Lining structure suitable for mountain tunnel and construction method thereof

Abstract

The invention relates to the technical field of tunnels, and provides a lining structure suitable for a mountain tunnel and a construction method thereof.The lining structure comprises an arch wall lining assembly and an inverted arch assembly, the arch wall lining assembly comprises an arch wall corrugated steel plate layer and an arch wall secondary lining layer, and the inverted arch assembly comprises an inverted arch corrugated steel plate layer, an inverted arch secondary lining layer, a frame column layer and a pavement layer; the bottom of the frame column layer is pre-buried in the inverted arch secondary lining layer, the pavement layer is laid on the top of the frame column layer, and the end of the inverted arch corrugated steel plate layer is connected with the end of the arch wall corrugated steel plate layer. According to the novel lining structure, particularly, a traditional inverted arch backfill layer is arranged to be of a frame layer structure, the use amount of concrete can be greatly reduced, the safety and stability of a tunnel are guaranteed, meanwhile, the material cost and the construction cost are reduced, and economic benefits are improved. In addition, the invention further provides a construction method and a design method of the frame column layer, and the construction method and the design method have direct guiding significance on actual engineering.

Description

Technical Field

[0001] The invention relates to the technical field of tunnels, in particular to a lining structure suitable for mountain tunnels and a construction method thereof. Background Art

[0002] At present, the lining structure of mountain tunnels generally adopts a composite lining structure, that is, the initial support + secondary lining structure. The lining structure includes an arch wall lining structure and an inverted arch lining structure. The arch wall lining structure mainly includes the initial support of the arch wall and the secondary lining of the arch wall. The initial support of the arch wall is a support structure immediately constructed after the tunnel is excavated. It mainly includes anchor rods, steel mesh, and shotcrete. It is used to quickly close the excavation surface to prevent the surrounding rock from loosening and collapsing. The main function of the secondary lining of the arch wall is to further enhance the safety and stability of the tunnel.

[0003] The tunnel invert structure mainly includes the initial support of the invert, the secondary lining of the invert, the backfill layer and the pavement layer. Among them, the initial support of the invert is the support structure constructed immediately after the tunnel excavation, which mainly includes anchor rods, steel mesh and shotcrete, which is used to quickly close the excavation surface to prevent the surrounding rock from loosening and collapsing. The main function of the secondary lining of the invert is to further enhance the safety and stability of the tunnel. The backfill layer is located between the secondary lining and the pavement layer. The main function of the backfill layer is to fill the gaps generated during tunnel excavation, reduce ground settlement, and play a role in water isolation. The pavement layer directly bears the pressure of vehicle loads and people walking. The pavement layer is usually paved with materials such as asphalt concrete or cement concrete.

[0004] The existing lining structure has the problems of complex construction, long construction period, and high concrete consumption. In particular, the backfill layer of the tunnel arch is usually filled with C15 concrete, with a large amount per linear meter, which can reach 8~10m³ / linear meter, and then the reinforced concrete pavement base is poured, and finally the asphalt layer is laid. This not only consumes a lot of concrete, but also has a long construction period.

[0005] In view of this, it is necessary to propose a lining structure suitable for mountain tunnels and a construction method thereof to solve or at least alleviate the above-mentioned defects. Summary of the invention

[0006] The main purpose of the present invention is to provide a lining structure suitable for mountain tunnels and a construction method thereof, so as to solve the technical problems of large amount of construction materials and long construction period in the prior art lining structure.

[0007] To achieve the above-mentioned object, the present invention provides a lining structure suitable for mountain tunnels, comprising an arch wall lining assembly and an inverted arch assembly, wherein the arch wall lining assembly and the inverted arch assembly are enclosed to form an annular structure; wherein the arch wall lining assembly comprises an arch wall corrugated steel plate layer and an arch wall secondary lining layer which are sequentially arranged from the outside to the inside along the radial direction of the tunnel; wherein the arch wall corrugated steel plate layer is provided with a first grouting hole and a first anchor hole for a first system anchor to penetrate, and foam concrete is injected into the interlayer space between the arch wall corrugated steel plate layer and the surrounding rock through the first grouting hole to form a first foam concrete layer; The inverted arch assembly comprises an inverted arch corrugated steel plate layer, an inverted arch secondary lining layer, a frame column layer and a pavement layer arranged in sequence from bottom to top; wherein, The inverted arch corrugated steel plate layer is provided with a second grouting hole and a second anchor hole for a second system anchor to penetrate. Foamed concrete is injected into the interlayer space between the inverted arch corrugated steel plate layer and the surrounding rock through the second grouting hole to form a second foamed concrete layer. The bottom of the frame column layer is pre-buried in the inverted arch secondary lining layer. The pavement layer is laid on the top of the frame column layer. The end of the inverted arch corrugated steel plate layer is connected to the end of the arch wall corrugated steel plate layer.

[0008] Preferably, the frame column layer includes a cover plate and a plurality of spaced column units, the lower end of each column unit is pre-buried in the secondary lining layer of the invert, the cover plate and the column unit are integrally cast as one, and the cover plate is arranged on the top of the column unit.

[0009] Preferably, the arch wall corrugated steel plate layer comprises a first corrugated steel plate body and two first connecting components respectively connected to the ends of the first corrugated steel plate body, each of the first connecting components comprises a first connecting plate and a second connecting plate, the first connecting plate is connected to the bottom of the first corrugated steel plate body, the second connecting plate is connected to the side of the first connecting plate close to the inverted arch corrugated steel plate layer, and the second connecting plate and the first connecting plate form an L-shaped structure; The inverted corrugated steel plate layer comprises a second corrugated steel plate body and two second connecting assemblies respectively connected to the ends of the second corrugated steel plate body, each of the second connecting assemblies comprises a third connecting plate, a fourth connecting plate and a fifth connecting plate arranged in parallel and spaced apart, the fourth connecting plate is connected to the end of the second corrugated steel plate body, the third connecting plate is connected between the fourth connecting plate and the fifth connecting plate, and the third connecting plate, the fourth connecting plate and the fifth connecting plate are enclosed to form a U-shaped structure with the opening facing downward; Wherein, the second connecting plate is connected in the inner cavity of the U-shaped structure.

