A tunnel construction method

Abstract

The application relates to a tunnel construction method and relates to the technical field of tunnel construction, and the construction method is as follows: S1, soil quality analysis and investigation are completed in the early construction stage, soil excavation is carried out after the construction preparation is completed, initial support is well prepared, and then large pipe shed support is carried out; S2, small guide pipe construction is carried out after the large pipe shed support is completed; S3, horse head door construction is carried out, and then the middle hole excavation construction is carried out after the horse head door construction is completed; S4, the CRD method is used for construction, and the initial support is set in the excavated tunnel simultaneously during the construction; S41, during the CRD construction, the two sides of the middle hole are respectively divided into four guide holes for excavation, the excavation step distance of adjacent guide holes is 10-15 m, small guide pipe construction needs to be carried out on the top of the guide hole before excavation, and temporary support is made on the excavated part after excavation; S5, construction monitoring needs to be carried out during the CRD construction, and settlement control is carried out in time according to the monitoring result. The application has the effect of improving the construction efficiency and improving the construction safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a tunnel construction method. BACKGROUND

[0002] In the city, especially in the center of a megacity, the population and traffic are dense. In order to solve the traffic problem, a street tunnel often appears. The building density is large, and the surrounding environment is complex. The original infrastructure often cannot meet the needs of the existing development, so it is necessary to develop underground space.

[0003] In the construction process of subway, highway, railway, pipe gallery and the like, the section form is complex and changeable, and the existing street tunnel needs to control the stability of the soil body and the safety of the existing structure in the stratum during the construction process. The appearance of the excavation unloading effect increases with the sensitivity of the surrounding environment. When the deformation of the soil body is too large, not only does the construction process become uncontrollable, but also the deformation is transmitted to the surrounding buildings, affecting their safety and normal use. In order to limit the adverse environmental effects caused by urban tunnel construction, generally, when excavating a tunnel, a support plate and a support structure are used to support and reinforce the excavated tunnel after a certain distance is excavated.

[0004] With reference to the related art in the foregoing, when constructing a street tunnel, sufficient support force is needed to support the excavated tunnel. When the support structure is set and the excavated tunnel is reinforced, the waiting time for the concrete to solidify is relatively long, and the construction cannot continue during the waiting period, resulting in a long construction time, low construction efficiency and potential safety hazards. SUMMARY

[0005] In order to improve the construction efficiency and improve the construction safety, the present application provides a tunnel construction method.

[0006] The tunnel construction method provided by the present application adopts the following technical scheme:

[0007] A tunnel construction method, the construction method is as follows: S1, soil quality analysis and investigation are done in the early construction period, soil excavation is performed after the construction preparation is completed, and initial support is done, then large pipe shed support is performed;

[0008] S2, after the large pipe shed support is completed, small guide pipe construction is performed, the small guide pipe is arranged on the top of the large pipe shed to support the top of the large pipe shed;

[0009] S3, horse head door construction is performed, and after the horse head door construction is completed, middle hole excavation construction is performed;

[0010] S31, after the middle hole is excavated, initial support is added in the excavated tunnel in time, and the working face is closed;

[0011] S32, when the middle hole is excavated, a vertical slope and a longitudinal staggered bench construction method is used;

[0012] S4, the CRD method is used for construction, and initial support is set in the excavated tunnel during construction;

[0013] S41, when the CRD method is used for construction, the two sides of the middle hole are divided into four pilot holes for excavation, the adjacent pilot holes are excavated at a step distance of 10-15m, and small guide pipe construction is required at the top of the pilot hole before excavation, and temporary support is provided in the excavated part after excavation;

[0014] S5, construction monitoring is required when the CRD method is used for construction, and settlement control is performed in real time according to the monitoring results.

[0015] By using the above technical solution, the middle hole is excavated after multiple support, then the two sides of the middle hole are divided into four pilot holes for excavation, temporary support is provided during excavation, and the tunnel is excavated in sequence and monitored in real time, which reduces the solidification time of the concrete during waiting for support, improves the construction efficiency and improves the construction safety.

[0016] Optionally, during initial support, a first layer of steel mesh is first hung on the inner wall of the tunnel, and grating reinforcement is used for reinforcement, a second layer of steel mesh is hung after reinforcement, and the grating reinforcement is supported by a lock foot anchor pipe, and finally the concrete is sprayed and waits for the concrete to solidify, and the initial support is completed.

