Integral cover arch structure of large-section multi-arch tunnel in soft stratum
By setting up an integral arch structure at the tunnel entrance, including arch sections for the main tunnel and the intermediate guide tunnel, the supporting capacity was enhanced, the safety problem of constructing large-section continuous arch tunnels in soft strata was solved, and the stability and safety of construction were achieved.
Patent Information
- Application Number
- CN202520105351.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2035-01-16
AI Technical Summary
In existing technologies, it is difficult to ensure the safety of the tunnel entrance during the construction of large-section continuous arch tunnels in soft strata, especially since the advanced small guide pipe protection of the pilot tunnel is insufficient, resulting in high construction risks.
An integral arch structure is adopted, including arch sections that match the main tunnel and the intermediate tunnel. The arch sections of the main tunnel and the intermediate tunnel are cast together as a whole through steel frames and orifice pipe rows to enhance the support capacity. Double-layer long pipe sheds are set at the orifice section for advanced support.
It improves the support capacity for weak surrounding rock, ensures the safety and stability of tunnel entrance construction, and reduces construction risks.
Smart Images
Figure CN223724628U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to tunnel engineering technical field especially a whole type sleeve arch structure of soft weak stratum large section multi-arch tunnel. BACKGROUND
[0002] At present, multi-arch tunnel has been used in large quantities, with the increasing of highway traffic volume, more and more large section multi-arch tunnels, and the multi-arch tunnel is usually shallow buried depth, poor geology. The multi-arch tunnel portal generally adopts the conventional scheme of advance small catheter + pipe shed, that is, the tunnel main hole sets up pipe shed and sleeve arch, and the middle pilot hole sets up advance small catheter, this scheme is generally used in the middle pilot hole of stone tunnel.
[0003] However, for the soft weak stratum large section multi-arch tunnel, the middle pilot hole portal adopts the advance small catheter protection type, it is difficult to ensure the safety of the construction into the hole, and the main hole section is large, the geological condition is poor, the buried depth is shallow, the advance protection should be strengthened to ensure the safety of the tunnel portal construction. How to ensure the safety of the construction of the soft weak stratum large section multi-arch tunnel portal is a problem that must be solved at present.
[0004] Therefore, it is necessary to provide a whole type sleeve arch structure of soft weak stratum large section multi-arch tunnel to solve or at least alleviate the above-mentioned defects. CONTENT OF THE UTILITY MODEL
[0005] The main purpose of the utility model is to provide a whole type sleeve arch structure of soft weak stratum large section multi-arch tunnel to solve the technical problem that the conventional scheme of advance small catheter + pipe shed is used in the soft weak stratum large section multi-arch tunnel in the prior art, which cannot guarantee the safety of the construction of the tunnel portal.
[0006] To achieve the above-mentioned purpose, the utility model provides a whole type sleeve arch structure of soft weak stratum large section multi-arch tunnel, which comprises a main hole sleeve arch section matched with the shape of the tunnel main hole and a middle pilot hole sleeve arch section matched with the shape of the middle pilot hole, and the middle pilot hole sleeve arch section is connected with the main hole sleeve arch section, wherein,
[0007] The main hole sleeve arch section has a first end and a second end oppositely arranged along the tunnel ring, the first end is lapped at the tunnel outside arch foot, and the second end is connected with the top of the middle pilot hole sleeve arch section;
[0008] The main hole set of arch segments comprises a first set of arch reinforcement assembly, at least one first guide load-bearing layer arranged along the radial direction of the tunnel, each first guide load-bearing layer comprises a first steel frame and a first orifice pipe row arranged along the radial direction of the tunnel, the first orifice pipe row comprises a plurality of first orifice pipes arranged along the circumferential direction of the tunnel, each first orifice pipe extends along the extension direction of the tunnel, the first orifice pipe is connected with the first steel frame, the first steel frame is in an arch shape, and the first steel frame, the first orifice pipe row and the first set of arch reinforcement assembly are integrally casted.
