Improving estimates of structural seismic motion

Abstract

A critical field in civil engineering is the evaluation of structural damage after severe earthquakes. Seismic events are taken into serious consideration in areas of the world such as California and countries adjacent to the Mediterranean. After these events, structural engineers are called to evaluate structural damage and to enhance the structure's future capabilities and serviceability. Due to the large number of structures and the significant time needed to evaluate the potential damage in each structure, other methods for structural behavior observation were needed. One of those has been established in the late 1950's and had to do with the implementation of electronic monitoring devices in structures. This dissertation evaluates the placement of today's motion sensing instruments and proposes an algorithm that proposes optimized instrumentation schemes in buildings. The dissertation starts with a presentation and critique of today's instrumentation techniques and suggests how they could be optimized or refined to get a better approximation of the structure's behavior. Furthermore, optimization schemes provided by the literature are presented. In addition, the author proposes an algorithm that estimates and proposes instrumentation schemes of buildings. The proposed instrumentation schemes take into consideration all three dimensions. The algorithm is described by a flow chart and mathematical equations and is implemented in MATLAB. To check the validity of the algorithm, case studies are conducted. These case studies are based on finite element models of buildings that were hit by the Northridge earthquake and were instrumented during that period. Actual recorded accelerations from the base of the structures have been used to conduct the case studies. Finally, the results of these case studies are presented. The results present the exact positions of the sensors in order to get better approximation of the structure's behavior in a cost effective manner. In addition, an evaluation is conducted for the estimation of the behavior of the algorithm on different earthquake data.