An improved numerical manifold method for crack propagation of concrete gravity dams under seismic loads

Abstract

In the safety analysis of concrete gravity dams it is necessary to consider the external load and internal load of the dam body within a reasonable range, in which the influence of strong earthquake can not be ignored. The modified Mohr-Coulomb strength criterion is introduced into the numerical manifold method (NMM), meanwhile, the calculation mechanism of dynamic load is introduced, and the calculation part considering the Hydro-Mechanical coupling principle is added to the NMM. The effectiveness and accuracy of the improved NMM are verified by the displacement of the central point of the circular arch under dynamic load containing an analytical solution. Based on the improved NMM, the crack propagation of concrete gravity dam is predicted and analyzed. The crack propagation of Koyna concrete gravity dam under seismic conditions is analyzed, and the results are compared with XFEM and experimental results. The influence of adding Hydro-Mechanical coupling module on crack propagation and seismic response of concrete gravity dam is discussed and it is proved that the improved NMM can accurately predict the crack propagation of concrete gravity dams under dynamic load and the advantage of NMM in dealing with continuous-discontinuous problems.