Structural Control Under Stochastic Seismic Loads

This paper presents a method of controlling nonlinear and hysteretic civil engineering structures subjected to stochastic earthquake ground excitations. Emphasis is placed on control of base-isolated buildings. The earthquake ground motion is modeled as a filtered short noise and the equations of motion of the structure are augmented by the earthquake model. This results in a feedforward compensation in addition to the state feedback loop as obtained using the instantaneous optimal control algorithm. The nonstationary mean square response is computed using the method of stochastic equivalent linearization. Numerical results indicate that for a range of earthquake model parameters of practical interest, the control method using both the feedforward compensation and the feedback loop may not offer a significant advantage over the control method using only the state feedback.