流变效应对面板堆石坝应力变形的影响规律分析

摘要

【Objective】The study was done in order to analyze the influence of rock-fill rheological on stress deformation of CFRD,and provide a reference for predicting the law of dam long-term deformation and the stress-strain analysis method.【Method】This paper combined with concrete face rock-fill dam engineering practice,analyzed and selected the rheological properties of the rock-fill,rheological calculation model and the finite element method.On this basis,taking a high concrete faced rock-fill dam project as an example,three-dimensional nonlinear finite element method was used to analyze the rheological effects on stress and deformation of the dam,taking into consideration of two calculation programs of rock-fill rheology effects or not.【Result】The results showed that the rheological effect deformed the dam and the panel,showing a tendency to increase.In comparison,the effect of rheological on the upstream displacement of the dam was greater,and to the downstream and vertical displacement was lesser,and on the panel deflection and panel downslope to the stress was very small.Rheology for the dam settlement deformation occurred mainly in the rock-fill embankment in approximately 10 months;Additional nodes caused by the rheological load showed the change of the hump-shaped change over time,which generally disappeared two years after the rock-fill filling.【Conclusion】Therefore,it is necessary to consider the rheological effect and impact of rock-fill in engineering practice.%【目的】研究堆石流变效应对面板堆石坝应力变形的影响规律，为预测坝体长期变形规律及应力应变分析提供参考。【方法】结合面板堆石坝工程实际，对堆石料的流变特性、流变计算模型及其有限元计算方法进行了分析与选择，在此基础上，结合国内某高面板堆石坝工程实例，运用三维有限元法，按考虑堆石流变效应和不考虑堆石流变效应2种计算方案，分析了流变效应对大坝应力变形的影响。【结果】流变使坝体及面板的应力变形均呈现增大的趋势，相比较而言，流变对于坝体向上游水平位移的影响最大，对坝体向下游水平位移和坝体竖向位移的影响次之，对面板挠度和面板顺坡向应力的影响则较小；流变对于坝体沉降变形的影响主要发生在堆石填筑后约10个月内；流变引起的附加节点荷载随时间的延长而呈先增大后减小的变化过程，大致在堆石填筑2年以后，流变影响基本消失。【结论】在工程实际中，考虑堆石料的流变效应及其影响是必要的。