A mountain shed tunnel

Abstract

The present invention provides a mountain-side shed tunnel, comprising at least one group of continuous arch structures, each group of continuous arch structures consisting of a plurality of single-arch single-span structures, the span direction of the single-arch single-span structure being parallel to the preset driving direction. Thus, the span of the shed tunnel is not too long due to the change of the road width, and the span length and the number of continuous arch structure groups can be flexibly adjusted according to the bearing capacity requirements. At the same time, during the construction of the structure, since the span direction of the single-arch single-span structure is kept parallel to the driving direction, the construction safety is strong, the number of construction working surfaces that can be excavated at the same time is increased, and the construction efficiency of the shed tunnel is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to a mountainside shed tunnel. Background Art

[0002] A shed tunnel is a special type of tunnel, which is an open tunnel structure that is not completely closed. One side of the shed tunnel structure is against the mountain and the other side is open to the sky. The side against the mountain is a protective wall attached to the wall, and the side facing the sky is a column, frame or arched window. The top is closed and backfilled with soil and rocks to form a semi-shelter structure. Shed tunnels are often used in tunnel oblique entrance sections or road sections along rivers and mountains, with steep slopes, etc. They are shed structures set up to conform to the terrain, protect the environment, reduce slope excavation, and protect the safety of people and vehicles in sections prone to geological disasters such as landslides and falling rocks. Taking the more common outer column flat-top inner arch wall or rectangular shed tunnels in road engineering as an example, the following two construction methods are generally required:

[0003] 1. Cut and fill method

[0004] like Figure 1 As shown, the construction sequence of the open cut and backfill method is: excavate the mountain to form a temporary slope surface; build the pile foundation on the air side of the shed tunnel structure or expand the foundation and the bottom longitudinal beam between the columns; build the retaining wall on the air side of the shed tunnel structure and backfill under the bottom plate; construct the bottom plate, outer columns, side walls on the side facing the mountain, top plate and retaining walls above the top plate of the shed tunnel structure to form an integral structure; build the internal roadbed and pavement of the shed tunnel, drainage pipes, curbstone anti-collision, maintenance trails and other ancillary structures; backfill the soil and stone above the top plate of the shed tunnel structure and green the slope. The mountainside tunnel built by the open-cut and backfill method is a cast-in-place reinforced concrete frame structure, which has strong integrity, clear force, simple process and mature technology; but it also has significant disadvantages: this structural construction method requires excavation of the original mountain to open up construction space for building the tunnel structure. The artificial excavation slope formed is a large-scale high and steep slope, which is contrary to the original intention of using a tunnel to minimize the slope excavation range, reduce the slope excavation height, and protect the natural vegetation and environmental features.

[0005] 2. Half-light and half-dark method

[0006] The semi-open and semi-hidden method is to construct a mountain-side tunnel with half section open and half section dark excavation, such as Figure 2As shown, the construction sequence is as follows: select a reasonable position according to the terrain to determine the cross-section open and dark excavation dividing slope, clean the surface, and form a temporary slope surface through artificial excavation; install locking anchor rods or anchor cables to stabilize the mountain; build the pile foundation of the exposed part of the shed-hole structure or expand the foundation and the bottom longitudinal beam between the columns; build the retaining wall of the exposed part of the shed-hole structure and backfill under the bottom plate; construct the arched bottom plate of the exposed part of the shed-hole structure; build the outer columns of the exposed part of the shed-hole structure; erect temporary supporting columns; build the exposed part of the shed-hole structure The flat top plate of the part is constructed; the advanced large pipe shed support of the dark excavation part of the shed tunnel structure is constructed; the rock and soil of the dark excavation part of the shed tunnel structure is excavated, and the anchor rods of the system around the tunnel and the initial support arch side wall and arch bottom plate in the composite lining of the dark excavation part of the shed tunnel structure are constructed as the excavation progresses; the secondary lining arch side wall and arch bottom plate in the composite lining of the dark excavation part of the shed tunnel structure are constructed; the substructures such as the roadbed and pavement, drainage pipe trench, curbstone anti-collision, and inspection trail inside the shed tunnel structure are constructed; the soil and stone above the top plate of the shed tunnel structure and the green slope are backfilled. The mountain-side shed tunnel constructed by the semi-open and semi-dark method is a combination of the cast-in-place reinforced concrete structure of the open part and the composite lining structure of the dark excavation part, forming an overall structure with a flat roof of outer columns and an inner arch wall. This structure and construction method are the structural forms and construction methods with many application cases of existing technical solutions. The technology is relatively mature and the structural integrity is good. Its biggest advantage is that since the tunnel structure is located below the mountain and the dark excavation method is used for construction, the excavation of the original natural terrain slope of the mountain is avoided, and the natural vegetation and environmental features of the proposed shed tunnel section are effectively protected; but the biggest disadvantage is that the construction risk is relatively high. Due to the special location of the road along the mountain, the excavation of the dark excavation part of the shed tunnel structure is a great destruction and disturbance to the stability of the foot of the half-cut slope of the natural mountain. The natural mountain or covering layer at the location of the proposed route is thick, the soil and stone and other slope deposits are loose, or the rock mass is highly weathered and the joints and fissures are developed. There are risks such as slope instability, bias, rockfall, collapse, and large deformation for the construction of the dark excavation part.

