Cross-sectional device and method for large-span tunnel construction based on passing through shallowly buried broken zone

Abstract

A device and method for constructing a large-span tunnel section based on passing through a shallowly buried broken zone, comprising a pipe group device for forming a grouting reinforcement layer 6 in a shallowly buried broken zone, and an initial support 4 arranged in the large-span tunnel and used to support the pipe group device. Through the pipe group device and the initial support 4, a grouting reinforcement layer 6 is built into the shallowly buried broken zone, and construction operations of the large-span tunnel in divided cross-sectional areas are realized, thereby realizing large-span tunnel excavation operations in the shallowly buried broken zone.

Description

Technical Field

[0001] The invention relates to a large-span tunnel construction section device and method, in particular to a large-span tunnel construction section device and method based on underpass through a shallow buried broken zone. Background Art

[0002] Due to the limitation of geological environment, large-span tunnels may need to pass through shallow-buried broken zones. Therefore, the large-span tunnel construction section device and method based on passing through shallow-buried broken zones is an important construction method. Among the existing large-span tunnel construction section devices and methods based on passing through shallow-buried broken zones, there are two main construction techniques for shallow-buried broken zones in underground tunneling projects. One is to use open-cut construction and then backfill to restore the original surface. Open-cut construction requires more land acquisition, large earthwork excavation, long construction period, and is greatly affected by the surrounding environment. The other is to use surface grouting reinforcement technology. Surface grouting construction requires the demolition of surface structures and seedlings, the cleaning of original surface soil, and the application of grouting plates. After the surface grouting is completed, the grouting plates need to be removed to restore the surface cultivated soil, seedlings, etc. Surface grouting reinforcement requires a large demolition range, poor grouting effect, and poor reinforcement effect for broken zones. The temporary construction project of surface grouting construction requires a large investment, especially in the shallow buried broken zone in the middle of the tunnel. It is also necessary to requisition temporary access roads and build construction access roads. The temporary construction project requires a large investment, which has a great impact on surface seedlings, especially forest land and cultivated land in mountainous areas.

[0003] Based on the technical briefing document provided by the applicant on January 12, 2022, which solves practical technical problems in the work process, and the existing technical problems, technical features and technical effects in similar patent documents and background technologies obtained through retrieval, the technical application scheme of the present invention was made. Summary of the invention

[0004] The object of the present invention is a large-span tunnel construction section device based on passing through a shallow buried broken zone.

[0005] The object of the present invention is a large-span tunnel construction method based on passing through a shallowly buried broken zone.

[0006] In order to overcome the above technical shortcomings, the purpose of the present invention is to provide a large-span tunnel construction section device and method based on passing through a shallow buried broken zone, thereby realizing large-span tunnel excavation operations in a shallow buried broken zone.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a large-span tunnel construction section device based on passing through a shallowly buried broken zone, comprising a pipe group device for forming a grouting reinforcement layer in the shallowly buried broken zone, and an initial support arranged in the large-span tunnel and used to support the pipe group device.

[0008] Due to the design of the pipe group device and the initial support, it is possible to build a grouting reinforcement layer in the shallow broken zone through the pipe group device and the initial support, and to carry out cross-sectional area construction operations for large-span tunnels, thus realizing large-span tunnel excavation operations in shallow broken zones.

[0009] The present invention is designed to interconnect the pipe group device and the initial support in a manner of carrying out a large-span tunnel excavation operation in a shallowly buried fractured zone.

[0010] The present invention is designed to connect the pipe group device with the initial support in a manner of carrying out cross-sectional area construction work on the large-span tunnel.

[0011] The present invention designs that the tube group device is arranged to include an advanced middle tube, a high elevation angle advanced tube and a low elevation angle advanced tube.

[0012] The technical effect of the above four technical solutions is that through the internal grouting reinforcement layer and the cross-sectional area excavation of the large-span tunnel, the large-span tunnel excavation operation in the shallow buried broken zone is realized.

[0013] The present invention is designed to further include a first accessory device, and the first accessory device is arranged on the large-span tunnel, and the first accessory device is arranged as a lining layer.

[0014] The present invention designs that the density of the grouting reinforcement layer is arranged to be distributed in a step manner.

[0015] The technical effect of the above technical solution is: to realize the integrated installation of other components, and to expand the technical effect of the present invention.

[0016] The present invention is designed to set up initial support in the large-span tunnel, respectively set up an advance middle pipe, a high-elevation advance pipe and a low-elevation advance pipe between the shallow-buried fracture zone and the initial support, and set up a lining layer on the inner wall of the large-span tunnel.

[0017] The technical effect of the above technical scheme is that the basic technical scheme of the present invention is formed by the advanced middle pipe, the high-elevation advanced pipe, the low-elevation advanced pipe, the initial support and the lining layer, which solves the technical problem of the present invention.

[0018] The present invention designs that the initial support is arranged as an arch frame and the initial support is arranged to be connected with the leading middle pipe, the high elevation angle leading pipe and the low elevation angle leading pipe respectively.

[0019] The technical effect of the above technical solution is to achieve safe support and fixed support setting in large-span tunnels.

[0020] The present invention is designed that the advance middle pipe, the high-elevation advance pipe and the low-elevation advance pipe are respectively arranged as grouting pipes, and the inner end of the advance middle pipe, the inner end of the high-elevation advance pipe and the inner end of the low-elevation advance pipe are arranged in the shallow buried broken zone, and the outer end of the advance middle pipe, the outer end of the high-elevation advance pipe and the outer end of the low-elevation advance pipe are arranged to be connected with the initial support.

[0021] The present invention designs that the grouting reinforcement layer is arranged to be distributed in a fan-shaped surface along the top section of the large-span tunnel to be excavated, the fan-shaped angle δ of the grouting reinforcement layer is set to 118-122°, and the thickness of the grouting reinforcement layer is set to 2.5-3.5m.

[0022] The technical effects of the above two technical solutions are: realizing the implantation of the grouting reinforcement layer in the shallow buried broken zone, and forming a solidification reinforcement layer in the top section of the large-span tunnel.

[0023] The present invention is designed that the elevation angle α of the leading middle tube is set to 5°-12°, the circumferential spacing of adjacent leading middle tubes is set to 0.3-0.4m, the length of the leading middle tube is set to 2.5-3.5m, the elevation angle β of the high-elevation-angle leading tube is set to 20°-30°, the circumferential spacing of adjacent high-elevation-angle leading tubes is set to 0.3-0.4m, the length of the high-elevation-angle leading tube is set to 1.5-2.5m, the elevation angle γ of the low-elevation-angle leading tube is set to 5°-12°, the circumferential spacing of adjacent low-elevation-angle leading tubes is set to 0.3-0.4m, and the length of the low-elevation-angle leading tube is set to 0.5-1.5m.

[0024] The technical effect of the above technical solution is: realizing grouting treatment in different directions of the grouting reinforcement layer, making the grouting liquid in the grouting reinforcement layer staggered and superimposed, generating a raised edge in the grouting reinforcement layer, and increasing the supporting strength of the grouting reinforcement layer.

