CN211573535U - Large-scale karst cavity tunnel large deformation frame rock fall prevention structure - Google Patents

Abstract

A large deformation frame rockfall prevention structure of a large karst cavity tunnel can effectively solve the safety and economic problems of the tunnel structure in the large karst cavity. The tunnel structure is cast as a whole with reinforced concrete, the bottom is located on the tunnel foundation on the stable rock foundation, and the backfill protection bodies are set up on both sides of the lateral side, which are formed by filling the tunnel with waste ballast to the top elevation of the tunnel structure. A triangular frame structure, the two sides of the frame structure are tensioned and wrapped to fix the passive protective net; the upper end of the frame structure is fixedly connected with the lower end of the fixed anchor cable anchored in the stable rock mass at the top of the karst cavity at a longitudinal interval along the line, The bottom ends of the two sides are fixedly connected to the anchor foundations embedded in the filling protection bodies on both sides of the top of the tunnel structure through the tension anchor cables on which the elastic members are arranged.

Description

A large-scale karst cavity tunnel large deformation frame anti-rockfall structure

technical field

The utility model relates to geotechnical engineering, in particular to a large deformation frame anti-falling rock structure of a large-scale karst cavity tunnel.

Background technique

Karst landforms in my country are widely distributed. Karst cavities formed by karst rocks in karst areas are uncertain and usually difficult to detect accurately. For tunnel engineering, it is very common to encounter karst cavities through soluble rocks. When the karst cavity is large, it is very uneconomical to use concrete to fill the whole cavity. If it is not fully processed, the rocks on the top of the karst cavity will fall off, which will cause damage to the safety of the tunnel structure. Therefore, it is of great significance to propose a large deformation frame anti-rockfall structure and construction method for large-scale karst cavity tunnels, and should have the characteristics of good anti-rockfall impact effect, convenient construction, economical, environmental protection and promotion.

Utility model content

The technical problem to be solved by the utility model is to provide a large deformation frame anti-rockfall structure of a large-scale karst cavity tunnel, so as to effectively solve the safety and economic problems of the tunnel structure in the large-scale karst cavity.

The technical scheme adopted by the utility model to solve the above-mentioned technical problems is as follows:

The large deformation frame anti-rockfall structure of a large-scale karst cavity tunnel of the utility model comprises a tunnel structure passing through a large-scale karst cavity. On the foundation of the tunnel, a filling protection body formed by filling the tunnel with waste ballast to the top elevation of the tunnel structure is installed on both sides of the lateral side, and a frame structure with a triangular cross-section is suspended above, and the two sides of the frame structure are tensioned and wrapped to fix the passive protective net; The upper end of the frame structure is fixedly connected with the lower extending end of the fixed anchor cable anchored in the stable rock mass at the top of the karst cavity at a longitudinal interval along the line, and the bottom ends on both sides are connected with the tension anchor cable on which the elastic member is provided. The anchor foundation is fixed and connected in the filling protection body on both sides of the top of the tunnel structure at the longitudinal interval along the line.

The beneficial effect of the utility model is that a frame structure wrapped with a passive protective net is arranged above the top of the tunnel structure to block the rockfall at the top of the karst cavity, so as to prevent the rockfall from directly impacting the tunnel structure; The lower large triangular light frame structure is light in weight, and its upper and lower ends are connected and fixed by flexible fixed anchor cables and tension anchor cables, so that the frame structure can have a large controllable deformation on the left and right sides, so that the impact force of falling rocks on the frame structure will be reduced. Great attenuation, the frame structure mainly guides the falling rocks; the lower part of the frame structure is connected by the tension anchor cable with the elastic structure, which can not only make the frame structure have better plane positioning, but also produce large deformation and after the deformation Can automatically restore the position.

Description of drawings

This manual includes the following two drawings:

Fig. 1 is the cross-sectional schematic diagram of a large-scale karst cavity tunnel large-deformation frame anti-falling rock structure of the present utility model;

2 is a schematic front view of a large-scale karst cavity tunnel large-deformation frame anti-falling rock structure of the present invention;

Component names and corresponding marks are shown in the figure: tunnel structure 1, tunnel foundation 2, filling protection body 3, anchor foundation 4, fixed anchor cable 5, frame structure 6, passive protection net 7, tension anchor cable 8, The elastic member 9 and the boundary A of the karst cavity.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the utility model is further described:

1, a large-scale karst cavity tunnel large deformation frame anti-rockfall structure of the present invention includes a tunnel structure 1 passing through a large karst cavity, the tunnel structure 1 is integrally cast with reinforced concrete, and the bottom is located on the stable rock foundation. On the tunnel foundation 2 of the tunnel structure 2, a filling protection body 3 formed by filling the tunnel waste ballast to the top elevation of the tunnel structure 1 is arranged on both sides of the transverse direction, and a frame structure 6 with a triangular cross-section is suspended above, and the two sides of the frame structure 6 are tensioned. Wrap the fixed passive protective net 7. The upper end of the frame structure 6 is fixedly connected with the lower extending end of the fixed anchor cable 5 which is anchored in the stable rock mass at the top of the karst cavity at a longitudinal interval along the line, and the bottom ends of the two sides are provided with the tension force of the elastic member 9 thereon. The anchor cables 8 are fixedly connected to the anchor foundations 4 embedded in the filling protection bodies 3 on both sides of the top of the tunnel structure 1 at intervals along the line.