[0007] However, when the cross-sectional span of the tunnel is large, the span of the corresponding arch or rectangular section is also large. Under the action of the overlying rock and soil load and the eccentric load, there are still deficiencies such as insufficient structural bearing capacity, large amount of support and reinforcement measures invested to stabilize the slope and surrounding rock, poor economy, low construction efficiency, and long construction period.

[0008] Therefore, there is an urgent need to provide an improved mountain shed tunnel that can solve the problems of high construction risk, long construction period and insufficient structural bearing capacity in the prior art. Summary of the invention

[0009] The present invention aims to provide a mountain shed tunnel which can solve the above-mentioned technical problems.

[0010] According to one aspect of the present invention, a mountain shed tunnel is provided, comprising at least one group of continuous arch structures, each group of continuous arch structures consisting of a plurality of single-arch single-span structures, the span direction of the single-arch single-span structure being parallel to a preset driving direction.

[0011] Preferably, the single-arch single-span structure includes: an arch top, used to bear the overlying load; a support beam, arranged at the arch foot of the arch top along the longitudinal direction of the single-arch single-span structure; and columns, located at both ends of the support beam and connected to the arch top and the support beam to form a whole.

[0012] Preferably, the vault comprises: a concealed excavation vault close to the mountain side, which is composed of an outer concealed excavation vault primary support 3-2 and an inner concealed excavation vault secondary lining structure 4-1, and a waterproof layer is provided between the concealed excavation vault primary support 3-2 and the concealed excavation vault secondary lining structure 4-1; and an exposed vault 4-2 away from the mountain side, the cross-section of the exposed vault 4-2 is the same as and aligned with the cross-section of the concealed excavation vault secondary lining structure 4-1.

[0013] Preferably, the arch of the dark excavation section also includes an arch large pipe shelf advance support 2-3 and an arch system anchor rod 2-4, which are used to stabilize the surrounding mountain rock formations of the tunnel.

[0014] Preferably, the columns include: concealed section wall columns 7-1, located on the end wall of the tunnel on the mountain side; exposed section columns 7-2, located on the air side of the tunnel, with the lower end connected to an exposed section pile foundation 7-4 or an exposed section enlarged foundation.

[0015] Preferably, the exposed section pile foundation 7-4 is connected through the exposed section column bottom cap 7-3 and the exposed section column 7-2; the exposed section enlarged foundation is directly connected to the exposed section column 7-2.

[0016] Preferably, the mountainside shed tunnel also includes a plurality of longitudinal beams 8, which are arranged along the driving direction, specifically including: a plurality of longitudinal beams 8-1 in the dark-cut section, which are located in the middle of the end wall and are respectively connected between two adjacent support beams; a bottom longitudinal beam 8-2 in the dark-cut section, which is arranged through the bottom of the end wall; and a plurality of bottom longitudinal beams 8-3 between columns in the exposed section, which are respectively connected between the bottom pedestals 7-3 of two adjacent exposed section columns or between two adjacent exposed section enlarged foundations.

[0017] Preferably, the part below the roadbed surface of the proposed road of the exposed section of the tunnel is filled with subgrade backfill 9-2. When exposed section pile foundation 7-4 is adopted, an exposed section pile retaining wall 9-1 is arranged between two adjacent exposed section pile foundations 7-4 to support the subgrade backfill 9-2.