[0025] The present invention designs that the lining layer is arranged as a cement mortar spraying layer and the lining layer is arranged to be connected with the inner wall of the large-span tunnel in an attached manner.

[0026] The technical effect of the above technical solution is to reinforce the large-span tunnel.

[0027] The present invention designs that the high-elevation-angle leading tube and the low-elevation-angle leading tube are respectively arranged as anchor rods.

[0028] The technical effect of the above technical solution is that the excavation efficiency of the large-span tunnel is improved through the support of the cross rods.

[0029] The present invention is designed that the advanced middle tube, high-elevation-angle advanced tube and low-elevation-angle advanced tube and the initial support are arranged to be distributed in a manner of forming a built-in reinforcement layer, and the advanced middle tube, high-elevation-angle advanced tube, low-elevation-angle advanced tube, the initial support and the lining layer are arranged to be distributed in a manner of forming an attached reinforcement layer.

[0030] The present invention designs a large-span tunnel construction method based on passing through a shallowly buried broken zone, and the steps are: a pipe group device and initial support are used to realize an internal grouting reinforcement layer in the shallowly buried broken zone, thereby realizing cross-sectional area construction operations for the large-span tunnel.

[0031] The technical effect of the above technical solution is that it satisfies the requirement of setting up regional excavation for large-span tunnels and realizes the setting of retention buffer time during the construction period.

[0032] The present invention is designed, and the steps are: installing the initial support in the large-span tunnel, and performing the down-the-hole operation in the shallow-buried broken zone of the top section of the large-span tunnel to be excavated in the range of the fan angle δ of the grouting reinforcement layer of 118-122°, according to the elevation angle α of 5°-12°, the circumferential spacing of 0.3-0.4m and the depth of 2.5-3.5m; after the down-the-hole operation is completed, installing the advanced middle pipe in the down-the-hole, connecting the outer end of the advanced middle pipe with the initial support, connecting the outer end of the advanced middle pipe with the grouting machine, making the grouting machine in a working state, and performing grouting treatment on the shallow-buried broken zone of the top section of the large-span tunnel to be excavated by the advanced middle pipe, A grouting reinforcement layer is prepared, and the grouting machine is placed in a non-working state. After the grouting reinforcement layer is reinforced, a down-the-hole operation is performed in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated at an elevation angle β of 20°-30°, an annular spacing of 0.3-0.4m and a depth of 1.5-2.5m. After the down-the-hole operation is completed, a high-elevation-angle advance pipe is installed in the down-the-hole, the outer end of the high-elevation-angle advance pipe is connected to the initial support, and the outer end of the high-elevation-angle advance pipe is connected to the grouting machine, so that the grouting machine is placed in a working state, and the high-elevation-angle advance pipe is used to perform grouting treatment on the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, The grouting machine is in a non-working state. After the grouting reinforcement layer is reinforced, the soil and rock in area I are excavated. When the depth of area I is 1.2-1.5m, the down-the-hole operation is carried out in the shallow buried broken zone of the top section of the large-span tunnel to be excavated according to the elevation angle γ of 5°-12°, the circumferential spacing of 0.3-0.4m and the depth of 0.5-1.5m. After the down-the-hole operation is completed, the low-elevation angle advance pipe is installed in the down-the-hole, the outer end of the low-elevation angle advance pipe is connected to the exploration beam on the initial support, and the outer end of the low-elevation angle advance pipe is connected to the grouting machine, so that the grouting machine is in a working state. The low-elevation angle advance pipe is used to irradiate the large span tunnel to be excavated. The shallowly buried broken zone of the top section of the cross-tunnel is grouting treated. After the grouting treatment is completed, the grouting machine is put into non-working state. After the grouting reinforcement layer is reinforced, the soil and rock in area I are excavated. After the depth of area I is 3.3-3.6m, the soil and rock in area II are excavated. After the depth of area II is 3.3-3.6m, the soil and rock in area III are excavated. After the depth of area III is 3.3-3.6m, the soil and rock in area IV are excavated. After the depth of area IV is 3.3-3.6m, the soil and rock in area V are excavated. After the depth of area V is 3.3-3.6m later, the soil and rock in area VI are cleaned. After the soil and rock in area VI are cleaned, the soil and rock in area VII are cleaned. After the soil and rock in area VII are cleaned, one section of the large-span tunnel is completed. The outer end of the advanced middle pipe is separated from the initial support, the outer end of the high-elevation advanced pipe is separated from the initial support, and the outer end of the low-elevation advanced pipe is separated from the extension beam on the initial support. The initial support is moved forward, and the spray lining layer is carried out on the inner wall of this section of the large-span tunnel.

[0033] The present invention is designed that area I is set as the upper end of the large-span tunnel, area VI is set as the middle part of the large-span tunnel, area VII is set as the lower end of the large-span tunnel, area II is set as the upper left part of the large-span tunnel, area III is set as the upper right part of the large-span tunnel, area IV is set as the lower left part of the large-span tunnel, and area V is set as the lower right part of the large-span tunnel.

[0034] The technical effect of the above two technical solutions is that when area I is vacant, the grouting reinforcement layer is in a stable state, and operations in other areas are set up. When operations in other areas are performed, the impact on the grouting reinforcement layer is reduced by retaining the buffer time.

[0035] The present invention designs that the raw materials of the grouting reinforcement layer are set to include 10-15 parts of cement, 8-12 parts of gypsum, 10-18 parts of quartz sand, 20-26 parts of redispersible latex powder, 1-3 parts of sulfonated melamine-based water reducer and 1-4 parts of sodium silicate.

[0036] The technical effect of the above technical solution is that it realizes the self-flowing paving operation of the grouting reinforcement layer in the shallow buried broken zone, thereby increasing the formation area of ​​the grouting reinforcement layer.

[0037] The present invention is designed, and its steps are: by adjusting the height, width and length of the upper step of the underground dark excavation project in advance, providing a construction platform for equipment such as a down-the-hole drill and a grouting machine, using a down-the-hole drill to construct an outer layer of advanced middle pipe, using grouting equipment to carry out grouting construction, ensuring that the broken zone around the outer middle pipe shed is filled with cement slurry, and after the outer layer of advanced middle pipe drilling and grouting are completed and a certain strength is reached, the tunnel excavation section is adjusted to a three-step seven-step excavation method section, and tunnel excavation and initial support operations are carried out within the first cycle reinforcement range of the outer middle pipe shed. When the section is adjusted, the upper step area is excavated first, and a ring of high-elevation-angle advanced pipes is constructed within the range of 120° of the arch top, which is firmly welded to the outer side of the initial support steel arch frame, and the inner layer of high-elevation-angle advanced pipe is grouted with the outer layer The middle pipe and the shed are combined with grouting to form a surrounding rock grouting reinforcement zone. After the slurry is strong, subsequent excavation and support operations are carried out. After the longitudinal excavation and support of the upper step is completed for 1.5m, the inner layer of low-elevation advance pipe is constructed. The low-elevation advance pipe passes through the web of the steel arch frame and is firmly welded to the steel arch frame to form a grouting reinforcement zone with the high-elevation advance pipe. The low-elevation advance pipe and the high-elevation advance pipe are cross-constructed to jointly supplement the grouting range of the outer layer of advance middle pipe to ensure the integrity and stability of the surrounding rock in the shallow buried broken zone in front and top of the underground tunneling project. This cycle is repeated, and the outer layer of advance middle pipe, the inner layer of high-elevation advance pipe, and the inner layer of low-elevation advance pipe are repeatedly constructed and grouting is performed to form a broken zone reinforcement zone to ensure the safety of large-span tunnels passing under shallow buried broken zones.

