عنوان مقاله [English]
In the present study, the effect of earthquake on the crack propagation of Sefidrud dam is presented using the concept of dynamic fracture mechanics. After the introduction of displacement and traction boundary integral
equations, the dual boundary element method and multi region boundary element method are mixed to simplify the modeling of complicated configuration of buttress dams. Seismic crack propagation of buttress No.15 of Sefidrud dam is analyzed using the proposed mixed method. Different parts of the dam body and dynamic crack propagation can be modeled easily with regard to simultaneous application of boundary element method and multi-domain dual boundary element method. Also, new elements are added to the previous elements in the crack growth modeling, which causes the reduction of calculation time.
Seven cases based on the level and length of initial cracks in the body of the downstream wall is considered. The time domain analysis for stable crack condition is considered in the case A. In other cases (B, C, D, E, F and G),
analysis are performed for different unstable crack considering the crack growth and crack faces contact. The effect of initial crack length on the crack propagation in the Sefidrud dam can be observed by comparison of cases B, C and D. When larger initial crack length is considered, the crack reaches to the body of upstream wall before the main shock of acceleration records. Four cases D, E, F and G are analysed for camparison of intial crack level. The results of the present study are in good agreement with the observed crack profiles of the dam after the earthquake. But it is worth to mention that a 3D analyses is preferred for a better simulation.