考虑级配空间随机特性的堆石坝变形应力分析

为研究坝壳料填筑级配的空间变异性及其对土石坝变形、应力的影响，以两河口心墙堆石坝最大断面坝段为例，选取分形分布作为级配模型，引入地质统计学方法，以指数模型、高斯模型为变异函数模型，分析级配分形维数的空间变异结构，采用克里金估计方法模拟堆石料、过渡料级配的空间随机分布；将随机模拟与有限元方法相结合，对大坝进行500次随机应力、变形计算后得到收敛结果，并与确定性有限元法作比较。结果表明：考虑级配空间分布的随机性时，坝体水平向位移、最大沉降量等都有不同程度的增大；若不考虑随机性，有超出50%的概率低估坝体应力、变形；考虑级配随机特性的计算方法对于高堆石坝设计及变形控制问题具有较好的应用价值。

Deformation and stress analysis of rockfill dams considering spatial randomness of gradation parameter

To study the impact of spatial randomness of the gradation parameter on the deformation and stress of rockfill dams, the fractal model was selected to describe the gradation distribution. The exponential model and the Gauss model were introduced as the variogram model to analyze the spatial varying structure of gradation fractal dimension D, and some geological statistical methods such as the Kriging method were introduced to simulate the spatial random distribution of gradation parameters of rockfill material and transition material in the Lianghekou core-wall rockfill dam. With the combination of stochastic modeling and finite element method, this paper carried out 500 deformation and stress simulations for the dam to obtain the convergent results and compared the results with the deterministic finite element method. It is determined that when the spatial variability of rockfill materials is considered, the maximum displacement in horizontal direction and the maximum settlement will increase. Therefore, when the spatial variability is not considered, the probability of underestimating dam stress and deformation will exceed 50%. The calculation method considering the spatial random distribution of gradation parameter has good application value for the design and deformation control of high rockfill dams.