Tunnel open-cut-tunnel underground-excavation construction technology under complicated geologic environment

Abstract

The invention discloses a tunnel open-cut-tunnel underground-excavation construction technology under a complicated geologic environment. The tunnel open-cut-tunnel underground-excavation constructiontechnology comprises the following steps that first, surveying, setting-out and construction layout are conducted; second, water interception and drainage construction at the roof is conducted; third, a side and face upward slope is excavated and supported; fourth, a soil loose tooling is formed and constructed, specifically, when the side and face upward slope is excavated to get close to the elevation of the roof of an open-cut tunnel, large-range excavation is stopped, measuring staff set the lining axis and elevation of the open-cut tunnel on site, and earthwork stone on the two sides islongitudinally excavated along the axis of the open-cut tunnel through a reserved core soil method; fifth, cast-in-place concrete is conducted, specifically, an isolation layer is arranged on the outer surface of the formed soil loose tooling, and the isolation layer sequentially comprises a graded broken stone base with the thickness being 8 cm, a 1:3 cement mortar leveling layer with the thickness being 2 cm, and a color strip cloth interlayer from inside to outside; sixth, a protective arch of the open-cut tunnel is constructed; seventh, the open-cut tunnel is excavated and supported; and eighth, lining of the open-cut tunnel is conducted. According to the construction technology, landslide and collapse during tunnel excavation can be effectively prevented, the surrounding environment of a tunnel is protected, and construction is convenient, quick, safe and reliable.

Description

Technical field [0001] The invention belongs to the technical field of tunnel excavation, and particularly relates to a tunnel excavation construction technology. Background technique [0002] In the construction of modern tunnels, most of the tunnel entrances are shallowly buried, the roof covering is thin, and the geological conditions are complex. To facilitate early entry and ensure safety, a certain length of open hole is usually set at both ends of the tunnel entrance and exit. As a transition between the light and dark junctions of the tunnel, the open tunnel is an important part of the tunnel. It has the dual characteristics of ground and underground buildings. Its function is to connect the light and dark tunnels, resist the external forces of landslides and landslides, and support the stability of the slope. According to the construction principle of “early entry and late exit”, open tunnel construction is the key to tunnel entry and exit, which directly affects the con...

AI Technical Summary

Problems solved by technology

However, bias pressure and complex geological conditions often exist in the location of the tunnel open hole. The open excavation construction will form a high cut slope, and the excavation of the foundation trench will weaken the slope toe, causing disasters such as landslides, collapses, and mountain instability, resulting in construction failures. In this case, it is imminent to design a construction process with obvious effects in speeding up the progress, protecting the environment, and ensuring safety.

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