考虑围岩蠕变全过程与扩容的深埋隧洞非线性位移解

深埋隧洞围岩变形是一个复杂的非线性力学问题，其中岩石的蠕变全过程和扩容是两个重要的影响因素。引入扩容角考虑塑性体积变化的影响，推导Hoek-Brown屈服准则下考虑与不考虑洞周面力的深埋隧洞围岩非线性应力解。借助可描述蠕变全过程行为的河海模型，获得了围岩黏弹塑性区蠕变位移表达式。针对不同NVPB蠕变参数和不同材料参数m值情况，讨论分析了洞周面力与扩容角对隧洞洞壁蠕变位移的影响规律。结果表明：在高地应力作用下，采用非线性蠕变模型描述深埋隧洞围岩蠕变问题可获得蠕变全过程曲线；扩容角增大或洞周面力和材料参数m值减小时，相同时刻隧洞洞壁蠕变位移增大，对围岩长期稳定不利。研究结论对深埋隧洞围岩临崩预报具有一定指导意义。

Nonlinear displacement solutions for deep tunnels considering whole process of creep and dilatation of surrounding rock

The deformation of surrounding rock around a deep tunnel is a complex nonlinear mechanical problem. The creep in whole process and dilatation of the rock are two significant factors. Based on the Hoek-Brown criterion, the nonlinear stress solutions are obtained with and without the condition of the surface force around the tunnel, and dilatancy angle is introduced to consider the influence of the plastic volume change. Then an expression of viscoelastoplastic creep displacement is deduced under the nonlinear stress state using Hohai model which can describe the whole process of creep. Finally, the influence of the surface force around tunnel and dilatancy angle on the creep displacement of tunnel wall is discussed with different NVPB creep parameters and different material parameters m. The results show that under high ground stress the whole creep curve can be obtained by describing the creep problem of deep tunnel surrounding rock with the nonlinear creep model. In addition, the creep displacement of tunnel wall increases with the decrease of the surface force around tunnel and the value m, or the increase of the dilatancy angle, which is unfavorable to the long-term stability of surrounding rock. The results can be used to forecast the surrounding rock collapse of deep tunnels.