Small-spacing unsymmetrical pressure tunnel portal protection structure
The small-span biased tunnel entrance protection structure stabilizes tunnel entrances and mountain slopes using anchor bolts, backfill concrete, and edge slope protection, addressing structural instability and collapse risks in high-speed railway tunnels.
Patent Information
- Application Number
- CN202422540334.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-10-21
AI Technical Summary
When laying high-speed railways in mountainous areas, small-pitch tunnels pass through steep slopes lead to unstable tunnel structure and prone to bias, which may lead to tunnel rupture and collapse.
Anchor piles, backfill concrete layers and slope protection structures are adopted, including retaining walls, interceptor gutters, frame anchors and skeleton slope protection, to enhance the stability of tunnels and mountain slopes.
It improves the stability of the tunnel structure, avoids tunnel damage, enhances the stability of the mountain slope, and prevents tunnel collapse.
Smart Images
Figure CN223104570U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of tunnel portal protection, in particular to a protection structure for the portal of a small-spacing bias tunnel. Background Technique
[0002] When high-speed railways are laid in mountainous areas, the portals need to be set in steep terrain sections. However, the terrain and landforms in steep sections are complex, the geological conditions are poor, and the soil mass is unstable, which will lead to insufficient local burial depth of the tunnel portal and unstable structure, forming a bias tunnel. At the same time, when small-spacing tunnels pass through this section simultaneously, the structural stress will be more complex and the stability will be worse.
[0003] A bias tunnel is formed due to asymmetric terrain or geological rock stratum factors, resulting in asymmetric loads on both sides of the tunnel structure. When the tunnel entrance is located on an unstable hillside with poor terrain conditions and there is a significant difference in the thickness of the soil layers on both sides of the tunnel top, it is a bias phenomenon. If not properly handled, the tunnel may crack and collapse in severe cases.
[0004] When the pressure on one side of the tunnel is too high, the stress on the tunnel structure is uneven, and local stress concentration and excessive deformation may lead to shear failure of the tunnel structure. Content of the Utility Model
[0005] Aiming at the deficiencies of the prior art, the utility model provides a protection structure for the portal of a small-spacing bias tunnel, which solves the problems mentioned in the above background.
[0006] The utility model provides the following technical solution: a protection structure for the portal of a small-spacing bias tunnel, including: a first tunnel and a second tunnel passing through the mountain body, a first secondary lining is arranged in the first tunnel, and a second secondary lining is arranged in the second tunnel;
[0007] A retaining wall is arranged on the side of the first tunnel close to the mountain body, a plurality of anchor piles are arranged on both sides of the first tunnel, a backfill concrete layer is provided at the base of the portal section of the second tunnel, and slope protection structures are arranged on the mountain body at the portals of the first tunnel and the second tunnel;
[0008] The slope protection structure includes a water intercepting gutter arranged on the mountain body, frame anchor rods buried in the mountain slope, and a skeleton slope protection arranged on the mountain slope.
[0009] Preferably, the retaining wall is made of C35 reinforced concrete, the height of the retaining wall is 10m, the top width is 1.75m, the length is 6m, and the slope of the retaining wall is 1:0.25.
[0010] Preferably, there are two anchor piles on the side of the first tunnel away from the second tunnel, and five anchor piles are located between the first tunnel and the second tunnel. Multiple said anchor piles are all made of C35 reinforced concrete, and the cross-sectional dimension of the anchor pile is 2.5m×2.25m, the length of the anchor pile is 22m, and the length of the anchor pile exposed outside the foundation is 11m.
[0011] Preferably, the backfill concrete layer is made of C20 plain concrete.
[0012] Preferably, a first ear wall and a second ear wall are respectively arranged on the back mountain sides of the first tunnel and the second tunnel, and the first ear wall is connected to the first secondary lining, so the second ear wall is connected to the second secondary lining. The first ear wall and the second ear wall are both made of C35 reinforced concrete, and the inner sides of the first ear wall facing the first tunnel and the second ear wall facing the second tunnel are both arc-shaped.
[0013] Preferably, the center line of the water intercepting gutter is more than 5m away from the edge of the side slope and cutting slope excavation line, and the water intercepting gutter is made of C25 concrete, and the wall thickness of the water intercepting gutter is 30cm.
