Evaluation of the Seismic Performance of a Dwelling of Confined Masonry Walls

Abstract

The usage of confined masonry walls in the construction of one or two floor houses in Chile is a common practice. For the analysis and design of these structures is used NCh2123 and the decree DS61, however, with these standards it’s not possible to estimate the seismic performance in front of an earthquake. The purpose of this study is to evaluate the seismic performance in a two-floor house with confined masonry walls, the house is structured with ceramic bricks walls type MQM of 14 cm thickness, bordered with columns and concrete beams. To evaluate the seismic performance of the house, the methodology FEMA P-695 is used, which involves static non-linear analysis and incremental dynamic analysis. A simplified nonlinear model of the structure is developed in the OpenSees program, and to simulate the nonlinear behavior of the walls, force-displacement relationships proposed in the literature are considered and obtained in experimental tests. For the incremental dynamic analysis a total of 44 seismic records occurred in Chile and the maximum acceleration of the soil is used as a measure of seismic intensity. From the analysis, the over-resistance factor and the ductility are determined, the acceptability of the response factor of the structure (R = 4) is verified. Additionally, collapse fragility curves are obtained that estimate the probability of collapse of this type of housing as a function of the intensity.