Structure for counteracting transverse convergence of lower-layer tunnel

Abstract

The utility model provides a structure for counteracting transverse convergence of a lower-layer tunnel, and belongs to the technical field of tunnel construction. A structure for counteracting transverse convergence of a lower-layer tunnel comprises feet-lock anchor pipes, cast-in-place concrete piles, joists and a secondary lining. The two cast-in-place concrete piles are arranged on the two sides of the lower-layer tunnel correspondingly, and a single cast-in-place concrete pile is connected with the joist above the cast-in-place concrete pile in a steel bar binding mode; feet-lock anchor pipes are arranged on the two sides, close to an upper-layer tunnel arch foot, of the joist, the feet-lock anchor pipes and the joist are connected in a welded mode, the feet-lock anchor pipes firmly lock the joist at the position of the tunnel arch foot, and the joist, the feet-lock anchor pipes and the tunnel arch foot form an integral supporting structure. Wherein the joist plays a transverse connection role, the load of the arch springing of the upper-layer tunnel is transmitted to the concrete cast-in-place pile through the joist, the cast-in-place pile provides strong vertical supporting force for the arch springing of the upper-layer tunnel, and the joist and the cast-in-place pile are combined to stabilize the structure of the upper-layer tunnel.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of tunnel construction and relates to a structure for offsetting lateral convergence of a lower tunnel. BACKGROUND

[0002] With the continuous growth of traffic demand, the reconstruction and expansion projects of existing tunnels are increasing. In the process of tunnel reconstruction and expansion, especially when double-layer tunnel structure is involved, the lower tunnel often faces the problem of lateral convergence during construction and operation.

[0003] The following technical problems exist in the process of reconstruction and expansion of the tunnel to offset the lateral convergence of the lower tunnel: (1) During the reconstruction and expansion of the tunnel, the excavation of the lower tunnel will break the original stress state of the surrounding rock and soil. The stress of the rock and soil will be redistributed, causing pressure to the tunnel periphery. This pressure is one of the important reasons for the lateral convergence of the tunnel. (2) When the reconstruction and expansion is carried out on the basis of the existing tunnel, the existing tunnel structure itself will affect the newly excavated lower tunnel. The load transmitted by the existing tunnel lining structure will increase the pressure borne by the lower tunnel, and the existence of the existing structure will limit the deformation release path of the lower tunnel during construction, aggravating the lateral convergence. (3) In the double-layer tunnel structure, the connection design between the upper and lower tunnel structures is crucial. If the connection structure is unreasonable, it cannot effectively transmit the load and coordinate the deformation, and the lower tunnel is prone to local stress concentration when bearing the upper load and its own rock and soil pressure, thereby causing lateral convergence. (4) After the completion of the reconstruction and expansion of the tunnel, it enters the operation stage, and long-term operation loads such as vehicle dynamic load, seismic load, etc. will have a continuous impact on the lower tunnel. These loads will cause fatigue damage to the tunnel structure, leading to gradual lateral convergence deformation of the tunnel.

[0004] The existing technology often needs to use complex and time-consuming construction processes to deal with the problem of lateral convergence of the lower tunnel, such as multiple temporary support reinforcement and repeated deformation monitoring and adjustment, and the existing temporary support measures and post-maintenance treatment measures have limitations in dealing with the problem of lateral convergence of the lower tunnel, often leading to an increase in construction cost. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide a structure that can effectively offset the lateral convergence of the lower tunnel during the reconstruction and expansion of the tunnel to ensure the safety of tunnel construction and the stability of long-term operation.

[0006] The utility model provides a structure for offsetting lateral convergence of a lower tunnel, which comprises a locking foot anchor pipe, a concrete bored pile, a joist and a secondary lining.

[0007] And the concrete bored pile is provided with two pieces respectively arranged on both sides of the lower tunnel, and the single-piece concrete bored pile is connected with the joist above it by means of steel bar binding;

[0008] The lock foot anchor pipe is connected with the joist by welding, and the lock foot anchor pipe firmly locks the joist at the tunnel foot, and the joist, the lock foot anchor pipe and the tunnel foot form an integral support structure; wherein, the joist plays a role of horizontal connection, and transmits the load of the upper tunnel foot to the concrete bored pile through the joist.