[0009] The middle pilot hole set of arch segments has a third end and a fourth end arranged opposite along the circumferential direction of the middle pilot hole, and the third end and the fourth end are located at the arch bottom of the tunnel; the middle pilot hole set of arch segments comprises a second set of arch reinforcement assembly, a second steel frame and a second orifice pipe row, the second orifice pipe row comprises a plurality of second orifice pipes arranged along the circumferential direction of the middle pilot hole, each second orifice pipe extends along the extension direction of the tunnel, the second orifice pipe is connected with the second steel frame, the second steel frame is in an arch shape, and the second set of arch reinforcement assembly, the second steel frame and the second orifice pipe row are integrally casted.
[0010] Preferably, the first steel frame comprises a fifth end and a sixth end arranged opposite along the extension direction of the first steel frame, the fifth end is overlapped at the outer arch spring of the tunnel, and the sixth end is connected with the middle pilot hole set of arch segments.
[0011] Preferably, the plurality of first orifice pipes of each first orifice pipe row are arranged to the two sides from the arch top of the tunnel respectively, and the corresponding central angle range of the first orifice pipe row is arranged between 110° and 120°.
[0012] Preferably, the plurality of second orifice pipes of each second orifice pipe row are arranged to the two sides from the top of the middle pilot hole respectively, and the corresponding central angle range of the second orifice pipe row is arranged between 110° and 130°.
[0013] Preferably, the arch waist expansion foundation is further arranged, the arch waist expansion foundation is connected to the outer side of the main hole set of arch segments and extends along the transverse direction of the tunnel, and the arch waist expansion foundation is arranged corresponding to the excavation boundary line of the portal step.
[0014] Preferably, the arch spring expansion foundation is further arranged, the arch spring expansion foundation is connected to the outer bottom of the main hole set of arch segments and extends along the transverse direction of the tunnel.
[0015] Preferably, the number of the first guide load-bearing layers is two, and the first orifice pipes of the adjacent two first guide load-bearing layers are arranged in staggered intervals along the circumferential direction of the tunnel.
[0016] Preferably, a first grouting small duct assembly arranged at the first end is further included, the first grouting small duct assembly includes a plurality of first grouting small duct rows arranged along the tunnel extension direction, each of the first grouting small duct rows includes a plurality of first grouting small ducts arranged along the tunnel transverse direction, the lower end of each of the first grouting small ducts extends downward into the arch bottom surrounding rock, and the upper end of each of the first grouting small ducts is embedded into the main hole arch segment.
[0017] Preferably, a second grouting small duct assembly arranged at the third end and a third grouting small duct assembly arranged at the fourth end are further included, wherein,
[0018] The second grouting small duct assembly includes a plurality of second grouting small duct rows arranged along the tunnel extension direction, each of the second grouting small duct rows includes a plurality of second grouting small ducts arranged along the tunnel transverse direction, the lower end of each of the second grouting small ducts extends downward into the arch bottom surrounding rock, and the upper end of each of the second grouting small ducts is embedded into the middle pilot hole arch segment;
[0019] The third grouting small duct assembly includes a plurality of third grouting small duct rows arranged along the tunnel extension direction, each of the third grouting small duct rows includes a plurality of third grouting small ducts arranged along the tunnel transverse direction, the lower end of each of the third grouting small ducts extends downward into the arch bottom surrounding rock, and the upper end of each of the third grouting small ducts is embedded into the middle pilot hole arch segment.
[0020] Preferably, the thickness of the main hole arch segment is set to 105 cm, and the thickness of the middle pilot hole arch segment is set to 80 cm.
[0021] Compared with the prior art, the utility model has the beneficial effects that:
[0022] The utility model provides a kind of overall type arch structure of soft stratum large section multi-arch tunnel, including and the main hole shape matching of tunnel main hole arch segment, and the middle pilot hole shape matching of middle pilot hole arch segment, main hole arch segment includes first arch reinforcement assembly, at least one first guide load layer being arranged along the radial direction of tunnel, first steel frame, first orifice pipe row and first arch reinforcement assembly are integrally cast as a whole, middle pilot hole arch segment includes second arch reinforcement assembly, second steel frame and second orifice pipe row, second arch reinforcement assembly, second steel frame and second orifice pipe row are integrally cast as a whole.
