Algorithm for optimal design of adjacent buildings connected by fluid viscous devices

This paper presents a versatile and robust algorithm for the optimal seismic design of adjacent structures using passive energy dissipation devices. The algorithm works both with a single earthquake record and with a set of earthquake records. It is a two-stage design procedure first determines an active control law, then, second, adds damper and stiffness coefficients that are computed based on the minimization of the difference between the response of the actively controlled system and an equivalent passive control system. The algorithm is an iterative procedure that leads to a close form global optimal solution for the damping and stiffness coefficients in such a way to obtain a response as close as possible to the active control. The method is tested for two adjacent shear-type buildings of 10 stories. Sensitivity analysis is carried out studying the effects of period variation, height variation and link location using a white noise input as ground acceleration. Results show that the same performance can be achieved with less amount of damping when the viscous damper is located at the upper story level. When dampers are located in one of the node of the mode shape the total amount of damping is higher to achieve the same performance.