[0009] Further, the diameter of the concrete bored pile is set to 0.7-1m.

[0010] Further, the longitudinal spacing between the two concrete bored piles is set to 1-1.5m.

[0011] Further, a support is arranged between the two concrete bored piles, and the two parallel side ends of the support are fixedly connected with the inner side faces of the two concrete bored piles.

[0012] Further, the support is set as an arched truss structure composed of a plurality of I-shaped steel.

[0013] Further, a plurality of temporary cross braces are arranged between the two parallel side ends of the support; the plurality of temporary cross braces are arranged in the vertical direction of the concrete bored pile and are spaced apart from each other, and the spacing between the adjacent two temporary cross braces is set to 2-3m.

[0014] Further, a plurality of lock foot anchor pipes are arranged between the adjacent two concrete bored piles; the plurality of lock foot anchor pipes are arranged in a layered manner along the vertical direction and the upper and lower positions of the adjacent two layers are staggered, and each layer of lock foot anchor pipes is provided with a plurality of pieces arranged at intervals.

[0015] Further, the distance between the adjacent two layers of lock foot anchor pipes along the vertical direction is set to 170-200mm, the inner angle ψ of the lock foot anchor pipe is set to 10-30°, the outer angle β of the lock foot anchor pipe is set to 20-30°, and the spacing between the adjacent two lock foot anchor pipes in a single layer is set to 250-375mm.

[0016] Further, a gusset plate is arranged between the single lock foot anchor pipe and the support, and the gusset plate and the support are welded at the position close to the inner side flange of the tunnel, and the gusset plate and the exposed end of the lock foot anchor pipe are welded, and the welding thickness is set to 10-15mm.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] (1) The utility model discloses a lock foot anchor pipe is struck into the outside of the upper tunnel arch foot and the reinforced concrete bored pile is struck into the downside, and the lock foot anchor pipe provides the horizontal support force for the upper tunnel, and the bored pile provides the powerful vertical support force for the upper tunnel arch foot, and the combination of the two stabilizes the upper tunnel structure. This combination mode can more effectively prevent the horizontal and lateral displacement of the upper tunnel arch foot, avoids the excessive additional stress of the lower tunnel due to the excessive deformation of the upper tunnel, thereby reducing the inducement of the horizontal convergence of the lower tunnel.

[0019] (2) The utility model discloses a lock foot anchor pipe and concrete bored pile are connected, and an integral structure is formed. The joist plays the role of horizontal contact, and the load of the upper tunnel arch foot is transmitted to the bored pile through the joist, and the bored pile is made to work cooperatively, the ability of the whole structure to resist deformation is improved, and the horizontal convergence of the lower tunnel is reduced.

[0020] (3) The utility model discloses a lock foot anchor pipe and temporary support of the lower tunnel form multiple lines of defense to resist the horizontal convergence of the lower tunnel. The lock foot anchor pipe limits the displacement of the arch foot, and the temporary support restrains the horizontal deformation of the whole tunnel section, and the two complement each other, and the horizontal convergence of the lower tunnel can be more effectively offset than single supporting measure.

[0021] (4) The utility model discloses a lock foot anchor pipe and temporary support structure are connected through the gusset plate, and the connection strength is ensured through welding. The connection mode guarantees the integrity and reliability of the temporary support structure. The load can be effectively transmitted between the supporting members, and the resistance of the temporary support structure to the horizontal convergence of the lower tunnel is enhanced.

[0022] (5) The utility model discloses a secondary lining is constructed for the lower tunnel to provide the final long-term stable support. The secondary lining is constructed on the basis that the temporary support measures such as support and lock foot anchor pipe have effectively controlled the deformation of the tunnel, can better fit the tunnel contour, and fully play the bearing capacity.

