Half-cover and half-dark construction method of separated tunnel passing through high and steep v-shaped gully bias section

Abstract

The invention relates to a semi-covering semi-darkened construction method for separated tunnels downwards penetrating through a high and steep V-shaped gully eccentric compression section. The semi-covering semi-darkened construction method mainly comprises the steps of (1) carrying out construction preparation, (2) carrying out a cover-excavation method construction technology on a previous shallowly-buried side main tunnel, (3) carrying out a six-step bench excavation method construction technology on a later deeply-buried side main tunnel, (4) taking a slope supporting measure for a high and steep gully region, and (5) carrying out an earth surface waterproof and drainage construction technology. The semi-covering semi-darkened construction method is reasonable in design, compact in construction step and convenient to construct, ground surface subsidence, subsidence of a left tunnel vault and a right tunnel vault, contraction of the peripheries of the interiors of the tunnels and stability of a slope of the high and steep gully region can be effectively controlled, the number of construction disasters is reduced, the project cost is reduced, stability of tunnel surrounding rock and the gully slope is ensured, and the risk of construction of the separated tunnels penetrating through the high and steep V-shaped gully eccentric compression section is reduced.

Description

technical field [0001] The invention relates to a semi-covered semi-dark construction method for a separated tunnel passing through a bias section of a high and steep V-shaped gully, which belongs to the technical field of tunnel construction. Background technique [0002] With the development of my country's national economy, the construction of highway network continues to increase, and a large number of tunnel projects have emerged. The construction of mountain tunnels will inevitably encounter high and steep V-shaped gullies that pass through shallow overburden layers, which at the same time leads to the formation of shallow buried bias tunnels. Generally speaking, mountain gullies are eroded by rainwater all year round, and the geological environment is generally poor. The surrounding rock of the tunnel has low strength, poor self-stability, loose and broken rock mass, and is accompanied by a certain degree of surface water seepage. At the same time, Due to the uneven ...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the defects of existing construction methods, avoid large deformation and instability disasters in tunnels, and apply to separate tunnels that pass through high and steep V-shaped gullies under mountainous terrain and geological conditions. At this time, the left and right tunnels have obvious bias. And the buried depth of one side of the tunnel is large, and the buried depth of the other side is small. The purpose of the present invention is to provide a half-covered and semi-dark construction method for a separate tunnel passing through a high and steep V-shaped gully bias section.

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