乌鞘岭隧道F7断层的黏弹性位移反演分析

工程材料受力变形的性态常与时间有关,这类现象一般称为材料变形的黏性效应,材料发生随时间而增长的变形时,如果始终处于弹性受力状态,则称发生的变形为黏弹性变形。结合乌鞘岭隧道穿越F7断层段所取得的量测资料,将计算区域内的岩石视为均质各向同性体,初始地应力假设成均匀分布,采用三单元模型,对有限元黏弹性问题进行优化反演分析,得出围岩区域内的水平侧压力系数和所使用模型中的弹性模量和黏滞系数。反演分析表明,该隧道发生较大变形的主要原因是较大应力场的存在、围岩的软弱和较强的蠕变性。结论可为挤压性断层中隧道的支护设计、施工组织提供可靠的依据。

The Elastic-visco Displacement Back Analysis of Wushaoling Tunnel F7 fault

The characteristics of loading-deformation of engineering materials connect with temporal variations,which is called the visco effects,and the dispalcement is always keeping in the elastic-visco state.Combining the measurement data of the F7 fault where the Wushaoling Tunnel traverses and taking the surrounding rock as being isotropic,the initial ground stresses are postulated to be in well-proportioned distribution.The tri-element model is utilized.The optimum back analysis of the elastic-visco finite element problem is made.The horizontal coefficient of the lateral earth pressures in the surrounding rock area,the elastic modulus and coefficient of viscosity of the model are obtained.The back analysis proves that the main reasons causing large displacement are the huge ground stress field,soft rock and strong creeping.The results provide reliable reference for support designing and construction organizing for tunnels through extrusion faults.