[0017] By using the above technical solution, by setting the initial support, the self-stability of the surrounding rock after excavating the tunnel is improved, and the safety during construction is improved.

[0018] Optionally, a receiving assembly is provided in step S2, the receiving assembly comprising a receiving plate, the receiving plate being detachably connected below the small guide pipe, and the peripheral side wall of the small guide pipe being capable of abutting against the side of the receiving plate close to the small guide pipe.

[0019] By using the above technical solution, when the small guide pipe is installed, the receiving plate is first fixed on the tunnel section, and the upper surface of the receiving plate and the position where the small guide pipe is installed are both tangentially arranged, so that the upper surface of the receiving plate can receive the small guide pipe when the small guide pipe is installed, and the small guide pipe can be easily driven into the small guide pipe drilling hole.

[0020] Optionally, the side of the receiving plate close to the small guide pipe is detachably connected with a positioning plate, a plurality of positioning grooves are formed in the positioning plate, and the positioning grooves correspond to the positions of the small guide pipe.

[0021] By using the above technical solution, the positioning grooves on the positioning plate can facilitate the receiving and guiding of the small guide pipe, and the positioning plate can be detached, so that the positioning plate can be replaced according to the different number of small guide pipes set in the specific construction, improving the applicability of the receiving plate.

[0022] Optionally, a slide rail is arranged below the receiving plate, and a cutting assembly is mounted on the slide rail, the cutting assembly being used for cutting the temporary support in the tunnel, the cutting assembly comprising a cutting member and a driving member, the driving member being detachably connected to the slide rail and being capable of sliding along the slide rail, a sliding direction of the driving member being parallel to a large section of the tunnel, the cutting member being connected to the driving member, and the driving member being used for driving the cutting member to translate along a depth direction of the tunnel, and the cutting member being used for cutting the temporary support in the tunnel.

[0023] By using the above technical scheme, when the temporary support is cut, the cutting assembly is slid to one side of the temporary support, the driving member is started, the driving member drives the cutting member to enter the deep part of the tunnel, and the temporary support is cut, so that the temporary support is conveniently removed, and the construction efficiency is improved.

[0024] Optionally, the slide rail is provided with a connecting block, the connecting block being capable of sliding along the slide rail, a sliding direction of the connecting block being parallel to the large section of the tunnel, the connecting block being provided with a fixing bolt, the driving member comprising a screw rod, a guide rod and a rotating motor, axes of the screw rod and the guide rod being parallel to an axis of the tunnel, one end of the screw rod close to the connecting block being provided with a first mounting plate, the first mounting plate being rotatably connected to the connecting plate, the first mounting plate being provided with a locking member, the locking member being used for fixing the first mounting plate, one end of the screw rod away from the first mounting plate being provided with a second mounting plate, the second mounting plate being detachably connected to an inner wall of the tunnel, the screw rod being rotatably connected to the first mounting plate and the second mounting plate, both ends of the guide rod being connected to the first mounting plate and the second mounting plate, and the rotating motor being connected to the screw rod, the rotating motor being used for driving the screw rod to rotate.

[0025] By using the above technical scheme, the fixing of the connecting block by the fixing bolt is released, the connecting block is moved, the fixing bolt is tightened to fix the connecting block, the same steps are used to adjust the angle of the first mounting plate by using the locking member, the cutting section of the cutting member is close to the side wall of the tunnel, when the temporary support is cut, the rotating motor is started, the rotating motor drives the screw rod to rotate, the screw rod drives the cutting member to move along the axis of the guide rod, and the temporary support is cut, so that the temporary support is conveniently removed, and the construction efficiency is improved.

[0026] Optionally, the cutting member comprises a driving motor and a cutting knife, the screw rod and the guide rod are provided with a mounting block, the driving motor is hinged to the mounting block, the mounting block is provided with a locking bolt, the locking bolt being used for fixing the driving motor, a hinging axis of the driving motor being parallel to the axis of the screw rod, the cutting knife being connected to the driving motor, and the driving motor being used for driving the cutting knife to rotate.

[0027] By using the above technical scheme, the driving motor is hinged to the mounting block, the fixing of the driving motor by the locking bolt is released, the angle between the driving motor and the mounting block is adjusted, then the locking bolt is tightened to fix the driving motor, and thus the cutting angle between the cutting knife and the temporary support is adjusted, so that the temporary support is conveniently cut.

