Tunnel open cut tunnel structure on soft foundation
By using pile-slab structures and protective mechanisms in the open-cut tunnel, the problem of uneven settlement in the open-cut tunnel on soft foundations was solved, achieving a tunnel structure design that is uniformly stressed, easy to construct, and low-cost, thus ensuring operational safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CCCC THIRD HARBOR ENGINEERING CO LTD
- Filing Date
- 2025-05-21
- Publication Date
- 2026-05-15
AI Technical Summary
When constructing open-cut tunnels on soft foundations, uneven settlement of the structure poses operational safety risks, and construction is complex and costly.
The tunnel adopts a pile-slab structure and a protective structure. The pile foundation, beams and bottom slab constitute the foundation of the open tunnel. Combined with slope protection and uphill slope protection, a tunnel structure with uniform stress is formed.
It achieves uniform stress distribution in the open-cut tunnel structure, simplifies construction, reduces costs, and ensures operational safety and functional stability.
Smart Images
Figure CN224243953U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a tunnel opening structure on a soft foundation. Background Technology
[0002] When highways and railways are laid in mountainous areas, they need to pass through the strata due to the influence of terrain and existing ground buildings, requiring the construction of a large number of tunnels.
[0003] When the terrain at the tunnel entrance is relatively steep, the uphill slope often presents hazards such as unstable rocks or falling stones, necessitating the extension of the tunnel's open section. When the open section is located on a weak foundation, it will cause uneven settlement of the structure, affecting the operational safety of the line. Therefore, to address these issues, a tunnel open section structure for weak foundations is proposed. Utility Model Content
[0004] The purpose of this utility model is to overcome the existing defects and provide a tunnel open-cut structure on a weak foundation, which has uniform stress distribution, convenient construction, low cost, and ensures functionality and operational safety.
[0005] The technical solution to achieve the above objective is: a tunnel open-cut structure on a soft foundation, comprising a pile-slab mechanism, an open-cut section, and a protective mechanism; the open-cut section is disposed on the pile-slab mechanism, and the protective mechanism is disposed around the open-cut section;
[0006] The pile-slab structure includes a pile foundation, a crossbeam, and a base plate; the upper end of the pile foundation is connected to the crossbeam, and the base plate is connected to the side of the crossbeam;
[0007] The open passage includes an inverted arch, a passage body, and a passage entrance; the inverted arch is set on the crossbeam and the bottom plate, the passage body is set on the inverted arch, and the passage entrance is set at one end of the passage body;
[0008] The protective mechanism includes slope protection and back slope protection; the slope protection is installed on both sides of the tunnel entrance, and the back slope protection is installed above the tunnel entrance.
[0009] Preferably, there are multiple piles, multiple crossbeams, and multiple base plates; each pair of piles is connected to a crossbeam at its upper end, and the base plate is connected between each pair of crossbeams.
[0010] Preferably, the hole is provided with two expansion joints.
[0011] Preferably, the slope protection includes multiple slope mortar anchors and a first slope sprayed concrete, with the multiple slope mortar anchors arranged on both sides of the tunnel body, and the first slope sprayed concrete installed on the multiple slope mortar anchors.
[0012] Preferably, the slope protection includes multiple slope mortar anchors and a second slope sprayed concrete, with the multiple slope mortar anchors installed on the upper side of the tunnel body and the second slope sprayed concrete installed on the multiple slope mortar anchors.
[0013] Preferably, a backfill layer is provided above the tunnel body, and a waterproof layer is provided above the backfill layer.
[0014] Preferably, mortar-grouted rubble masonry is installed between the tunnel body and the slope protection.
[0015] The beneficial effects of this utility model are: the tunnel open-cut structure on soft foundation, by setting pile foundations, crossbeams and bottom slabs below the open-cut, and setting slope protection and uphill slope protection above the open-cut, makes the formed tunnel open-cut structure uniformly stressed, easy to construct and low in cost, and ensures the functionality and operational safety. Attached Figure Description
[0016] Figure 1 This is a front view of the tunnel opening structure on a soft foundation according to this utility model;
[0017] Figure 2 This is a side view of the tunnel opening structure on a soft foundation according to this utility model.
[0018] In the diagram: 1. Pile foundation; 2. Horizontal beam; 3. Invert arch; 4. Tunnel body; 5. Masonry rubble masonry; 6. Slope protection; 7. Slope mortar anchor; 8. Invert slope protection; 9. Invert slope mortar anchor; 10. Waterproof layer; 11. Base slab; 12. Tunnel portal; 13. Expansion joint; 14. Backfill line; 15. Backfill layer. Detailed Implementation
[0019] The technical solution of this utility model will now be clearly and completely described in conjunction with the accompanying drawings. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0020] The present invention will be further described below with reference to the accompanying drawings.
[0021] like Figure 1-2As shown, a tunnel structure with an open section on a weak foundation includes a pile-slab structure, an open section, and a protective structure. The open section is set on the pile-slab structure, and the protective structure is set around the open section. The pile-slab structure includes pile foundations 1, crossbeams 2, and a base plate 11. The upper end of the pile foundation 1 is connected to the crossbeam 2, and the base plate 11 is connected to the side of the crossbeam 2. There are multiple pile foundations 1, multiple crossbeams 2, and multiple base plates 11. The upper end of every two pile foundations 1 is connected to a crossbeam 2, and the base plate 11 is connected between every two crossbeams 2.
[0022] Specifically, pile foundation 1 is a 0.8m diameter bored cast-in-place pile with C35 concrete strength, 20m length, 2 piles arranged with a transverse spacing of 10m, and 8 piles arranged with a longitudinal spacing of 6m.
[0023] Specifically, beam 2 is made of C35 reinforced concrete, with a length of 11.8m, a width of 1.8m, and a height of 1.6m. The top of pile 1 is embedded 10cm into beam 2.
