Research On Strengthen Measures Of Concrete Gravity Dam To Resist Earthquake

A number of concrete gravity dams are built or proposed in southwest China, where the geological conditions are cmoplex and the earthquake are common, the intensity of which are higher. Therefore it has become the research focus to analyze the seismic failure mechanism of concrete gravity dam and propose reasonable seismic measures.Based on these, several work is carried out as follows in this paper:(1) Damage evaluation about gravity dam is still relatively weak. The dynamic response of concrete gravity dam is simulated under massless linear elastic foundation conditions, plastic-damage model employed, using Abaqus software. And then calculate the reactions considering DP model describing foundation. The infinite elements are adopted to simulate dynamic response of the gravity dam.According to the plastic damage responses, the overall damage evaluation index based on the energy dissipation is presented.(2) Damage and Crack has become a key factor affecting the dam safety under seismic load. According to the damage part and degree under massless foundation model, different forms of seismic reinforcement are presented. Based on the embedded model of reinforced concrete, the seismic responses of concrete gravity dam are calculated under different reinforcement schemes. The consequences verifies the necessity and practicality arranging reinforcemen for seismic resistance at the weak parts of the dam(3) New composite materials provide a new way of strengthening concrete gravity dam. In this paper, the Ultra High Toughness Cementitious Composites (UHTCC), developed by Xu shilang team, is used to replace the surface concrte of dam and then present three schemes to reinforce seismic weak parts of concrete gravity dam. Simple linear hardening constitutive model for UHTCC and concrete plastic damage constitutive model are considered to simulate the dynamic response of concrete gravity dam reinforced with UHTCC. Comparing the results before and after reinforcement, it could be gotten that UHTCC in strengthening dam field is effective, which can enhance the overall safety of the concrete dam and improve the seismic performance of the dam.