[0010] Preferably, the fourth connecting plate is provided with a first connecting hole for bolts to pass through, the fifth connecting plate is provided with a second connecting hole corresponding to the first connecting hole, the second connecting plate is provided with a third connecting hole corresponding to the first connecting hole, a first water stop strip is provided between the second connecting plate and the fourth connecting plate, and a second water stop strip is provided between the second connecting plate and the fifth connecting plate. The second connecting plate is connected to the inner cavity of the U-shaped structure by bolts passing through the first connecting hole, the second connecting hole and the third connecting hole. The first water stop strip and the second water stop strip are both provided on the side of the bolt close to the third connecting plate.

[0011] Preferably, it also includes a vertical drainage pipe assembly and a central longitudinal drainage ditch; wherein, the central longitudinal drainage ditch is arranged at the bottom center of the second corrugated steel plate body, and is used to collect surrounding rock seepage from the outer wall of the second corrugated steel plate body, and the vertical drainage pipe assembly includes a plurality of vertical drainage pipes arranged at intervals along the extension direction of the central longitudinal drainage ditch, each of the vertical drainage pipes penetrates the second corrugated steel plate body and the secondary lining layer of the invert from bottom to top in sequence and enters the interval space of the column unit, and the bottom of the vertical drainage pipe is connected to the central longitudinal drainage ditch.

[0012] Preferably, the second connecting plate is provided with a drainage hole facing the second corrugated steel plate body at a position below the fourth connecting plate.

[0013] The present invention also provides a construction method for a lining structure suitable for a mountain tunnel, which is applied to the lining structure as described above and comprises the following steps: S1, after excavating the tunnel chamber, assemble the arch wall corrugated steel plate layer, inject foam concrete on the back of the arch wall corrugated steel plate layer through the first grouting hole to form a first foam concrete layer, and then drive the first system anchor bolt through the first anchor bolt hole; S2, after excavating the inverted arch, first excavate a central longitudinal drainage ditch at the center of the arch bottom, fill the central longitudinal drainage ditch with air bags, assemble the inverted arch corrugated steel plate layer, and then connect the end of the inverted arch corrugated steel plate layer with the end of the arch wall corrugated steel plate layer; S3, injecting foam concrete at the bottom of the inverted arch corrugated steel plate layer through the second grouting hole to form a second foam concrete layer, and then driving a second system anchor through the second anchor hole, and after the foam concrete solidifies, puncturing the air bag through the vertical drainage pipe; S4, pouring the secondary lining layer of the inverted arch, and reserving assembly holes on the top surface of the secondary lining layer of the inverted arch according to the design requirements, and after the secondary lining layer of the inverted arch solidifies, constructing the frame column layer; wherein, the column unit is inserted into the corresponding assembly hole, and the cover plate is assembled on the top of the column unit. After the column unit and the cover plate are fully assembled, the first steel cage is inserted into the column unit, and a single-layer steel mesh is laid on the cover plate. Finally, the cover plate and the column unit are integrally poured; wherein the cover plate is reserved with pouring holes corresponding to the column unit; S5, after the concrete of the cover plate is solidified, the secondary lining layer of the arch wall is poured, and then the pavement layer is laid on the top of the cover plate.

[0014] Preferably, the frame column layer in step S4 is obtained by the following design steps: S41, obtaining the axial pressure design value of the frame column layer ; S42, according to the axial pressure design value Determine the cross-sectional area of ​​the column unit ; S43, according to the formula Determine the cross-sectional area of ​​the longitudinal main reinforcement of the column unit ;in, is the longitudinal main reinforcement ratio of the column unit; S44, according to the formula Determine the allowable stress of the longitudinal tensile ordinary steel bars of the cover plate Value; among them, is the component stress characteristic coefficient of the cover plate; is the longitudinal main reinforcement strain non-uniformity coefficient between cracks, is the elastic modulus of the steel bars of the cover plate, It is the distance from the outer edge of the outermost longitudinal main reinforcement to the bottom edge of the tension zone. is the equivalent diameter of the longitudinal main reinforcement, is the longitudinal main reinforcement ratio calculated based on the effective tensile concrete cross-sectional area; When ; is the maximum crack width limit of the cover plate; S45, according to the formula Determine the maximum mid-span bending moment value of the cover plate , is the effective height of the cover section; S46, according to the formula Back-calculate the maximum span of the cover under the vehicle load ;in, is the equivalent uniformly distributed load of the vehicle, Concentrated load for vehicles; S47, according to the formula Calculate the distance from the longitudinal main reinforcement force point to the tensile edge of the section ; and according to the formula Determine the height of the cover plate section relative to the pressure zone ;in, is the design value of concrete axial compressive strength, is the equivalent rectangular stress figure coefficient of the concrete compression zone, b is the span per linear meter of the cover plate; S48, according to the formula and Determine the minimum reinforcement area of ​​the cover plate that meets the requirements , and then according to the minimum reinforcement area Determine the reinforcement method of the cover plate; wherein, is the design value of the tensile strength of the steel bar, is the minimum reinforcement ratio of the cover slab.

[0015] Preferably, the step S41 specifically includes the following steps: According to the formula Obtain the axial pressure design value of the frame column layer ;in, is the deadweight of the pavement layer, is the self-weight of the frame column layer, It is the larger value between the deadweight load of the construction machinery during construction and the vehicle load during operation.

