Analytical Evaluation of Various Passive Isolation Systems on Seismic Performance of a Low-Cost Chilean Masonry House

In this study, a multi-degree-of-freedom numerical model is created to represent the elastic behavior of a typical Chilean two-family, low-cost, confined masonry house. Ambient vibration testing was performed to determine the fundamental natural frequencies of the structure in the longitudinal and transverse directions through a non-parametric system identification technique. Based on the ambient vibration data, an estimation of equivalent viscous damping of the structure is made using the bandwidth method. The stiffness values are estimated using the natural frequencies measured from the ambient vibration testing. A number of passive isolation devices are considered as potential isolation systems for the structure. Each device is numerically modeled using fuzzy logic. The fuzzy models are created using experimental and analytical data to predict the force exerted on the structure by the device. The passive isolation systems considered include friction pendulum systems, high-damping rubber bearings, and two hybrid systems involving use of high-damping rubber bearings and shape memory alloy wire. Seismic performance of the structure in the longitudinal direction, augmented with each of the isolation systems mentioned above is compared with the performance of the traditionally-constructed structure using several performance indices.