Model Reduction and Seismic Active Control of an Multi-Spanned Highway Bridge

Abstract

The Eigen mode reduction method and active control and passive base isolation strategies are exerted on one continuous isolated prestressed concrete bridge. The goal of this study is to check the applicability of the eigen mode reduction method and LQR control law on the isolated continuous or rigid-connection type bridge, to find a more effective control strategy when nonlinearity is introduced. A spaced frame finite-element model is developed by a MATLAB program coded by the author, its validity is checked through comparisons with a sap2000 model. In this program, the nonlinearities of 3 different columns and 5 isolators are considered with their bilinear force-deformation relationship. the factors such as the control devices, sensors, and the corresponding noises and time delay are all considered in the model. Eigen mode reduction method was applied to set up the controllers. The seismic response measurements and regulated outputs are adjusted to optimize control effects.