[0038] The technical effect of the above technical solution is that it is suitable for a construction area where grouting reinforcement can be carried out on a shallowly buried broken zone at one time, thereby improving the construction efficiency of a large-span tunnel.

[0039] The technical effect of the present invention is that it eliminates the impact of surface grouting technology on the large demand for surface land and the large amount of demolition of structures and seedlings, reduces the interference with the surrounding environment, realizes multiple reinforcement of shallow buried broken zones in the tunnel, reduces the impact on surface structures to zero, and ensures the safety of underground excavation construction of large-span tunnels.

[0040] In this technical solution, the pipe group device and initial support for large-span tunnel excavation operations in shallow buried broken zones are important technical features. In the technical field of large-span tunnel construction section devices and methods based on passing through shallow buried broken zones, it has novelty, creativity and practicality. The terms in this technical solution can be explained and understood using patent documents in this technical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 is a schematic diagram of the present invention,

[0043] Figure 2 is a schematic cross-sectional view of the present invention,

[0044] Advanced middle pipe-1, high elevation angle advanced pipe-2, low elevation angle advanced pipe-3, initial support-4, lining layer-5, grouting reinforcement layer-6. DETAILED DESCRIPTION

[0045] According to the Examination Guidelines, terms such as “having”, “including” and “comprising” used in the present invention should be understood as not dispensing with the existence or addition of one or more other elements or their combinations.

[0046] The present invention is further described below in conjunction with the examples, which are intended to illustrate the present invention rather than to further limit the present invention. The steps are:

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. In addition, unless otherwise specified, the equipment and materials used in the following examples are commercially available. If the processing conditions are not clearly stated, please refer to the purchased product manual or proceed according to conventional methods in the art.

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] A cross-sectional device for large-span tunnel construction based on passing through a shallowly buried broken zone. Figure 1 This is one of the first embodiments of the present invention. This embodiment is specifically described in conjunction with the accompanying drawings. It includes an advance middle pipe 1, a high-elevation advance pipe 2, a low-elevation advance pipe 3, an initial support 4 and a lining layer 5. The initial support 4 is arranged in the large-span tunnel, and the advance middle pipe 1, the high-elevation advance pipe 2 and the low-elevation advance pipe 3 are respectively arranged between the shallow buried broken zone and the initial support 4, and the lining layer 5 is arranged on the inner wall of the large-span tunnel.

[0053] In this embodiment, the advance middle pipe 1, the high-elevation-angle advance pipe 2 and the low-elevation-angle advance pipe 3 are respectively arranged as grouting pipes and the inner end of the advance middle pipe 1, the inner end of the high-elevation-angle advance pipe 2 and the inner end of the low-elevation-angle advance pipe 3 are arranged in the shallow buried broken zone, and the outer end of the advance middle pipe 1, the outer end of the high-elevation-angle advance pipe 2 and the outer end of the low-elevation-angle advance pipe 3 are arranged to be connected with the initial support 4.

[0054] A supporting connection point for the initial support 4 is formed by the advance middle pipe 1, the high-elevation advance pipe 2 and the low-elevation advance pipe 3. The connection with the initial support 4 is realized by the advance middle pipe 1, the high-elevation advance pipe 2 and the low-elevation advance pipe 3. The technical purpose is to be used as a component for preparing a grouting reinforcement layer 6 in a shallow buried broken zone.

[0055] In this embodiment, the grouting reinforcement layer 6 is arranged to be distributed in a fan-shaped surface along the top section of the large-span tunnel to be excavated, and the fan-shaped angle δ of the grouting reinforcement layer 6 is set to 118-122°, and the thickness of the grouting reinforcement layer 6 is set to 2.5-3.5m.

[0056] Its technical purpose is to reinforce the shallow buried broken zone.

[0057] In this embodiment, the elevation angle α of the leading middle tube 1 is set to 5°-12°, the circumferential spacing between adjacent leading middle tubes 1 is set to 0.3-0.4m, the length of the leading middle tube 1 is set to 2.5-3.5m, the elevation angle β of the high-elevation-angle leading tube 2 is set to 20°-30°, the circumferential spacing between adjacent high-elevation-angle leading tubes 2 is set to 0.3-0.4m, the length of the high-elevation-angle leading tube 2 is set to 1.5-2.5m, the elevation angle γ of the low-elevation-angle leading tube 3 is set to 5°-12°, the circumferential spacing between adjacent low-elevation-angle leading tubes 3 is set to 0.3-0.4m, and the length of the low-elevation-angle leading tube 3 is set to 0.5-1.5m.

[0058] The technical purpose is to form a grouting mesh pipe for producing a grouting reinforcement layer 6 in a shallowly buried broken zone.

[0059] In this embodiment, the initial support 4 is configured as an arch frame and the initial support 4 is configured to be connected to the leading middle tube 1, the high-elevation-angle leading tube 2 and the low-elevation-angle leading tube 3 respectively.

[0060] Through the initial support 4, support connection points for the advanced middle tube 1, the high-elevation-angle advanced tube 2 and the low-elevation-angle advanced tube 3 are formed. The initial support 4 realizes the connection with the advanced middle tube 1, the connection with the high-elevation-angle advanced tube 2, and the connection with the low-elevation-angle advanced tube 3. Its technical purpose is to serve as a supporting carrier for the advanced middle tube 1, the high-elevation-angle advanced tube 2 and the low-elevation-angle advanced tube 3.

[0061] In this embodiment, the lining layer 5 is configured as a cement mortar spraying layer and the lining layer 5 is configured to be attached to the inner wall of the large-span tunnel.

[0062] Its technical purpose is to be used as a component for reinforcing large-span tunnels.

[0063] In this embodiment, the advanced middle pipe 1, the high-elevation-angle advanced pipe 2, the low-elevation-angle advanced pipe 3 and the initial support 4 are arranged to be distributed in a manner of forming a built-in reinforcement layer, and the advanced middle pipe 1, the high-elevation-angle advanced pipe 2, the low-elevation-angle advanced pipe 3, the initial support 4 and the lining layer 5 are arranged to be distributed in a manner of forming an attached reinforcement layer.

