Annular grouting device for back cavity of tunnel primary support structure

Abstract

The utility model relates to the technical field of tunnel reinforcement, in particular to an annular grouting device for a back cavity of a tunnel primary support structure, and solves the problems that the construction steps are tedious, the grouting efficiency is low and the grouting termination condition is not clear when a grouting pipe is driven into a fixed point at present. An annular grouting device for a cavity behind a tunnel primary support structure comprises rock around the cavity and the primary support structure. A plurality of cavities exist between the rock around the cavity and the primary support structure; the grouting device further comprises a grouting hose and a plurality of four-way connectors. The primary support structure comprises a sprayed concrete layer and a steel arch; a plurality of fixed circular rings are welded on the outer side surface of the steel arch; the grouting hose comprises a plurality of grouting main pipes and a plurality of grouting branch pipes; the multiple grouting main pipes are connected to connectors at the left ends and the right ends of the multiple four-way connectors, and a plurality of grouting holes are formed in the pipe wall of each grouting main pipe and the pipe wall of each grouting branch pipe. The annular grouting device is suitable for annular grouting of the back cavity of the tunnel primary support structure.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel reinforcement, in particular to an annular grouting device for a cavity behind a tunnel primary support structure. Background Art

[0002] With the further implementation of the western development and construction and transportation power strategy, the construction of mountainous expressways is about to enter a new stage of development. It has become an inevitable trend to build expressways in areas with special geological and topographical conditions. The construction of expressways in mountainous areas usually requires crossing complex terrains such as passes and steep canyons. At this time, tunnel excavation becomes the main solution for expressways to cross such terrains. However, over-excavation often occurs during tunnel excavation, and due to the obstruction of the primary support steel arch frame, incomplete spraying and filling is also prone to occur during the spraying of concrete; over-excavation and incomplete concrete spraying and filling will form cavities behind the primary support structure of the tunnel, that is, cavities are formed between the rock around the hole and the primary support structure of the tunnel, resulting in uneven force on the primary support structure of the tunnel; in actual tunnel construction, for the cavities behind the primary support structure of the tunnel, the method of injecting grouting pipes at fixed points is currently mainly used for grouting filling.

[0003] However, the method of driving grouting pipes into fixed points for grouting filling requires the construction of grouting pipes and grouting at multiple fixed points. The grouting machine needs to be moved frequently, the construction steps are cumbersome and the grouting efficiency is low. In addition, the grouting pipes are driven into the rock around the hole and the primary support structure of the tunnel. The termination conditions for grouting into the grouting pipes are unclear, and the filling may not be complete.

[0004] Based on this, it is necessary to invent an annular grouting device for the cavity behind the primary support structure of the tunnel to solve the current problems of cumbersome construction steps, low grouting efficiency and unclear grouting termination conditions when driving grouting pipes at fixed points. Utility Model Content

[0005] In order to solve the problems of complicated construction steps, low grouting efficiency and unclear grouting termination conditions existing in driving grouting pipes at fixed points, the utility model provides an annular grouting device for the cavity behind the primary support structure of the tunnel.

[0006] The utility model is realized by adopting the following technical solutions:

[0007] A circumferential grouting device for a cavity behind a tunnel primary support structure comprises a rock around the tunnel and a primary support structure; there are a plurality of cavities between the rock around the tunnel and the primary support structure; and also comprises a grouting hose and a plurality of cross-joints;

[0008] The primary support structure includes a shotcrete layer and a steel arch frame; a plurality of fixing rings are welded on the outer side of the steel arch frame;

[0009] The grouting hose comprises a plurality of grouting main pipes and a plurality of grouting branch pipes; the plurality of grouting main pipes are connected to the left and right end interfaces of a plurality of four-way joints, and the plurality of grouting main pipes are sequentially connected in series through the four-way joints and are arranged in a plurality of fixed circular rings, and every two grouting branch pipes are connected to the upper and lower end interfaces of the same four-way joint; the pipe wall of each grouting main pipe and each grouting branch pipe is provided with a plurality of grouting holes;

[0010] The left and right ends of the grouting hose are respectively connected with grouting pipes, and the highest point of the grouting hose is connected with a slurry outlet pipe.

