Construction method of high-crustal-stress soft rock extrusion large-deformation tunnel

Abstract

The invention discloses a construction method of a high-ground-stress soft rock extrusion large-deformation tunnel. The main control measures of the construction method comprises advanced pre-grouting, large-section excavation, large-diameter foot locking, resin pre-stressed anchor cable construction, double-control ring forming step pitch construction, cover arch installation and mechanical matching rapid construction. The construction method can improve the strength and stability of surrounding strata, reduce the disturbance frequency of excavation on broken surrounding rocks, actively support the surrounding rocks, quickly anchor and early load, control the expansion of a loose circle, strengthen the rigidity of resisting deformation of a primary support structure, compress an unfavorable stress state of the structure to be the shortest, improve the working efficiency, remarkably improve the working environment, reduce the labor intensity and save the labor, the construction problems that the tunnel face of the high ground stress soft rock extrusion large deformation tunnel is prone to collapse, deformation is uncontrollable, the progress is not ideal and the like are effectively solved, and the method has the advantages of overall utilization of resources, ordered management, guarantee of engineering safety and quality and the like.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering construction, in particular to a construction method of a high-stress soft rock extrusive large-deformation tunnel. Background technique [0002] With the rapid development of my country's railways and highways, there are more and more long tunnels, the overall buried depth of the tunnels is also increasing, the geological conditions are becoming more and more complex, and there are more and more geological problems corresponding to it, especially There are more and more large-deformation tunnels in extrusive surrounding rocks, and the prominent problem of large deformation has brought severe challenges to tunnel construction. At present, the domestically deformed and influential tunnels include Jiazhujing Tunnel of Nankun Railway, Wu Sheathing Tunnel, Muzhailing Tunnel of Lanzhou-Chongqing Railway, etc. Tunnels with large deformation due to extrusion of soft rock are all located in area...

AI Technical Summary

Problems solved by technology

Tunnels with large deformation due to extrusion of soft rock are all located in areas of high and extremely high ground stress, with large deformation and displacement velocity of surrounding rock, high rheological properties, long deformation duration, and various forms of support failure. The final trend is that the clear space inside the tunnel will be encroached, the support system will be seriously damaged, and the phenomenon of arch removal and replacement is common, resulting in extremely slow construction progress. At the same time, it is easy to form geological disasters, endangering the safety of personnel and property

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