摘要
降雨入渗导致土坡土体强度下降 ,容重增加是引起边坡失稳的主要原因。应用饱和土 -非饱和土的非定常渗流方程可以求得土坡中任一点的饱和度。根据土体物理指标和现场土工试验可以建立含水量与强度指标之间的关系。应用极限分析的下限法可以求得不同降雨量时边坡的极限承载力大小 ,该法借助于有限单元法和线性规划法 ,可以较容易地建立静力许可场 。
Rainfall has a direct effect on occurrence of landslides. It increases soil weight and reduces the shear strength of soil. A procedure is built to gain the undrained shear strength of soil under different degree of saturation based on its physical index or testing data in situ. Using the undrained shear strength of soil so obtained and the degree of saturation getting from the solution of saturated unsaturated seepage equation, the bearing capacity of slope at different intensity of rainfall can be calculated. The rigorous lower bound solutions are presented by using linear programming and finite element discretization. The stress field is modeled by using linear 3 nodded triangles and the statically admissible stress discontinuities may occur at the edges of each triangle. Imposition of the stress boundary condition, equilibrium and yield conditions lead to an expression for the collapse load which is maximized subject to a set of linear constraints on the nodal stresses. The linear programmingproblem is solved by using an active set algorithm. A set of simulating results shows that the method is powerful.
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2002年第4期109-113,共5页
Journal of the China Railway Society
基金
铁道部科技专项经费资助项目 (J97G0 1 3)
