Advanced pre-grouting method for high-pressure water-rich soft surrounding rock mountain tunnel

Abstract

The invention discloses an advanced pre-grouting method for a high-pressure water-rich soft surrounding rock mountain tunnel. Drainage holes, a lower fracture face, a tunnel face, a grout stopping laccolith, a grout stopping wall, an upper fracture face, upper-stage grouting holes, a tunnel, an advanced grouting area, a grouting curtain reinforcing area and a lower-stage grouting area are included. The advanced pre-grouting method has the beneficial effects that surrounding rock located in front of the tunnel face is reinforced through an upper-blocking and lower-draining grouting method, andthe grouting holes are formed in the upper fracture face to conduct full fracture face curtain grouting; the drainage holes are formed in the lower fracture face, the water pressure of the surroundingrock in front of the tunnel face is reduced through the drainage holes, and draining and blocking are conducted simultaneously, so that the effects of uniform and dense grouting and soft surroundingrock reinforcing are achieved; and the problem that the pressure of water in the high-pressure water-rich surrounding rock is high, and thus grouting is difficult is solved, and the grouting construction cost is reduced advantageously.

Description

technical field [0001] The invention relates to an advanced pre-grouting method for tunnels, in particular to an advanced pre-grouting method for high-pressure water-rich tunnels with weak surrounding rocks, and belongs to the technical field of construction applications. Background technique [0002] Tunnel is a key project of construction projects. Some tunnel construction areas need to cross water-rich fault zones. It is prone to construction disasters such as collapse, water inrush and mud inrush during construction. At present, the treatment method of tunnel water gushing is mainly based on "drainage", and most of the current tunnels adopt the scheme of "drainage" as the main treatment method for large-flow water. Although the tunnels built mainly on "drainage" have solved many tunnel problems, However, there are also hidden dangers in some tunnels: the tunnel has become a drain hole, which absorbs a large amount of groundwater around it, thus causing the loss of groun...

AI Technical Summary

Problems solved by technology

At present, the treatment method of tunnel water gushing is mainly based on "drainage", and most of the current tunnels adopt the scheme of "drainage" as the main treatment method for large-flow water. Although the tunnels built mainly on "drainage" have solved many tunnel problems, However, there are also hidden dangers in some tunnels: the tunnel has become a drain hole, which absorbs a large amount of groundwater around it, thus causing the loss of groundwater and causing a series of problems, such as affecting the lining structure and driving safety, and causing environmental problems. The aquifer in the area is drained, which deteriorates the ecological environment, etc.

[0003] During the construction of some current tunnels, water inrush occurs on active faults. When the water inflow is high, it is a key issue to take measures to strengthen the weak surrounding rock in front of the tunnel face to ensure the safe construction of the tunnel after the water inrush has been dealt with. For weak surrounding rocks with high water pressure and large water volume, full-section curtain grouting is used for advanced pre-reinforcement. The required grouting pressure is high, and there may be grouting blind spots during grouting, which will reduce the grouting effect

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