(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China;2. Institute of Geotechnical Engineering,Hohai University,Nanjing,Jiangsu 210098,China)
PREDICTION OF WATER INFLOW IN TUNNEL BASED ON STOCHASTIC FINITE ELEMENT OF UNSTEADY SEEPAGE
WANG Yuan1,2,WANG Fei1,2,NI Xiaodong1,2
(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China;2. Institute of Geotechnical Engineering,Hohai University,Nanjing,Jiangsu 210098,China)
Abstract:In prediction of water inflow in tunnel,the water inflow is generally random because of the spatial variability of permeability in rock mass,so the random analysis of prediction of water inflow is necessary. Thus, the spatial variability of permeability in rock mass is described by regarding permeability tensor as three- dimensional anisotropic random field,and vector separable local average method is adopted for discretion of random field. Then the stochastic finite element governing equations of three-dimensional unsteady seepage are deduced based on random variational principle in first order perturbation method. Furthermore,the three- dimensional unsteady random seepage field can be derived and the formulas of mean and standard deviations of flow rate are deduced combining with the first order Taylor series stochastic finite element method. Finally,some programs are developed for proposed method;and an example for stochastic prediction of water inflow is given. The results indicate that the proposed method is feasible.