[0064] One of the supporting examples of one of the first embodiments of the present invention, the grouting reinforcement layer 6 is arranged to be distributed in a fan-shaped surface along the top section of the large-span tunnel to be excavated, and the fan-shaped angle δ of the grouting reinforcement layer 6 is set to 118°, and the thickness of the grouting reinforcement layer 6 is set to 2.5m.

[0065] In this embodiment, the elevation angle α of the leading middle tube 1 is set to 5°, the circumferential spacing between adjacent leading middle tubes 1 is set to 0.3m, the length of the leading middle tube 1 is set to 2.5m, the elevation angle β of the high-elevation-angle leading tube 2 is set to 20°, the circumferential spacing between adjacent high-elevation-angle leading tubes 2 is set to 0.3m, the length of the high-elevation-angle leading tube 2 is set to 1.5m, the elevation angle γ of the low-elevation-angle leading tube 3 is set to 5°, the circumferential spacing between adjacent low-elevation-angle leading tubes 3 is set to 0.3m, and the length of the low-elevation-angle leading tube 3 is set to 0.5m.

[0066] In the second supporting example of one of the first embodiments of the present invention, the grouting reinforcement layer 6 is arranged to be distributed in a fan-shaped surface along the top section of the large-span tunnel to be excavated, and the fan-shaped angle δ of the grouting reinforcement layer 6 is set to 122°, and the thickness of the grouting reinforcement layer 6 is set to 3.5m.

[0067] In this embodiment, the elevation angle α of the leading middle tube 1 is set to 12°, the circumferential spacing between adjacent leading middle tubes 1 is set to 0.4m, the length of the leading middle tube 1 is set to 3.5m, the elevation angle β of the high-elevation-angle leading tube 2 is set to 30°, the circumferential spacing between adjacent high-elevation-angle leading tubes 2 is set to 0.4m, the length of the high-elevation-angle leading tube 2 is set to 2.5m, the elevation angle γ of the low-elevation-angle leading tube 3 is set to 12°, the circumferential spacing between adjacent low-elevation-angle leading tubes 3 is set to 0.4m, and the length of the low-elevation-angle leading tube 3 is set to 1.5m.

[0068] In the third supporting example of one of the first embodiments of the present invention, the grouting reinforcement layer 6 is arranged to be distributed in a fan-shaped surface along the top section of the large-span tunnel to be excavated, and the fan-shaped angle δ of the grouting reinforcement layer 6 is set to 120°, and the thickness of the grouting reinforcement layer 6 is set to 3.0m.

[0069] In this embodiment, the elevation angle α of the leading middle tube 1 is set to 8°, the circumferential spacing between adjacent leading middle tubes 1 is set to 0.35m, the length of the leading middle tube 1 is set to 3.0m, the elevation angle β of the high-elevation-angle leading tube 2 is set to 25°, the circumferential spacing between adjacent high-elevation-angle leading tubes 2 is set to 0.35m, the length of the high-elevation-angle leading tube 2 is set to 2.0m, the elevation angle γ of the low-elevation-angle leading tube 3 is set to 8°, the circumferential spacing between adjacent low-elevation-angle leading tubes 3 is set to 0.35m, and the length of the low-elevation-angle leading tube 3 is set to 0.8m.

[0070] The present invention is further described below in conjunction with examples. The following examples are intended to illustrate the present invention rather than to further limit the present invention.

[0071] A large-span tunnel construction method based on passing through a shallow-buried broken zone, one of the first embodiments of the present invention, the steps are: installing an initial support 4 in the large-span tunnel, and performing a down-the-hole operation in the shallow-buried broken zone of the top section of the large-span tunnel to be excavated at an elevation angle α of 5°-12°, an annular spacing of 0.3-0.4m and a depth of 2.5-3.5m within the fan-shaped angle δ of the grouting reinforcement layer 6 of 118-122°. After the down-the-hole operation is completed, installing an advanced middle pipe 1 in the down-the-hole, connecting the outer end of the advanced middle pipe 1 to the initial support 4, connecting the outer end of the advanced middle pipe 1 to a grouting machine, and putting the grouting machine in a working state, and the advanced middle pipe 1 is used to irradiate the shallow-buried broken zone at the top section of the large-span tunnel to be excavated. The shallowly buried broken zone of the top section of the large-span tunnel to be excavated is subjected to grouting treatment to obtain a grouting reinforcement layer 6, and the grouting machine is placed in a non-working state. After the grouting reinforcement layer 6 is reinforced, a down-the-hole operation is performed in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated at an elevation angle β of 20°-30°, an annular spacing of 0.3-0.4m and a depth of 1.5-2.5m. After the down-the-hole operation is completed, a high-elevation-angle advance pipe 2 is installed in the down-the-hole, the outer end of the high-elevation-angle advance pipe 2 is connected to the initial support 4, and the outer end of the high-elevation-angle advance pipe 2 is connected to the grouting machine, so that the grouting machine is placed in a working state, and the high-elevation-angle advance pipe 2 is used to grout the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. Carry out grouting treatment, and after the grouting treatment is completed, put the grouting machine in a non-working state, and after the grouting reinforcement layer 6 is reinforced, the soil and rock located in area I are excavated, and when the depth of area I is 1.2-1.5m, carry out down-the-hole operation in the shallow buried broken zone of the top section of the large-span tunnel to be excavated according to the elevation angle γ of 5°-12°, the circumferential spacing of 0.3-0.4m and the depth of 0.5-1.5m. After the down-the-hole operation is completed, install the low-elevation-angle advance pipe 3 in the down-the-hole, connect the outer end of the low-elevation-angle advance pipe 3 to the exploration beam located on the initial support 4, connect the outer end of the low-elevation-angle advance pipe 3 to the grouting machine, and put the grouting machine in a working state. The advance pipe 3 performs grouting treatment on the shallowly buried broken zone at the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, the grouting machine is put into a non-working state. After the grouting reinforcement layer 6 is reinforced, the soil and rock in area I are excavated. After the depth of area I is 3.3-3.6m, the soil and rock in area II are excavated. After the depth of area II is 3.3-3.6m, the soil and rock in area III are excavated. After the depth of area III is 3.3-3.6m, the soil and rock in area IV are excavated. After the depth of area IV is 3.3-3.6m, the soil and rock in area V are excavated. After the depth of area V is 3.3-3.6m later, the soil and rocks in area VI are cleaned. After the soil and rocks in area VI are cleaned, the soil and rocks in area VII are cleaned. After the soil and rocks in area VII are cleaned, one section of the large-span tunnel is completed. The outer end of the advanced middle pipe 1 is separated from the initial support 4, the outer end of the high-elevation advanced pipe 2 is separated from the initial support 4, and the outer end of the low-elevation advanced pipe 3 is separated from the extension beam on the initial support 4. The initial support 4 is moved forward, and the sprayed lining layer 5 is carried out on the inner wall of this section of the large-span tunnel.