[0028] Optionally, the cutting knife is detachably connected with the driving motor, and the driving motor is further provided with a grinding head for grinding the residual temporary support after cutting.

[0029] By adopting the above technical scheme, the residual temporary support such as concrete on the inner wall of the tunnel after cutting the temporary support can be ground and removed by the grinding head, so that the residual temporary support on the inner wall of the tunnel is conveniently cleaned.

[0030] To sum up, the present application has at least one of the following beneficial technical effects:

[0031] 1. By adopting the middle hole and CRD method, the principle of the middle hole of the double-arch tunnel being first is followed, the vertical excavation method of the outer side holes of the two main holes being sequentially excavated is implemented, the tunnel can be excavated in sections, the construction efficiency is improved, the supporting means such as advanced grouting small guide pipes, net hanging and steel frame sprayed concrete are supplemented, the middle hole and CRD method have small disturbance to the surrounding rock of the tunnel during tunneling, and the construction safety is improved.

[0032] 2. By setting the receiving assembly and the cutting assembly on the receiving assembly, the receiving assembly receives the small guide pipe during tunnel construction, the small guide pipe construction is facilitated, after the small guide pipe construction is completed, the cutting assembly can slide along the receiving assembly to cut and remove the temporary support during tunnel construction, the convenience of tunnel construction is improved, and the construction efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a tunnel construction schematic diagram of an embodiment of the present application.

[0034] Figure 2 is a structure schematic diagram of a receiving assembly of an embodiment of the present application.

[0035] Figure 3 is Figure 2 is an enlarged view of the middle A part.

[0036] Figure 4 is a perspective sectional view of the receiving assembly of an embodiment of the present application.

[0037] Figure 5 is a structure schematic diagram of another view of the receiving assembly of an embodiment of the present application.

[0038] Explanation of reference signs: 1, small conduit; 2, middle hole; 3, receiving assembly; 31, receiving plate; 32, positioning plate; 321, positioning groove; 33, sliding rail; 34, connecting block; 341, sliding groove; 35, fixing bolt; 4, cutting assembly; 41, cutting piece; 411, driving motor; 412, cutting knife; 42, driving piece; 421, screw rod; 422, guide rod; 423, rotating motor; 43, first mounting plate; 44, locking piece; 45, second mounting plate; 5, mounting block; 51, locking bolt; 6, polishing head. DETAILED DESCRIPTION

[0039] The following will be described in detail below with reference to the accompanying drawings. Figures 1-5 The application is further described in detail.

[0040] The embodiment of the application discloses a tunnel construction method.

[0041] Reference Figure 1 A tunnel construction method, the construction method is as follows:

[0042] S1, soil analysis and investigation are done before construction, soil excavation is performed after construction preparation is completed, and initial support is done, and then large pipe shed support is performed;

[0043] S2, small conduit 1 construction is performed after the large pipe shed support is completed, the small conduit 1 is arranged on the top of the large pipe shed, and the top of the large pipe shed is supported; when the large pipe shed is supported, a spiral drilling machine HTG-200 is used, a Φ110mm drill bit is used for drilling, so that the jacking of the pipe shed is facilitated, the drilling machine is moved to a drilling position, the height of the drilling machine is adjusted, the drill rod is placed in the guide pipe, the guide pipe, the rotating shaft of the drilling machine and the drill rod are arranged on the same straight line, the direction of the drill bit and the drill rod is controlled to be consistent by using a total station instrument, the inclination angle is controlled to be within the range of 1-3°, when drilling, wet drilling is used, the guide pipes are numbered on the well wall of the cross passage, and the construction is performed according to the number, the principle is that drilling, pipe jacking and grouting are performed in the order of from high to low, from the middle to the two sides, and from odd to even; the hole skipping method is used, odd holes are constructed first, and even holes are constructed then. After the height of the drilling machine, the inclination angle and the external insertion angle of the drill rod are adjusted, the drilling machine is slowly started, drilling is performed by about half the length of the drill rod (1.5-2m), then drilling is performed at a normal speed, and at the same time, the inclination of the down-the-hole drilling machine track is checked by using a level and a caliper in combination, and the hole depth, the hole diameter and the hole direction angle are inspected after drilling.

