Full-section sealing extrusion grouting method

Abstract

The invention relates to an auxiliary method for tunnel excavation construction, namely, a full-section sealing extrusion grouting method for tunnel excavation, comprising a working surface slurry stop wall, grouting holes and discharge checking holes, wherein the slurry stop wall can improve the drilling precision of the grouting hole and the discharge checking hole, and also can prevent the phenomenon of grout oozing out of the working surface due to overhigh grouting pressure. The grouting holes are uniformly distributed in a working surface in the annular direction and the radial direction, and the discharge checking holes and the grouting holes are arranged at intervals and both incline by a certain angle during drilling. The discharge checking holes are arranged between endless belts of the grouting holes, so as to be beneficial to the smooth discharge of clearance water in a soft soil layer when the clearance water is extruded during grouting, and be convenient for coring of rock soil body after grouting so as to check the grouting effect of the working surface. A sleeve valve pipe (namely a splitting grouting pipe) is adopted as the grouting pipe, and a retreating type splitting grouting method is adopted to conduct grouting sequentially from the periphery to the inner ring of of the working surface. According to the design, the stability of the working surface during the excavation of the tunnel in the soft soil layer can be ensured, and sediment quantity caused by the tunnel excavation can be reduced.

Description

technical field [0001] The design of the invention relates to an auxiliary method for tunnel construction, in particular to a full-section closed extrusion grouting method. Background technique [0002] In the construction process of shallow burial and underground excavation, sometimes the self-stabilization ability of the surrounding rock is poor, or even has no self-stabilization ability. Strength and stability, change the loose structure of the surrounding rock, increase the cohesive force and internal friction angle, seal the cracks, and significantly increase the strength of the rock mass. At present, the mechanism of grouting reinforcement mainly includes infiltration grouting, splitting grouting, compaction grouting, and high-pressure spray grouting. Different grouting mechanisms are suitable for different geological conditions. For the impermeable clay (slurry) with fine particles, low porosity, and poor strength formation, it is advisable to adopt the split groutin...

AI Technical Summary

Problems solved by technology

The grouting reinforcement methods used mainly include: advanced small conduit grouting, advanced curtain grouting, etc. These grouting methods can stabilize the surrounding rock of the tunnel to a certain extent, but after grouting, only cylindrical reinforcement is formed around the tunnel Once encountering a stratum with low strength, low porosity, poor water permeability, high sensitivity, and poor groutability, it is difficult to ensure the stability of the tunnel face, which indirectly affects the supports such as pipe sheds and grid arches. The effect of the measures makes it difficult to control the surface subsidence caused by tunnel excavation, and the design of the present invention is intended to stabilize the tunnel face, effectively solving this problem

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