[0018] Preferably, the mountain shed tunnel also includes an air-side retaining wall 9-3, which is arranged above multiple arches along the driving direction and is used to support the arch backfill 11 filled between the mountain slope 1, the air-side retaining wall 9-3 and the arch enclosed area.

[0019] Preferably, a deformation joint is provided between two adjacent groups of linked arch structures.

[0020] The present invention provides a mountain-side shed tunnel, comprising at least one group of continuous arch structures, each group of continuous arch structures consisting of a plurality of single-arch single-span structures, the span direction of the single-arch single-span structure being parallel to the preset driving direction. Thus, the span of the shed tunnel is not too long due to the change of the road width, and the span length and the number of continuous arch structure groups can be flexibly adjusted according to the bearing capacity requirements. At the same time, during the construction of the tunnel, since the span direction of the single-arch single-span structure is kept parallel to the driving direction, the construction safety is strong, the number of construction working surfaces that can be excavated at the same time is increased, and the construction efficiency of the shed tunnel is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 It is a structural schematic diagram of a shed tunnel using the open cut and backfill method according to the prior art;

[0023] Figure 2 It is a schematic diagram of the structure of a shed tunnel using a semi-bright and semi-dark method according to the prior art;

[0024] Figure 3 is a schematic diagram of the three-dimensional structure of a mountain shed tunnel according to an embodiment of the present invention;

[0025] FIG4 is a schematic diagram of the construction process of a mountain shed tunnel according to an embodiment of the present invention;

[0026] Among them, 1. Mountain slope; 2-1. Advance support of large pipe shed for upper guide tunnel in dark excavation section; 2-2. Anchor rod of upper guide tunnel system in dark excavation section; 2-3. Advance support of large pipe shed for arch in dark excavation section; 2-4. Anchor rod of arch system in dark excavation section; 2-5. Anchor rod of lower guide tunnel system in dark excavation section; 3-1. Initial support of upper guide tunnel in dark excavation section; 3-2. Initial support of arch in dark excavation section; 3-3. Initial support of lower guide tunnel in dark excavation section; 4-1. Secondary lining structure of arch in dark excavation section; 4-2. Arch in open section; 5-1. Support beam in dark excavation section; 5-2. Support beam in open section; 6-1. The upper part of the end wall; 6-2, the lower part of the end wall; 7-1, the wall columns of the concealed section; 7-2, the columns of the exposed section; 7-3, the bottom pedestal of the columns of the exposed section; 7-4, the pile foundation of the exposed section; 8-1, the middle longitudinal beam of the concealed section; 8-2, the bottom longitudinal beam of the concealed section; 8-3, the bottom longitudinal beam between the columns of the exposed section; 9-1, the retaining wall between the piles of the exposed section; 9-2, the backfill under the roadbed; 9-3, the retaining wall on the side facing the air; 10, the roadbed and pavement, drainage pipe trench, curb collision prevention, maintenance walkway and other ancillary structures inside the tunnel; 11, the backfill of the arch; 12, the construction limit of the proposed road. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] Reference will now be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and described below. For ease of interpretation and precise definition in the appended claims, the terms "upper", "lower", "inner" and "outer" are used to describe features of the exemplary embodiments shown in the drawings with reference to their positions.

[0029] Figure 3 4 and 5 respectively show a schematic diagram of the three-dimensional structure and a schematic diagram of the construction process of a mountainside shed tunnel according to an embodiment of the present invention. As shown in the figure, the mountainside shed tunnel includes at least one group of connected arch structures, each group of connected arch structures is composed of a plurality of single-arch single-span structures, and the span direction of the single-arch single-span structure is parallel to the preset driving direction.

[0030] According to an embodiment of the present invention, a deformation joint is arranged between two adjacent groups of linked arch structures.

[0031] In the related technology, a mountain-side shed tunnel with a flat roof and an inner arch wall or a rectangular cross-section is used. However, when the width of the proposed road surface is large, the stability of the above structure is poor. When the mountain structure is not stable enough, the construction safety risk is high and the construction period is long.

[0032] Different from the related art in which the span direction of the arched shed tunnel or the rectangular shed tunnel (that is, the main force direction) is perpendicular to the driving direction, the mountainside shed tunnel in the embodiment of the present invention arranges one or more groups of serially connected arch structures along the driving direction, and each group of connected arch structures is connected by several single-arch and single-span structures whose spans are parallel to the driving direction. This can improve the stress condition of the mountainside shed tunnel structure, reduce the construction risk of the mountainside shed tunnel structure, avoid large-scale cutting of the mountain when building the shed tunnel along the mountain, maintain the stability of the natural slope, and protect the natural environment and ecological landscape.