[0023] The application sets the overall type arch structure of "main hole-middle pilot hole-main hole" in the tunnel portal segment, that is, in addition to the pipe shed arch (main hole arch segment) arranged in the main hole of the tunnel, the pipe shed arch (middle pilot hole arch segment) is also arranged in the middle pilot hole and falls to the bottom, and the main hole arch segment and the middle pilot hole arch segment are constructed together, which can effectively improve the supporting capacity of soft surrounding rock and ensure the construction safety of the tunnel portal. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0025] Figure 1 This is an application scenario diagram of the overall structure in one embodiment of the present utility model;
[0026] Figure 2 for Figure 1 Enlarged diagram of point A in the diagram;
[0027] Figure 3 This is a schematic diagram of the overall structure in one embodiment of the present invention;
[0028] Figure 4 This is a schematic diagram of the structure for applying steel pipe advance support in the first orifice pipe in one embodiment of the present invention;
[0029] Figure 5 This is a schematic diagram showing the connection between the first steel frame and the second steel frame in one embodiment of the present invention.
[0030] The purpose, features, and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.
[0031] Explanation of icon numbers:
[0032] 10. Main tunnel arch section; 110. First end; 120. Second end; 130. First guide bearing layer; 131. First steel frame; 132. First orifice pipe; 140. Arch waist enlarged foundation; 150. Arch foot enlarged foundation; 20. Middle guide tunnel arch section; 210. Third end; 220. Fourth end; 230. Second steel frame; 240. Second orifice pipe; 30. First grouting small guide pipe; 40. Second grouting small guide pipe; 50. Third grouting small guide pipe; 60. Main tunnel; 70. Middle guide tunnel; 80. Steel pipe; 90. Continuous connecting steel plate. Detailed Implementation
[0033] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.
[0034] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.
[0035] It should be noted that all the directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship and movement condition between components in a certain specific posture (as described in the drawings), and if the specific posture changes, the directional indications will also change accordingly.
[0036] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of the technical solutions appears contradictory or unachievable, it should be considered that the combination of the technical solutions does not exist, and is not within the protection scope required by the present application.
[0037] Please refer to the accompanying drawings Figures 1 to 5 The present application provides a kind of soft weak stratum large section multi-arch tunnel's integral type sleeve arch structure in an embodiment, including and the shape of tunnel main hole 60 matching main hole sleeve arch section 10, and the shape of middle pilot hole 70 matching middle pilot hole sleeve arch section 20, the middle pilot hole sleeve arch section 20 and the main hole sleeve arch section 10 are connected, wherein,
[0038] The main hole sleeve arch section 10 has the first end 110 and the second end 120 oppositely arranged along the tunnel ring, the first end 110 is overlapped at the tunnel outside arch foot, and the second end 120 is connected with the top of the middle pilot hole sleeve arch section 20;
[0039] The main hole set-arch section 10 comprises a first set-arch reinforcement assembly (not shown in the figure), at least one first guide load-bearing layer 130 arranged along the radial direction of the tunnel, each first guide load-bearing layer 130 comprising a first steel frame 131 and a first row of orifice pipes (not shown in the figure) arranged along the radial direction of the tunnel, the first row of orifice pipes comprising a plurality of first orifice pipes 132 arranged along the circumferential direction of the tunnel, each first orifice pipe 132 extending along the extension direction of the tunnel, the first orifice pipes 132 being connected to the first steel frame 131, the first steel frame 131 being in an arch shape, and the first set-arch reinforcement assembly, the first steel frame 131 and the first row of orifice pipes being integrally casted.
