Stability and sub-classification study on the tunnel surrounding rock of Xigeda strata considering the influence of moisture content
Zhou Ping1 Wang Zhijie1 Xu Haiyan1 Zhao Qichao1 Sun Changsheng2
1. Key Laboratory of Transportation Tunnel Engineering of the Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China;
2. China Railway Design Corporation, Tianjin 300142, China
Abstract：The surrounding rock of Xigeda strata is extremely sensitive to water and undergoes the argillization induced by water. Thus, a lot of geologic hazards appear, including large deformation of surrounding rock, cracking and disintegration of supporting structure, collapse of tunnel face, and so on. By means of field collection, laboratory tests, numerical simulation and theoretical analysis, the physical and mechanical properties, and the sub-classification of the surrounding rock of Xigeda strata considering the water content are studied. The results show that the water content has the largest negative impact on the cohesive strength and the internal friction angle of the gray shale with interbedded sandstone of Xigeda strata. When the water content reaches 25%, mutation will appear in the accumulated deformation values of tunnel vault, tunnel invert, the horizontal converge and the tunnel face. The maximum accumulated deformation values of the tunnel invert uplifting, the tunnel face extruding, the vault settlement, and the horizontal converge value of the tunnel decrease in turn. The physical and mechanical property of the sub-classification of the tunnel surrounding rock of Xigeda strata basically lies in the level of Ⅳ3、Ⅴ1 and Ⅴ2. Except the light gray shale with interbedded sandstone of No.2 soil sample which belongs to the level of Ⅳ3, other soil samples all belong to the level of Ⅴ. Moreover, the characteristic of the surrounding rock, the range of water content and the value of BQ of the sub-classification of Xigeda strata are gotten after the correction of the water content, and the relevant engineering measures related with the surrounding rock under the sub-classification are proposed. The research results can provide guidance for the safe and rapid construction of Xigeda strata tunnel.
周平 王志杰 徐海岩 赵启超 孙长升 . 考虑含水率的昔格达地层隧道围岩稳定及亚级分级研究[J]. 土木工程学报, 2017, 50(12): 97-110.
Zhou Ping Wang Zhijie Xu Haiyan Zhao Qichao Sun Changsheng . Stability and sub-classification study on the tunnel surrounding rock of Xigeda strata considering the influence of moisture content. 土木工程学报, 2017, 50(12): 97-110.