[0033] The span of the single-arch single-span structure of the embodiment of the present invention can be flexibly determined according to the rationality and economy of the structural stress; the number of holes (i.e., the number of spans) of each group of multi-span continuous arch structures is determined after structural stress analysis, and can generally be 3 continuous arches or 5 continuous arches or more; the number of groups of continuous arch structures is determined according to the terrain, geology, and route design conditions, that is, the length of the road section to be protected. When the geological conditions or slope stability are poor, the span can be reduced to reduce the load borne by the single-arch single-span structure and the continuous arch structure, so as to achieve the purpose of improving the structural stress conditions, improving the cross-section economy, and reducing the construction risk. The continuous arch structure of the mountain-side shed tunnel in the embodiment of the present invention can form multiple adjacent, parallel, coordinated, but mutually less interfering construction working surfaces, get rid of the constraints of the existing technical solution that there are only two construction working surfaces at the inlet and outlet ends along the longitudinal direction of the proposed road, and can further speed up the construction progress; at the same time, each single-arch single-span structure and continuous arch structure has the same cross-section, the same excavation method, and the same structural construction method, which has good construction consistency, is conducive to forming standardized construction, and is conducive to carrying out circulating flow operations. When multiple sets of connected arch structures are provided, deformation joints are provided between two adjacent sets of connected arch structures to prevent the tunnel from cracking or more serious structural damage due to settlement, expansion and contraction, or earthquake.

[0034] According to an embodiment of the present invention, the single-arch single-span structure includes: an arch top, used to bear the overlying load; a support beam, arranged at the arch foot of the arch top along the longitudinal direction of the single-arch single-span structure; and columns, located at both ends of the support beam, connected to the arch top and the support beam to form a whole.

[0035] According to an embodiment of the present invention, the vault includes: a dark-excavated vault close to the mountain side, which is composed of an outer layer of dark-excavated vault primary support 3-2 and an inner layer of dark-excavated vault secondary lining structure 4-1, and a waterproof layer is provided between the dark-excavated vault primary support 3-2 and the dark-excavated vault secondary lining structure 4-1; an exposed vault 4-2 away from the mountain side, the cross-section of the exposed vault 4-2 is the same as and aligned with the cross-section of the dark-excavated vault secondary lining structure 4-1.

[0036] In the related art, the shed tunnel structure is divided into an open part and a dark excavation part in the cross section. In the embodiment of the present invention, each single-arch single-span structure is divided into an open section and a dark excavation section along its longitudinal direction (with the driving direction as the transverse direction). The arch top and support beam of each single-arch single-span structure are longitudinally connected (with the driving direction as the transverse direction), and are connected to the columns on both sides as a whole. They are the main load-bearing components that bear the overlying load. Compared with the traditional shed tunnel structure, the force is more uniform, and the modular property of the structure is stronger, which is convenient for the simultaneous construction of multiple single-arch single-span structures and shortens the construction time. Specifically, the distribution range of one or more groups of serially connected arch structures in the embodiment of the present invention along the driving direction covers the length of the proposed mountainside road that needs to be protected, that is, the length of the mountainside shed tunnel. When the distribution range of the arch structure along the driving direction remains unchanged, reducing the span of the single-arch single-span structure means that the number of holes in the single-arch single-span structure increases accordingly, and at the same time, the number of common support beams at the arch foot of each arch top also increases accordingly, which is conducive to reducing the load distributed to the common support beam and improving its stress state. The span of the support beam is the cross-sectional width of the proposed road. When the support beam is required to bear a larger load, it can be achieved by increasing the beam height. The bottom elevation of the support beam must be higher than the top elevation of the proposed road construction limit. Further increasing the beam height upward is not limited by space, and only the rationality of the structural force and the economic efficiency of the section need to be considered.

[0037] The arch of the underground section adopts a composite lining consisting of an initial support 3-2 for the arch of the underground section composed of a steel grid arch frame or a steel arch frame and shotcrete, and a secondary lining structure 4-1 for the arch of the underground section made of cast-in-place reinforced concrete. The arch of the exposed section adopts a cast-in-place reinforced concrete structure, and its structural section is an extension of the secondary lining structural section of the arch of the underground section away from the mountain.