[0044] When the pipe roof is made, the steel frame is bent by a bending machine according to the curvature of the tunnel section, and then the trial assembly is carried out in the processing site. The steel frame is assembled with accurate size and smooth arc. The steel pipes are numbered and matched in advance according to the design, and the artificial pipe feeding is adopted. When the resistance increases and the manpower cannot be fed, the jack or other methods are used to push in. The pipe roof is installed by using the drilling machine and jacking, and is connected section by section. In order to avoid the overlapping of the steel pipes at the same position, the first pipe at the front end of the large pipe roof can be made into two lengths to ensure that the steel pipe joint position is staggered, and the number of joints in the same section is not more than 50%. When the pipe roof is placed in the tunnel, the one-time full-hole grouting method of sectional grouting is adopted, that is, the grouting hole and the exhaust hole are reserved at the grouting plug, the exhaust hole is on the top, and the grouting hole is on the bottom. After the grout is discharged from the exhaust hole, the exhaust hole is closed, and the grouting is continued. When the final pressure reaches 0.5 MPa, the grouting is stopped.

[0045] When the small pipe 1 is constructed, the position of the small pipe 1 is released according to the design requirements. The small pipe 1 is installed after being drilled by a high-pressure air drill. It must be punched into the soil from the web of the steel grid, and the outer 20 cm supports the steel frame behind the excavation surface. The steel pipe is welded firmly with the arch frame to form a pre-supporting system together with the steel frame. The tail end of the small pipe 1 is welded with a Φ8 steel hoop to reduce the possibility of cracking at the tail end of the small pipe 1 during jacking construction. The steel pipe is drilled by a punch or plasma cutting to open the overflow hole, with a diameter of 6mm-8mm, a longitudinal distance of 15cm, and a ring distance of 90°, arranged in a plum blossom type. The small pipe 1 is jacked by using a wind drill and a wind pick, with the tail end exposed 5cm from the concrete spraying surface. The small pipe 1 is punched through the outside of the steel frame and the upper row of main reinforcement, and is connected by point welding between the steel frame main reinforcement to improve the grouting quality. The grouting slurry of the small pipe 1 uses cement slurry, and the cement strength used for preparing the slurry is not less than 32.5MPa. The cement slurry mix ratio is determined through field test according to the geological conditions of the project, and the water-cement ratio is preferably 0.8:1-1:1. The grouting pressure is determined through field test according to the geological conditions, surrounding buildings, pipelines and construction requirements, and the grouting pressure is preferably 0.5-0.8MPa. The grouting amount is calculated according to different geological conditions.

[0046] S3, the horse head door construction is carried out, and the horse head door construction is completed before the excavation construction of the middle hole 2 is carried out; when the middle hole 2 is excavated, mechanical excavation is adopted in cooperation with manual excavation, manual cleaning is adopted at the position of the grid steel frame, the upper earthwork is transported out to the vertical shaft spoil pit through the upper passage, and the lower earthwork is transported to the vertical shaft spoil pit from the horizontal passage through the inverted arch. When excavating, the middle hole 2 adopts the construction method of vertical slope and longitudinal staggered steps according to the principle of "small sub-block, short step, early ring, ring-in-ring"; after the construction of the middle hole 2 is completed, the two side holes are simultaneously excavated from top to bottom to form a ring by using the positive step method, without longitudinal staggering. The upper half section of the middle hole 2 is preferably excavated in a ring, and the core soil is preferably retained as much as possible; when the lower half section is excavated, the side wall is preferably excavated by single-sided or double-sided crossing, the inverted arch should be excavated as soon as possible to shorten the whole-section closure time.

[0047] S31, after the middle hole 2 is excavated, initial support should be added in the excavated tunnel in time and the working face is closed;

[0048] S32, when the middle hole 2 is excavated, the construction method of vertical slope and longitudinal staggered steps is adopted;

[0049] S4, the CRD method is used for construction, and initial support is set in the excavated tunnel during construction; the specific construction steps of the CRD method are as follows: after the large pipe shed construction is completed, the A1 part of the small advance pipe 1 is made; the A1 part of the soil is excavated, and the initial support and the temporary support are made. The lower part of the A1 part of the soil is excavated, and the initial support and the temporary support are made.

[0050] After the A1 part construction is completed, the A2 part of the small advance pipe 1 is made to grout the stratum; the upper part of the soil is excavated, and the initial support and the temporary support are made. The lower half of the A2 part of the soil is excavated, and the initial support and the temporary support are made.

[0051] The A3 part of the small advance pipe 1 is made to grout the stratum; the upper and lower parts are excavated in steps, and the initial support and the temporary support are made. The A3 part of the small advance pipe 1 is made to grout the stratum; the upper, middle and lower parts are excavated in steps, and the initial support and the temporary support are made.

