基于COMSOL Multiphysics的高拱坝渗流–应力全耦合分析

FULL COUPLED ANALYSIS OF SEEPAGE-STRESS FIELDS FOR HIGH ARCH DAM BASED ON COMSOL MULTIPHYSICS

基于COMSOL Multiphysics平台提供的M语言进行二次开发,研制多物理场全耦合分析模型,并开发计算程序。结合黄河上游某水电站工程建立拱坝渗流场与应力场耦合的三维有限元模型,对比分析水库正常运行期考虑与不考虑耦合情况下坝体和坝基的渗流场与应力场。结果表明,2种情况下渗流场、应力场和位移场的分布规律一致,数值有差别。相比不考虑耦合作用,考虑耦合作用所得到的渗流场等势线偏向下游,各位移分量都有不同程度的增加,且坝体上游岩体的拉应力增加,坝肩和坝基下游岩体的压应力增加,造成坝基渗流场局部分布规律变化,扬压力明显增大,对坝体和坝基稳定产生不利影响。可见,高坝考虑渗流–应力耦合作用效应是十分必要的。

Based on M language offered by COMSOL Multiphysics,a full coupled analysis model was developed, and the corresponding calculating program was complied. And then,a three-dimensional finite element model of an arch dam located on Yellow River was established. The coupled seepage-stress field was compared with uncoupled condition under a selected reservoir operation case. The seepage field,stress field and displacement field were analyzed for deep understanding of the significance of coupling analysis in the high arch dam. The results showed the same distribution of seepage,stress and displacement fields in those two cases. However, compared with the uncoupled case,the equipotential lines of seepage field were close to downstream. Every displacement component increased at different rates,the tensile stress of the upstream rock increased and the compressive stress of the downstream rock also increased in the coupled case. The uplift pressure increased in the foundation and it was not beneficial to the stability of the dam. So,it is necessary to consider the coupled seepage-stress effect for high arch dam.