An improved numerical manifold method for stability of heterogeneous gravity dams

In the study of the stability of gravity dam, the situation of dam and rock mass is complicated, there may be pore water and various kinds of heterogeneous materials to affect the stability of rock mass, among which the deformation and failure of the dam cannot be ignored. In this paper, an improved high-order covering function is applied to the Numerical Manifold Method (NMM), and the Hermite form weight function is used, which not only improves computational accuracy but also facilitates preprocessing. In elastoplastic analysis, a modified Mohr-Coulomb criterion is introduced, which can consider both tensile and shear failure, and consider the distribution of plastic zone more comprehensively. In addition, a comprehensive calculation method for safety factors considering regional damage is proposed. Based on the improved NMM, the gravity dam is simulated, and the physical response of two various actions of water to gravity dam is discussed. It is fully proved that the improved NMM can accurately calculate the hydraulic and mechanical field, and can effectively solve the discontinuity problem of some physical quantities. At the same time, considering the rationality of seepage volume force and the method of considering regional safety factor is of practical significance in engineering.