The extended finite element method (XFEM) can make the characterization of discontinuous displacement field independent of cell boundaries through enriching discontinuous displacement mode on the influence domain of related nodes. With this capacity, XFEM can effectively describe the crack propagation in concrete. The damaged process of Koyna gravity dam during earthquake was analyzed, the distribution of cracking damage is consistent with the actual condition and the model test results in literature, which verifies the validity of the calculation model. Then we applied this technique to analyze a domestic concrete gravity dam, and obtained its dynamic response and failure mode subjected to strong earthquake. Based on these results the seismic safety and overload potential of the dam were assessed. The research shows that initially cracks emerge at the change in the downstream slope and then extend to the upstream side of the dam to form penetrating cracks. At the same time the dam heel and the change in upstream slope are also prone to suffer cracking destruction. The factor of safety of the concrete gravity dam under the design seismic loads is 1.59~1.76 times, which meets the design requirements of seismic safety.
ZHANG She-rong;WANG Gaohui;PANG Bohui;YAN Lei.
Seismic failure mode and safety evaluation of concrete gravity dam based on XFEM[J]. Journal of Vibration and Shock, 2012, 31(22): 138-142
PDF(1887 KB)
