Study on Safety Evaluation Based on Nonlinear Finite Element Method for High Arch Dams

Under action of water pressure and self-weight, the stress concentration is occur at the heel of high arch dams. It forms the oblique principal tensile stress and will cause the concrete to crack because of the combination of shearing stress and normal stress. Taking the xiluodu high arch dam as an example, suppose dam damage only occurs nearby the foundation plane. The dam self-weight is simulated with the change of the construction process, the water pressure and temperature loads are applied after the dam construction. For the Gauss points where crack failure happen, the stress along the maximum principal tensile stress direction reduces to zero, and the stiffness also adjusts to zero. For the Gauss points where compressive failure happen, the stress along the maximum principal compressive stress direction reduces to the compressive strength of concrete, the stress along other principal stress direction remains unchanged, and the stiffness adjusts to zero. Three strength criterions of uniaxial, blaxial and triaxial are used to check the influence of the strength criterions. The failure regions of the dam with three kinds of different strength criterions are compared and analyzed, the safety of the dam is evaluated.