[0072] In this embodiment, area I is set to the upper end of the large-span tunnel, area VI is set to the middle part of the large-span tunnel, area VII is set to the lower end of the large-span tunnel, area II is set to the upper left part of the large-span tunnel, area III is set to the upper right part of the large-span tunnel, area IV is set to the lower left part of the large-span tunnel, and area V is set to the lower right part of the large-span tunnel.

[0073] The technical purpose is to realize the regional construction of large-span tunnels.

[0074] In this embodiment, the raw materials of the grouting reinforcement layer 6 are set to include 10-15 parts of cement, 8-12 parts of gypsum, 10-18 parts of quartz sand, 20-26 parts of redispersible latex powder, 1-3 parts of sulfonated melamine-based water reducer and 1-4 parts of sodium silicate.

[0075] The technical purpose is to achieve self-flowing paving in shallow broken zones.

[0076] One of the supporting examples of one of the first embodiments of the present invention comprises the following steps: installing the initial support 4 in a large-span tunnel, and performing a down-the-hole operation in a shallowly buried broken zone in the top section of the large-span tunnel to be excavated at an elevation angle α of 5°, an annular spacing of 0.3m and a depth of 2.5m within the range of a fan-shaped angle δ of 118° of the grouting reinforcement layer 6; after the down-the-hole operation is completed, installing the advanced middle pipe 1 in the down-the-hole, connecting the outer end of the advanced middle pipe 1 to the initial support 4, connecting the outer end of the advanced middle pipe 1 to a grouting machine, putting the grouting machine in a working state, and performing grouting treatment on the shallowly buried broken zone in the top section of the large-span tunnel to be excavated by the advanced middle pipe 1 to obtain a grouting reinforcement layer 6; putting the grouting machine in a non-working state, and waiting until the grouting reinforcement layer 6 is reinforced. , and then carry out down-the-hole operation in the shallow buried broken zone of the top section of the large-span tunnel to be excavated according to the elevation angle β of 20°, the circumferential spacing of 0.3m and the depth of 1.5m. After the down-the-hole operation is completed, install the high-elevation-angle advance pipe 2 in the down-the-hole, connect the outer end of the high-elevation-angle advance pipe 2 with the initial support 4, connect the outer end of the high-elevation-angle advance pipe 2 with the grouting machine, put the grouting machine in a working state, and use the high-elevation-angle advance pipe 2 to carry out grouting treatment on the shallow buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, put the grouting machine in a non-working state, wait until the grouting reinforcement layer 6 is reinforced, and then excavate the soil and rock located in area I. When the depth of area I reaches 1.2m, carry out down-the-hole operation in the shallow buried broken zone of the top section of the large-span tunnel to be excavated according to the elevation angle γ of 5°, the circumferential spacing of 0.3m and The depth of the down-the-hole operation is 0.5m, and the shallow buried broken zone of the top section of the large-span tunnel to be excavated is carried out. After the down-the-hole operation is completed, the low-elevation advance pipe 3 is installed in the down-the-hole, and the outer end of the low-elevation advance pipe 3 is connected to the exploration beam on the initial support 4, and the outer end of the low-elevation advance pipe 3 is connected to the grouting machine, so that the grouting machine is in a working state, and the low-elevation advance pipe 3 is used to perform grouting treatment on the shallow buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, the grouting machine is put into a non-working state, and after the grouting reinforcement layer 6 is reinforced, the soil and rock in area I are excavated. After the depth of area I is 3.3m, the soil and rock in area II are excavated. After the depth of area II is 3.3m, the soil and rock in area When the depth of area III reaches 3.3m, the soil and rock in area IV are excavated. When the depth of area IV reaches 3.3m, the soil and rock in area V are excavated. When the depth of area V reaches 3.3m, the soil and rock in area VI are cleared. When the soil and rock in area VI are cleared, the soil and rock in area VII are cleared. When the soil and rock in area VII are cleared, the construction of one section of the large-span tunnel is completed, the outer end of the advance middle pipe 1 is separated from the initial support 4, the outer end of the high-elevation advance pipe 2 is separated from the initial support 4, the outer end of the low-elevation advance pipe 3 is separated from the exploration beam on the initial support 4, the initial support 4 is moved forward, and the sprayed lining layer 5 is carried out on the inner wall of this section of the large-span tunnel.

[0077] In this embodiment, the raw materials of the grouting reinforcement layer 6 are set to include 10 parts of cement, 8 parts of gypsum, 10 parts of quartz sand, 20 parts of redispersible latex powder, 1 part of sulfonated melamine-based water reducer and 1 part of sodium silicate.

[0078] The technical purpose is to achieve self-flowing paving in shallow broken zones.

[0079] The second supporting example of one of the first embodiments of the present invention comprises the following steps: installing the initial support 4 in a large-span tunnel, and performing a down-the-hole operation in a shallowly buried broken zone in the top section of the large-span tunnel to be excavated at an elevation angle α of 12°, an annular spacing of 0.4m and a depth of 3.5m within the range of a fan-shaped angle δ of 122° of the grouting reinforcement layer 6; after the down-the-hole operation is completed, installing the advanced middle pipe 1 in the down-the-hole, connecting the outer end of the advanced middle pipe 1 to the initial support 4, connecting the outer end of the advanced middle pipe 1 to a grouting machine, putting the grouting machine in a working state, and performing grouting treatment on the shallowly buried broken zone in the top section of the large-span tunnel to be excavated by the advanced middle pipe 1 to obtain a grouting reinforcement layer 6; putting the grouting machine in a non-working state, and waiting until the grouting reinforcement layer 6 is reinforced. After that, the down-the-hole operation is carried out in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated at an elevation angle β of 30°, an annular spacing of 0.4m and a depth of 2.5m. After the down-the-hole operation is completed, the high-elevation-angle advance pipe 2 is installed in the down-the-hole, the outer end of the high-elevation-angle advance pipe 2 is connected to the initial support 4, and the outer end of the high-elevation-angle advance pipe 2 is connected to the grouting machine, so that the grouting machine is in a working state, and the high-elevation-angle advance pipe 2 is used to perform grouting treatment on the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, the grouting machine is put into a non-working state, and after the grouting reinforcement layer 6 is reinforced, the soil and rock located in area I are excavated. After the depth of area I reaches 1.5m, the elevation angle γ is 12°, the annular spacing is 0.4m and a depth of 1.5m in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the down-the-hole operation is completed, the low-elevation advance pipe 3 is installed in the down-the-hole, the outer end of the low-elevation advance pipe 3 is connected to the exploration beam on the initial support 4, and the outer end of the low-elevation advance pipe 3 is connected to the grouting machine, so that the grouting machine is in a working state, and the low-elevation advance pipe 3 is used to perform grouting treatment on the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, the grouting machine is put into a non-working state, and the soil and rock in area I is excavated after the grouting reinforcement layer 6 is reinforced. After the depth of area I is 3.6m, the soil and rock in area II is excavated. After the depth of area II is 3.6m, the soil and rock in area The soil and rock in area III are excavated. When the depth of area III is 3.6m, the soil and rock in area IV are excavated. When the depth of area IV is 3.6m, the soil and rock in area V are excavated. When the depth of area V is 3.6m, the soil and rock in area VI are cleared. When the soil and rock in area VI are cleared, the soil and rock in area VII are cleared. When the soil and rock in area VII are cleared, the construction of one section of the large-span tunnel is completed, the outer end of the advance middle pipe 1 is separated from the initial support 4, the outer end of the high-elevation advance pipe 2 is separated from the initial support 4, the outer end of the low-elevation advance pipe 3 is separated from the exploration beam on the initial support 4, the initial support 4 is moved forward, and the sprayed lining layer 5 is carried out on the inner wall of this section of the large-span tunnel.