[0016] Preferably, the step S42 specifically includes the following steps: According to the formula Determine the cross-sectional area of ​​the column unit ,unit: ,in, is the axial compression ratio limit, and d is the outer diameter of the column unit.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The invention provides a lining structure suitable for a mountain tunnel and a construction method thereof, comprising an arch wall lining assembly and an inverted arch assembly, wherein the arch wall lining assembly comprises an arch wall corrugated steel plate layer and an arch wall secondary lining layer, and the inverted arch assembly comprises an inverted arch corrugated steel plate layer, an inverted arch secondary lining layer, a frame column layer and a pavement layer, wherein the bottom of the frame column layer is pre-buried in the inverted arch secondary lining layer, the pavement layer is laid on the top of the frame column layer, and the end of the inverted arch corrugated steel plate layer is connected to the end of the arch wall corrugated steel plate layer.

[0018] The present application provides a new type of lining structure, in particular, using corrugated steel plates as initial support and setting the traditional invert backfill layer as a frame layer structure, which can greatly reduce the amount of concrete used, while ensuring the safety and stability of the tunnel, it also reduces the material cost and construction cost, and improves economic benefits. In addition, the present application also provides a construction method and a design method for the frame column layer to avoid construction errors, improve construction efficiency, and ensure structural safety and durability, avoid blind selection in the actual process, reduce engineering waste, and ultimately promote technical standardization and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 the structures shown in these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of an application scenario of the overall structure in one embodiment of the present invention; Figure 2 It is a schematic diagram of drainage of an invert in one embodiment of the present invention; Figure 3 It is a schematic diagram of the connection between the end of the inverted arch corrugated steel plate layer and the end of the arch wall corrugated steel plate layer in one embodiment of the present invention; Figure 4 It is a side view of the corrugated steel plate layer of the arch wall in one embodiment of the present invention; Figure 5 is a schematic structural diagram of a frame column layer in one embodiment of the present invention; Figure 6 is a schematic plan view of a PVC board in one embodiment of the present invention; Figure 7 is a schematic structural diagram of a column unit in an embodiment of the present invention; Figure 8 is a cross-sectional schematic diagram of a PVC board in one embodiment of the present invention; Fig. 9 It is a schematic flow chart of a construction method in one embodiment of the present invention.

[0021] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0022] Description of Figure Numbers: 10. Arch wall lining assembly; 110. Arch wall corrugated steel plate layer; 111. First corrugated steel plate body; 112. First connecting plate; 113. Second connecting plate; 114. Drain hole; 120. Arch wall secondary lining layer; 20. Inverted arch assembly; 210. Inverted arch corrugated steel plate layer; 211. Second corrugated steel plate body; 212. Third connecting plate; 213. Fourth connecting plate; 214. Fifth connecting plate; 215 , bolts; 220, first water stop; 230, second water stop; 240, secondary lining layer of the invert; 250, frame column layer; 251, cover plate; 2511, PVC board; 2512, annular docking groove; 2513, casting hole; 252, column unit; 2521, PVC vertical pipe; 2522, longitudinal main reinforcement; 260, pavement layer; 30, vertical drainage pipe assembly; 40, central longitudinal drainage ditch. DETAILED DESCRIPTION

[0023] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0024] 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.

[0025] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, the descriptions of "right part", "middle part" and the like in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "right part" and "middle part" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] Please refer to the attached Figures 1 to 8In one embodiment of the present invention, a lining structure suitable for a mountain tunnel comprises an arch wall lining assembly 10 and an inverted arch assembly 20, wherein the arch wall lining assembly 10 and the inverted arch assembly 20 are enclosed to form an annular structure; wherein the arch wall lining assembly 10 comprises an arch wall corrugated steel plate layer 110 and an arch wall secondary lining layer 120 which are sequentially arranged from the outside to the inside along the radial direction of the tunnel; wherein the arch wall corrugated steel plate layer 110 is provided with a first grouting hole (not shown) and a first anchor hole (not shown) for a first system anchor to penetrate, and foamed concrete is injected into the interlayer space between the arch wall corrugated steel plate layer 110 and the surrounding rock through the first grouting hole to form a first foamed concrete layer (not shown); The inverted arch assembly 20 includes an inverted arch corrugated steel plate layer 210, an inverted arch secondary lining layer 240, a frame column layer 250 and a pavement layer 260 arranged in sequence from bottom to top; wherein, The inverted arch corrugated steel plate layer 210 is provided with a second grouting hole (not shown in the figure) and a second anchor hole (not shown in the figure) for the second system anchor to penetrate. Foamed concrete is injected into the interlayer space between the inverted arch corrugated steel plate layer 210 and the surrounding rock through the second grouting hole to form a second foamed concrete layer (not shown in the figure). The bottom of the frame column layer 250 is pre-buried in the inverted arch secondary lining layer 240. The pavement layer 260 is laid on the top of the frame column layer 250. The end of the inverted arch corrugated steel plate layer 210 is connected to the end of the arch wall corrugated steel plate layer 110.

[0028] Specifically, the arch wall corrugated steel plate layer 110 serves as the outer initial support structure, providing preliminary support and protection. The foamed concrete is injected through the first grouting hole to fill the interlayer space between the arch wall corrugated steel plate layer 110 and the surrounding rock, which can effectively release the surrounding rock pressure and increase the stability and bearing capacity of the overall structure. In addition, since the corrugated steel plate itself is impermeable, it can play a good waterproof effect. On the other hand, the water seepage characteristics of the foamed concrete can be used to provide a drainage channel, so that the groundwater can seep along the foamed concrete on the outer surface of the arch wall corrugated steel plate layer 110 to below the arch foot. The groundwater can be discharged from the original underground drainage channel through the cracks in the surrounding rock. The arch wall secondary lining layer 120 serves as the inner layer structure, providing further support and protection to ensure the stability and durability of the tunnel. It can be obtained by spraying construction or mold construction.

