Drainage construction method for tunnel passing through clastic rock steeply inclined reverse thrust water-rich fault

Abstract

The invention discloses a drainage construction method for a tunnel passing through a clastic rock steeply inclined reverse thrust water-rich fault. The drainage construction method is characterized in that a construction tunnel main cave is divided into a rear side tunnel section, a front side tunnel section and a middle portion tunnel section passing through the clastic rock steeply inclined reverse thrust water-rich fault, wherein a by-pass pilot tunnel and a drain cavern are formed in the same side of the construction tunnel main cave. When drainage construction is carried out in the construction tunnel main cave, the drainage construction method comprises the steps of: 1, carrying out preliminary excavation construction on the rear side tunnel section; 2, synchronously carrying out excavation construction on the rear side tunnel section and a drainage hole body of the drain cavern; 3, synchronously carrying out excavation construction on the rear side tunnel section, the drainagehole body of the drain cavern and a rear side by-pass pilot tunnel section; 4, and carrying out construction on the front portion drainage hole body, and synchronously carrying out construction on theby-pass pilot tunnel and the tunnel main cave. The drainage construction method provides a new construction working plane by means of the by-pass pilot tunnel, improves the working efficiency, provides the high-altitude drainage hole between the tunnel main cave and the by-pass pilot tunnel, can drain water embedded in the fault to the greatest extent, reduces water pressure in the fault in frontof a tunnel face, ensures safety construction of each tunnel face and can shorten the construction period.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a drainage construction method for tunnels passing through clastic rocks steeply dipping and thrusting water-rich faults. Background technique [0002] The fault zone refers to the zone composed of the main fault plane and the broken rock blocks on both sides, as well as several secondary faults or rupture surfaces. In China, a high-angle thrust fault with a dip angle greater than 45° or 30° is called a thrust fault, and it is more difficult to construct a tunnel that crosses a steep thrust fault with a dip angle greater than 60°. Thrust faults greater than 60°. Clastic rock refers to the rock formed by the transport, deposition, compaction and cementation of minerals and rock debris produced by mechanical weathering of the parent rock; its components include matrix and cement in addition to clastic particles. Tunnel construction in clastic rock strata i...

AI Technical Summary

Problems solved by technology

Tunnel construction in clastic rock strata is difficult, especially when the stratum is a water-rich stratum rich in groundwater. Rock mass fragmentation provides more favorable conditions for the occurrence and enrichment of groundwater, and the construction is very difficult. Large, water gushing and sand gushing are very likely to occur during construction. In addition, the inclination angle of the fault section is greater than 60°, which can easily cause catastrophic consequences and seriously affect the safety and efficiency of construction.

Therefore, when constructing tunnels that cross steeply inclined thrust water-rich faults in clastic rocks, the construction risks are very high. For steep thrust faults in the strata, when the clastic rocks are excavated to the steep thrust water-rich faults, the face of the face is prone to sudden water and sand gushes, and because the clastic rocks are steeply inclined, the water-rich faults are fragmented. The clastic rock is rich in groundwater, and under the action of high water pressure, it is more likely to form geological disasters such as water gushing and sand gushing. The construction risk is high, the construction is difficult and the construction progress is slow

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