[0080] In this embodiment, the raw materials of the grouting reinforcement layer 6 are set to include 15 parts of cement, 12 parts of gypsum, 18 parts of quartz sand, 26 parts of redispersible latex powder, 3 parts of sulfonated melamine-based water reducer and 4 parts of sodium silicate.

[0081] The technical purpose is to achieve self-flowing paving in shallow broken zones.The third supporting example of one of the first embodiments of the present invention comprises the following steps: installing the initial support 4 in a large-span tunnel, and performing a down-the-hole operation in a shallowly buried broken zone in the top section of the large-span tunnel to be excavated at an elevation angle α of 8°, an annular spacing of 0.35m and a depth of 3.0m within the range of a fan-shaped angle δ of 120° of the grouting reinforcement layer 6; after the down-the-hole operation is completed, installing the advanced middle pipe 1 in the down-the-hole, connecting the outer end of the advanced middle pipe 1 to the initial support 4, connecting the outer end of the advanced middle pipe 1 to the grouting machine, putting the grouting machine in a working state, and performing grouting treatment on the shallowly buried broken zone in the top section of the large-span tunnel to be excavated by the advanced middle pipe 1 to obtain a grouting reinforcement layer 6; putting the grouting machine in a non-working state, and waiting until the grouting reinforcement layer 6 is reinforced. After that, the down-the-hole operation is carried out in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated according to the elevation angle β of 25°, the circumferential spacing of 0.35m and the depth of 2.0m. After the down-the-hole operation is completed, the high-elevation-angle advance pipe 2 is installed in the down-the-hole, the outer end of the high-elevation-angle advance pipe 2 is connected to the initial support 4, and the outer end of the high-elevation-angle advance pipe 2 is connected to the grouting machine, so that the grouting machine is in a working state, and the high-elevation-angle advance pipe 2 is used to perform grouting treatment on the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, the grouting machine is put into a non-working state, and after the grouting reinforcement layer 6 is reinforced, the soil and rock located in area I are excavated. When the depth of area I reaches 1.3m, the elevation angle γ is 8°, the circumferential spacing of 0.35 m and a depth of 1.0m are used to carry out down-the-hole operations in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the down-the-hole operations are completed, the low-elevation advance pipe 3 is installed in the down-the-hole, the outer end of the low-elevation advance pipe 3 is connected to the exploration beam on the initial support 4, and the outer end of the low-elevation advance pipe 3 is connected to the grouting machine, so that the grouting machine is in a working state, and the low-elevation advance pipe 3 is used to carry out grouting treatment on the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, the grouting machine is put into a non-working state, and the soil and rock in area I are excavated after the grouting reinforcement layer 6 is reinforced. After the depth of area I is 3.5m, the soil and rock in area II are excavated. After the depth of area II is 3.5m, the soil and rock in area The soil and rock in area III are excavated, and when the depth of area III is 3.5m, the soil and rock in area IV are excavated. When the depth of area IV is 3.5m, the soil and rock in area V are excavated. When the depth of area V is 3.5m, the soil and rock in area VI are cleared. When the soil and rock in area VI are cleared, the soil and rock in area VII are cleared. When the soil and rock in area VII are cleared, the construction of one section of the large-span tunnel is completed, and the outer end of the advanced middle pipe 1 is separated from the initial support 4, the outer end of the high-elevation advanced pipe 2 is separated from the initial support 4, the outer end of the low-elevation advanced pipe 3 is separated from the exploration beam on the initial support 4, the initial support 4 is moved forward, and the sprayed lining layer 5 is carried out on the inner wall of this section of the large-span tunnel.

[0082] In this embodiment, the raw materials of the grouting reinforcement layer 6 are set to include 13 parts of cement, 10 parts of gypsum, 14 parts of quartz sand, 23 parts of redispersible latex powder, 2 parts of sulfonated melamine-based water reducer and 3 parts of sodium silicate.

[0083] The technical purpose is to achieve self-flowing paving in shallow broken zones.

[0084] In the second embodiment of the first embodiment of the present invention, the high elevation angle leading tube 2 and the low elevation angle leading tube 3 are respectively configured as anchor rods.

[0085] Its technical purpose is to adapt to different conditions in shallow buried broken zones and improve the construction efficiency of large-span tunnels.

[0086] A large-span tunnel construction method based on passing through a shallow buried broken zone, one of the first embodiments of the present invention, comprises the following steps: by adjusting the height, width and length of the upper step of the underground dark excavation project in advance, providing a construction platform for equipment such as a down-the-hole drill and a grouting machine, using a down-the-hole drill to construct an outer layer of advanced middle pipe 1, using grouting equipment to perform grouting construction, ensuring that the broken zone around the outer middle pipe shed is filled with cement slurry, and after the outer layer of advanced middle pipe 1 is drilled and grouting is completed and reaches a certain strength, the tunnel excavation section is adjusted to a three-step seven-step excavation section, and tunnel excavation and initial support operations are carried out within the first cycle reinforcement range of the outer middle pipe shed. When adjusting the section, the upper step area is excavated first, and a ring of high-elevation advanced pipes 2 are constructed within 120° of the arch, which are firmly welded to the outer side of the initial support steel arch frame, and the inner layer of high The grouting of the elevation advance pipe 2 is combined with the grouting of the outer middle pipe shelf to form a surrounding rock grouting reinforcement belt. After the slurry is strong, subsequent excavation and support operations are carried out. After the longitudinal excavation and support of the upper step is completed for 1.5m, the inner low-elevation advance pipe 3 is constructed. The low-elevation advance pipe 3 passes through the web of the steel arch frame and is firmly welded to the steel arch frame to form a grouting reinforcement belt with the high-elevation advance pipe 2. The low-elevation advance pipe 3 and the high-elevation advance pipe 2 are cross-constructed to jointly supplement the grouting range of the outer advance middle pipe 1 to ensure the integrity and stability of the surrounding rock in the shallowly buried broken zone in front and top of the underground excavation project. This cycle is repeated, and the outer advanced middle pipe 1, the inner high-elevation advance pipe 2, and the inner low-elevation advance pipe 3 are repeatedly constructed and grouting is performed to form a broken zone reinforcement belt to ensure the safety of large-span tunnels passing under shallowly buried broken zones.

