| Title |
Determination of Inelastic Demand Spectrum in Consideration of Soil Conditions and Hysteretic Characteristics |
| Keywords |
Inelastic Demand ; Hysteretic Characteristics ; Ductility Factor ; Performance Point ; Capacity Spectrum Method |
| