Weak surrounding rock section tunnel double-side-wall pilot tunnel construction method

Abstract

The invention discloses a weak surrounding rock section tunnel double-side-wall pilot tunnel construction method. The method comprises the following steps that S1, a tunnel face is cleaned, and surveying and setting-out are conducted; a tunnel hole of a constructed tunnel is divided into a main hole located in the middle, a left pilot tunnel and a right pilot tunnel, wherein the left pilot tunnel and the right pilot tunnel are symmetrically located on the two sides of the main hole; s2, main tunnel pipe shed advanced grouting or advanced small guide pipe grouting pre-supporting is carried out; s3, the upper half section of the right pilot tunnel is excavated and primarily supported, and the lower half section of the right pilot tunnel is excavated and primarily supported; s4, the upper half section of the left pilot tunnel is excavated and primarily supported, and the lower half section of the left pilot tunnel is excavated and primarily supported; s5, excavation and primary support of an upper pilot tunnel of the main hole, excavation and primary support of a middle pilot tunnel of the main hole, and excavation and primary support of a lower pilot tunnel of the main hole; s6, ring forming of an inverted arch primary support; and S7, removing the primary support of the to-be-lined section, and integrally pouring the secondary lining by using the trolley.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of tunnel construction, in particular to a tunnel double-side-wall pilot tunnel construction method for soft surrounding rock sections. BACKGROUND

[0002] The double-side-wall pilot tunnel method is a tunnel excavation method, also known as a double-side-wall pilot tunnel method or a glasses method, and belongs to a branch of the New Austrian Tunneling Method (NATM) and is based on the basic principles of the NATM. When the double-side-wall pilot tunnel method is used for tunnel excavation, the space on both sides is relatively narrow because the middle part is excavated after the two sides are excavated, and anchor rods need to be driven into the side walls on both sides, which increases the construction difficulty. SUMMARY

[0003] The application aims to provide a tunnel double-side-wall pilot tunnel construction method for soft surrounding rock sections to improve the problem that beam high-altitude construction is relatively troublesome and has high safety hazards.

[0004] The application provides a tunnel double-side-wall pilot tunnel construction method for soft surrounding rock sections, which adopts the following technical scheme: A tunnel double-side-wall pilot tunnel construction method for soft surrounding rock sections comprises the following steps: S1, cleaning and measuring and laying out a working face; a tunnel hole of a tunnel to be constructed is divided into a main hole located at a middle position and left and right side guide holes symmetrically located on both sides of the main hole; S2, main hole pipe shed advanced grouting or advanced small guide pipe grouting pre-supporting; S3, right side guide hole upper half section excavation and initial support, right side guide hole lower half section excavation and initial support; S4, left side guide hole upper half section excavation and initial support, left side guide hole lower half section excavation and initial support; S5, main hole upper guide hole excavation and initial support, main hole middle guide hole excavation and initial support, and main hole lower guide hole excavation and initial support; S6, initial support of an inverted arch is removed, and a trolley is used to integrally pour secondary lining.

[0005] Optionally, in steps S2 and S3, the initial support is composed of a steel mesh, sprayed concrete and anchor rods, and the anchor rods are self-advancing mortar anchor rods.

[0006] Optionally, the self-advancing mortar anchor rod is driven into the side wall through a self-drilling device.

[0007] Optionally, the self-drilling device comprises a vehicle frame and an adjusting mechanism and a drilling mechanism arranged on the vehicle frame, the vehicle frame is used to drive the adjusting mechanism to move along the Y direction, the adjusting mechanism is used to adjust the angle of the drilling mechanism, and the drilling mechanism is used to drive the self-advancing mortar anchor rod into the side wall.

[0008] Through the technical scheme, since the main hole is not constructed when the left and right side drift holes are constructed, the space of the left and right side drift holes is narrow, and the traditional drilling machine cannot be used, so the adjusting mechanism is moved along the Y direction by the frame, the angle of the drilling mechanism is adjusted by the adjusting mechanism, and the self-advancing mortar anchor rod is punched into the side wall by the drilling mechanism, thereby improving the construction efficiency.

[0009] Optionally, the adjusting mechanism comprises a first X linear module, a first Z linear module and a first stepping motor, the first X linear module is fixedly connected to the frame, the first Z linear module is fixedly connected to the movable end of the first X linear module, the first stepping motor is fixedly connected to the movable end of the first Z linear module, and the output end of the first stepping motor is connected with the drilling mechanism.

[0010] Through the technical scheme, the drilling mechanism is moved along the Z direction and the X direction by the first X linear module and the first Z linear module, so as to adjust the drilling position, and the angle of the drilling mechanism is adjusted by the first stepping motor, so as to adjust the drilling angle.

[0011] Further, the drilling mechanism comprises a drilling frame, a drilling assembly arranged on the drilling frame and a bin, the bin is used for storing the self-advancing mortar anchor rod, and the drilling assembly is used for punching the self-advancing mortar anchor rod into the side wall.

[0012] Optionally, the drilling mechanism comprises a second X linear module, a second stepping motor and a tool head, the second X linear module is fixedly connected to the drilling frame, the second stepping motor is connected with the movable end of the second X linear module, the tool head is connected with the output end of the second stepping motor, the self-advancing mortar anchor rod is provided with a grouting hole along the axis thereof, and one end of the self-advancing mortar anchor rod is provided with a square hole in communication with the grouting hole, the square hole is used for inserting the tool head and is matched with the tool head.

[0013] Through the technical scheme, the second stepping motor is moved by the second X linear module to realize feeding, the tool head is rotated by the second stepping motor, and the self-advancing mortar anchor rod is rotated, thereby realizing drilling.

[0014] Optionally, the output end of the second X linear module is connected with an adjusting plate, the second stepping motor slides on the adjusting plate along the X direction, the adjusting plate is fixedly connected with a baffle, and the first compression spring is arranged between the baffle and the second stepping motor.

[0015] Through the technical scheme, the tool head is automatically clamped into the square hole in the process of rotation by the first compression spring exerting pressure on the second stepping motor.

[0016] Optionally, a cone hopper is connected below the bin, a feeding channel is connected below the cone hopper, and a working area is arranged below the feeding channel. A control assembly is arranged on the sidewall of the feeding channel for controlling the self-advancing mortar anchor to fall into the working area.

[0017] Optionally, the control assembly comprises first and second electric cylinders arranged in the vertical direction, the second electric cylinder is arranged below, the movable end of the first electric cylinder is fixedly connected with a first card, the movable end of the second electric cylinder is fixedly connected with a second card, the first and second cards are arranged to be inserted into the feeding channel, and only one self-advancing mortar anchor can be accommodated between the first and second cards.

[0018] Through the above technical scheme, during work, the first card is first inserted into the feeding channel, the anchors are all arranged on the first card, then the second card is inserted into the feeding channel, so that only one anchor is arranged between the first and second cards, then the first card is separated from the feeding channel, the anchor between the first and second cards falls into the working area, then the second card is inserted into the feeding channel again, and the first card is separated from the feeding channel, and the reciprocating operation is performed.

[0019] In summary, the present application has at least one of the following beneficial technical effects: 1. Since the main hole is not constructed when the left and right pilot holes are constructed, the space of the left and right pilot holes is relatively narrow, and the traditional drilling machine is difficult to operate, so the frame drives the adjusting mechanism to move along the Y direction, the adjusting mechanism adjusts the angle of the drilling mechanism, the drilling mechanism drives the self-advancing mortar anchor into the side wall, and the construction efficiency is improved. 2. The first X-direction linear module and the first Z-direction linear module drive the drilling mechanism to move along the Z direction and the X direction to adjust the drilling position, and the first stepping motor adjusts the angle of the drilling mechanism to adjust the drilling angle. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a flowchart of a tunnel double-side-wall-pit construction method in soft surrounding rock section.

[0021] Figure 2 is a schematic view of a self-drilling device.

[0022] Figure 3 is a three-dimensional schematic view of a feeding channel.

[0023] Figure 4 is a schematic view of a first card and a second card.

[0024] Figure 5 is a schematic diagram embodying an anchor rod in the present application.

[0025] Figure 6 is a schematic diagram embodying a screwing device in the present application.

[0026] Figure 7 is a schematic diagram embodying a sliding block in the present application.

[0027] Figure 8 is a schematic diagram embodying a blocking assembly in the present application.

[0028] Figure 9 is a schematic diagram embodying a torque sensor in the present application.

[0029] In the figure, 1, frame; 2, adjusting mechanism; 21, first X-direction linear module; 22, first Z-direction linear module; 23, first stepping motor; 3, drilling mechanism; 31, hopper; 311, conical hopper; 312, feeding channel; 313, first electric cylinder; 314, second electric cylinder; 315, first card; 316, second card; 32, second X-direction linear module; 33, second stepping motor; 34, tool head; 35, adjusting plate; 351, first compression spring; 352, baffle; 4, anchor rod; 41, cover plate; 42, screwing nut; 5, shell; 6, nut bin; 7, cover bin; 71, sleeve rod; 711, sliding groove; 712, sliding block; 713, second compression spring; 72, blocking assembly; 721, blocking block; 722, third compression spring; 723, pull rod; 8, screwing assembly; 81, fifth stepping motor; 82, screw rod; 83, sliding plate; 84, guide rod; 85, fourth stepping motor; 86, limiting sleeve; 87, torque sensor. DETAILED DESCRIPTION

[0030] The present application will now be further described in greater detail in connection with the enclosed drawings. These drawings form a part of this specification and are included to further describe and demonstrate the present application and, like the specification, illustrate embodiments in which the present application can be made and used. Those of ordinary skill in the art will appreciate that the images in these figures are simplified representations of the typical and preferred embodiments of the application, and are made merely to preserve clarity of these figures. Thus, the present application is fully applicable to the practice of the application in all of its embodiments, and represents the typical and preferred embodiments of the application.

[0031] In the description of the present application, it is to be understood by those skilled in the art that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] Embodiment one A tunnel double-side wall guide hole construction method for soft surrounding rock section, referring to Figure 1 , comprising the following steps: S1, cleaning and measuring the working face; The tunnel hole of the constructed tunnel is divided into a main hole located in the middle position, and a left guide hole and a right guide hole symmetrically located on both sides of the main hole; S2, main hole pipe shed advanced grouting or advanced small guide pipe grouting pre-supporting; S3, right side guide hole upper half section excavation and primary support, right side guide hole lower half section excavation and primary support; S4, left side guide hole upper half section excavation and primary support, left side guide hole lower half section excavation and primary support; S5, main hole upper guide hole excavation and primary support, main hole middle guide hole excavation and primary support, main hole lower guide hole excavation and primary support; S6, initial support of inverted arch to form a ring; S7, removing the primary support of the to-be-lining section, and pouring the secondary lining as a whole by using a trolley.

[0033] In steps S2 and S3, the primary support is composed of a steel mesh, a sprayed concrete and an anchor rod 4. The anchor rod 4 is a self-advancing mortar anchor rod 4. The self-advancing mortar anchor rod 4 is punched into the side wall through a self-drilling device. One end of the self-advancing mortar anchor rod 4 is connected with a drill bit.

[0034] Specifically, referring to Figures 2 to 4 , the self-drilling device comprises a frame 1, an adjusting mechanism 2 and a drilling mechanism 3 arranged on the frame 1, the frame 1 is used to drive the adjusting mechanism 2 to move along the Y direction, the adjusting mechanism 2 is used to adjust the angle of the drilling mechanism 3, and the drilling mechanism 3 is used to drill the self-advancing mortar anchor rod 4 into the side wall. Since the main hole is not constructed when the left and right pilot holes are constructed, the space of the left and right pilot holes is relatively narrow, and the traditional drilling machine is difficult to use, so the frame 1 drives the adjusting mechanism 2 to move along the Y direction, the adjusting mechanism 2 adjusts the angle of the drilling mechanism 3, and the drilling mechanism 3 drills the self-advancing mortar anchor rod 4 into the side wall, thereby improving the construction efficiency. The frame 1 is provided with moving wheels below.