[0011] Furthermore, the pipe openings of the grouting pipe and the slurry outlet pipe are both wrapped with PVC film.

[0012] Furthermore, two grouting pipes are respectively located at the arch feet on both sides of the steel arch frame, and the grouting pipe is located at the arch top of the steel arch frame.

[0013] Furthermore, the grouting hoses are arranged symmetrically along the central axis of the primary support structure.

[0014] Furthermore, the fixing ring is a steel bar ring, and the diameter of the fixing ring is larger than the diameter of the grouting main pipe.

[0015] The utility model has a reasonable and reliable structural design. By pre-buried grouting hoses instead of driving grouting pipes at fixed points, the construction steps of construction personnel when grouting and filling the voids behind the primary support structure of the tunnel are effectively reduced, thereby improving the grouting efficiency. At the same time, with the help of the grouting pipes on the arch, construction personnel can visually observe the termination conditions of grouting, effectively avoiding the situation of incomplete grouting and filling. The utility model effectively solves the grouting problem of the voids behind the primary support structure of the tunnel, realizes the close force between the primary support structure and the rock around the tunnel, and ensures the safety of tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 It is a structural schematic diagram of a steel arch frame and a fixed ring in the utility model.

[0018] Figure 3 It is a structural schematic diagram of the grouting hose in the utility model.

[0019] In the figure: 1-rock around the hole, 2-primary support structure, 21-sprayed concrete layer, 22-steel arch, 3-cavity, 4-grouting hose, 41-grouting main pipe, 42-grouting branch pipe, 43-grouting pipe, 44-grouting pipe, 5-four-way joint, 6-fixing ring, 7-grouting hole. DETAILED DESCRIPTION

[0020] A circumferential grouting device for a cavity behind a tunnel primary support structure, comprising a rock around the tunnel 1 and a primary support structure 2; a plurality of cavities 3 are provided between the rock around the tunnel 1 and the primary support structure 2; a grouting hose 4 and a plurality of cross-joints 5;

[0021] The primary support structure 2 includes a shotcrete layer 21 and a steel arch frame 22; a plurality of fixing rings 6 are welded on the outer side of the steel arch frame 22;

[0022] The grouting hose 4 includes a plurality of grouting main pipes 41 and a plurality of grouting branch pipes 42; the plurality of grouting main pipes 41 are connected to the left and right end interfaces of a plurality of four-way joints 5, and the plurality of grouting main pipes 41 are sequentially connected in series through the four-way joints 5 and are inserted into a plurality of fixed rings 6, and every two grouting branch pipes 42 are connected to the upper and lower end interfaces of the same four-way joint 5; the pipe wall of each grouting main pipe 41 and each grouting branch pipe 42 is provided with a plurality of grouting holes 7;

[0023] The left and right ends of the grouting hose 4 are connected to grouting pipes 43 respectively, and the highest point of the grouting hose 4 is connected to a grouting outlet pipe 44 .

[0024] The pipe openings of the grouting pipe 43 and the slurry discharging pipe 44 are all wrapped with PVC film. When the sprayed concrete layer 21 is applied, the PVC film can avoid blocking the grouting pipe 43 and the slurry discharging pipe 44.

[0025] The two grouting pipes 43 are respectively located at the arch feet on both sides of the steel arch frame 22 , and the grouting pipe 44 is located at the arch top of the steel arch frame 22 .

[0026] The grouting hose 4 is disposed symmetrically along the central axis of the primary support structure 2 .

[0027] The fixing ring 6 is a steel bar ring, and the diameter of the fixing ring 6 is greater than the diameter of the grouting main pipe 41 .