[0087] In a second embodiment of the present invention, the pipe group device and the initial support 4 are connected to each other in a manner of performing a large-span tunneling operation in a shallowly buried fractured zone.

[0088] In this embodiment, the pipe group device is connected to the initial support 4 in a manner of carrying out cross-sectional area construction work on a large-span tunnel.

[0089] In this embodiment, the tube group device is configured to include an advanced middle tube 1, a high elevation angle advanced tube 2 and a low elevation angle advanced tube 3.

[0090] In this embodiment, a first accessory device is also included and is arranged on the large-span tunnel. The first accessory device is arranged as a lining layer 5 .

[0091] In this embodiment, the density of the grouting reinforcement layer 6 is arranged to be distributed in a step manner.

[0092] The second embodiment of the present invention is based on the first embodiment.

[0093] The second embodiment of the present invention comprises the following steps: a grouting reinforcement layer 6 is built into the shallowly buried broken zone by the pipe group device and the initial support 4, thereby realizing the construction work of the large-span tunnel in the divided cross-section area.

[0094] The second embodiment of the present invention is based on the first embodiment.

[0095] The present invention has the following characteristics:

[0096] 1. Due to the design of the pipe group device and the initial support 4, a built-in grouting reinforcement layer 6 is realized in the shallow buried broken zone through the pipe group device and the initial support 4, and the cross-sectional area construction operation of the large-span tunnel is realized, thereby realizing the large-span tunnel excavation operation in the shallow buried broken zone.

[0097] 2. Due to the design of the advanced middle pipe 1, the high-elevation-angle advanced pipe 2 and the low-elevation-angle advanced pipe 3, deep and shallow grouting treatment is achieved in the shallow buried broken zone.

[0098] 3. Due to the design of lining layer 5, reinforcement of large-span tunnels is achieved.

[0099] 4. Since the design limits the numerical range of the structural shape, the numerical range is the technical feature in the technical solution of the present invention, rather than a technical feature calculated by a formula or obtained through a limited number of tests. Tests have shown that the technical feature of this numerical range has achieved good technical effects.

[0100] 5. Due to the design of the technical features of the present invention, the effects of the individual and combined technical features have been shown through experiments to have various performance indicators of the present invention that are at least 1.7 times the existing performance indicators, and have been evaluated to have good market value.

[0101] There are other technical features connected with the pipe group device and the initial support 4 for large-span tunnel excavation operations in shallow buried broken zones, which are all embodiments of the present invention, and the technical features of the above-mentioned embodiments can be combined arbitrarily. In order to meet the requirements of the Patent Law, Patent Implementation Rules and Examination Guidelines, all possible combinations of the technical features in the above-mentioned embodiments will no longer be described.

[0102] The above embodiment is only one implementation form of the large-span tunnel construction section device and method based on passing through a shallow buried broken zone provided by the present invention. Other variations of the scheme provided by the present invention, adding or reducing components or steps therein, or applying the present invention to other technical fields close to the present invention, all fall within the scope of protection of the present invention.

Claims

1. A large-span tunnel construction method based on passing through a shallowly buried broken zone, characterized in that the steps are: The pipe group device and the initial support (4) realize the built-in grouting reinforcement layer (6) in the shallow buried broken zone, and realize the cross-sectional regional construction work of the large-span tunnel. The initial support (4) is installed in the large-span tunnel, and the fan angle δ of the grouting reinforcement layer (6) is within the range of 118-122°, and the down-the-hole operation is carried out in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated according to the elevation angle α of 5°-12°, the circumferential spacing of 0.3-0.4m and the depth of 2.5-3.5m. After the down-the-hole operation is completed, the advanced middle pipe (1) is installed in the down-the-hole, the outer end of the advanced middle pipe (1) is connected to the initial support (4), and the outer end of the advanced middle pipe (1) is connected to the grouting machine, so that the grouting machine is in working state, and the advanced middle pipe (1) is used to perform grouting treatment on the shallowly buried broken zone of the top section of the large-span tunnel to be excavated, so as to obtain a grouting machine. The grouting reinforcement layer (6) is formed, and the grouting machine is placed in a non-working state. After the grouting reinforcement layer (6) is reinforced, a down-the-hole operation is performed in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated at an elevation angle β of 20°-30°, an annular spacing of 0.3-0.4m and a depth of 1.5-2.5m. After the down-the-hole operation is completed, the high-elevation-angle advance pipe (2) is installed in the down-the-hole, the outer end of the high-elevation-angle advance pipe (2) is connected to the initial support (4), and the outer end of the high-elevation-angle advance pipe (2) is connected to the grouting machine, so that the grouting machine is placed in a working state, and the high-elevation-angle advance pipe (2) is used to perform grouting treatment on the shallowly buried broken zone of the top section of the large-span tunnel to be excavated. After the grouting is completed, After the treatment, the grouting machine is placed in a non-working state. After the grouting reinforcement layer (6) is reinforced, the soil and rock located in area I are excavated. When the depth of area I reaches 1.2-1.5m, the down-the-hole operation is carried out in the shallowly buried broken zone of the top section of the large-span tunnel to be excavated according to the elevation angle γ of 5°-12°, the circumferential spacing of 0.3-0.4m and the depth of 0.5-1.5m. After the down-the-hole operation is completed, the low-elevation-angle advance pipe (3) is installed in the down-the-hole, the outer end of the low-elevation-angle advance pipe (3) is connected to the extension beam located on the initial support (4), and the outer end of the low-elevation-angle advance pipe (3) is connected to the grouting machine, so that the grouting machine is placed in a working state. (3) Grouting treatment is performed on the shallowly buried broken zone at the top section of the large-span tunnel to be excavated. After the grouting treatment is completed, the grouting machine is placed in a non-working state. After the grouting reinforcement layer (6) is reinforced, the soil and rock in area I are excavated. After the depth of area I is 3.3-3.6 m, the soil and rock in area II are excavated. After the depth of area II is 3.3-3.6 m, the soil and rock in area III are excavated. After the depth of area III is 3.3-3.6 m, the soil and rock in area IV are excavated. After the depth of area IV is 3.3-3.6 m, the soil and rock in area V are excavated. After the depth of area V is 3.3-3.6m later, the soil and rocks in area VI are cleaned. After the soil and rocks in area VI are cleaned, the soil and rocks in area VII are cleaned. After the soil and rocks in area VII are cleaned, one section of the large-span tunnel is completed. The outer end of the advanced middle pipe (1) is separated from the initial support (4), the outer end of the high-elevation advanced pipe (2) is separated from the initial support (4), and the outer end of the low-elevation advanced pipe (3) is separated from the extension beam on the initial support (4). The initial support (4) is moved forward, and the sprayed lining layer (5) is carried out on the inner wall of this section of the large-span tunnel. Or, area I is set as the upper end of the large-span tunnel, area VI is set as the middle part of the large-span tunnel, area VII is set as the lower end of the large-span tunnel, area II is set as the upper left part of the large-span tunnel, area III is set as the upper right part of the large-span tunnel, area IV is set as the lower left part of the large-span tunnel, and area V is set as the lower right part of the large-span tunnel. Or, the raw materials of the grouting reinforcement layer (6) are set to include 10-15 parts of cement, 8-12 parts of gypsum, 10-18 parts of quartz sand, 20-26 parts of redispersible latex powder, 1-3 parts of sulfonated melamine-based water reducing agent and 1-4 parts of sodium silicate, Alternatively, by adjusting the height, width and length of the upper step of the underground tunneling project in advance, providing a construction platform for equipment such as a down-the-hole drill and a grouting machine, using a down-the-hole drill to construct the outer layer of the advanced middle pipe (1), and using grouting equipment to carry out grouting construction, ensuring that the broken zone around the outer middle pipe shed is filled with cement slurry, the outer layer of the advanced middle pipe (1) is drilled and grouting is completed, and after reaching a certain strength, the tunnel excavation section is adjusted to a three-step seven-step excavation section, and tunnel excavation and initial support operations are carried out within the first cycle reinforcement range of the outer middle pipe shed. When the section is adjusted, the upper step area is excavated first, and a ring of high-elevation-angle advanced pipes (2) are constructed within the range of 120° of the arch top, and are firmly welded to the outer side of the initial support steel arch frame. The surrounding rock injection is formed by combining the grouting of the inner layer of the high-elevation-angle advanced pipe (2) with the grouting of the outer layer of the middle pipe shed. After the grouting reinforcement belt is strengthened, the subsequent excavation and support work is carried out. After the longitudinal excavation and support of the upper step is completed for 1.5m, the inner layer low-elevation angle advance pipe (3) is constructed. The low-elevation angle advance pipe (3) passes through the web of the steel arch frame and is firmly welded to the steel arch frame to form a grouting reinforcement reinforcement belt with the high-elevation angle advance pipe (2). The low-elevation angle advance pipe (3) and the high-elevation angle advance pipe (2) are cross-constructed to jointly supplement the grouting range of the outer layer advance middle pipe (1) to ensure the integrity and stability of the surrounding rock of the shallow buried broken zone in front and top of the underground dark excavation project. In this cycle, the outer layer advance middle pipe (1), the inner layer high-elevation angle advance pipe (2), and the inner layer low-elevation angle advance pipe (3) are repeatedly constructed and grouting is performed to form a broken zone reinforcement belt to ensure the safety of the large-span tunnel passing through the shallow buried broken zone. A large-span tunnel construction section device based on a large-span tunnel construction method that passes through a shallowly buried broken zone comprises a pipe group device for forming a grouting reinforcement layer (6) in a shallowly buried broken zone, and an initial support (4) arranged in the large-span tunnel and used to support the pipe group device.