[0029] The inverted arch corrugated steel plate layer 210 serves as the initial supporting structure of the inverted arch and provides preliminary support. Foamed concrete is injected through the second grouting hole to fill the interlayer space between the inverted arch corrugated steel plate layer 210 and the surrounding rock, which can effectively release the surrounding rock pressure and increase the stability and bearing capacity of the overall structure. In addition, since the corrugated steel plate itself is impermeable, it can have a good waterproof effect. On the other hand, the water seepage property of foamed concrete can be used to provide a drainage channel, so that groundwater can seep along the foamed concrete on the outer surface of the inverted arch corrugated steel plate layer 210 to below the arch bottom, and the groundwater can be discharged from the original underground drainage channel through the cracks in the surrounding rock.

[0030] The secondary lining layer 240 of the inverted arch serves as the inner structure of the inverted arch, providing further support and protection. The frame column layer 250 is pre-buried in the secondary lining layer 240 of the inverted arch, and the top supports the pavement layer 260 to form the longitudinal support structure of the tunnel.

[0031] The present application enhances the stability and bearing capacity of the tunnel invert structure through the combined effects of the corrugated steel layer, the foamed concrete layer, the system anchor rod and the secondary lining layer; the combined use of the corrugated steel layer and the secondary lining layer, as well as the filling of the foamed concrete, improves the waterproof performance and durability of the structure; the prefabrication and on-site construction of the corrugated steel layer and the frame column layer 250, as well as the grouting construction of the foamed concrete, shortens the construction period and reduces the amount of materials used in the project; greatly simplifies the construction process and shortens the construction period. In addition, the present application sets the traditional invert backfill layer as a frame layer structure, which can greatly reduce the amount of concrete used, while ensuring the safety and stability of the tunnel, it also reduces the material cost and construction cost, and improves the economic benefits.

[0032] Preferably, the pavement layer 260 includes a prefabricated pavement panel and an asphalt layer, wherein the prefabricated pavement panel is laid on the top of the cover plate 251, and the asphalt layer is laid on the top of the prefabricated pavement panel. The prefabricated pavement panel is produced in a factory, which can achieve standardized and large-scale production, greatly improve production efficiency, and the prefabricated pavement panel can be laid quickly, reducing on-site construction time and labor costs. The asphalt layer, as a surface layer, can be laid after the prefabricated pavement panel is laid, further shortening the construction period.

[0033] Preferably, the thickness of the prefabricated road panel is set between 15 cm and 25 cm, and the thickness of the asphalt layer is set between 8 cm and 10 cm.

[0034] As a preferred embodiment, the frame column layer 250 includes a cover plate 251 and a plurality of column units 252 arranged at intervals, the lower end of each of the column units 252 is pre-buried in the secondary lining layer 240 of the inverted arch, the cover plate 251 and the column unit 252 are integrally cast as one, and the cover plate 251 is arranged on the top of the column unit 252.

[0035] Specifically, the frame column layer 250 is integrally cast through multiple column units 252 and cover plates 251 to form a solid support system, which not only enhances the longitudinal support capacity of the tunnel invert, but also helps to resist the load from the tunnel side walls and top, thereby improving the stability of the entire tunnel structure; at the same time, the frame column layer 250 adopts the form of multiple column units 252 arranged at intervals, which can transform the existing invert backfill layer into a frame structure, while ensuring the safety and stability of the tunnel, greatly reducing the amount of concrete used, thereby reducing material costs and construction costs, and improving economic benefits.

[0036] Preferably, the plurality of column units 252 are arranged in a rectangular array, and the spacing between two adjacent column units 252 is set to 100×100 cm. By setting the spacing between two adjacent column units 252 to 100 cm×100 cm, it can be ensured that the load is distributed more evenly between the frame column layers 250, which helps to reduce the risk of structural damage caused by load concentration and improve the bearing capacity of the tunnel. It is understandable that in other embodiments, those skilled in the art can also set the spacing between the column units 252 to other values ​​according to actual needs.

[0037] Preferably, each of the column units 252 includes a PVC vertical pipe 2521 and a first steel cage (not shown in the figure), the cover plate 251 includes a PVC board 2511 and a single-layer steel mesh (not shown in the figure), the first steel cage is arranged on the inner side of the PVC vertical pipe 2521, the single-layer steel mesh is arranged on the inner side of the PVC board 2511, the bottom of the PVC board 2511 is formed with an annular docking groove 2512 matching the PVC vertical pipe 2521, the PVC board 2511 is docked to the top of the PVC vertical pipe 2521 through the annular docking groove 2512, and the top of the PVC board 2511 is reserved with a casting hole 2513 corresponding to the PVC vertical pipe 2521, the longitudinal main reinforcement 2522 of the first steel cage extends upward to be connected to the single-layer steel mesh, and concrete is poured through the casting hole 2513 to fill the cavity enclosed by the PVC vertical pipe 2521 and the PVC board 2511 with concrete.

[0038] Specifically, the first steel cage, as the main bearing part of the column unit 252, provides high strength and rigidity. The longitudinal main reinforcement 2522 is connected with the single-layer steel mesh to form a continuous steel skeleton, which further enhances the integrity and cooperative working ability between the column unit 252 and the cover plate 251, thereby improving the bearing capacity of the frame column layer 250; it is worth noting that the PVC vertical pipe 2521, as the outer layer of the column unit 252, has certain anti-corrosion, waterproof and durable properties, which can protect the internal reinforced concrete structure from erosion by the external environment, extend the service life of the column unit 252, and can also be used as a template for pouring concrete in the PVC vertical pipe 2521, so as to achieve permanent and temporary use. Similarly, the PVC board 2511 can also be used as a template for upper pouring. The construction personnel can first construct the PVC vertical pipe 2521, the first steel cage, the PVC board 2511, and the single-layer steel mesh, and then cast the concrete on site to achieve overall pouring and improve construction efficiency and quality.