[0014] Preferably, the frame anchor bolts are arranged on the first-level slope of the mountain body, the length of the frame anchor bolts is 10m, the spacing between adjacent frame anchor bolts is 3m, and the horizontal angle of the frame anchor bolts is 15°.
[0015] Preferably, the skeleton slope protection is arranged on the second-level slope and slopes above the second-level of the mountain body. The skeleton slope protection is made of C25 concrete cast in situ, and the thickness of the skeleton slope protection is 80cm.
[0016] Compared with the prior art, the present utility model has the following beneficial effects:
[0017] For the protection structure at the entrance of the small-spacing bias-pressure tunnel, by arranging anchor piles, a backfill concrete layer and a slope protection structure, the anchor piles and the backfill concrete layer respectively improve the stability of the structure between the first tunnel and the second tunnel and the stability of the structures of the first tunnel and the second tunnel itself. At the same time, the slope protection structure improves the stability of the mountain slope to avoid tunnel damage. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is the layout plan of the present utility model;
[0019] Figure 2 It is the structural schematic diagram at the retaining wall position of the A-A section of the present utility model;
[0020] Figure 3 It is the structural schematic diagram at the position of the first secondary lining of the B-B section of the present utility model;
[0021] Figure 4 This is a schematic structural diagram of the first tunnel and the second tunnel at the C-C section of the present utility model.
[0022] In the figure: 1. The first tunnel; 2. The second tunnel; 3. The first secondary lining; 4. The second secondary lining; 5. The retaining wall; 6. The anchor pile; 7. The backfill concrete layer; 8. The intercepting gutter; 9. The frame anchor bolt; 10. The skeleton slope protection; 11. The first ear wall; 12. The second ear wall; 13. The mountain body. Specific embodiments
[0023] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.
[0024] Please refer to Figures 1-4 , a protection structure for the entrance of a small-spacing bias tunnel, comprising: the first tunnel 1 and the second tunnel 2 passing through the mountain body 13, the first secondary lining 3 is arranged in the first tunnel 1, and the second secondary lining 4 is arranged in the second tunnel 2;
[0025] A retaining wall 5 is arranged on one side of the first tunnel 1 close to the mountain body 13, and a plurality of anchor piles 6 are arranged on both sides of the first tunnel 1. A backfill concrete layer 7 is provided at the base of the entrance section of the second tunnel 2. The backfill concrete layer 7 is made of C20 plain concrete. Slope protection structures are arranged at the entrances of the first tunnel 1 and the second tunnel 2 on the mountain body 13;
[0026] The slope protection structure includes an intercepting gutter 8 arranged on the mountain body 13, a frame anchor bolt 9 buried in the slope of the mountain body 13, and a skeleton slope protection 10 arranged on the slope of the mountain body 13. The retaining wall 5 is made of C35 reinforced concrete. The height of the retaining wall 5 is 10 m, the top width is 1.75 m, the length is 6 m, and the slope of the retaining wall 5 is 1:0.25.
[0027] In a specific embodiment, the number of anchor piles 6 on the side of the first tunnel 1 far from the second tunnel 2 is two, and the number of anchor piles 6 between the first tunnel 1 and the second tunnel 2 is five. The multiple anchor piles 6 are all cast with C35 reinforced concrete. The cross-sectional dimension of the anchor pile 6 is 2.5m×2.25m, the length of the anchor pile 6 is 22m, and the length of the anchor pile 6 exposed outside the foundation is 11m. The temporary protection of the vertical surface between the anchor piles 6 adopts shotcrete with wire mesh. The anchor rods of the wire mesh adopt mortar anchor rods with a diameter of 22 and a length of 4m, with a spacing of 1.5×1.5m and arranged in a plum blossom pattern; the shotcrete adopts 10cm thick C25 shotcrete with wire mesh, and the wire mesh adopts φ8 with a grid of 25×25cm.
[0028] The first ear wall 11 and the second ear wall 12 are respectively arranged on the back mountain sides of the first tunnel 1 and the second tunnel 2, and the first ear wall 11 is connected to the first secondary lining 3, so the second ear wall 12 is connected to the second secondary lining 4. The first ear wall 11 and the second ear wall 12 are both cast with C35 reinforced concrete. The inner sides of the first ear wall 11 facing the first tunnel 1 and the second ear wall 12 facing the second tunnel 2 are both arc-shaped.
[0029] The center line of the water intercepting gutter 8 is set more than 5m away from the edge of the side slope and cutting excavation line, and the water intercepting gutter 8 is cast with C25 concrete. The wall thickness of the water intercepting gutter 8 is 30cm.
