Seismic analysis of buildings with basements

Abstract

This research work analyzes how seismic waves affect buildings with basements that are usually studied independently: In surface structures the inertial forces originated by the movement of their base and in subway structures the deformations due to ground motion are considered. The building located in the city of Quito with twelve elevated floors and five subfloors is studied using nonlinear finite element modeling, considering that the subsoil depends on seismic excitations in a dynamic soil-basement-structure set, for which it is modeled together with its geotechnical components. The superstructure is integrated to the infrastructure and a time-history analysis is included with the most representative earthquakes can affect the building. The present investigation has three basic components: seismic, geotechnical, and structural, which are merged by means of specialized 3D structural engineering programs. In the seismic component, local and regional information about tectonic faults within Ecuador is collected; the building is then located on a seismic risk map and the magnitudes, types, and other parameters of the site where the building is located are determined. Using the results of the Earthquake Risk Assessment Project for the city of Quito (TREQ) and the Pacific Earthquake Engineering Research Center (PEER) database, three relevant seismic events are chosen for the time-history analysis that meet the seismic risk data for the building. For the geotechnical soil component, the geotechnical parameters of the original design of the building foundation, stratigraphy, and characteristics of soil solids, among others, are used. The structural component considers the type of material, geometry, dimensions, joints between elements and others of the original design for both basements and superstructure. The connection of these three components is carried out using Midas Gen and Midas GTS NX. The results of deformations as a function of time are compared with similar standards, studies, and investigations.