论文部分内容阅读
探讨了一种将随机场模拟技术与有限元方法相结合的随机有限元法在土石坝地震反应分析中的应用途径。采用局部平均细分法模拟堆石料物理力学性质随机场,使得能够考虑堆石料的空间变异性。提出尽量利用建立材料物理性质与力学性质关系的计算模型,以降低获取材料力学性质统计特性信息的成本。以一实际工程为例,采用该随机有限元法计算了堆石料的干密度、孔隙比、不均匀系数、平均粒径、Duncan–Chang E–B模型模量系数以及初始摩擦角具有不确定性时土石坝的随机地震响应及永久变形。结果表明:筑坝堆石料的不确定性会使大坝响应及永久变形发生一定程度的离散;忽略材料的不确定性可能导致低估大坝的地震反应;表征大坝地震反应的各性能指标并不一定都符合正态或对数正态分布。
In this paper, a method of random finite element method combining random field simulation with finite element method is introduced in seismic response analysis of earth-rock dam. The use of local average subdivision method to simulate the physical and mechanical properties of rockfill materials with random fields makes it possible to consider the spatial variability of rockfill materials. It is proposed to make full use of the computational model to establish the relationship between the physical properties and the mechanical properties of the material in order to reduce the cost of obtaining the statistical property information of the mechanical properties of the material. Taking an actual project as an example, the randomness finite element method was used to calculate the dry density, void ratio, non-uniform coefficient, average particle size, modulus coefficient of Duncan-Chang E-B model and initial friction angle with uncertainties Stochastic seismic response and permanent deformation of earth-rock dam. The results show that the uncertainty of dam rockfill materials will make the response and permanent deformation of the dam disperse to a certain degree. Ignoring the material uncertainty may lead to underestimation of the dam seismic response. Not necessarily in normal or logarithmic normal distribution.