[0035] The adjusting mechanism 2 comprises a first X-direction linear module 21, a first Z-direction linear module 22 and a first stepping motor 23, the first X-direction linear module is fixedly connected to the frame 1, the first Z-direction linear module 22 is fixedly connected to the movable end of the first X-direction linear module 21, the first stepping motor 23 is fixedly connected to the movable end of the first Z-direction linear module 22, and the output end of the first stepping motor 23 is connected with the drilling mechanism 3. The drilling mechanism 3 is driven by the first X-direction linear module 21 and the first Z-direction linear module 22 to move along the Z direction and the X direction, so as to adjust the drilling position, and the angle of the drilling mechanism 3 is adjusted by the first stepping motor 23, so as to adjust the drilling angle.

[0036] The drilling mechanism 3 comprises a drilling frame, a drilling assembly arranged on the drilling frame and a bin 31, the bin 31 is used to store the self-advancing mortar anchor rod 4, and the drilling assembly is used to drill the self-advancing mortar anchor rod 4 into the side wall.

[0037] More specifically, the drilling mechanism 3 comprises a second X-direction linear module 32, a second stepping motor 33 and a tool head 34, the second X-direction linear module 32 is fixedly connected to the drilling frame, the second stepping motor 33 is connected to the movable end of the second X-direction linear module 32, and the tool head 34 is connected to the output end of the second stepping motor 33. A grouting hole is arranged on the self-advancing mortar anchor rod 4 along the axis thereof, a square hole is arranged at one end of the self-advancing mortar anchor rod 4 and communicates with the grouting hole, the square hole is used for inserting the tool head 34 and is adapted to the tool head 34. The second X-direction linear module 32 drives the second stepping motor 33 to move to realize feeding, the second stepping motor 33 drives the tool head 34 to rotate, thereby driving the self-advancing mortar anchor rod 4 to rotate, and drilling is realized.

[0038] It needs to be explained that the output end of the second X-direction linear module 32 is connected with an adjusting plate 35, the second stepper motor 33 slides on the adjusting plate 35 along the X-direction, the adjusting plate 35 is fixedly connected with a baffle 352, and the first compression spring 351 is arranged between the baffle 352 and the second stepper motor 33. The first compression spring 351 exerts pressure on the second stepper motor 33, so that the tool head 34 is automatically clamped into the square hole during rotation.

[0039] In addition, the cone hopper 311 is connected below the material bin 31, the feeding channel 312 is connected below the cone hopper 311, and the working area is arranged below the feeding channel 312. When the self-advancing mortar anchor rod 4 falls into the working area, the self-advancing mortar anchor rod 4 is coaxial with the second stepper motor 33. The control assembly for controlling the self-advancing mortar anchor rod 4 to fall into the working area is arranged on the sidewall of the feeding channel 312.

[0040] The control assembly comprises the first electric cylinder 313 and the second electric cylinder 314 arranged in the vertical direction, the second electric cylinder 314 is located below, the movable end of the first electric cylinder 313 is fixedly connected with the first clamping piece 315, the movable end of the second electric cylinder 314 is fixedly connected with the second clamping piece 316, the first clamping piece 315 and the second clamping piece 316 are used for being inserted into the feeding channel 312, and only one self-advancing mortar anchor rod 4 can be accommodated between the first clamping piece 315 and the second clamping piece 316. The second clamping piece 316 can simultaneously limit the self-advancing mortar anchor rod 4 in the working area and prevent the self-advancing mortar anchor rod 4 from shaking.

[0041] During work, the first clamping piece 315 is first inserted into the feeding channel 312, the anchor rods 4 all fall on the first clamping piece 315, then the second clamping piece 316 is inserted into the feeding channel 312, so that only one anchor rod 4 is between the first clamping piece 315 and the second clamping piece 316, then the first clamping piece 315 is separated from the feeding channel 312, the anchor rod 4 between the first clamping piece 315 and the second clamping piece 316 falls into the working area, then the second clamping piece 316 is inserted into the feeding channel 312 again, and the first clamping piece 315 is separated from the feeding channel 312, and the reciprocating operation is performed.

[0042] Referring to Figures 5 to 9 After the anchor rod 4 is driven into the side wall, the cover plate 41 needs to be sleeved on the anchor rod 4, and then the anchor rod 4 is locked on the side wall through the locking nut, so the locking nut is screwed on the anchor rod 4 through the screwing device.

