考虑半渗透边界的隧道周围超孔隙水压力消散解

Analytical study on dissipation of excess pore water pressure around tunnels with semi-permeable boundary conditions

通过引入衬砌半渗透边界条件,将Terzaghi-Rendulic固结理论和Burgers黏弹性模型相结合建立土体固结–流变耦合模型,采用复变函数解法推导出求解黏弹性介质中半透水隧道周围超孔隙水压力的消散表达式,并以上海地铁二号线某区间隧道为工程背景分析了不同衬砌透水程度对隧道周围超孔隙水压力消散与分布的影响规律。研究发现,随着衬砌与土体相对渗透系数的增大,隧道外壁处超孔隙水压力的消散速度不断增快;隧道周围土体距离衬砌外壁越远,其初始超孔隙水压力越小,土体的超孔隙水压力消散速度也越慢。

A consolidation-theology coupling model for soils is established by introducing semi-permeable boundary condition based on the Terzaghi-Rendulic consolidation theory and the Burgers viscoelastic model. The dissipation expression of excess pore water pressure is derived, which is around the tunnel with partially sealed shell lining in viscoelastic media by means of the complex function method. Moreover, comprehensive analysis is carded out on the effect of various permeable conditions on the dissipation and distribution of the excess pore water pressure around the tunnel, with Shanghai Metro Line 2 as the engineering background. The results show that the dissipation rate outside the tunnel lining becomes faster as the relative permeability coefficient of lining to surrounding soils rises. The initial excess pore water pressure and its dissipation rate decrease as the distance from surrounding soils to the lining turns farther.