Semi-covering semi-darkened construction method for separated tunnels downwards penetrating through high and steep V-shaped gully eccentric compression 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 split-type tunnel passing through a biased section of a high-steep V-shaped gully, belonging to the technical field of tunnel construction. Background technique [0002] With the development of my country's national economy, the construction of highway network has continued to increase, and a large number of tunnel projects have emerged. The construction of mountain tunnels inevitably encounters high and steep V-shaped gully through shallow overburden, which at the same time leads to the formation of shallow buried biased tunnels. Generally speaking, the mountains and gullies are eroded by rain all the year round, the geological environment is generally poor, the surrounding rock strength of the tunnel is low, the self-stability is poor, the rock mass is loose and broken, and there is also a certain degree of surface seepage. The uneven stress distribution of the rock mass in ...

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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