多重势面模型在混凝土面板堆石坝应力变形分析中的应用

Application of multi-potential surface model to the stress-deformation analysis of CFRD

本文采用应力型多重势面模型模拟堆石体的本构关系,模型参数选择邓肯E-B模型的参数,利用自行开发的三维有限元程序对金钟面板堆石坝进行应力变形分析。本文计算的竣工期堆石体沉降量与实测最大值吻合较好。由于多重势面模型能够反映堆石体的剪胀性,因此计算的蓄水期面板应力以压应力为主,拉应力主要分布在两岸,这与已建工程的实测情况相符,克服了常用的邓肯E-B模型计算的面板底部顺坡向出现较大拉应力的缺点,表明多重势面模型能够较好地模拟面板堆石坝的应力与变形。

In this paper,a stress-type multi-potential surface model with the same model parameters as those of Duncan E-B model is adopted to simulate the constitutive relation of rock-fill material,and a 3-D FEM code is used to compute stresses and deformation of Jinzhong concrete faced rock-fill dam（CFRD）.The computed maximum settlement of the dam at construction completion stage is in a good agreement with the measured value.The computed results show that at storage stage,the compressive stress in the concrete face slabs is dominant,while the tensile stress occurs in relative small areas near the left and right banks.This feature of stress distribution has been measured and observed on many CFRDs under operation.This multi-potential surface model can describe the dilatancy of rock-fill material,so it overcomes the shortcoming of the widely used Duncan E-B model that often produces too high slope-wise tensile stresses at the bottom of face slabs.These results show that the multi-potential surface model can improve the accuracy of stress and deformation simulation of CFRD.