[0040] The middle pilot hole set-arch section 20 has a third end 210 and a fourth end 220 oppositely arranged along the circumferential direction of the middle pilot hole 70, and both the third end 210 and the fourth end 220 are located at the bottom of the tunnel arch, the middle pilot hole set-arch section 20 comprising a second set-arch reinforcement assembly (not shown in the figure), a second steel frame 230 and a second row of orifice pipes (not shown in the figure), the second row of orifice pipes comprising a plurality of second orifice pipes 240 arranged along the circumferential direction of the middle pilot hole 70, each second orifice pipe 240 extending along the extension direction of the tunnel, the second orifice pipes 240 being connected to the second steel frame 230, the second steel frame 230 being in an arch shape, and the second set-arch reinforcement assembly, the second steel frame 230 and the second row of orifice pipes being integrally casted.
[0041] Specifically, the application sets an overall set-arch structure of "main hole-middle pilot hole 70-main hole" at the tunnel portal section, that is, in addition to the pipe shed set-arch (main hole set-arch section 10) arranged at the main hole 60 of the tunnel, the pipe shed set-arch (middle pilot hole set-arch section 20) is also arranged at the middle pilot hole 70 and falls to the bottom, and the main hole set-arch section 10 is constructed together with the middle pilot hole set-arch section 20. As a preferred example, the thickness of the main hole set-arch section 10 is set to 105 cm, and the thickness of the middle pilot hole set-arch section 20 is set to 80 cm, which effectively improves the structural integrity and stability.
[0042] As a preferred example, the number of the first guide load-bearing layers 130 is two, and the first orifice pipes 132 of the adjacent two first guide load-bearing layers 130 are staggered and spaced in the circumferential direction of the tunnel. In this embodiment, the first orifice pipes 132 of the adjacent two first guide load-bearing layers 130 are staggered and spaced in the circumferential direction of the tunnel, which can ensure the range of the advanced long pipe shed grouting reinforcement. Preferably, φ108x6mm advanced long pipe shed is used in the first orifice pipe 132 for advanced support, the circumferential spacing of the inner ring first orifice pipe 132 is 40 cm, and the circumferential spacing of the outer ring first orifice pipe 132 is 41.6 cm. It can be understood that in other embodiments, the number of the first guide load-bearing layers 130 can also be set to multiple layers, for example, three layers, according to actual needs.
[0043] The second orifice pipe 240 is preferably provided with a φ108*6mm long pipe roof for advance support, and the annular spacing of the second orifice pipe 240 is 40cm.
[0044] As shown in the actual construction process, the corresponding steel pipe 80 is inserted into the first orifice pipe 132 to make a long pipe roof for advance support, and the corresponding steel pipe 80 is inserted into the second orifice pipe 240 to make a long pipe roof for advance support. Figure 4
[0045] The embodiment can effectively improve the supporting capacity of the soft surrounding rock by setting the double-layer long pipe roof + single-layer long pipe roof of the middle pilot tunnel 70 in the tunnel main hole 60, and ensure the construction safety of the tunnel portal.
[0046] The main hole arch segment 10 comprises a first arch reinforcement assembly and at least one first guide bearing layer 130, the guide bearing layer comprises a first steel frame 131 and a first orifice pipe row, and the first arch reinforcement assembly, the first steel frame 131 and the first orifice pipe row are integrally poured to enhance the strength and rigidity of the main hole arch segment 10.
[0047] The middle pilot tunnel arch segment 20 comprises a second arch reinforcement assembly, a second steel frame 230 and a second orifice pipe row, and is integrally poured to enhance the strength and rigidity of the middle pilot tunnel arch segment 20.
[0048] The main hole arch segment 10 and the middle pilot tunnel arch segment 20 are both of reinforced concrete structure, and meanwhile, in order to improve the supporting capacity of the arch to the long pipe roof, the arch steel bars in the range of the long pipe roof can be densified.
[0049] The orifice pipes in the first orifice pipe row and the second orifice pipe row extend along the extension direction of the tunnel and are connected with the steel frame, preferably welded. The first orifice pipe row and the second orifice pipe row provide guidance and bearing for the long pipe roof, realize the advance support of the tunnel construction, and further improve the stability and bearing capacity of the soil around the tunnel.