[0039] As a preferred embodiment, the arch wall corrugated steel plate layer 110 includes a first corrugated steel plate body 111 and two first connecting components (not shown) respectively connected to the ends of the first corrugated steel plate body 111, each of the first connecting components includes a first connecting plate 112 and a second connecting plate 113, the first connecting plate 112 is connected to the bottom of the first corrugated steel plate body 111, the second connecting plate 113 is connected to the first connecting plate 112 on one side close to the inverted arch corrugated steel plate layer 210, and the second connecting plate 113 and the first connecting plate 112 form an L-shaped structure; The inverted corrugated steel plate layer 210 includes a second corrugated steel plate body 211 and two second connecting components respectively connected to the ends of the second corrugated steel plate body 211, each of the second connecting components includes a third connecting plate 212, a fourth connecting plate 213 and a fifth connecting plate 214 arranged in parallel and spaced apart, the fourth connecting plate 213 is connected to the end of the second corrugated steel plate body 211, the third connecting plate 212 is connected between the fourth connecting plate 213 and the fifth connecting plate 214, the third connecting plate 212, the fourth connecting plate 213 and the fifth connecting plate 214 are enclosed to form a U-shaped structure with the opening facing downward; wherein, the second connecting plate 113 is connected in the inner cavity of the U-shaped structure.

[0040] Furthermore, the fourth connecting plate 213 is provided with a first connecting hole for the bolt 215 to pass through, the fifth connecting plate 214 is provided with a second connecting hole corresponding to the first connecting hole, the second connecting plate 113 is provided with a third connecting hole corresponding to the first connecting hole, a first water stop strip 220 is provided between the second connecting plate 113 and the fourth connecting plate 213, and a second water stop strip 230 is provided between the second connecting plate 113 and the fifth connecting plate 214. The second connecting plate 113 is connected to the inner cavity of the U-shaped structure by the bolt 215 passing through the first connecting hole, the second connecting hole and the third connecting hole. The first water stop strip 220 and the second water stop strip 230 are both provided on the side of the bolt 215 close to the third connecting plate 212.

[0041] It is worth noting that the initial support of the inverted arch and the arch wall in this application is made of corrugated steel plates. The connection between the inverted arch corrugated steel plate layer 210 and the arch wall corrugated steel plate layer 110 needs to take into account both construction convenience and structural waterproofing. Figure 3 As shown, a first L-shaped connecting component is arranged at the arch foot of the first corrugated steel plate body 111, and a second connecting component corresponding to the first connecting component is arranged at the end of the second corrugated steel plate body 211. The second connecting component is in a U-shaped structure, so it can be inverted on the L-shaped first connecting component, and the outer side of the second connecting component in the U-shaped structure is closely attached to the first connecting component, that is, the fifth connecting plate 214 is closely attached to the outer wall surface of the first corrugated steel plate body 111, which is conducive to the conduction of horizontal force, and then connected by bolts 215, and further provided with a first water stop strip 220 and a second water stop strip 230 on the inner cavity of the U-shaped structure, respectively placed on both sides of the second connecting plate 113, and after the bolts 215 are tightened, the first water stop strip 220 and the second water stop strip 230 can be squeezed to form two waterproof layers, thereby achieving both construction convenience and structural waterproofness.

[0042] As another preferred embodiment, it also includes a vertical drainage pipe assembly 30 and a central longitudinal drainage ditch 40; wherein, the central longitudinal drainage ditch 40 is arranged at the bottom center of the second corrugated steel plate body 211, and is used to collect surrounding rock seepage from the outer wall of the second corrugated steel plate body 211, and the vertical drainage pipe assembly 30 includes a plurality of vertical drainage pipes arranged at intervals along the extension direction of the central longitudinal drainage ditch 40, each of the vertical drainage pipes penetrates the second corrugated steel plate body 211 and the secondary lining layer 240 of the inverted arch from bottom to top in sequence and enters the interval space of the column unit 252, and the bottom of the vertical drainage pipe is connected to the central longitudinal drainage ditch 40.

[0043] It should be noted that the existing technology of Zhongshanling Tunnel drainage design has always used the following scheme: laying a waterproof layer between the initial support and the secondary lining, setting longitudinal drainage pipes at the arch feet on both sides, and wrapping the longitudinal drainage pipes with a waterproof layer to introduce groundwater into the longitudinal drainage pipes, and then introduce them into the longitudinal drainage ditch in the tunnel through the transverse drainage pipes to discharge the groundwater out of the tunnel.

[0044] It is worth noting that this plan changes the original drainage channel, which may lead to changes in the regional surface water system, causing the original ponds and streams to dry up, thereby affecting the local ecological environment and even affecting the local residents' domestic water use.

[0045] Secondly, waterproof materials and construction techniques have a great impact on the waterproofing and drainage effect. (1) Traditional waterproof materials and techniques are difficult to meet the special environmental requirements of tunnels, and are prone to aging, damage and other problems, resulting in tunnel leakage. For example, in some tunnels under water or in high humidity environments, materials such as waterproof boards and waterstops are affected by water erosion and structural deformation for a long time, shortening their service life. (2) When laying waterproof boards, if the initial support surface is uneven and there are sharp objects, it is easy to puncture the waterproof board; there may also be problems such as leaking welds and cold welds during the welding process, affecting the waterproofing effect.

[0046] Finally, this solution of the prior art is prone to blockage and inconvenient to maintain. (1) The circumferential, longitudinal and transverse drainage pipes in the tunnel drainage system may be blocked by mud, debris, concrete residues, etc. during use. In particular, the drainage pipes behind the lining are difficult to repair and dredge once they are blocked. (2) When designing the drainage system, there may be deviations in the prediction of the amount of water inflow in the tunnel. When encountering special circumstances such as heavy rain, abnormally abundant groundwater, or changes in geological conditions after years of tunnel operation, the originally designed drainage system may not be able to meet the drainage needs, resulting in water accumulation in the tunnel. (3) In the existing drilling and blasting tunnel drainage system, the drainage pipes and other facilities behind the lining have small maintenance space, are difficult to operate, and have high maintenance costs. A lot of manpower and material resources are required for maintenance, and it may even be necessary to partially dismantle the lining for maintenance.

