Impact of the Vertical Component of Earthquake Ground Motion in the Performance Level of Steel Buildings

Jesús-Gerardo Valdés-Vázquez,Miguel Á Jaimes,Adrián David García-Soto

doi:10.3390/app11041925

Abstract

This study discusses the impact of the vertical component of earthquake ground motion in the performance level of steel building subjected to earthquake excitations. Analyses are carried out for the strong column-weak beam philosophy because the structural performance is focused on these elements. A realistic steel frame is also considered to investigate the impact of including the seismic vertical component in the non-linear response of the building. The main findings of this study are: (1) When an analysis is performed by considering the horizontal and vertical components of ground motion acting simultaneously (near the causative fault), larger plastic rotations in the beams are obtained as compared to those resulting by considering only the horizontal component. (2) Due to the previous finding, if a codified criterion to inspect the steel beams performance in terms of the plastic rotation is considered, the beam performance could lie within a different acceptation criterion (i.e., from immediate occupancy to collapse prevention) if the vertical component is included in the analysis.

Highlights

It has been reported in the works by Papazoglou et al [1] and Elnashai et al [2]that the vertical earthquake ground motion component of some earthquakes located near the causative fault can have an important detrimental impact in the structural behavior of different systems
The plastic hinges of steel beams to be studied are indicated by red dots in Figure 1; they are selected because the analyses indicated that they are the most critical in terms of plastic rotations
Current structural design regulations for the construction of buildings in seismic zones specify that a non-linear seismic analysis could be performed

Summary

Introduction

It has been reported in the works by Papazoglou et al [1] and Elnashai et al [2]that the vertical earthquake ground motion component of some earthquakes located near the causative fault can have an important detrimental impact in the structural behavior of different systems. Papazoglou et al [1] attributed seismic failures to the effect of the vertical component of three studied earthquakes on structures. Besides possible compressive overstress or tension failure, the vertical response can lead to failures for the ultimate limit states of flexure moment and shear. The latter (i.e., shear) may explain observed failures perhaps associated with underlying vertical motion effects, because the compression can be reduced, or even mild tension could be reached, decreasing the contribution of concrete to shear resistance. Elnashai et al [2] based on modal analysis proposed a conservative simple approach to assess vertical seismic forces for buildings. Kim et al [3] by means of

Objectives

Findings

Discussion

Conclusion