[0050] Further, the first steel frame 131 comprises a fifth end (not marked in the figure) and a sixth end (not marked in the figure) oppositely arranged along the extension direction thereof, the fifth end is overlapped at the outer side springing of the tunnel, and the sixth end is connected with the middle pilot tunnel arch segment 20.
[0051] Specifically, the fifth end of the first steel frame 131 is overlapped at the outer side springing of the tunnel, and the sixth end is connected with the top of the middle pilot tunnel arch segment 20. By using the effective support of the first steel frame 131, the overall bearing capacity of the arch is improved, and the connection stability between the main hole arch segment 10 and the middle pilot tunnel arch segment 20 is enhanced.
[0052] Further, as shown in the actual construction process, the corresponding steel pipe 80 is inserted into the first orifice pipe 132 to make a long pipe roof for advance support, and the corresponding steel pipe 80 is inserted into the second orifice pipe 240 to make a long pipe roof for advance support. Figure 5 As shown, the first steel frame 131 and the second steel frame 230 preferably adopt I-beams, the longitudinal spacing is 80 cm, and the first steel frame 131 and the second steel frame 230 are each arranged as 3 bays along the extension direction of the tunnel. In order to improve the integrity of the arch structure, a through-connection steel plate 90 is arranged at the connection position of the first steel frame 131 and the second steel frame 230 along the extension direction of the tunnel, the length of the through-connection steel plate 90 is 2 m, and the two sides of the through-connection steel plate 90 are respectively welded and fixed with the first steel frame 131 and the second steel frame 230.
[0053] As a preferred example, the plurality of first orifice pipes 132 of each first orifice pipe row are arranged from the tunnel vault to both sides respectively, and the corresponding central angle range of the first orifice pipe row is arranged between 110°-120°.
[0054] Specifically, the plurality of first orifice pipes 132 of the first orifice pipe row are arranged from the tunnel vault to both sides respectively, which can ensure that the range of the advanced long pipe shed grouting reinforcement covers the vault and the two side areas of the tunnel. Since the vault area is a weak area and a key bearing area, and in order to reduce the engineering cost, the embodiment focuses on grouting reinforcement of the area with the central angle range arranged between 110°-120°.
[0055] As a preferred example, the plurality of second orifice pipes 240 of each second orifice pipe row are arranged from the top of the middle pilot hole 70 to both sides respectively, and the corresponding central angle range of the second orifice pipe row is arranged between 110°-130°.
[0056] Specifically, the plurality of second orifice pipes 240 of the second orifice pipe row are arranged from the top of the middle pilot hole 70 to both sides respectively, which can ensure that the range of the advanced long pipe shed grouting reinforcement covers the top and the two side areas of the middle pilot hole 70. Since the top area is a weak area and a key bearing area, and in order to reduce the engineering cost, the embodiment focuses on grouting reinforcement of the area with the central angle range arranged between 110°-130°.
[0057] As a preferred embodiment, it further includes a haunch enlarged foundation 140, which is connected to the outside of the main hole arch section 10 and extends along the transverse direction of the tunnel, and the haunch enlarged foundation 140 is arranged corresponding to the tunnel portal step excavation boundary.
[0058] Specifically, the tunnel portal section preferably adopts the step reserved core soil construction method. After the upper step excavation of the portal is completed, the upper half of the arch needs to be constructed first. At the tunnel portal step excavation boundary, the haunch enlarged foundation 140 is arranged at the waist position of the main hole arch section 10. Preferably, the length of the haunch enlarged foundation 140 is 100 cm, and the height is 80 cm. By increasing the bearing area, the settlement of the arch is effectively reduced.
[0059] As another preferable embodiment, an arch foot enlarged foundation 150 is further included, which is connected to the outer bottom of the main hole lining arch segment 10 and extends along the tunnel transversely.
[0060] Specifically, the arch foot enlarged foundation 150 is arranged at the outer bottom of the main hole lining arch segment 10, preferably, the arch foot enlarged foundation 150 is 80 cm long and 60 cm high, which increases the bearing area of the lining arch and can effectively reduce the settlement of the lining arch.