[0047] In view of the above-mentioned problems, the embodiment of the present application adopts a corrugated steel plate layer as the initial support, and wraps the tunnel in the corrugated steel plate layer. Since the corrugated steel plate layer itself is impermeable, it can play a good waterproof role. The second foam concrete layer obtained by backfilling the foam concrete on the outside of the corrugated steel plate layer can be used as a buffer layer on the one hand, and on the other hand, the water seepage property of the foam concrete can be used to provide a drainage channel, so that the groundwater can seep along the foam concrete on the outer surface of the inverted arch corrugated steel plate layer 210 to the central longitudinal drainage ditch 40 at the bottom of the arch. A part of the groundwater can be discharged from the original underground drainage channel through the surrounding rock cracks, and the excess groundwater can be discharged from the central longitudinal drainage ditch 40 at the bottom of the arch.

[0048] In particular, when the groundwater level rises sharply during the rainy season and the central longitudinal drainage ditch 40 at the bottom of the arch cannot meet the drainage requirements, the excess groundwater can be introduced into the cave through the vertical drainage pipe assembly 30, and the spacing between the column units 252 can be fully utilized to discharge the groundwater from the cave to the outside. In this way, the groundwater resources can be protected and the original drainage channel can be restored, and the safety of the tunnel structure can be protected when the groundwater level rises sharply. This embodiment completely changes the tunnel drainage design, reduces the impact on groundwater, and helps to protect the ecological environment. Secondly, various types of drainage pipes in the cave are eliminated, solving the hidden danger of drainage blockage caused by the failure of the drainage pipes, and is simple to maintain.

[0049] Preferably, the diameter of the vertical drainage pipe is set between 200 mm and 300 mm, and the width of the central longitudinal drainage ditch 40 is set between 50 cm and 80 cm.

[0050] Furthermore, the second connecting plate 113 is provided with a drain hole 114 facing the second corrugated steel plate body 211 at a position below the fourth connecting plate 213. The drain hole 114 provided on the second connecting plate 113 has the main function of draining water. When water accumulates in the area between the second corrugated steel plate body 211 and the fourth connecting plate 213, the water can flow out through the drain hole 114, thereby avoiding the accumulation of water in the area. This is beneficial for preventing corrosion, keeping the structure dry, and improving the durability of the overall structure.

[0051] Please refer to the attached Fig. 9 The present invention also provides a construction method for a lining structure suitable for a mountain tunnel, which is applied to the lining structure as described above, and comprises the following steps: S1, after excavating the tunnel chamber, assemble the arch wall corrugated steel plate layer 110, inject foam concrete on the back of the arch wall corrugated steel plate layer 110 through the first grouting hole to form a first foam concrete layer, and then drive the first system anchor bolt through the first anchor bolt hole; S2, after excavating the inverted arch, first excavate a central longitudinal drainage ditch 40 at the center of the arch bottom, fill the central longitudinal drainage ditch 40 with air bags, assemble the inverted arch corrugated steel plate layer 210, and then connect the end of the inverted arch corrugated steel plate layer 210 with the end of the arch wall corrugated steel plate layer 110; The specific steps are as follows: the second connecting component with a U-shaped structure is buckled into the first connecting component with an L-shaped structure, and by extrusion, it is determined whether the bolt 215 reaches the preset position, and when it reaches the preset position, it is fixed by the bolt 215, so as to achieve a sealed connection between the end of the inverted arch corrugated steel plate layer 210 and the end of the arch wall corrugated steel plate layer 110; S3, injecting foamed concrete at the bottom of the inverted corrugated steel plate layer 210 through the second grouting hole to form a second foamed concrete layer, and then driving a second system anchor through the second anchor hole, and after the foamed concrete solidifies, puncturing the air bag through the vertical drainage pipe; S4, pouring the secondary lining layer 240 of the inverted arch, and reserving assembly holes on the top surface of the secondary lining layer 240 according to the design requirements, after the secondary lining layer 240 of the inverted arch solidifies, constructing the frame column layer 250; wherein, the column unit 252 is inserted into the corresponding assembly hole, and the cover plate 251 is assembled on the top of the column unit 252, and after the column unit 252 and the cover plate 251 are fully assembled, the first steel cage is inserted into the column unit 252, and a single-layer steel mesh is laid on the cover plate 251, and finally the cover plate 251 and the column unit 252 are integrally poured; wherein the cover plate 251 is reserved with pouring holes corresponding to the column unit 252; S5, after the concrete of the cover plate 251 is solidified, the secondary lining layer 120 of the arch wall is poured, and then the pavement layer 260 is laid on the top of the cover plate 251.

