第六章 不同饱和度下破碎软岩隧道掌子面破坏范围上限分析.pdf

46 6 () Vol.46 No.6 2015 6 Journal of Central South University (Science and Technology) June 2015 DOI: 10.11817/j.issn.1672-7207.2015.06. ( 410075) Hoek−Brown 0.8 651.541 kPa U 451 A 1672−7207(2015)06−2267−07 Upper bound analysis of collapsing area of tunnel face in broken soft rocks under different saturations YANG Zihan, YANG Xiaoli, ZHANG Jiahua, LI Yongxin (School of Civil Engineering,Central South University, Changsha 410075, China) Abstract: Based on the multi-blocks failure mechanism, a computing method for estimating the scale of the collapsing area of the tunnel face under different degrees of saturation was proposed by non-linear Hoek−Brown failure criterion and the relationship between the strength of soft rocks and saturation. Taking the accident of water gushing and mud outburst in Yaozhai Tunnel as an example, the scope of the collapsing area in the front of the tunnel face was computed under different degrees of saturation. The results show that the compressive strength of rock decreases gradually with the increase of the degree of saturation, so does the cohesion and internal friction angle which is obtained by the parameter transformation. However, both the scale of collapsing area of the tunnel face and the supporting forces tend to