[0043] The screwing device comprises the shell 5, the nut warehouse 6, the cover warehouse 7 and the screwing assembly 8 arranged in the shell 5, the nut warehouse 6 is used for storing the screwing nut 42, the cover warehouse 7 is used for storing the cover plate 41, and the screwing assembly 8 is used for screwing the screwing nut 42 on the anchor rod 4. The handle and the shoulder strap can be mounted on the shell 5, so as to be carried by the operator.

[0044] The cover bin 7 is fixedly connected with a sleeve rod 71, the sleeve rod 71 is used for sleeving the cover plate 41, and the cover bin 7 is provided with a blocking assembly 72 at an outlet. A sliding groove 711 is formed in the side wall of the sleeve rod 71 in the axial direction of the sleeve rod 71, a sliding block 712 is slidably connected in the sliding groove 711, and a second compression spring 713 is arranged in the sleeve rod 71, one end of the second compression spring 713 abuts against the sliding block 712, and the other end of the second compression spring 713 abuts against one end of the sleeve rod 71 away from the blocking assembly 72.

[0045] The blocking assembly 72 comprises a blocking block 721, a third compression spring 722 and a pull rod 723, the side wall of the cover bin 7 is provided with a blocking groove, the blocking block 721 slides in the blocking groove, the third compression spring 722 is arranged in the blocking groove, the pull rod 723 is fixedly connected to the blocking block 721, one end of the pull rod 723 away from the blocking block 721 extends out of the cover bin 7, and the blocking block 721 is used for blocking the cover plate 41 from being separated from the cover bin 7, and the blocking block 721 can be pulled back into the blocking groove through the pull rod 723, so that the cover plate 41 can be put in or taken out.

[0046] The nut bin 6 has the same structure as the cover bin 7, and thus will not be described again.

[0047] The screwing assembly 8 comprises a moving piece and a fourth stepper motor 85, the fourth stepper motor 85 is connected to the moving end of the moving piece, the output end of the fourth stepper motor 85 is fixedly connected with a limiting sleeve 86, the limiting sleeve 86 is provided with a limiting groove for placing the screw nut 42 and the cover plate 41, the output end of the fourth stepper motor 85 is connected with a torque sensor 87, and the torque sensor 87 is electrically connected with the fourth stepper motor 85.

[0048] The moving piece comprises a fifth stepper motor 81, a lead screw 82 and a guide rod 84, the fifth stepper motor 81 is fixedly installed in the shell 5, the output end of the fifth stepper motor 81 is fixedly connected with the lead screw 82, the lead screw 82 is threadedly connected with a sliding plate 83, the sliding plate 83 is fixedly connected with the fourth stepper motor 85, the guide rod 84 is fixedly connected with the shell 5, the guide rod 84 passes through the sliding plate 83, and the fifth stepper motor 81 is electrically connected with the torque sensor 87.

[0049] In work, the operator takes the cover plate 41 and the screw nut 42 from the cover bin 7 and the nut bin 6, then places the screw nut 42 and the cover plate 41 in the limiting groove, then moves the shell 5, so that the cover plate 41 is sleeved on the anchor rod 4, and the shell 5 abuts against the wall body, then the fourth stepper motor 85 and the fifth stepper motor 81 are started, the screw nut 42 is screwed on the anchor rod 4, after being screwed, the torque sensor 87 is triggered, the fourth stepper motor 85 and the fifth stepper motor 81 stop working, and the fifth stepper motor 81 is reset.

[0050] The examples of this specific embodiment are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, any equivalent changes made based on the structure, shape, and principle of this application should be included in the scope of protection of this application.