[0023] In addition to the purposes, features and advantages described above, the utility model has other purposes, features and advantages. The utility model will be further explained in detail below with reference to the drawings. DRAWINGS

[0024] The drawings that form a part of this application are intended to provide further understanding of the utility model, and the schematic embodiments of the utility model and the explanation thereof are used to explain the utility model, and do not constitute improper limitation to the utility model. In the drawings:

[0025] Figure 1 It is the layout schematic drawing of the structure of offsetting the horizontal convergence of the lower tunnel in the utility model embodiment;

[0026] Figure 2 is Figure 1 Schematic diagram of structure arrangement on the left side of the middle and lower layer tunnel;

[0027] Figure 3 is Figure 1 Axonometric schematic diagram of structure arrangement on the left side of the middle and lower layer tunnel;

[0028] Figure 4 is Figure 1 Schematic diagram of cross section of the pad plate on the left side of the middle and lower layer tunnel.

[0029] wherein:

[0030] 1, lock foot anchor pipe, 2, concrete bored pile, 3, joist, 4, temporary cross brace, 5, support, 6, pad plate, 7, secondary lining. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the utility model and the like more clear and easy to understand, the specific embodiments of the utility model will be described in detail below with reference to the drawings. It should be noted that the drawings of the utility model all adopt a simplified form and all use non-accurate proportions, and are only used to facilitate and clearly assist in explaining the implementation of the utility model; the number of several mentioned in the utility model is not limited to the specific number in the drawing examples; the directions or positional relationships of 'front','middle','rear', 'left', 'right', 'top', 'bottom', 'top', 'bottom','middle' and the like mentioned in the utility model are all based on the directions or positional relationships shown in the drawings of the utility model, and do not indicate or imply that the devices or parts referred to must have a specific direction, and cannot be understood as a limitation on the utility model.

[0032] Embodiment:

[0033] Referring to Figures 1 to 4 , the utility model provides a structure for offsetting the lateral convergence of the lower layer tunnel, which comprises a lock foot anchor pipe 1, a concrete bored pile 2, a joist 3, a temporary cross brace 4, a support 5, a pad plate 6 and a secondary lining 7.

[0034] The diameter of the concrete bored pile 2 is preferably 0.7m-1m, and the concrete bored pile 2 is provided with two pieces arranged on the two sides of the lower layer tunnel respectively, and the longitudinal spacing between the two pieces of concrete bored piles 2 is preferably 1m-1.5m; a single piece of concrete bored pile 2 is connected with the joist 3 above it in the form of steel bar binding.

[0035] Locking foot anchor pipes 1 are arranged on both sides of the joist 3 near the upper tunnel arch foot, and the locking foot anchor pipes 1 are connected with the joist 3 by welding. The locking foot anchor pipes 1 lock the joist 3 firmly at the tunnel arch foot, and the joist 3, the locking foot anchor pipes 1 and the tunnel arch foot form an integral support structure. The joist 3 plays a role of horizontal connection, and transmits the load of the upper tunnel arch foot to the concrete bored pile 2 through the joist 3, and promotes the cooperative work of the concrete bored pile 2, improves the ability of the whole structure to resist deformation, and further reduces the lateral convergence of the lower tunnel.

[0036] Further, a support 5 is arranged between the two concrete bored piles 2, and the support 5 is arranged as an arched truss structure composed of a plurality of I25b H-shaped steels. Adjacent two H-shaped steels are connected by bolts, and the two parallel side ends of the support 5 are fixedly connected with the inner side end surfaces of the two concrete bored piles 2.

[0037] Further, a plurality of temporary cross braces 4 are arranged between the two parallel side ends of the support 5. The plurality of temporary cross braces 4 are arranged in the vertical direction of the concrete bored pile 2, and the distance between adjacent two temporary cross braces 4 is preferably 2m-3m. During installation, the horizontal and vertical degrees of the temporary cross braces 4 need to meet the requirements, so that the temporary cross braces 4 can effectively support the tunnel side wall.

[0038] Further, a plurality of locking foot anchor pipes 1 with a diameter of 89mm and a length of 350cm are arranged between adjacent two concrete bored piles 2. The plurality of locking foot anchor pipes 1 are arranged in a layered manner along the vertical direction, and the upper and lower positions of the adjacent two layers are staggered. Each layer of the locking foot anchor pipes 1 is provided with a plurality of locking foot anchor pipes 1 arranged at intervals.

