水下岩巷围岩蠕变Norton-Hoff解法与分析

Norton-Hoff analytical solution for surrounding rock creep in rocks tunnels below water table

富水环境中岩体巷道的长期稳定性与水的渗流、岩体流变等因素紧密相关。文章假设围岩蠕变行为服从Norton-Hoff定律,建立水下岩巷扰动区蠕变的计算模型,并利用Laplace变换以及有效应力原理解答水下岩巷受力与变形的时效问题;在Norton-Hoff解法基础上获得了与时间相关的水下岩巷变形计算式,并对扰动区的蠕变变形进行参数敏感性分析。研究表明:随着岩石黏滞系数的增大,岩巷蠕变变形逐渐减小,呈现非线性特性;水力传导系数仅对深处围岩的时效变形产生影响,增大该系数,岩巷围岩深处任一点位的位移分布增大。该研究可为更复杂的水下岩巷蠕变变形的数值计算提供理论参考。

The long-term stability of rocks tunnels in the water-rich environment relates closely to the seepage and the rheology behavior .It is assumed that the creep behavior of surrounding rock complies with the Nor-ton-Hoff law ,thereby the calculation model of time-dependent deformation in rocks tunnels below the water table is established .The Laplace transform method and principle of effective stress are utilized to calculate the stress and displacement field of rocks tunnels .The expression of time-dependent deformation in rocks tunnels below the water table is given ,and the sensitivity analysis of relevant parameters is carried out .The results show that time-dependent deformation gradually degrades with the increase in the viscosity ,which represents nonlinearity ;the rock hydraulic conductivity only has significant influence on time-dependent deformation in the deep surrounding rock ,with increasing the values of this coefficient ,the increase of displacement occurs everywhere except at the tunnel wall .This analytical solution provides a useful reference for the more complex numerical simulation in this respect .