter holder body (1); The cutter disc assembly (2) comprises an inner cutter disc (2.1), an outer cutter disc (2.2), a first telescopic member (2.3) and a second telescopic member (2.4); The inner cutter disc (2.1) and the outer cutter disc (2.2) are both provided with a tool (3) for excavation; the two ends of the first telescopic member (2.3) are respectively connected to the inner cutter disc (2.1) and the tool holder body (1); the telescopic direction of the first telescopic member (2.3) is consistent with the excavation direction of the inner cutter disc (2.1); the outer cutter disc (2.2) is movably arranged on the inner cutter disc (2.1); the two ends of the second telescopic member (2.4) are respectively connected to the outer cutter disc (2.2) and the inner cutter disc (2.1); the diameter of the cutter disc is changed by telescoping the second telescopic member (2.4); The tool holder body (1) comprises a central tube (1.1) and a tool beam (1.2); a plurality of groups of tool beams (1.2) are fixed to the central tube (1.1) at equal intervals along the circumference of the central tube (1.1), and the tool disc assemblies (2) are arranged on the tool beams (1.2) in a one-to-one correspondence; A guide cylinder (4) is fixedly arranged on the knife beam (1.2); a first telescopic member (2.3) is coaxially arranged in the guide cylinder (4), and one end of the first telescopic member (2.3) is hinged to the inner wall of the knife beam (3) or the inner wall of the guide cylinder (4), and the telescopic end of the first telescopic member (2.3) is fixedly connected to the inner knife disc (2.1); Before the excavation method is performed, the driving body (6) of the excavation system uses a cutting device (8) to excavate in a soft soil layer; when encountering a hard rock layer or an ultra-hard rock layer, the cutting device (8) is removed, and an annular cutter head is installed on the driving body (6) of the excavation system, and then the excavation system is lowered, and the annular cutter head excavates the annular groove; The specific steps are as follows: Step S1: The driving body (6) drives the annular cutter disc to rotate; Step S2: the first telescopic member (2.3) of the annular cutter disc drives the inner cutter disc (2.1) to extend downward, and the inner cutter disc (2.1) cuts an annular groove on the tunnel face. When the annular groove reaches a specified depth H1, the first telescopic member (2.3) retracts; Step S3: the second telescopic member (2.4) drives the outer cutter disc (2.2) to extend, so that the cutting diameter of the annular cutter disc increases; the first telescopic member (2.3) drives the inner cutter disc (2.1) and the outer cutter disc (2.2) to dig downward to a specified depth H2, and after the annular groove is expanded, the second telescopic member (2.4) drives the outer cutter disc (2.2) to retract, and the first telescopic member (2.3) drives the inner cutter disc (2.1) and the outer cutter disc (2.2) to retract; Step S4: the pipe segment (7) is sunk and inserted into the rock soil; Step S5: pouring concrete (9) in the annular groove to seal and stop water; Step S6: Continue excavating the tunnel face until the construction is completed.

2. The excavation method according to claim 1, characterized in that: A sealing member is provided between the inner peripheral wall of the guide cylinder (4) and the outer wall of the first telescopic member (2.3).

3. The excavation method according to any one of claims 1 to 2, characterized in that: The cutter disc assembly (2) further comprises a baffle (2.5) arranged on the inner cutter disc, and the baffle (2.5) is used to limit the position of the outer cutter disc (2.2).

4. The excavation method according to any one of claims 1 to 2, characterized in that: The cutter disc assembly (2) also includes a slurry pump (5) arranged on the inner cutter disc (2.1).

5. The excavation method according to claim 1, characterized in that: In step S6, the tunnel face is further excavated by using the drilling and blasting method.

6. The excavation method according to claim 5, characterized in that: In step S6, before excavating the tunnel face, the underground mud is first pumped out of the well.

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