[0052] The A4 part of the small advance pipe 1 is made to grout the stratum; the upper, middle and lower parts are excavated in steps, and the initial support and the temporary support are made. At the same time, the lower part of the temporary support is removed, the surface is treated, the waterproof layer is laid, the remaining support is firmly welded with the I-beam, the temporary support is restored, and finally the bottom plate, the bottom plate backfill layer and part of the side wall secondary lining are made. The A4 part of the small advance pipe 1 is made to grout the stratum; the upper and middle parts are excavated in steps, and the initial support and the temporary support are made. At the same time, the length of the temporary inverted arch end part is broken, the side wall arch secondary lining is made; the temporary support is erected. The A4 part of the small advance pipe 1 is made to grout the stratum; the lower part is excavated in steps, and the initial support and the temporary support are made. At the same time, the middle temporary support is removed, and the top secondary lining is made.

[0053] The lower part of the temporary support is removed, the leveling treatment is performed, the waterproof layer is laid, the I-beams are firmly welded with the remaining support, the temporary support is restored, and finally the bottom plate, bottom plate backfilling and partial secondary lining of the side wall are performed. The middle temporary support is removed, the top secondary lining is performed, and the temporary support is removed in stages.

[0054] S41, during the CRD construction, the two sides of the middle hole 2 are respectively divided into four guide holes for excavation, the excavation step distance of adjacent guide holes is 10-15 m, the excavation of each guide hole is one grid spacing at a time, and before excavation, small guide pipes 1 need to be constructed at the top of the guide hole, and temporary support is made after excavation in the excavated part;

[0055] S5, during the CRD construction, construction monitoring needs to be performed, and settlement control is performed in real time according to the monitoring results.

[0056] Among them, after the tunnel is excavated, it is necessary to support it to make it enter a stable state when the surrounding rock is insufficient in self-stability. During the initial support, a first layer of steel mesh needs to be hung on the inner wall of the tunnel first, and grid reinforcement is used for reinforcement. After reinforcement, a second layer of steel mesh is hung, and the grid reinforcement is supported by the lock foot anchor pipe. Finally, the concrete is sprayed and waits for the concrete to solidify, and the initial support is completed.

[0057] The middle hole 2 is excavated, the mine method is used for construction, then the CRD method is used to excavate the three guide holes outside the two main holes in turn, then the middle partition wall construction is completed, then the three guide holes inside the left line main hole close to the middle wall are excavated, and finally the three guide holes inside the right line main hole close to the middle wall are excavated in turn. During the excavation process, the initial support, temporary support and the like are erected in time, so as to improve the construction efficiency and improve the construction safety.

[0058] Referring to Figure 2 and Figure 3 In step S2, a receiving assembly 3 is provided, which includes a receiving plate 31 fixedly installed below the small guide pipe 1 by bolts, and the peripheral side wall of the small guide pipe 1 can abut against one side of the receiving plate 31 close to the small guide pipe 1. The side of the receiving plate 31 close to the small guide pipe 1 is detachably connected with a positioning plate 32, a plurality of positioning grooves 321 are formed in the positioning plate 32, and the positioning grooves 321 correspond to the positions of the small guide pipe 1. The detachable connection mode of the positioning plate 32 and the receiving plate 31 can be a bolted connection mode or a clamped fixed connection mode. In the embodiment, the detachable connection mode of the positioning plate 32 and the receiving plate 31 is a clamping block and clamping groove. The positioning grooves 321 on the positioning plate 32 are arc grooves that fit the peripheral side wall of the guide pipe.

[0059] Referring to Figure 2 and Figure 3The supporting plate 31 is welded with a slide rail 33 below, the cutting assembly 4 is installed on the slide rail 33, the cutting assembly 4 is used for cutting the temporary support in the tunnel, the cutting assembly 4 comprises a cutting piece 41 and a driving piece 42, the driving piece 42 is detachably connected to the slide rail 33 and can slide along the slide rail 33, the sliding direction of the driving piece 42 is parallel to the large section of the tunnel, the cutting piece 41 is connected to the driving piece 42, and the driving piece 42 is used for driving the cutting piece 41 to translate in the depth direction of the tunnel, and the cutting piece 41 is used for cutting the temporary support in the tunnel.