[0038] According to an embodiment of the present invention, the arch of the dark excavation section also includes an arch large pipe shelf advance support 2-3 and an arch system anchor rod 2-4, which are used to stabilize the surrounding mountain rock formations of the tunnel.

[0039] Affected by the complexity of the terrain of the proposed road and the horizontal and vertical alignment design of the road, when the semi-bright and semi-dark method in the existing technology is used to construct the shed-tunnel structure, the position of the natural slope surface of the original mountain in the cross section of the proposed road changes with the terrain trend. From the perspective of the excavation cross section, the boundary between the open part and the dark excavation part of the section changes with the "thickness" and "thinness" of the mountain to be excavated, fully exposing the characteristics and difficulty of mountainside wiring. The semi-bright and semi-dark method adopted by the existing technical solution has a high difficulty when using large pipe sheds as advance support due to the "thickness" and "thinness" changes of the mountain excavated by the dark excavation part in its cross section. At the same time, since the construction direction of the semi-bright and semi-dark method is longitudinal along the driving direction, excavated from the two ends of the shed-tunnel entrance and exit to the middle and finally penetrated, this requires that the construction direction of the large pipe shed and other advanced stratum reinforcement and advanced protection measures should also be set along the longitudinal direction of the proposed shed-tunnel. Limited by the construction technology, precision and effective length of the large pipe shed, when advance protection is required throughout the entire length of the proposed shed-tunnel, there will be a situation where the tunnel section cannot be effectively protected under certain terrain conditions.

[0040] The construction direction of the mountain shed tunnel in the embodiment of the present invention is perpendicular to the driving direction, and the protection range of the advance support only needs to cover the cross-sectional width of the proposed road. When the dark excavation section needs to be equipped with advance support such as a large pipe shed, the effective protection length of the large pipe shed of 30m-40m in the prior art is sufficient to meet the actual needs of the project. At the same time, since the construction direction of the embodiment of the present invention is perpendicular to the driving direction, it is more conducive to excavating the tunnel perpendicular to the mountain contour line direction, and there are no problems such as uneven thickness and bias pressure caused by the half-bright and half-dark construction cross-sectional direction in the prior art.

[0041] According to an embodiment of the present invention, the column includes: a concealed section wall column 7-1, located on the end wall of the tunnel on the mountain side; an exposed section column 7-2, located on the air side of the tunnel, and its lower end is connected to an exposed section pile foundation 7-4 or an exposed section enlarged foundation.

[0042] According to the embodiment of the present invention, the exposed segment pile foundation 7-4 is connected through the exposed segment column bottom cap 7-3 and the exposed segment column 7-2; the exposed segment enlarged foundation is directly connected to the exposed segment column 7-2.

[0043] The end wall on the side close to the mountain adopts a straight wall section, and the exposed section columns can use different foundation forms according to the terrain and geological conditions. When the bedrock below the ground at the construction location of the tunnel is buried deep and the bearing capacity of the foundation is insufficient, the pile foundation form is applicable, and the exposed section column bottom pedestal 7-3 is set between the exposed section column 7-2 and the exposed section pile foundation 7-4; when the bedrock below the ground at the construction location of the tunnel is buried shallowly, the expanded foundation form is applicable, and the exposed section expanded foundation is directly connected to the exposed section column 7-2 above.

[0044] According to an embodiment of the present invention, the mountainside shed tunnel also includes a plurality of longitudinal beams 8, which are arranged along the driving direction, specifically including: a plurality of longitudinal beams 8-1 in the dark-cut section, which are located in the middle of the end wall and are respectively connected between two adjacent support beams; a bottom longitudinal beam 8-2 in the dark-cut section, which is arranged through the bottom of the end wall; and a plurality of bottom longitudinal beams 8-3 between columns in the exposed section, which are respectively connected between the bottom pedestals 7-3 of two adjacent columns in the exposed section or between two adjacent expanded foundations of the exposed section.

[0045] According to an embodiment of the present invention, the part below the roadbed surface of the proposed road of the exposed section of the tunnel is filled with subgrade backfill 9-2. When the exposed section pile foundation 7-4 is adopted, an exposed section pile retaining wall 9-1 is arranged between two adjacent exposed section pile foundations 7-4 to support the subgrade backfill 9-2.