Claims

1. A method for constructing a double-side wall pilot tunnel in a soft surrounding rock area, characterized in that: The steps include: S1. Clean the tunnel face and measure and lay out the lines; Dividing the tunnel of the tunnel under construction into a main tunnel located in the middle, and a left pilot tunnel and a right pilot tunnel symmetrically located on both sides of the main tunnel; S2. Pre-grouting of main tunnel pipe shed or pre-grouting of small pipes; S3: Excavation and initial support of the upper half section of the right pilot tunnel, excavation and initial support of the lower half section of the right pilot tunnel; S4, excavation and initial support of the upper half section of the left pilot tunnel, excavation and initial support of the lower half section of the left pilot tunnel; S5. Excavation and initial support of the pilot pit in the upper part of the main tunnel, excavation and initial support of the pilot pit in the middle part of the main tunnel, and excavation and initial support of the pilot pit in the lower part of the main tunnel; S6, the initial support of the inverted arch forms a ring; S7. Remove the initial support of the section to be lined and use a trolley to cast the secondary lining as a whole.

2. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 1, characterized in that: In steps S2 and S3, the initial support is composed of hanging steel mesh, sprayed concrete and anchor rods (4), and the anchor rods (4) are self-propelled mortar anchor rods (4).

3. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 2, characterized in that: The self-propelled mortar anchor rod (4) is driven into the side wall by a self-drilling device.

4. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 3, characterized in that: The self-drilling device comprises a vehicle frame (1), an adjusting mechanism (2) and a drilling mechanism (3) arranged on the vehicle frame (1); the vehicle frame (1) is used to drive the adjusting mechanism (2) to move along the Y direction; the adjusting mechanism (2) is used to adjust the angle of the drilling mechanism (3); and the drilling mechanism (3) is used to drive a self-propelled mortar anchor rod (4) into a side wall.

5. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 4, characterized in that: The adjustment mechanism (2) comprises a first X-direction linear module (21), a first Z-direction linear module (22) and a first stepper motor (23); the first X-direction linear module is fixedly connected to the vehicle frame (1); the first Z-direction linear module (22) is fixedly connected to the movable end of the first X-direction linear module (21); the first stepper motor (23) is fixedly connected to the movable end of the first Z-direction linear module (22); and the output end of the first stepper motor (23) is connected to the drilling mechanism (3).

6. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 5, characterized in that: The drilling mechanism (3) comprises a drilling frame, a drilling assembly arranged on the drilling frame, and a silo (31). The silo (31) is used to store self-propelled mortar anchor rods (4). The drilling assembly is used to drive the self-propelled mortar anchor rods (4) into the side wall.

7. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 6, characterized in that: The drilling mechanism (3) comprises a second X-direction linear module (32), a second stepping motor (33) and a tool head (34); the second X-direction linear module (32) is fixedly connected to the drilling frame; the second stepping motor (33) is connected to the movable end of the second X-direction linear module (32); the tool head (34) is connected to the output end of the second stepping motor (33); a grouting hole is provided on the self-propelled mortar anchor rod (4) along its own axis; one end of the self-propelled mortar anchor rod (4) is provided with a square hole connected to the grouting hole; the square hole is used for inserting the tool head (34) and is adapted to the tool head (34).

8. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 7, characterized in that: The output end of the second X-direction linear module (32) is connected to an adjustment plate (35); the second stepping motor (33) slides on the adjustment plate (35) along the X-direction; a baffle (352) is fixedly connected to the adjustment plate (35); and a first compression spring (351) is provided between the baffle (352) and the second stepping motor (33).

9. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 8, characterized in that: A cone bucket (311) is connected below the hopper (311), a feed channel (312) is connected below the cone bucket (311), a working area is provided below the feed channel (312), and when the self-propelled mortar anchor rod (4) falls into the working area, the self-propelled mortar anchor rod (4) is coaxial with the second stepping motor (33); A control assembly for controlling the self-propelled mortar anchor rod (4) to fall into the working area is provided on the side wall of the feed channel (312).

10. The method for constructing a double-sidewall pilot tunnel in a soft rock area according to claim 8, characterized in that: The control component comprises a first electric cylinder (313) and a second electric cylinder (314) arranged in a vertical direction, wherein the second electric cylinder (314) is located at the bottom, the movable end of the first electric cylinder (313) is fixedly connected to a first card (315), and the movable end of the second electric cylinder (314) is fixedly connected to a second card (316), the first card (315) and the second card (316) are both used to be inserted into the feed channel (312), and only one self-propelled mortar anchor rod (4) can be accommodated between the first card (315) and the second card (316).

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