In the present invention, a frame structure 6 wrapped with a passive protection net 7 is arranged above the top of the tunnel structure 1 to block the rockfall from the top of the karst cavity and prevent the rockfall from directly impacting the tunnel structure 1 . The frame structure 6 is made of steel pipes or high-strength composite profiles to form a triangular light frame with a small upper part and a large lower part, which is light in weight. Therefore, the impact force of the rockfall on the frame structure 6 is greatly attenuated, and the frame structure 6 mainly plays a guiding role for the rockfall. The lower part of the frame structure 6 is connected by the tension anchor cable 8 provided with the elastic structure 9, which can not only make the frame structure 6 have better plane positioning, but also generate large deformation and automatically restore the position after deformation. Referring to Figure 1, the frame structure 6 is made of steel pipes or high-strength composite profiles, and the width of the bottom opening end is greater than the width of the tunnel structure 1 by 2-4m. The lengthwise sections are arranged along the line, the number of fixed anchor cables 5 suspended and connected to each section is not less than two, and the distance between the fixed anchor cables 5 is not more than 5m. The tunnel foundation 2 is generally made of concrete pouring or mortar masonry.

Referring to Figure 1, a large-scale karst cavity tunnel large-deformation frame anti-rockfall structure of the present utility model is constructed according to the following steps:

①Remove the loose soil and rock at the corresponding position at the bottom of tunnel structure 1 until the bedrock surface is stabilized;

② Construction of tunnel foundation 2;

③ After the tunnel foundation 2 reaches 80% of the design strength, construct the reinforced concrete for the tunnel structure 1;

④ The protection body 3 shall be constructed by layered and symmetrical construction of tunnel discarded ballast;

⑤ Excavate the foundation pit on the filling protection body 3, construct the reinforced concrete of the anchor foundation 4, and embed the steel pull ring on the top;

⑥Construct fixed anchor cable 5 on the rock mass of the karst cavity roof corresponding to the top of tunnel structure 1;

⑦ Use steel pipes or high-strength composite profiles to assemble the frame structure 6;

⑧Tightly wrap passive protective nets 7 on both sides of each segmented frame structure 6;

⑨ The hoisting frame structure 6, the upper end of which is fixedly connected with the downwardly extending end of the fixed anchor cable 5;

⑩ Install the elastic member 9 on the tension anchor cable 8;

⑾ The upper end of the tension anchor cable 8 is fixedly connected with the bottom end of the same side of the frame structure 6, and the lower end is fixedly connected with the embedded steel pull ring on the tension anchor foundation 4;

⑿ Anti-corrosion ropes are used to bind and fix the adjacent segmented frame structures 6 as a whole.

The above is only to illustrate some principles of the large deformation frame rockfall prevention structure of a large-scale karst cavity tunnel according to the present invention, and it is not intended to limit the present invention to the scope of application of the specific structures and construction methods shown and described, Therefore, all corresponding modifications and equivalents that may be used belong to the scope of the patent application for this utility model.

Claims (4)

1. The utility model provides a large deformation frame rockfall prevention structure of large karst cavity tunnel, includes tunnel structure (1) that passes through large karst cavity, characterized by: the tunnel structure (1) is integrally cast by adopting reinforced concrete, the bottom of the tunnel structure is located on a tunnel foundation (2) positioned on a stable rock foundation, filling protective bodies (3) formed by filling tunnel waste to the top elevation of the tunnel structure (1) are arranged outside the two transverse sides of the tunnel structure, a frame structure (6) with a triangular section is hung above the tunnel structure, and two sides of the frame structure (6) are tensioned, wrapped and fixed with a passive protective net (7); the upper end of the frame structure (6) is fixedly connected with the downward extending end of a fixed anchor rope (5) which is anchored in a stable rock body at the top of the karst cavity at intervals along the longitudinal direction of the line, and the bottom ends at the two sides are fixedly connected with a pull anchor foundation (4) which is embedded in a filling protection body (3) at the two sides of the top of the tunnel structure (1) at intervals along the longitudinal direction of the line through a pull anchor rope (8) which is provided with a spring pull member (9) on the pull anchor rope.

2. The large deformation frame rockfall prevention structure of the large karst hollow tunnel as claimed in claim 1, wherein: the frame structure (6) is made of steel pipes or high-strength composite section bars, and the width of the opening end at the bottom of the frame structure is 2-4m larger than that of the tunnel structure (1).

3. The large deformation frame rockfall prevention structure of the large karst hollow tunnel as claimed in claim 2, wherein: the cable is arranged in sections along the longitudinal direction of the line, the number of the fixed anchor cables (5) which are connected with the sections in a hanging mode is not less than two, and the distance between the fixed anchor cables (5) is not more than 5 m.

4. The large deformation frame rockfall prevention structure of the large karst hollow tunnel as claimed in claim 1, wherein: the tunnel foundation (2) is formed by pouring concrete or building mortar rubble.

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