Dynamic fracture analysis of gravity dam

Based on the scaled boundary finite element method(SBFEM) the variation of the dynamic stress intensity factors(SIF) at the heel of gravity dams subjected to earthquake excitation is analyzed.The SBFEM has the advantage that the displacement field along the radial direction can be solved analytically and the SIF is determined directly from its definition so that no special crack tip treatment is needed.The Koyna gravity dam is analyzed as an numerical example for demonstration.The time domain and frequency domain analysis are carried out.The SIFs for different length of cracks at dam heel are evaluated and the variations of stress along the dam foundation interface are calculated.In addition,the effect of the water pressure distribution inside the crack is also studied. The results show that the maximum value of K_Ⅰ varies distinctly with the increase of crack length.Furthermore,the SIF tends to increase with higher internal water pressure of crack.The proposed analysis method is useful for aseismic safety evaluation of gravity dam.