A Construction Method of Diagonal Entry in Bias-Pressure Tunnel

Abstract

The invention relates to a construction method of an unsymmetrical loading tunnel heterotropic hole. A heterotropic hole construction method in which a trapezoid cover arch large-pipe shed is utilized as a presupport is adopted, so that the height of a lateral upward slop inside a tunnel portal is effectively reduced, the construction requirement of underground excavation of wall rock coverage thickness of arch shoulders outside the tunnel is met, coordinated fusion of the tunnel portal and the ambient environment is realized, and the ambient environment of the tunnel portal is protected; the large large-pipe shed presupport and back-pressure backfilling outside the tunnel are adopted for improving the bias state of a wall rock and a lining structure and advantageous conditions are created for safe construction in the hole. The trapezoid cover arch is adopted for well solving the problem that the hole forming surface oblique crossing and a steel support as well as hole gate are uncoordinated in orthogonality, so that the difficulty of underground excavation in the hole is reduced, and the safety and practicability of construction of the unsymmetrical loading tunnel heterotropic hole are ensured; by virtue of hole greening protection, the problem of incoordination between the tunnel portal and the ambient environment due to back-pressure backfilling outside the tunnel is reduced and a 'green tunnel portal' engineering concept is realized.

Description

technical field [0001] The invention relates to the field of tunnel engineering, in particular to a construction method for an oblique entry into a biased tunnel. Background technique [0002] The construction method of tunnel excavation and entry generally adopts the construction method of orthogonal entry. However, for eccentric tunnels with oblique topography, when entering the tunnel perpendicularly, the height of the uphill slope on the inner side of the tunnel is too high and the thickness of the surrounding rock cover on the outer spandrel of the tunnel is too thin. It is beneficial to the construction and operation safety of the tunnel project. If the elevation of the side slope is too high, it will also cause coordination problems between the tunnel entrance and the surrounding environment, which is not conducive to environmental protection. [0003] The construction method of oblique tunnel entry can reduce the height of the uphill slope at the side of the tunnel ...

AI Technical Summary

Problems solved by technology

However, since the tunnel surrounding rock and lining structure at the oblique opening are in a state of bias stress, the stress situation is relatively complicated, and the surrounding rock collapse and lining structure cracking are prone to occur during construction, and the requirements for construction organization are relatively high. high

At present, the construction method of oblique tunneling is generally only applicable to situations where the angle between the topographic contour line and the center line of the route is not less than 45° and the geological conditions are good. For soft and soft strata with poor geological conditions, oblique tunneling is generally not suitable. The construction method of entering the hole

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