Tunnel portal dangerous rock falling multi-stage protection method and structure body thereof

Abstract

The invention discloses a tunnel portal dangerous rock falling multi-stage protection method and a structure body thereof. The tunnel portal dangerous rock falling multi-stage protection method concretely comprises the following steps: step I, when rockfall impact energy is small, a high-strength rigid ceiling guides falling rocks to the two sides of a traffic line; step II, when the rockfall impact energy is medium, the high-strength rigid ceiling transfers the impact energy to a shock absorption and energy dissipation device and guides the falling rocks to the two sides of the traffic line at the same time; and step III, when the rockfall impact energy is large, the high-strength rigid ceiling carries out light plastic deformation and transfers the energy to the shock absorption and energy dissipation device at the same time, and the shock absorption and energy dissipation device carries out compressive deformation to realize the protection action. The structure body of the tunnel portal dangerous rock falling multi-stage protection method comprises the high-strength rigid ceiling, the shock absorption and energy dissipation device, a supporting structure and a permanent anchoring base. The tunnel portal dangerous rock falling multi-stage protection method and the structure body thereof realize multi-stage protection in a mode with the synergistic effect of avoidance, energy dissipation and guide and have the characteristics of obvious flexibility, applicability, economy and environmental protection property.

Description

technical field [0001] The invention relates to the field of engineering construction and the field of rockfall prevention and control engineering at tunnel entrances, in particular to a multi-stage protection method for dangerous rockfalls at tunnel entrances and a structure thereof. Background technique [0002] With the continuous advancement of the strategic plan for the development of the western region, the transportation industry in the western region is developing vigorously. The western part of my country is a mountainous and hilly area, with steep terrain and dense distribution of mountains. In recent years, rolling stone disasters have occurred frequently. While large-scale engineering projects such as the Yiwan Railway, Shanghai-Chengdu-West Expressway, and West-East Gas Pipeline are being carried out, human engineering activities Induced rockfall disasters have occurred frequently. During the "5.12" earthquake, rockfalls had countless impacts on traffic fortresse...

AI Technical Summary

Problems solved by technology

However, after being impacted by falling rocks, gravel remains on the top of the structure, which will easily cause a large overlying load on the structure and low safety. Moreover, the structure body used is rigid. Once damaged, the whole will fail, unable to be repaired, and the durability is poor. more difficult

[0010] Another example is the Chinese patent CN105603893A which discloses a "flexible nose-shaped rolling stone row guide shed structure at the tunnel mouth and its design method", which includes a plurality of herringbone prevention and control structure monomers, support structures and slope energy-dissipating shock-absorbing anchor bases, The herringbone prevention and control structure unit is installed on the energy-dissipating and shock-absorbing anchor base of the slope through the support structure, and the prevention and control structure unit is covered with a composite energy-dissipating cover plate. This technical method absorbs the impact of dangerous rockfall through the upper composite energy-dissipating cover plate However, once the energy-consuming material fails, the protective effect will be lost, and the protective effect will be almost zero in the case of dangerous rockfall disasters with relatively large impact force, and the construction volume is large and difficult. It is difficult to maintain in the later stage, and the applicability is poor in projects with high installation requirements such as bridge-tunnel connection, and the use limitations are relatively large

[0011] Rigid protection method The structural body is very rigid. Once damaged, it cannot be repaired. The durability is poor. The structural replacement requires a large amount of work, a long period, and difficult maintenance in the later stage.

The special energy-consuming materials used in the flexible protection method are expensive, poor in economy, low in durability and safety, require a large amount of construction work, difficult to maintain in the later stage, and have relatively limited use

Images