[0061] As a preferable embodiment, a first grouting small duct assembly (not shown in the figure) is further included at the first end 110, which includes a plurality of first grouting small duct rows (not shown in the figure) arranged at intervals along the extension direction of the tunnel, each of the first grouting small duct rows includes a plurality of first grouting small ducts 30 arranged at intervals along the transverse direction of the tunnel, the lower end of each of the first grouting small ducts 30 extends downward into the surrounding rock at the arch bottom, and the upper end of the first grouting small duct 30 is embedded into the main hole lining arch segment 10.
[0062] Notably, the first grouting small duct 30 assembly is used for foundation reinforcement at the first end 110 of the main hole lining arch segment 10, preferably, the size of the first grouting small duct 30 is φ42 mm x 3.5 m, and the embedding depth of the first grouting small duct 30 into the main hole lining arch segment 10 is 30-50 cm, so as to improve the integrity and effectively improve the bearing capacity of the lining arch foundation and reduce the settlement of the lining arch.
[0063] As another preferable embodiment, a second grouting small duct assembly is further included at the third end 210 and a third grouting small duct assembly is further included at the fourth end 220, wherein,
[0064] The second grouting small duct assembly includes a plurality of second grouting small duct rows arranged at intervals along the extension direction of the tunnel, each of the second grouting small duct rows includes a plurality of second grouting small ducts 40 arranged at intervals along the transverse direction of the tunnel, the lower end of each of the second grouting small ducts 40 extends downward into the surrounding rock at the arch bottom, and the upper end of the second grouting small duct 40 is embedded into the middle pilot hole lining arch segment 20;
[0065] The third grouting small duct assembly includes a plurality of third grouting small duct 50 rows arranged at intervals along the extension direction of the tunnel, each of the third grouting small duct 50 rows includes a plurality of third grouting small ducts 50 arranged at intervals along the transverse direction of the tunnel, the lower end of each of the third grouting small ducts 50 extends downward into the surrounding rock at the arch bottom, and the upper end of the third grouting small duct 50 is embedded into the middle pilot hole lining arch segment 20.
[0066] Specifically, the second grouting small catheter is used at the third end 210 of the middle pilot hole lining arch section 20, and the third grouting small catheter 50 is used at the fourth end 220 of the middle pilot hole lining arch section 20 to carry out the foundation reinforcement, preferably, the size of the second grouting small catheter 40 and the third grouting small catheter 50 is preferably φ42mm*3.5m, the depth of the second grouting small catheter 40 and the third grouting small catheter 50 embedded in the middle pilot hole lining arch section 20 is 30-50cm, so as to improve the integrity, effectively improve the lining arch foundation bearing capacity, and reduce the lining arch settlement.
[0067] The above is only the preferred embodiment of the utility model, and does not limit the patent range of the utility model, and equivalent structures or equivalent process transformations using the utility model specification and the attached drawing contents, or direct or indirect application in other related technical fields, are also included in the patent protection range of the utility model.
Claims
1. A monolithic sleeve arch structure of a large-section multi-arch tunnel in a weak stratum, characterized in that, The main hole lining section matches the shape of the main hole, and the middle pilot hole lining section matches the shape of the middle pilot hole. The main hole lining section has a first end and a second end arranged opposite along the tunnel ring direction, the first end overlaps at the outer side of the tunnel arch foot, and the second end is connected with the top of the middle pilot hole lining section. The main hole lining section includes a first lining reinforcement assembly, at least one first guide load layer arranged along the tunnel radial direction, and the first guide load layer is used for guiding and bearing the advanced long pipe shed, each first guide load layer includes a first steel frame and a first orifice pipe row arranged along the tunnel radial direction, the first orifice pipe row includes a plurality of first orifice pipes arranged along the tunnel ring direction, each first orifice pipe extends along the tunnel extension direction, the first orifice pipe is connected with the first steel frame, the first steel frame has an arch shape, and the first steel frame, the first orifice pipe row and the first lining reinforcement assembly are integrally casted. The middle pilot hole lining section has a third end and a fourth end arranged opposite along the middle pilot hole ring direction, and the third end and the fourth end are located at the tunnel arch bottom; the middle pilot hole lining section includes a second lining reinforcement assembly, a second steel frame and a second orifice pipe row, the second orifice pipe row includes a plurality of second orifice pipes arranged along the middle pilot hole ring direction, each second orifice pipe extends along the tunnel extension direction, the second orifice pipe is connected with the second steel frame, the second steel frame has an arch shape, and the second lining reinforcement assembly, the second steel frame and the second orifice pipe row are integrally casted.
