Active/robust moment controllers for seismic response control of a large span building on top of ship lift towers

Abstract

The feasibility of using a vertical ship lift to provide a rapid transfer of ships over a large dam is being actively investigated in China. One of the problems encountered in the feasibility study is how to reduce excessive seismic response of a large span machinery building on the top of huge ship lift towers due to a whipping effect. This paper thus explores the possibility of using active/robust piezoelectric moment controllers to prevent the machinery building without/with parameter uncertainty from the whipping effect. The use of moment controllers meets the special space requirement for the machinery building. Basic equations for piezoelectric moment controllers interacting with the building are first derived. The active control of seismic response of the building–ship lift tower system with moment controllers is then presented. The robust moment controllers for the building–ship lift tower system with structural uncertainty are finally addressed. By taking an actual large ship lift structure to be built in China as example, the effectiveness of the proposed moment controllers and the behavior of the controlled ship lift structure are examined. The results show that the active moment controllers can effectively prevent the whipping effect and reduce the seismic response of the building. In the presence of structural uncertainty, the robust moment controllers give superior performance to the active moment controllers but require larger control power.