Numerical Study On Seismic Performance And Reinforcement Measures Of Concrete Gravity Dams

With the effective implementation of the 13 th Five-Year Hydraulic Conservancy Reform Plan,China will continue to concentrate on promoting a series of large-scale Hydraulic Engineering projects which are long-term thoughtful and benefit our country and people.Among the projects,as the representatives which are still under construction and at the lower reaches of the Jinsha River in the southwest of China have the poor geological conditions,the concentrated frequent earthquake.With the complicated landform and high-intensity earthquake,the anti-seismic safety of large dam is dominant and life-threatening.The paper based on the ABAQUS software platform by using the finite element dynamic analysis method compared the dynamic characteristics of the simplified concrete gravity dam model with earthquake and seismic effects of two reinforced concrete finite element models with various placing steel bars and reinforced items.It clarified the weak parts of the dam body,compared and raised the optimized conditions of two reinforced concrete finite element models and the reasonable reinforced schemes,which provides the references of anti-seismic strengthening designs for the 200 m high dams with rebar.The specific works of this paper are as follows:Based on the plastic damage constitutive of the ABAQUS software which simulates the nonlinear concrete,it have studied the displacement response,acceleration response,stress response,damage and anelastic strain distribution of non-overflow section which the gravity dam in the action of self-weight,hydrostatic pressure and seismic load influenced and ascertained the weak locations of the plain concrete dam body which remain to be reinforced with steels.Aiming at the weak bodies of the dam,three kinds of reinforcement schemes are proposed.The finite element model of the integrated reinforced concrete is established by the method of improving the fracture energy of the reinforcement area and carried out the comparative analysis of the displacement response and acceleration response,stress response,damage and plastic strain distribution of the same dam with strong earthquake and then obtain the optimum scheme established on the integrated model.According to the above-mentioned three reinforced schemes,the paper has established the discrete reinforcement concrete finite element model by using truss element Embeded method and carried out the comparative analysis of the displacement response and acceleration response,stress response,damage and plastic strain distribution of the same dam with strong earthquake and then obtain the optimum scheme established on the discrete model.According to the comprehensive comparison that seismic reinforcement effect of the unreinforced concrete and the optimum scheme between the integrated model and the discrete model,the paper proposes the evaluation that which model is preferred for different reinforced parts of the dam and the reasonable reinforcement scheme.