Construction method for controlling stability of tunnel face of high-water-pressure water-rich stratum tunnel

Abstract

The invention discloses a construction method for controlling the stability of a tunnel face of a high-water-pressure water-rich stratum tunnel. The construction method for controlling the stability of the tunnel face of the high-water-pressure water-rich stratum tunnel comprises the following steps of positioning a water-rich stratum, carrying out an advanced geological forecast on the tunnel, ascertaining the distribution condition of the water-rich stratum of the front tunnel face and underground water occurrence characteristics, and determining surrounding rock parameters of the water-rich stratum by combining a geological exploration report and a field test; establishing a mechanical calculation model of the water-rich stratum and a middle rock disc of the front tunnel face, calculating and guaranteeing the safe distance L between the water-rich stratum and the middle rock disc of the front tunnel face, and determining the construction position of an advanced high-position drainage structure according to the safe distance L; arranging the advanced high-position drainage structure; monitoring the water inflow of the tunnel face, continuing to conduct tunnel excavation when the water inflow is lower than a preset value, and constructing a grouting ring and a grout stop wall till the tunnel penetrates through the water-rich stratum; and arranging a lining back drainage system, and constructing a secondary lining. According to the construction method for controlling the stability of the tunnel face of the high-water-pressure water-rich stratum tunnel, detection and drainage are integrated, remote drainage and pressure reduction and high-position drainage are achieved, construction safety and stability are ensured, and the method has high practicability.

Description

technical field [0001] The invention belongs to the technical field of tunnel engineering construction, and in particular relates to a construction method for controlling the stability of the face of a tunnel in a high-pressure water-rich stratum. Background technique [0002] With the in-depth development of the western development strategy and the rapid development of the national economy, more long tunnel projects will be built in the fields of railways, highways, hydropower, inter-basin water transfer and mineral resources. Encountering high water pressure and water-rich formations has brought great challenges to tunnel construction safety and later operation. [0003] During the construction of tunnels in high water pressure formations, due to the complex space environment, high water pressure, and strong excavation disturbance, the tunnel face is prone to extrusion deformation, and even geological disasters such as water gushing and mud outbursts, which in turn cause t...

AI Technical Summary

Problems solved by technology

The current pilot pit drainage used on the face will cause a large loss of filling material in the rock mass cracks in the formation, which will seriously damage the structure of the surrounding rock and seriously reduce its self-stabilization ability, especially in the unconsolidated high In the fractured zone of hydraulic faults, the loss of fine grains is an important reason for the relaxation of surrounding rocks

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