After water impounding

stress and deformation of the soil-rock fill dam become more complicated than that in the construction period. The calculating methods mainly contain total stress method and effective stress method. Total stress method is more simplified and it is reasonable with the macroscopic viewpoint in taking account of total stress and surface force as a big element for core wall

but it is unreasonable for every element of core wall with the microscopic viewpoint. Effective stress method takes account of effective stress and seepage force

in addition

uplift force and equivalent force to the damping deformation of the dam shell and core wall for every element of dam under the saturation line is considered

so that effective stress method is more reasonable not only with the macroscopic viewpoint but with the microscopic viewpoint.