[0024] Specifically, the base plate 11 is made of C35 reinforced concrete, 0.5m thick and 11.8m wide, and is cast as a whole through the reserved steel bars of the crossbeam 2.
[0025] Specifically, the open passage includes an inverted arch 3, a passage body 4, and a passage entrance 12; the inverted arch 3 is set on the crossbeam 2 and the bottom plate 11, the passage body 4 is set on the inverted arch 3, and the passage entrance 12 is set at one end of the passage body 4; the passage entrance 12 is a cap-shaped sloping type with an inclination of 1:1.25.
[0026] Specifically, two expansion joints 13 are provided on the tunnel body 4. The expansion joints 13 are 2cm wide, and there are 2 joints with a spacing of 27m.
[0027] Specifically, a backfill layer 15 is set above the tunnel body 4, and a waterproof layer 10 is set above the backfill layer 15. The backfill layer 15 has a particle size ≤30cm, is compacted in layers, and the thickness of each backfill layer is no more than 0.3m. The slope of the backfill line 14 at the tunnel entrance is 1:1.25, and the backfill height is 2m higher than the top of the open tunnel.
[0028] Specifically, mortar-grouted rubble masonry 5 is installed between the tunnel body 4 and the slope protection 6. The mortar-grouted rubble masonry 5 is M10 and is placed between the open tunnel and the slope protection 6.
[0029] Specifically, the invert arch 3 and the tunnel body 4 are made of C35 reinforced concrete with a permeability grade of ≥P10 and a thickness of 85cm.
[0030] Specifically, the protective structure includes slope protection 6 and back slope protection 8; slope protection 6 is installed on both sides of the tunnel entrance 12, and back slope protection 8 is installed above the tunnel entrance 12.
[0031] Specifically, the slope protection 6 includes multiple mortar anchors 7 and a first slope shotcrete. The multiple mortar anchors 7 are installed on both sides of the tunnel body 4, and the first slope shotcrete is installed on the multiple mortar anchors 7. The slope is a 1:1 secondary slope with a middle platform width of 1m. The mortar anchors 7 are 22mm diameter mortar anchors, 3m long, spaced 1.5m × 1.5m apart, arranged in a staggered pattern; the slope shotcrete uses 8cm thick C20 mesh shotcrete with 8mm diameter steel mesh, and the mesh size is 25cm × 25cm.
[0032] Specifically, the slope protection 8 includes multiple mortar anchor rods 9 and a second slope shotcrete. The multiple mortar anchor rods 9 are installed on the upper side of the tunnel body 4, and the second slope shotcrete is installed on the multiple mortar anchor rods 9. The mortar anchor rods 9 are 22mm diameter mortar anchor rods, 3m long, spaced 1.5m×1.5m apart, arranged in a quincunx pattern; the slope shotcrete uses 8cm thick C20 mesh shotcrete with 8mm diameter steel mesh, and the mesh size is 25cm×25cm.
[0033] The tunnel open-cut structure on this soft foundation is constructed by setting pile foundation 1, crossbeam 2 and bottom slab 11 below the open-cut; and setting slope protection 6 and uphill slope protection 8 above the open-cut. This results in a tunnel open-cut structure with uniform stress, convenient construction, low cost, and ensures functionality and operational safety.
[0034] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A tunnel structure for use on soft foundations, characterized in that, It includes a pile plate mechanism, an open channel, and a protective mechanism; the open channel is located on the pile plate mechanism, and the protective mechanism is located around the open channel; The pile-slab structure includes a pile foundation (1), a crossbeam (2), and a base plate (11); the upper end of the pile foundation (1) is connected to the crossbeam (2), and the base plate (11) is connected to the side of the crossbeam (2); The open passage includes an inverted arch (3), a passage body (4), and a passage door (12); the inverted arch (3) is set on the crossbeam (2) and the bottom plate (11), the passage body (4) is set on the inverted arch (3), and the passage door (12) is set at one end of the passage body (4); The protective mechanism includes slope protection (6) and uphill slope protection (8); the slope protection (6) is set on both sides of the tunnel entrance (12), and the uphill slope protection (8) is set above the tunnel entrance (12).
2. The tunnel structure for open-cut sections on soft foundations according to claim 1, characterized in that, The pile foundation (1) consists of multiple piles, the crossbeam (2) consists of multiple crossbeams, and the base plate (11) consists of multiple pieces; the upper end of every two pile foundations (1) is connected to one crossbeam (2), and the base plate (11) is connected between every two crossbeams (2).
3. The tunnel structure for open-cut sections on soft foundations according to claim 1, characterized in that, Two expansion joints (13) are provided on the tunnel body (4).
4. The tunnel structure for open-cut sections on soft foundations according to claim 1, characterized in that, The slope protection (6) includes multiple slope mortar anchors (7) and a first slope sprayed concrete. The multiple slope mortar anchors (7) are set on both sides of the tunnel body (4), and the first slope sprayed concrete is set on the multiple slope mortar anchors (7).
5. A tunnel structure for use on a weak foundation according to claim 1, characterized in that, The slope protection (8) includes multiple slope mortar anchors (9) and a second slope sprayed concrete. The multiple slope mortar anchors (9) are set on the upper side of the tunnel body (4), and the second slope sprayed concrete is set on the multiple slope mortar anchors (9).
6. The tunnel structure for open-cut sections on soft foundations according to claim 1, characterized in that, A backfill layer (15) is provided above the tunnel body (4), and a waterproof layer (10) is provided above the backfill layer (15).
7. A tunnel structure for open-cut sections on soft foundations according to claim 1, characterized in that, A masonry rubble masonry (5) is installed between the tunnel body (4) and the slope protection (6).