Excavation construction method of mountain tunnel with vertical pre-reinforcement treatment

Abstract

The invention discloses a mountain body tunnel excavation construction method adopting vertical pre-reinforcement treatment. Before a cross section of tunnel under tunneling construction, cast-in-situ bored piles are formed in a rock-soil body above an excavation contour line of a tunnel for pre-reinforcement treatment. According to the construction method, integral one-time reinforcement and strengthening is carried out on a mountain body outside a tunnel contour line structure by driving the piles into the mountain body, and cement concrete in pile holes permeates into gaps of the rock-soil body, and is combined with a column pile structure at high strength to form a structural framework of a mountain body rock-soil layer, so that a stressed state of the mountain body rock-soil layer is changed; the stability, the compressive strength and the shearing strength of the mountain body rock-soil layer are improved; furthermore, the stability of wall rock after tunnel excavation is improved; the rock-soil layer is effectively prevented from collapsing; a surface subsidence phenomenon can be avoided; during tunneling construction, a situation that no vault soil body caves is ensured, and the construction smoothness and the construction safety are ensured consequently; a long-term stable effect can be achieved; the construction method is applicable to the construction of soft and weak rock layers and large section span tunnels, and is free from limitation of geographical conditions; the design and the construction method are simple, and can be completed at one step; and the project progress is improved greatly.

Description

technical field [0001] The invention relates to tunnel construction, in particular to a mountain tunnel excavation construction method with vertical pre-reinforcement treatment. Background technique [0002] After the excavation of the tunnel, the surrounding rock will be greatly deformed, and the stability will deteriorate. In severe cases, it will cause the settlement of the ground surface, which will cause serious damage to the ground structures. During the excavation of the tunnel, the stability of the rock and soil ahead is very important. It is related to the safety of engineering construction, in order to ensure the stability of tunnel excavation, it is very necessary to take certain pre-reinforcement measures. In the prior art, more pre-reinforcement measures used in tunnel excavation are grouting, small conduits, frontal bolt reinforcement measures, and the like. [0003] The small conduit is a pre-reinforcement measure for shed support. Generally, the surrounding ...

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Problems solved by technology

However, the front bolt support measures cannot seal the surrounding rock, nor can it prevent weathering. Over time, it will lead to the spalling of the rocks in the cracks between the bolts.

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