[0046] According to an embodiment of the present invention, the mountain shed tunnel also includes an air-side retaining wall 9-3, which is arranged above multiple arches along the driving direction and is used to support the arch backfill 11 filled between the mountain slope 1, the air-side retaining wall 9-3 and the enclosed area of ​​multiple arches.

[0047] Backfill is required above the arch of the tunnel constructed by the open-cut method, and the part below the roadbed of the proposed road needs to be filled with earth, stone or other backfill materials. Furthermore, the backfill below the roadbed needs to remain stable, otherwise it will lead to major safety problems such as roadbed collapse. Therefore, when the pile foundation is adopted, an open-section pile retaining wall 9-1 needs to be set between adjacent piles to bear the lateral pressure of the backfill 9-2 under the roadbed; backfill is also required above the multiple arches of the tunnel to restore the surface state and reduce the impact of falling rocks on the arch structure. Accordingly, it is necessary to set an air-facing side retaining wall 9-3 on the arch to support the arch backfill 11.

[0048] Figure 4-1 to Figure 4-9 Taking a mountain shed tunnel composed of a set of three-arch structures as an example, the specific construction process of each key step in the construction process of the embodiment of the present invention is specifically shown:

[0049] (1) According to the mountain slope 1, select a reasonable position to determine the boundary between the open section and the dark excavation section, clean the surface, and use manual excavation, mechanical excavation or drilling and blasting excavation method (the same for the following excavation methods) according to the geological conditions. First, along the vertical direction of the proposed road, carry out the advance support of the large pipe shed on the upper guide hole of the dark excavation section 2-1; excavate the upper guide hole and carry out the initial support of the upper guide hole of the dark excavation section 3-1; install the upper guide hole system anchor rod 2-2 as the excavation is carried out, see Figure 4-1 .

[0050] (2) Cast-in-place reinforced concrete support beam 5-1 in the upper pilot tunnel, see Figure 4-2 .

[0051] (3) Carry out advance support 2-3 of the large pipe shed for the arch of the dark excavation section; excavate the upper section of the shed tunnel structure and carry out initial support 3-2 of the arch of the dark excavation section along the hole of the upper section; install anchor rods 2-4 of the arch system of the dark excavation section as the excavation is carried out, see Figure 4-3 .

[0052] (4) Construct the secondary lining structure 4-1 of the arch of the dark excavation section to form the group of continuous arch structures; construct the upper part 6-1 of the end wall of the dark excavation section and the middle longitudinal beam 8-1 of the dark excavation section. The middle longitudinal beam 8-1 of the dark excavation section can strengthen the integrity of the continuous arch structure and provide safety guarantee for the foundation stability when the lower half section of the dark excavation section shed tunnel structure is excavated. For details, see Figure 4-4 .

[0053] (5) According to the topographic and geological conditions of the exposed section, the column foundation form of the exposed section is reasonably selected, and the pile foundation or the expanded foundation can be used. Taking the pile foundation as an example, the exposed section pile foundation 7-4 is constructed, the exposed section column bottom pedestal 7-3 is constructed, the exposed section column 7-2 is constructed, the exposed section column bottom longitudinal beam 8-3 is constructed, the exposed section support beam 5-2 and the arch 4-2 are constructed, and the exposed section support beam 5-2 and the exposed section arch 4-2 are connected with the dark excavation section support beam 5-1 and the dark excavation section arch secondary lining structure 4-1 respectively to form a whole. For details, see Figure 4-5 .

[0054] (6) Excavate the lower section of the tunnel and implement the initial support 3-3 of the lower pilot tunnel of the dark excavation section; install the anchor rods 2-5 of the lower pilot tunnel system of the dark excavation section as the excavation progresses. For details, see Figure 4-6 .

[0055] (7) The lower half of the dark excavation section is excavated to the end of the dark excavation section on the mountain side, and the dark excavation section wall-attached columns 7-1 and the dark excavation section bottom longitudinal beams 8-2 are cast. Figure 4-7 .

[0056] (8) Remove the initial support 3-3 of the lower guide tunnel of the dark excavation section and the anchor rod 2-5 of the lower guide tunnel system of the dark excavation section; construct the lower half of the end wall 6-2 of the dark excavation section; connect the bottom longitudinal beam 8-2 of the dark excavation section to achieve the foundation bottoming of the tunnel shed structure close to the mountain side; construct the retaining wall between the piles of the exposed section 9-1; according to the condition that the bottom surface of the foundation is higher than the existing ground line, backfill the subgrade backfill 9-2 below the subgrade surface of the proposed road; see Figure 4-8 .