[0028] When constructing a tunnel, firstly, a plurality of fixed rings 6 are welded on the outer side of the steel arch frame 22; a plurality of grouting main pipes 41 are connected to the left and right end interfaces of a plurality of four-way joints 5, and a plurality of grouting main pipes 41 are sequentially connected in series through the four-way joints 5 and penetrated into a plurality of fixed rings 6; then, every two grouting branch pipes 42 are connected to the upper and lower end interfaces of the same four-way joint 5; then, the steel arch frame 22 pre-pierced with the grouting hose 4 is erected and fixed in the excavated tunnel, and a sprayed concrete layer 21 is applied on the outer side of the steel arch frame 22. After the shotcrete layer 21 is formed, the PVC film on the pipe mouth of the grouting pipe 43 is removed, and grouting is performed into the two grouting pipes 43 at the arch feet on both sides of the steel arch frame 22 using a grouting machine. The slurry diffuses and flows out from the grouting holes 7 to fill the cavity 3 between the rock 1 around the hole and the shotcrete layer 21; when the slurry breaks through the PVC film and flows out from the grouting pipe 44 at the top of the arch, the grouting can be terminated; when constructing the tunnel, multiple steel arch frames 22 and corresponding multiple annular grouting devices for the cavity behind the primary support structure of the tunnel are constructed according to actual conditions.

[0029] During the specific implementation process, the length of the grouting pipe 43 exceeds the arch foot of the steel arch frame 22 by 50 cm, the grouting pipe 44 is placed on the arch top of the steel arch frame 22 and the mouth of the grouting pipe 44 hangs down by 50 cm; the diameters of the grouting main pipe 41 and the grouting branch pipe 42 are both 42 mm, the length of the grouting main pipe 41 is determined according to the arc length of the steel arch frame 22, and the length of the grouting branch pipe 42 is determined according to the spacing between two adjacent steel arch frames 22; the grouting holes 7 are long holes distributed in a plum blossom shape, the length range of the grouting holes 7 is 5 cm-8 cm, and the spacing range of the grouting holes 7 is 3 cm-5 cm; the spacing range of two adjacent fixed rings 6 is 0.5 m-1 m; the cement slurry used for grouting is a mixture of P.O42.5 cement, water reducer and water, and the ratio is P.O42.5 cement: water reducer: water = 1:0.006:0.45.

[0030] In the description of the present invention, it is necessary to understand that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A circumferential grouting device for a cavity behind a tunnel primary support structure, comprising rock surrounding the tunnel (1) and a primary support structure (2); a plurality of cavities (3) exist between the rock surrounding the tunnel (1) and the primary support structure (2); the device is characterized in that: It also includes a grouting hose (4) and a plurality of four-way connectors (5); The primary support structure (2) comprises a shotcrete layer (21) and a steel arch frame (22); a plurality of fixing rings (6) are welded on the outer side surface of the steel arch frame (22); The grouting hose (4) comprises a plurality of grouting main pipes (41) and a plurality of grouting branch pipes (42); the plurality of grouting main pipes (41) are connected to the left and right end interfaces of a plurality of four-way joints (5), and the plurality of grouting main pipes (41) are sequentially connected in series through the four-way joints (5) and are inserted into a plurality of fixed circular rings (6), and every two grouting branch pipes (42) are connected to the upper and lower end interfaces of the same four-way joint (5); the pipe wall of each grouting main pipe (41) and each grouting branch pipe (42) is provided with a plurality of grouting holes (7); The left and right ends of the grouting hose (4) are respectively connected to grouting pipes (43), and the highest point of the grouting hose (4) is connected to a grouting outlet pipe (44).

2. The annular grouting device for the cavity behind the primary support structure of a tunnel according to claim 1, characterized in that: The pipe openings of the grouting pipe (43) and the grouting pipe (44) are both covered with PVC films.

3. The annular grouting device for the cavity behind the primary support structure of a tunnel according to claim 1, characterized in that: The two grouting pipes (43) are respectively located at the arch feet on both sides of the steel arch frame (22), and the grouting pipe (44) is located at the arch top of the steel arch frame (22).

4. The annular grouting device for the cavity behind the primary support structure of a tunnel according to claim 1, characterized in that: The grouting hoses (4) are arranged symmetrically along the central axis of the primary support structure (2).

5. The annular grouting device for the cavity behind the primary support structure of a tunnel according to claim 1, characterized in that: The fixing ring (6) is a steel bar ring, and the diameter of the fixing ring (6) is greater than the diameter of the grouting main pipe (41).

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