Influence of directionality of spectral‐compatible Bi‐directional ground motions on critical seismic performance assessment of base‐isolation structures

Abstract

In this study, the effects of the degree of directionality on critical seismic performance assessment are investigated from two aspects: the bidirectional seismic demand represented by maximum‐direction spectrum and the performance indices obtained from nonlinear time‐history analysis. Firstly, typical representations of the bidirectional demand of ground motions are reviewed and compared, in seismic design practices (e.g., ASCE 7‐16, Eurocode8, and JRA). Statistical analysis using 83 ground motions underlines the implication of the spectrum‐compatible condition that has not been fully considered in past studies investigating the bidirectional effects. In the second part, a series of spectrum‐compatible bidirectional ground motions with various degrees of directionality are generated as inputs. The corresponding seismic performance assessment results of a base isolation building with the friction pendulum system are investigated. According to the simulation results, the current design practices could introduce unconservative assessment on the maximum bearing displacement due to the omission of the directionality effect included in the design ground motions, particularly, when the directionality parameter is at a large value (less directionality). The cases with nondirectionality always tend to result in a nearly constant envelope of the maximum interstory drift and the maximum floor acceleration assessment for the full directionality case, over all incident directions. For the critical seismic performance assessment, the two extreme cases, namely the full directionality and nondirectionality cases, are recommended to be considered.

Parametric Investigation of Self-Centering Prestressed Concrete Frame Structures with Variable Friction Dampers

“…In recent decades, major earthquakes occurring around the world have caused severe damage and even collapse to structures [1][2][3][4]. Serious damage to the structural components and larger residual displacement of entire structures have caused huge economic losses [5][6][7]. Therefore, different types of structures have been developed to increase their seismic performance and decrease the economic losses caused by earthquakes [8][9][10][11][12].…”

Influence of the angle of seismic incidence of long-period pulse-like ground motion on an irregular base-isolated building

“…The influence of the ASI on the probabilistic seismic assessment results has also been studied by Lagaros (Lagaros, 2010) and Skoulidou and Romao (Skoulidou and Romao, 2020;Skoulidou and Romao, 2021). Even though their numbers are limited, there are some studies concerning the influence of the ASI on the nonlinear responses of base-isolated buildings (e.g., Laguardia et al, 2019;Cavdar and Ozdemir, 2020;Cavdar and Ozdemir, 2022;Lin et al, 2022).…”

The Seismic Performance and Global Collapse Resistance Capacity of Infilled Reinforced Concrete Frames Considering the Axial–Shear–Bending Interaction of Columns

“…Therefore, it is a great challenge to accurately stimulate these three deformation components using finite element analysis software and to perform further evaluations of their seismic performance and global collapse resistance capacity [13,14]. Although the mainstream finite element model based on a fiber-based section can precisely stimulate the axial and bending deformations of a column, the shear deformation and the interaction between the shear, bending, and axial deformations cannot be modeled [16,17]. However, as previously mentioned, the RC columns exposed to earthquakes indicate that lateral deformations are mainly caused by the axial-shear-bending interaction of the beam-to-column connection [18].…”