[0052] As a preferred embodiment, the frame column layer 250 in step S4 is obtained by the following design steps: S41, obtaining the axial pressure design value of the frame column layer 250 ,unit: ; S42, according to the axial pressure design value Determine the cross-sectional area of ​​the column unit 252 ,unit: ; S43, according to the formula Determine the cross-sectional area of ​​the longitudinal main reinforcement of the column unit 252 ,unit: ;in, is the longitudinal main reinforcement ratio of the column unit 252; S44, according to the formula Determine the allowable stress of the longitudinal tensile ordinary steel bars of the cover plate 251 Value, unit: ,in, is the component force characteristic coefficient of the cover plate 251; is the longitudinal main reinforcement strain non-uniformity coefficient between cracks, is the elastic modulus of the steel bars of the cover plate 251, unit: , It is the distance from the outer edge of the outermost longitudinal main reinforcement to the bottom edge of the tension zone, unit: mm, is the equivalent diameter of the longitudinal main reinforcement, unit: mm, is the longitudinal main reinforcement ratio calculated based on the effective tensile concrete cross-sectional area; When ; is the maximum crack width limit of the cover plate 251, unit: mm. Considering the first-level highway load, the maximum width allowed by the crack control requirement is no more than 0.2 mm. Equal to 0.2mm; S45, according to the formula Determine the maximum mid-span bending moment value of the cover plate 251 ,unit: , is the effective height of the cross section of the cover plate 251, unit: m; S46, according to the formula The maximum span of the cover plate 251 under the vehicle load is calculated by back calculation. ;in, is the equivalent uniformly distributed vehicle load, unit: , is the concentrated load of the vehicle, unit: ; S47, according to the formula Calculate the distance from the longitudinal main reinforcement force point to the tensile edge of the section , unit: mm; and according to the formula Determine the cross-section height of the cover plate 251 relative to the pressure zone , unit: mm; where, is the design value of concrete axial compressive strength, is the equivalent rectangular stress figure coefficient of the concrete compression zone. For concrete C50 and below ; b take the span of the cover plate 251 per linear meter; S48, according to the formula and Determine the minimum reinforcement area of ​​the cover plate 251 that meets the requirements ,unit: , and then according to the minimum reinforcement area Determine the reinforcement method of the cover plate 251; wherein, is the design value of the tensile strength of the steel bar, unit: MPa, is the minimum reinforcement ratio of cover plate 251.

[0053] Furthermore, the step S41 specifically includes the following steps: According to the formula Obtain the axial pressure design value of the frame column layer 250 ;in, is the deadweight of pavement layer 260, unit: , The self-weight of the frame column layer 250, unit: , It is the larger value of the deadweight load of the construction machinery during the construction period and the vehicle load during the operation period, unit: .

[0054] Furthermore, the step S42 specifically includes the following steps: According to the formula Determine the cross-sectional area of ​​the column unit 252 ,unit: ,in, is the axial pressure ratio limit, and d is the outer diameter of the column unit 252.

[0055] It is worth noting that the design method of the frame column layer 250 provided in this embodiment, the cross-sectional area of ​​the column unit 252 obtained by the design steps is and cross-sectional area , according to the cross-sectional area and cross-sectional area The size and reinforcement of the column unit 252 required in the actual construction process can be determined, and the maximum span obtained through the design steps and minimum reinforcement area , the size and reinforcement of the cover plate 251 required in the actual construction process can be determined, so that the feasibility of the current construction plan can be clarified. By disclosing specific size and reinforcement data, the standardization and normalization of related technologies can be promoted, which has a direct guiding significance for actual construction, avoids construction errors, improves construction efficiency, and ensures structural safety and durability, avoids blind selection in the actual process, reduces engineering waste, and ultimately promotes technical standardization and promotion.

[0056] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A lining structure suitable for mountain tunnels, characterized in that: The invention comprises an arch wall lining assembly and an inverted arch assembly, wherein the arch wall lining assembly and the inverted arch assembly are combined to form an annular structure; wherein the arch wall lining assembly comprises an arch wall corrugated steel plate layer and an arch wall secondary lining layer which are sequentially arranged from the outside to the inside along the tunnel radial direction; wherein the arch wall corrugated steel plate layer is provided with a first grouting hole and a first anchor hole for a first system anchor to penetrate, and foamed concrete is injected into the interlayer space between the arch wall corrugated steel plate layer and the surrounding rock through the first grouting hole to form a first foamed concrete layer; The inverted arch assembly comprises an inverted arch corrugated steel plate layer, an inverted arch secondary lining layer, a frame column layer and a pavement layer arranged in sequence from bottom to top; wherein, The inverted arch corrugated steel plate layer is provided with a second grouting hole and a second anchor hole for a second system anchor to penetrate. Foamed concrete is injected into the interlayer space between the inverted arch corrugated steel plate layer and the surrounding rock through the second grouting hole to form a second foamed concrete layer. The bottom of the frame column layer is pre-buried in the inverted arch secondary lining layer. The pavement layer is laid on the top of the frame column layer. The end of the inverted arch corrugated steel plate layer is connected to the end of the arch wall corrugated steel plate layer.

2. The lining structure suitable for mountain tunnels according to claim 1 is characterized in that: The frame column layer includes a cover plate and a plurality of column units arranged at intervals, the lower end of each column unit is pre-buried in the secondary lining layer of the inverted arch, the cover plate and the column unit are integrally cast as one, and the cover plate is arranged on the top of the column unit.

3. The lining structure suitable for mountain tunnels according to claim 2 is characterized in that: The arch wall corrugated steel plate layer comprises a first corrugated steel plate body and two first connecting components respectively connected to the ends of the first corrugated steel plate body, each of the first connecting components comprises a first connecting plate and a second connecting plate, the first connecting plate is connected to the bottom of the first corrugated steel plate body, the second connecting plate is connected to the side of the first connecting plate close to the inverted arch corrugated steel plate layer, and the second connecting plate and the first connecting plate form an L-shaped structure; The inverted corrugated steel plate layer comprises a second corrugated steel plate body and two second connecting assemblies respectively connected to the ends of the second corrugated steel plate body, each of the second connecting assemblies comprises a third connecting plate, a fourth connecting plate and a fifth connecting plate arranged in parallel and spaced apart, the fourth connecting plate is connected to the end of the second corrugated steel plate body, the third connecting plate is connected between the fourth connecting plate and the fifth connecting plate, and the third connecting plate, the fourth connecting plate and the fifth connecting plate are enclosed to form a U-shaped structure with the opening facing downward; Wherein, the second connecting plate is connected in the inner cavity of the U-shaped structure.

