A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Seismic response of asymmetric steel isolated structures considering vertical component of earthquakes
Abstract The concept of isolated structure is to separate the structure from harmful effects of earthquakes by introducing bearing. Regarding earthquakes such as the Bam and Kobe records with relatively high vertical component amplitude, it is necessary to investigate the behavior of the base-isolated structures considering vertical component of the ground motions. For this purpose, a four-story building with different eccentricities supported on elastomeric isolators with different vibration periods and damping ratios as well as three different records is used to study the effects of vertical component of earthquakes on the seismic behavior of asymmetric steel isolated structures. A rubber isolator element is used to idealize the nonlinear behavior of the isolators and a linear elastic behavior is assumed for the superstructure. The results demonstrate the significant effect of the vertical component of earthquake on the responses of structure such as axial forces, local uplift of the columns, and overturning moment of the structure and shear force of beams. For the studied cases including vertical component of earthquakes increases the compressive axial force (more than 100%) in corner columns. In addition the vertical component of earthquake causes significantly augmentation of tensile axial force and therefore, it results local uplift phenomena in isolators. Ignoring the vertical component of earthquake with high vertical amplitude will result unacceptable estimation in beam shear force and for some cases this error reaches 100%. This error is more important while the eccentricity of structure is significant (30%). Overturning safety factor is reduced when the vertical component of earthquake was included and this effect is more significant under earthquakes with higher ratio of vertical to horizontal component of earthquake.
Seismic response of asymmetric steel isolated structures considering vertical component of earthquakes
Abstract The concept of isolated structure is to separate the structure from harmful effects of earthquakes by introducing bearing. Regarding earthquakes such as the Bam and Kobe records with relatively high vertical component amplitude, it is necessary to investigate the behavior of the base-isolated structures considering vertical component of the ground motions. For this purpose, a four-story building with different eccentricities supported on elastomeric isolators with different vibration periods and damping ratios as well as three different records is used to study the effects of vertical component of earthquakes on the seismic behavior of asymmetric steel isolated structures. A rubber isolator element is used to idealize the nonlinear behavior of the isolators and a linear elastic behavior is assumed for the superstructure. The results demonstrate the significant effect of the vertical component of earthquake on the responses of structure such as axial forces, local uplift of the columns, and overturning moment of the structure and shear force of beams. For the studied cases including vertical component of earthquakes increases the compressive axial force (more than 100%) in corner columns. In addition the vertical component of earthquake causes significantly augmentation of tensile axial force and therefore, it results local uplift phenomena in isolators. Ignoring the vertical component of earthquake with high vertical amplitude will result unacceptable estimation in beam shear force and for some cases this error reaches 100%. This error is more important while the eccentricity of structure is significant (30%). Overturning safety factor is reduced when the vertical component of earthquake was included and this effect is more significant under earthquakes with higher ratio of vertical to horizontal component of earthquake.
Seismic response of asymmetric steel isolated structures considering vertical component of earthquakes
Khoshnudian, Faramarz (author) / Motamedi, Danoush (author)
KSCE Journal of Civil Engineering ; 17 ; 1333-1347
2013-08-17
15 pages
Article (Journal)
Electronic Resource
English