[0039] Further, the distance between the adjacent two layers of the locking foot anchor pipes 1 along the vertical direction is preferably 170mm-200mm. The inner angle ψ of the locking foot anchor pipe 1 is 10°-30°, the outer angle β is 20°-30°, and the distance between the adjacent two locking foot anchor pipes 1 in a single layer is preferably 250mm-375mm.

[0040] Further, a gusset plate 6 with a length of 400mm-450mm and a width of 350mm-400mm is arranged between the single locking foot anchor pipe 1 and the support 5. The gusset plate 6 is welded with the support 5 near the inner side flange part of the tunnel and the exposed end part of the locking foot anchor pipe 1, and the welding thickness is 10mm-15mm. This connection mode ensures the integrity and reliability of the temporary support structure, ensures the effective transmission of the load between the support components, and enhances the resistance of the temporary support structure to the lateral convergence of the lower tunnel. Further, the gusset plate 6 is preferably a steel structure.

[0041] The secondary lining 7 adopts shotcrete to fully cover the support 5 and the lock foot anchor pipe 1, and provides final long-term stable support for the lower tunnel. The secondary lining 7 is constructed on the basis that the temporary support measures such as the support 5 and the lock foot anchor pipe 1 have effectively controlled the deformation of the tunnel, and can better fit the contour of the tunnel and fully exert the bearing capacity thereof.

[0042] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A structure to counteract lateral convergence of an underlying tunnel, characterized by, The application relates to a tunnel support structure, which comprises a lock foot anchor pipe (1), a concrete pouring pile (2), a support beam (3) and a secondary lining (7). The concrete pouring pile (2) is provided with two pieces arranged on the two sides of the lower tunnel respectively, and the single-piece concrete pouring pile (2) is connected with the support beam (3) above the same in a reinforcing bar binding mode. Lock foot anchor pipes (1) are arranged on the two sides of the support beam (3) close to the arch foot of the upper tunnel, the lock foot anchor pipes (1) are connected with the support beam (3) in a welding mode, the lock foot anchor pipes (1) lock the support beam (3) at the tunnel arch foot, and the support beam (3), the lock foot anchor pipes (1) and the tunnel arch foot form an integral support structure; wherein the support beam (3) plays a role in horizontal connection, and transmits the load of the arch foot of the upper tunnel to the concrete pouring pile (2) through the support beam (3).

2. The structure according to claim 1, wherein The diameter of the concrete pouring pile (2) is 0.7-1 m.

3. The structure according to claim 1 or 2, wherein The longitudinal spacing between the two concrete pouring piles (2) is 1-1.5 m.

4. The structure according to claim 3, wherein A support (5) is arranged between the two concrete pouring piles (2), and the two side ends of the support (5) are fixedly connected with the inner side faces of the two concrete pouring piles (2).

5. The structure according to claim 4, wherein The support (5) is arranged in an arched truss structure formed by a plurality of I-shaped steel.

6. The structure according to claim 4 or 5, wherein A plurality of temporary cross supports (4) are arranged between the two side ends of the support (5) in a spaced mode; the plurality of temporary cross supports (4) are arranged in a spaced mode along the vertical direction of the concrete pouring pile (2), and the spacing between the two adjacent temporary cross supports (4) is 2-3 m.

7. The structure according to claim 6, wherein A plurality of lock foot anchor pipes (1) are arranged between the two adjacent concrete pouring piles (2); the plurality of lock foot anchor pipes (1) are arranged in a layered mode along the vertical direction and in a staggered mode in the vertical direction, and each layer of the lock foot anchor pipes (1) is provided with a plurality of pieces arranged in a spaced mode.

8. The structure according to claim 7, wherein The distance between the two adjacent layers of the lock foot anchor pipes (1) along the vertical direction is 170-200 mm, the inner angle of the lock foot anchor pipe (1) is 10-30 degrees, the outer angle is 20-30 degrees, and the spacing between the two adjacent lock foot anchor pipes (1) in the single layer is 250-375 mm.

9. The structure according to claim 7 or 8, wherein The lock foot anchor pipe (1) is connected with the support (5) through a gusset plate (6), the gusset plate (6) is welded with the support (5) close to the inner side flange of the tunnel and with the exposed end of the lock foot anchor pipe (1), and the welding thickness is 10-15 mm.

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