2. The large-span tunnel construction section device based on passing through a shallow buried broken zone according to claim 1 is characterized by: The pipe assembly and the primary support (4) are connected to each other in the manner of carrying out a large-span tunnel excavation operation in a shallowly buried fractured zone.

3. The large-span tunnel construction section device based on passing through a shallow buried broken zone according to claim 2 is characterized by: The pipe group device is connected to the initial support (4) in the manner of carrying out cross-sectional area construction work on a large-span tunnel.

4. The large-span tunnel construction section device based on passing through a shallow buried broken zone according to claim 1 is characterized by: The tube group device is configured to include an advanced middle tube (1), a high elevation angle advanced tube (2) and a low elevation angle advanced tube (3). Or, it further comprises a first accessory device and the first accessory device is arranged on the large-span tunnel, and the first accessory device is arranged as a lining layer (5), Alternatively, the density of the grouting reinforcement layer (6) is arranged to be distributed in a step manner.

5. The large-span tunnel construction section device based on passing through a shallow buried broken zone according to claim 4 is characterized in that: An initial support (4) is arranged in the large-span tunnel, an advance middle pipe (1), a high-elevation-angle advance pipe (2) and a low-elevation-angle advance pipe (3) are arranged between the shallow-buried fracture zone and the initial support (4), and a lining layer (5) is arranged on the inner wall of the large-span tunnel.

6. The cross-sectional device for constructing a large-span tunnel based on passing through a shallowly buried broken zone according to claim 5 is characterized by: The initial support (4) is configured as an arch frame and the initial support (4) is configured to be connected to the leading middle tube (1), the high elevation angle leading tube (2) and the low elevation angle leading tube (3) respectively.

7. The large-span tunnel construction section device based on passing through a shallow buried broken zone according to claim 5 is characterized by: The advanced middle pipe (1), the high-elevation advanced pipe (2) and the low-elevation advanced pipe (3) are respectively arranged as grouting pipes, and the inner end of the advanced middle pipe (1), the inner end of the high-elevation advanced pipe (2) and the inner end of the low-elevation advanced pipe (3) are arranged in a shallow buried fracture zone, and the outer end of the advanced middle pipe (1), the outer end of the high-elevation advanced pipe (2) and the outer end of the low-elevation advanced pipe (3) are arranged to be connected to the initial support (4). Alternatively, the grouting reinforcement layer (6) is arranged to be distributed in a fan-shaped surface along the top section of the large-span tunnel to be excavated, and the fan-shaped angle δ of the grouting reinforcement layer (6) is set to 118-122°, and the thickness of the grouting reinforcement layer (6) is set to 2.5-3.5 m, Or, the elevation angle α of the leading middle tube (1) is set to 5°-12°, the circumferential spacing between adjacent leading middle tubes (1) is set to 0.3-0.4 m, the length of the leading middle tube (1) is set to 2.5-3.5 m, the elevation angle β of the high-elevation-angle leading tube (2) is set to 20°-30°, the circumferential spacing between adjacent high-elevation-angle leading tubes (2) is set to 0.3-0.4 m, the length of the high-elevation-angle leading tube (2) is set to 1.5-2.5 m, the elevation angle γ of the low-elevation-angle leading tube (3) is set to 5°-12°, the circumferential spacing between adjacent low-elevation-angle leading tubes (3) is set to 0.3-0.4 m, and the length of the low-elevation-angle leading tube (3) is set to 0.5-1.5 m, Or, the high elevation angle leading tube (2) and the low elevation angle leading tube (3) are respectively set as anchor rods, Alternatively, the lining layer (5) is configured as a cement mortar spraying layer and the lining layer (5) is configured to be attached to the inner wall of the large-span tunnel.

8. The cross-sectional device for constructing a large-span tunnel under a shallowly buried broken zone according to any one of claims 1 to 7, characterized in that: The advanced middle pipe (1), the high-elevation-angle advanced pipe (2), the low-elevation-angle advanced pipe (3) and the initial support (4) are arranged to be distributed in a manner of forming a built-in reinforcement layer, and the advanced middle pipe (1), the high-elevation-angle advanced pipe (2), the low-elevation-angle advanced pipe (3), the initial support (4) and the lining layer (5) are arranged to be distributed in a manner of forming an attached reinforcement layer.

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