Based on the characteristics of major unsafe hydroelectric projects and the data from field detection, in situ monitoring, and regular safety inspection, the funda-mental principles of operation risk assessment are pr...Based on the characteristics of major unsafe hydroelectric projects and the data from field detection, in situ monitoring, and regular safety inspection, the funda-mental principles of operation risk assessment are proposed in this paper. Mean-while, a three layer hierarchical system is constructed, and an improved analytical hierarchical process combining genetic algorithm and analytical hierarchical process is established, with corresponding program. The operation risk of some unsafe dam was assessed with the principles, method and program presented in this paper and the major factors which would affect the operation of the dam were pointed out.展开更多
In this study, a nonlinear model is presented for analysis of damage-cracking behavior in arch dams during strong earthquakes using different seismic input mechanisms. The nonlinear system includes a plastic-damage mo...In this study, a nonlinear model is presented for analysis of damage-cracking behavior in arch dams during strong earthquakes using different seismic input mechanisms. The nonlinear system includes a plastic-damage model for cyclic loading of concrete considering strain softening and a contact boundary model of contraction joint opening. Two different earthquake input mechanisms are used for comparison, including massless foundation input model and viscous-spring boundary model considering radiation damping due to infinite canyon. The results demonstrate that effects of seismic input mechanism and radiation damping on nonlinear response and damage-cracking of the dam are significant. Compared with the results of using massless foundation input model, the damage-cracking region and contraction joint opening are substantially reduced when using viscous-spring boundary model to take into account radiation damping. However, if the damping ratio of the dam is artificially increased to about 10%–15% for massless foundation input model, the joint opening and damage-cracking of the dam are comparable to the results obtained from the viscous-spring boundary model.展开更多
基金Key Project of NNSF and Yalongjiang Hydroelectric Development Joint Research Fund (Grant No. 50539110)Science and Tech-nology Support Plan (Grant No. 20006BAC14B03)+1 种基金National Natural Science Foundation Major Project (Grant Nos. 50539010, 50539030)National Natural Science Foundation of China (Grant No. 50579010)
文摘Based on the characteristics of major unsafe hydroelectric projects and the data from field detection, in situ monitoring, and regular safety inspection, the funda-mental principles of operation risk assessment are proposed in this paper. Mean-while, a three layer hierarchical system is constructed, and an improved analytical hierarchical process combining genetic algorithm and analytical hierarchical process is established, with corresponding program. The operation risk of some unsafe dam was assessed with the principles, method and program presented in this paper and the major factors which would affect the operation of the dam were pointed out.
基金Supported by the National Natural Science Foundation of China (Grant Nos.50539110,50809025,50539010,50579010,50539030)the Science and Technology Support Plan (Grant Nos.20006BAC14B03,2008BAB29B03)
文摘In this study, a nonlinear model is presented for analysis of damage-cracking behavior in arch dams during strong earthquakes using different seismic input mechanisms. The nonlinear system includes a plastic-damage model for cyclic loading of concrete considering strain softening and a contact boundary model of contraction joint opening. Two different earthquake input mechanisms are used for comparison, including massless foundation input model and viscous-spring boundary model considering radiation damping due to infinite canyon. The results demonstrate that effects of seismic input mechanism and radiation damping on nonlinear response and damage-cracking of the dam are significant. Compared with the results of using massless foundation input model, the damage-cracking region and contraction joint opening are substantially reduced when using viscous-spring boundary model to take into account radiation damping. However, if the damping ratio of the dam is artificially increased to about 10%–15% for massless foundation input model, the joint opening and damage-cracking of the dam are comparable to the results obtained from the viscous-spring boundary model.
