Studying on large deformation mechanism of soft rock tunnel fluenced by Yunxi-Yunxian fault

摘要

The Yunxi-Yunxian Fault is a large fractured zone having experienced complex structural evolution. Under its influence, geological conditions of surrounding rock masses of tunnels on the Shiyan-Manchuanguang Expressway are not favorable, large deformation is very likely to occur, and the Huocheling Tunnel is the most serious one. Based on the field investigation, engineering geological exploration and stress analysis, the mechanism of large deformation was studied. Large deformation is mainly due to lithologic character of rock masses, unsymmetrical load and tectonic effect of the Yunxi-Yunxian Fault. Finally, the treatment measures were carried out.