2. The monolithic lining structure of the soft ground large cross-section multi-arch tunnel according to claim 1, characterized in that, The first steel frame includes a fifth end and a sixth end arranged opposite along the extension direction of the first steel frame, the fifth end overlaps at the outer side of the tunnel arch foot, and the sixth end is connected with the middle pilot hole lining section.
3. The monolithic lining structure of the soft ground large cross-section multi-arch tunnel according to claim 2, characterized in that, The plurality of first orifice pipes of each first orifice pipe row are arranged to two sides from the tunnel arch top respectively, and the corresponding central angle range of the first orifice pipe row is set to be between 110° and 120°.
4. The monolithic lining structure of the soft ground large cross-section multi-arch tunnel according to claim 1, characterized in that, The plurality of second orifice pipes of each second orifice pipe row are arranged to two sides from the middle pilot hole top respectively, and the corresponding central angle range of the second orifice pipe row is set to be between 110° and 130°.
5. The monolithic lining structure of the soft ground large cross-section multi-arch tunnel according to claim 4, characterized in that, An arch waist expansion foundation is further included, the arch waist expansion foundation is connected to the outer side of the main hole lining section and extends along the tunnel transverse direction, and the arch waist expansion foundation is arranged corresponding to the tunnel opening step excavation boundary.
6. The monolithic lining structure of the soft ground large cross-section multi-arch tunnel according to claim 5, characterized in that, An arch foot expansion foundation is further included, the arch foot expansion foundation is connected to the outer bottom of the main hole lining section and extends along the tunnel transverse direction.
7. The monolithic lining structure of the soft ground large cross-section multi-arch tunnel according to claim 5, characterized in that, The number of the first guide load layers is two, and the first orifice pipes of the adjacent two first guide load layers are staggered and spaced in the tunnel ring direction.
8. The monolithic lining structure of the soft ground large cross-section multi-arch tunnel according to claim 6, characterized in that, A first grouting small catheter assembly is further included and arranged at the first end, the first grouting small catheter assembly includes a plurality of first grouting small catheter rows arranged along the tunnel extension direction, each first grouting small catheter row includes a plurality of first grouting small catheters arranged along the tunnel transverse direction, the lower end of each first grouting small catheter extends downward into the arch bottom surrounding rock, and the upper end of the first grouting small catheter is embedded into the main hole lining section.
9. The monolithic lining structure of a soft ground multi-arch tunnel according to claim 8, wherein, Further comprising a second grouting small catheter assembly arranged at the third end and a third grouting small catheter assembly arranged at the fourth end, wherein, The second grouting small catheter assembly comprises a plurality of second grouting small catheter rows arranged along the tunnel extension direction, each of the second grouting small catheter rows comprises a plurality of second grouting small catheters arranged along the tunnel transverse direction, the lower end of each of the second grouting small catheters extends downwardly into the surrounding rock at the arch bottom, and the upper end of each of the second grouting small catheters is embedded into the middle pilot hole arch segment; The third grouting small catheter assembly comprises a plurality of third grouting small catheter rows arranged along the tunnel extension direction, each of the third grouting small catheter rows comprises a plurality of third grouting small catheters arranged along the tunnel transverse direction, the lower end of each of the third grouting small catheters extends downwardly into the surrounding rock at the arch bottom, and the upper end of each of the third grouting small catheters is embedded into the middle pilot hole arch segment.
10. The monolithic lining structure of a soft ground multi-arch tunnel according to claim 1, wherein The thickness of the main hole arch segment is set to 105 cm, and the thickness of the middle pilot hole arch segment is set to 80 cm.