[0030] The frame anchor bolts 9 are arranged on the first-level slope of the mountain body 13. The length of the frame anchor bolts 9 is 10m, the spacing between adjacent frame anchor bolts 9 is 3m, and the horizontal included angle of the frame anchor bolts 9 is 15°. The skeleton slope protection 10 is arranged on the second-level slope and slopes above the second level of the mountain body 13. The skeleton slope protection 10 is cast in situ with C25 concrete, and the thickness of the skeleton slope protection 10 is 80cm.
[0031] The multiple anchor piles 6 can improve the stability of the surrounding structures of the first tunnel 1 and the second tunnel 2. The retaining wall 5 provides support for the soil of the unstable mountain body 13 with poor terrain conditions at the entrance. Multiple frame anchor bolts 9 are used to anchor the mountain body 13, and the slope surface is fixed by the skeleton slope protection 10 to prevent the slope from sloughing.
[0032] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A small-spacing bias tunnel portal protection structure, characterized in that include: A first tunnel (1) and a second tunnel (2) passing through a mountain (13), wherein a first secondary lining (3) is arranged in the first tunnel (1), and a second secondary lining (4) is arranged in the second tunnel (2); A retaining wall (5) is arranged on one side of the first tunnel (1) close to the mountain (13), a plurality of anchor piles (6) are arranged on both sides of the first tunnel (1), a backfill concrete layer (7) is arranged at the base of the opening section of the second tunnel (2), and slope protection structures are arranged at the openings of the first tunnel (1) and the second tunnel (2) on the mountain (13); The slope protection structure comprises a water intercepting ditch (8) arranged on a mountain (13), a frame anchor rod (9) buried in the slope of the mountain (13), and a skeleton slope protection (10) arranged on the slope of the mountain (13).
2. The small-spacing bias tunnel portal protection structure according to claim 1, characterized in that The retaining wall (5) is made of C35 reinforced concrete. The height of the retaining wall (5) is 10m, the top width is 1.75m, the length is 6m, and the slope of the retaining wall (5) is 1:0.
25.
3. The small-spacing bias tunnel portal protection structure according to claim 1, wherein, The number of anchor piles (6) on the side of the first tunnel (1) away from the second tunnel (2) is two, the number of anchor piles (6) located between the first tunnel (1) and the second tunnel (2) is five, the plurality of anchor piles (6) are made of C35 reinforced concrete, the cross-sectional dimensions of the anchor piles (6) are 2.5 m×2.25 m, the length of the anchor piles (6) is 22 m, and the length of the anchor piles (6) exposed outside the foundation is 11 m.
4. A small-spacing bias tunnel entrance protection structure according to claim 1, characterized in that, The backfill concrete layer (7) is made by pouring C20 plain concrete.
5. A small-spacing bias tunnel portal protection structure according to claim 1, characterized in that, A first ear wall (11) and a second ear wall (12) are respectively arranged on the back side of the first tunnel (1) and the second tunnel (2), and the first ear wall (11) is connected to the first secondary lining (3), and the second ear wall (12) is connected to the second secondary lining (4). The first ear wall (11) and the second ear wall (12) are both made of C35 reinforced concrete. The inner side of the first ear wall (11) facing the first tunnel (1) and the inner side of the second ear wall (12) facing the second tunnel (2) are both arc-shaped.
6. The small-spacing bias tunnel portal protection structure according to claim 1, characterized in that, The center line of the cut-off ditch (8) is greater than 5m away from the edge of the side slope excavation line, and the cut-off ditch (8) is made of C25 concrete casting, and the wall thickness of the cut-off ditch (8) is 30cm.
7. A small-spacing bias tunnel portal protection structure according to claim 1, characterized in that, The frame anchor rod (9) is arranged on the primary slope of the mountain (13), the length of the frame anchor rod (9) is 10 m, the spacing between adjacent frame anchor rods (9) is 3 m, and the horizontal angle of the frame anchor rod (9) is 15°.
8. A small-spacing bias tunnel portal protection structure according to claim 1, characterized in that, The skeleton slope protection (10) is arranged on the secondary slope and the slopes above the secondary slope of the mountain (13). The skeleton slope protection (10) is made of C25 cast-in-place concrete. The thickness of the skeleton slope protection (10) is 80 cm.