[0060] With reference to Figure 3 The slide rail 33 is slidably connected with a connecting block 34, the cross section of the slide rail 33 is dovetail-shaped, the connecting block 34 is provided with a sliding groove 341 close to the position of the slide rail 33, the sliding groove 341 is a dovetail groove, the slide rail 33 is located in the sliding groove 341, the sliding direction of the connecting block 34 is parallel to the large section of the tunnel, the connecting block 34 is screw-connected with a fixing bolt 35, and the fixing bolt 35 can be tightened or loosened to adjust the connecting block 34.

[0061] With reference to Figure 3 And Figure 4 The driving piece 42 comprises a screw rod 421, a guide rod 422 and a rotating motor 423, the axes of the screw rod 421 and the guide rod 422 are parallel to the axis of the tunnel, the screw rod 421 is provided with a first mounting plate 43 at one end close to the connecting block 34, the first mounting plate 43 is rotatably connected with the connecting plate through the screw rod 421, the first mounting plate 43 is provided with a locking piece 44, the locking piece 44 is a nut, and the locking piece 44 is used for fixing the first mounting plate 43; the screw rod 421 is provided with a second mounting plate 45 at one end away from the first mounting plate 43, the second mounting plate 45 is fixedly connected with the inner wall of the tunnel through a fixing plate and a bolt, the screw rod 421 is rotatably connected with the first mounting plate 43 and the second mounting plate 45 through bearings, the two ends of the guide rod 422 are welded with the first mounting plate 43 and the second mounting plate 45 respectively, the rotating motor 423 is connected with the screw rod 421 through a shaft coupling, the rotating motor 423 is a servo motor, and the rotating motor 423 is used for driving the screw rod 421 to rotate.

[0062] With reference to Figure 3 And Figure 4The cutting piece 41 comprises a driving motor 411 and a cutting knife 412, the screw rod 421 and the guide rod 422 are provided with a mounting block 5, the mounting block 5 is threadedly connected with the screw rod 421 and is slidingly connected with the guide rod 422, the driving motor 411 is hingedly connected with the mounting block 5, the mounting block 5 is threadedly connected with a locking bolt 51, when the locking bolt 51 is tightened, the locking bolt 51 can abut against the driving motor 411, the locking bolt 51 is used for fixing the driving motor 411, and an axis of the hinged connection of the driving motor 411 is parallel to an axis of the screw rod 421. When the locking of the driving motor 411 by the locking bolt 51 is released, the driving motor 411 can be rotated, and the position between the output end of the driving motor 411 and the temporary support can be adjusted. The cutting knife 412 is fixedly connected with the driving motor 411 through bolts, the driving motor 411 is used for driving the cutting knife 412 to rotate, and the driving motor 411 is a servo motor. The cutting knife 412 is also fixedly connected with the driving motor 411 through bolts, and a polishing head 6 can also be mounted on the driving motor 411, the polishing head 6 is used for polishing the residual temporary support after cutting, and the residual temporary support is conveniently polished and removed.

[0063] The implementation principle of the tunnel construction method is that, after the mounting plate 31 is mounted at the mounting position corresponding to the small conduit 1, the mounting plate 31 guides and supports the small conduit 1, after the small conduit 1 and the excavated tunnel are both constructed, the cutting assembly 4 is mounted on the slide rail 33 below the mounting plate 31, the position of the driving piece 42 and the connecting block 34 is adjusted, the position between the driving motor 411 and the temporary support is adjusted, part of the position of the temporary support is cut, after the cutting knife 412 extends into the first half of the temporary support, the position of the driving motor 411 on the mounting block 5 is fixed, the rotating motor 423 is started, the rotating motor 423 drives the screw rod 421 to rotate, the screw rod 421 drives the mounting block 5 to move along the guide rod 422, and thus the temporary support is cut, the temporary support can be completely separated from the connection with the top of the tunnel through multiple cutting, and the construction efficiency is improved.

[0064] The above are preferred embodiments of the application, and do not limit the protection scope of the application, therefore: equivalent changes made on the basis of the structure, shape and principle of the application should be covered within the protection scope of the application.

