Seismic Response Analysis Of Sluice-Foundation System

Sluices, playing the role of retaining and draining water, are a kind of low-head hydraulic structures, which have been used widely in hydraulic engineering. During the Tangshan Earthquake, the Wenchuan Earthquake and many earthquakes in Xinjiang region, sluices have suffered great losses. Some sluices that can’t been opened timely have resulted the danger of overflowing flood. According to the weakness and complex of anti-seismic of sluices, this study has carried out research on the following issues, including the dynamic calculation methods, the interaction between sluices and foundation and nonlinearity of soil foundation. The main research contents are as follows:(1) The survey about the damage of sluices in Tangshan earthquake, Wenchuan earthquake and Xinjiang region has been conducted. Through the analysis of the damage of some sluices, the main damage of sluices has been summarized. Meanwhile, the internal reason caused the damage and seismic measures are analyzed.(2) The dynamic calculation methods, including quasi static method, mode decomposition method and time-history analytical method, have been introduced. Differences about sluices between the revised and current codes have been analyzed. According to the results, the stiffness of gate has little effect on frequency analysis. However, the change of the descending of design response spectrum has enlarged the dynamic response of transverse direction. Compared the difference of the results among the previous methods, it’s suggested that dynamic distribution coefficient provided by quasi static method is safe.(3) Massless foundation model and rigid foundation model have been derived from equations of motion. Viscous-elastic boundary model has been studied and its accuracy has been verified. According to the results, considering the influence of soil-structure interaction can enlarge the acceleration and stress of sluices. The setting of viscous-elastic boundary can reduce dynamic response obviously. It is suggested to take the soil-structure interaction and radiation damping into consideration for sluices built on soil foundation.(4) The static and dynamic analysis of sluices is computed by using linear elastic foundation model and Mohr-Coulomb linear-plastic model. Under static loads, the maximum principal stress given by the nonlinear model is smaller, while the displacement is larger. Under both static loads and dynamic loads, the reaction of acceleration, displacement and stress computed by the nonlinear model is less than the results given by the elastic model. it is suggested to take nonlinearity of soil foundation into consideration.