COMPORTAMIENTO SÍSMICO DE EDIFICIOS DE CONCRETO REFORZADO CONSIDERANDO VARIABILIDAD EN PROPIEDADES ESTRUCTURALES

Abstract

In general, the structural design requirements are based on a set of rules that must be complied with. These rules include, among other parameters, strength and load factors, as well as strength and load nominal values. Once the structural system is built and used, the dynamic characteristics such as period, rigidity and strength (among others) will be different to the ones projected during the design. This difference is due to the factors mentioned previously, as well as the variability in the geometric and mechanical quality of the items during the construction process, and the own variability of the materials used. This implies that the dynamic responses, even for buildings with similar characteristics and founded on similar seismic zones, will be different in each of them. This work presents the influence study of the geometric and mechanical qualities variability, as well as the gravity loads on reinforced concrete buildings non-linear dynamic response. This influence is characterized by a rate that quantifies the difference between the response associated to buildings with uncertain characteristics and the response corresponding to the buildings with average qualities. This work analyzes 5, 10 and 15-stories, reinforced concrete buildings made with rigid frames, since they are the most representative type of buildings in Mexico City. The variability in the geometric and mechanical characteristics and in the vertical actions is obtained by means of Monte Carlo simulation technique. It is considered that the buildings are founded on the soft area of Mexico’s valley, since the 1985 seismic record of the Department of Communications and Transportation (SCT, acronym in Spanish), which is located in such zone, was used for the analysis. Each seismic record is considered an unsteady Gaussian stochastic process with statistical properties depending on the site magnitude and distance.