4. The lining structure suitable for mountain tunnels according to claim 3 is characterized in that: The fourth connecting plate is provided with a first connecting hole for bolts to pass through, the fifth connecting plate is provided with a second connecting hole corresponding to the first connecting hole, the second connecting plate is provided with a third connecting hole corresponding to the first connecting hole, a first water stop strip is provided between the second connecting plate and the fourth connecting plate, and a second water stop strip is provided between the second connecting plate and the fifth connecting plate. The second connecting plate is connected to the inner cavity of the U-shaped structure by bolts passing through the first connecting hole, the second connecting hole and the third connecting hole. The first water stop strip and the second water stop strip are both provided on the side of the bolt close to the third connecting plate.

5. The lining structure suitable for mountain tunnels according to claim 3 is characterized in that: It also includes a vertical drainage pipe assembly and a central longitudinal drainage ditch; wherein, the central longitudinal drainage ditch is arranged at the bottom center of the second corrugated steel plate body, and is used to collect surrounding rock seepage from the outer wall of the second corrugated steel plate body. The vertical drainage pipe assembly includes a plurality of vertical drainage pipes arranged at intervals along the extension direction of the central longitudinal drainage ditch, each of the vertical drainage pipes passes through the second corrugated steel plate body and the secondary lining layer of the invert from bottom to top in sequence and enters the interval space of the column unit, and the bottom of the vertical drainage pipe is connected to the central longitudinal drainage ditch.

6. The lining structure suitable for mountain tunnels according to claim 4, characterized in that: The second connecting plate is provided with a drainage hole facing the second corrugated steel plate body at a position below the fourth connecting plate.

7. A construction method for a lining structure suitable for a mountain tunnel, applied to the lining structure as claimed in any one of claims 5 to 6, characterized in that: The following steps are involved: S1, after excavating the tunnel chamber, assemble the arch wall corrugated steel plate layer, inject foam concrete on the back of the arch wall corrugated steel plate layer through the first grouting hole to form a first foam concrete layer, and then drive the first system anchor bolt through the first anchor bolt hole; S2, after excavating the inverted arch, first excavate a central longitudinal drainage ditch at the center of the arch bottom, fill the central longitudinal drainage ditch with air bags, assemble the inverted arch corrugated steel plate layer, and then connect the end of the inverted arch corrugated steel plate layer with the end of the arch wall corrugated steel plate layer; S3, injecting foam concrete at the bottom of the inverted arch corrugated steel plate layer through the second grouting hole to form a second foam concrete layer, and then driving a second system anchor through the second anchor hole, and after the foam concrete solidifies, puncturing the air bag through the vertical drainage pipe; S4, pouring the secondary lining layer of the inverted arch, and reserving assembly holes on the top surface of the secondary lining layer of the inverted arch according to the design requirements, and after the secondary lining layer of the inverted arch solidifies, constructing the frame column layer; wherein, the column unit is inserted into the corresponding assembly hole, and the cover plate is assembled on the top of the column unit. After the column unit and the cover plate are fully assembled, the first steel cage is inserted into the column unit, and a single-layer steel mesh is laid on the cover plate. Finally, the cover plate and the column unit are integrally poured; wherein the cover plate is reserved with pouring holes corresponding to the column unit; S5, after the concrete of the cover plate is solidified, the secondary lining layer of the arch wall is poured, and then the pavement layer is laid on the top of the cover plate.

8. The construction method of the lining structure suitable for mountain tunnels according to claim 7, characterized in that: The frame column layer in step S4 is obtained by the following design steps: S41, obtaining the axial pressure design value of the frame column layer ; S42, according to the axial pressure design value Determine the cross-sectional area of ​​the column unit ; S43, according to the formula Determine the cross-sectional area of ​​the longitudinal main reinforcement of the column unit ;in, is the longitudinal main reinforcement ratio of the column unit; S44, according to the formula Determine the allowable stress of the longitudinal tensile ordinary steel bars of the cover plate Value; among them, is the component stress characteristic coefficient of the cover plate; is the longitudinal main reinforcement strain non-uniformity coefficient between cracks, is the elastic modulus of the steel bars of the cover plate, It is the distance from the outer edge of the outermost longitudinal main reinforcement to the bottom edge of the tension zone. is the equivalent diameter of the longitudinal main reinforcement, is the longitudinal main reinforcement ratio calculated based on the effective tensile concrete cross-sectional area; When ; is the maximum crack width limit of the cover plate; S45, according to the formula Determine the maximum mid-span bending moment value of the cover plate , is the effective height of the cover section; S46, according to the formula Back-calculate the maximum span of the cover under the vehicle load ;in, is the equivalent uniformly distributed load of the vehicle, Concentrated load for vehicles; S47, according to the formula Calculate the distance from the longitudinal main reinforcement force point to the tensile edge of the section ; and according to the formula Determine the height of the cover plate relative to the compression zone ;in, is the design value of concrete axial compressive strength, is the equivalent rectangular stress figure coefficient of the concrete compression zone, b is the span per linear meter of the cover plate; S48, according to the formula and Determine the minimum reinforcement area of ​​the cover plate that meets the requirements , and then according to the minimum reinforcement area Determine the reinforcement method of the cover plate; wherein, is the design value of the tensile strength of the steel bar, is the minimum reinforcement ratio of the cover slab.

9. The construction method of the lining structure suitable for mountain tunnels according to claim 8, characterized in that: The step S41 specifically includes the following steps: According to the formula Obtain the axial pressure design value of the frame column layer ;in, is the deadweight of the pavement layer, is the self-weight of the frame column layer, It is the larger value between the deadweight load of the construction machinery during construction and the vehicle load during operation.

10. The construction method of the lining structure suitable for mountain tunnels according to claim 8, characterized in that: The step S42 specifically includes the following steps: According to the formula Determine the cross-sectional area of ​​the column unit ,unit: ,in, is the axial compression ratio limit, and d is the outer diameter of the column unit.

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