Claims

1. A tunnel construction method, characterized in that: The construction method is as follows: S1. Conduct soil analysis and investigation in the early stages of construction. After construction preparations are completed, carry out earth excavation and initial support, followed by large pipe shed support. S2. After the large pipe shed is supported, the small pipe (1) is constructed. The small pipe (1) is arranged on the top of the large pipe shed to support the top of the large pipe shed; S3, carry out the construction of the horse head gate, and after the construction of the horse head gate is completed, carry out the excavation construction of the middle tunnel (2); After the excavation of S31 and the middle tunnel (2), initial support should be added in time in the excavated tunnel and the tunnel face should be closed; When excavating S32 and the middle tunnel (2), a construction method of vertical slope retention and longitudinal staggering was adopted; S4. Use the CRD method for construction, and simultaneously set up initial support in the excavated tunnel; During the construction of S41 and CRD, the tunnels on both sides of the middle tunnel (2) are divided into four pilot tunnels for excavation, with the excavation step distance between adjacent pilot tunnels being 10-15m. Before excavation, a small guide tube (1) needs to be constructed on the top of the pilot tunnel, and temporary support is provided on the excavated part after excavation. S5. Construction monitoring is required during CRD construction, and settlement control should be carried out at any time based on the monitoring results; In step S2, a receiving assembly (3) is provided, wherein the receiving assembly (3) comprises a receiving plate (31), the receiving plate (31) being detachably connected to the bottom of the small conduit (1), and the peripheral side wall of the small conduit (1) being able to abut against a side of the receiving plate (31) close to the small conduit (1); A positioning plate (32) is detachably connected to a side of the receiving plate (31) close to the small conduit (1), and a plurality of positioning grooves (321) are provided on the positioning plate (32), and the positioning grooves (321) correspond to the positions of the small conduit (1); A slide rail (33) is provided below the receiving plate (31), and a cutting assembly (4) is installed on the slide rail (33). The cutting assembly (4) is used to cut temporary support in the tunnel. The cutting assembly (4) includes a cutting member (41) and a driving member (42). The driving member (42) is detachably connected to the slide rail (33) and can slide along the slide rail (33). The sliding direction of the driving member (42) is parallel to the large cross-section of the tunnel. The cutting member (41) is connected to the driving member (42). The driving member (42) is used to drive the cutting member (41) to move horizontally along the depth direction of the tunnel. The cutting member (41) is used to cut the temporary support in the tunnel. The slide rail (33) is provided with a connecting block (34), which can slide along the slide rail (33), and the sliding direction of the connecting block (34) is parallel to the large cross-section of the tunnel. The connecting block (34) is provided with a fixing bolt (35), and the driving member (42) includes a screw rod (421), a guide rod (422) and a rotating motor (423). The axes of the screw rod (421) and the guide rod (422) are parallel to the axis of the tunnel. A first mounting plate (43) is provided at one end of the screw rod (421) close to the connecting block (34). The first mounting plate (43) is rotatably connected to the connecting block. The first mounting plate (423) is provided with a fixing bolt (35). 3) is provided with a locking member (44), the locking member (44) is used to fix the first mounting plate (43), a second mounting plate (45) is provided at one end of the screw rod (421) away from the first mounting plate (43), the second mounting plate (45) is detachably connected to the inner wall of the tunnel, the screw rod (421) is rotatably connected to the first mounting plate (43) and the second mounting plate (45), the two ends of the guide rod (422) are respectively connected to the first mounting plate (43) and the second mounting plate (45), a rotating motor (423) is connected to the screw rod (421), and the rotating motor (423) is used to drive the screw rod (421) to rotate.

2. A tunnel construction method according to claim 1, characterized in that: During the initial support, the first layer of steel mesh needs to be hung on the inner wall of the tunnel and reinforced with grid steel bars. After reinforcement, the second layer of steel mesh is hung and the grid steel bars are supported with locking anchor pipes. Finally, concrete is sprayed and waited for the concrete to solidify to complete the initial support.

3. A tunnel construction method according to claim 1, characterized in that: The cutting member (41) comprises a driving motor (411) and a cutting blade (412). A mounting block (5) is provided on the screw rod (421) and the guide rod (422). The driving motor (411) and the mounting block (5) are hingedly connected. A locking bolt (51) is provided on the mounting block (5). The locking bolt (51) is used to fix the driving motor (411). The hinge axis of the driving motor (411) is parallel to the axis of the screw rod (421). The cutting blade (412) is connected to the driving motor (411). The driving motor (411) is used to drive the cutting blade (412) to rotate.

4. A tunnel construction method according to claim 3, characterized in that: The cutting blade (412) is detachably connected to the driving motor (411), and the driving motor (411) is further provided with a grinding head (6), which is used to grind the residual temporary support after cutting.

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