[0057] (9) Construct the airside retaining wall 9-3 above the arch, backfill the arch backfill 11; construct the roadbed pavement, drainage pipe ditch, curb collision prevention, maintenance walkway and other auxiliary structures 10 inside the tunnel; the internal space of the tunnel meets the requirements of the proposed road construction limit 12 and the road traffic requirements; see Figure 4-9 .

[0058] The present invention has the following effects:

[0059] (1) The structural force transmission path is clear and the structural force is reasonable and controllable;

[0060] (2) The advanced stratum reinforcement and protection measures are reliable, the structural construction technology is mature, the construction work surface is large, and the construction efficiency is high;

[0061] (3) Avoid large-scale cutting of the mountain when building a tunnel along the mountain, maintain the stability of the mountain, and protect the natural environment and ecological landscape.

[0062] The above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications may be made based on the following description, and these various changes, modifications, substitutions and deformations derived from the principles and spirit of the present invention still fall within the scope of protection of the present invention.

Claims

1. A mountain shed tunnel, characterized in that: It includes at least one group of continuous arch structures, each group of the continuous arch structures is composed of a plurality of single-arch single-span structures, and the span direction of the single-arch single-span structure is parallel to the preset driving direction; Wherein, the single-arch single-span structure comprises: The vault is used to carry the overlying loads; A support beam is arranged at the arch foot of the arch top along the longitudinal direction of the single-arch single-span structure; A column, located at both ends of the support beam, connected with the vault and the support beam to form an integral whole; Wherein, the vault comprises: The dark excavation section vault near the mountain side is composed of an outer layer of dark excavation section vault primary support (3-2) and an inner layer of dark excavation section vault secondary lining structure (4-1), and a waterproof layer is provided between the dark excavation section vault primary support (3-2) and the dark excavation section vault secondary lining structure (4-1); The exposed arch (4-2) is located away from the mountain side, and the cross section of the exposed arch (4-2) is the same as and aligned with the cross section of the secondary lining structure (4-1) of the concealed arch.

2. The mountain shed tunnel according to claim 1, characterized in that: The dark excavation section arch also includes a dark excavation section arch large pipe shed advance support (2-3) and dark excavation section arch system anchor rods (2-4), which are used to stabilize the surrounding mountain rock formations of the tunnel.

3. The mountain shed tunnel according to claim 1, characterized in that: The column comprises: The wall-attached columns (7-1) of the dark excavation section are located on the end wall of the tunnel on the side close to the mountain; The exposed section column (7-2) is located on the air-facing side of the tunnel, and its lower end is connected to the exposed section pile foundation (7-4) or the exposed section enlarged foundation.

4. The mountain shed tunnel according to claim 3, characterized in that: The exposed segment pile foundation (7-4) is connected via an exposed segment column bottom cap (7-3) and the exposed segment column (7-2); The exposed section enlarged foundation is directly connected to the exposed section column (7-2).

5. The mountain shed tunnel according to claim 4, characterized in that: It also includes a plurality of longitudinal beams (8) arranged along the driving direction, specifically including: A plurality of longitudinal beams (8-1) in the dark excavation section, located in the middle of the end wall and respectively connected between two adjacent support beams; A bottom longitudinal beam (8-2) of the dark excavation section is arranged through the bottom of the end wall; and A plurality of exposed section column bottom longitudinal beams (8-3) are respectively connected to two adjacent exposed section column bottom caps (7-3) or between two adjacent exposed section enlarged foundations.

6. The mountain shed tunnel according to claim 5, characterized in that: The part below the roadbed surface of the proposed road of the exposed section of the tunnel is filled with subgrade backfill (9-2). When the exposed section pile foundation (7-4) is used, an exposed section pile retaining wall (9-1) is provided between two adjacent exposed section pile foundations (7-4) to support the subgrade backfill (9-2).

7. The mountain shed tunnel according to claim 1, characterized in that: It also includes an air-side retaining wall (9-3) which is arranged above the plurality of arches along the driving direction and is used to support the arch backfill (11) filled between the mountain slope (1), the air-side retaining wall (9-3) and the arch enclosed area.

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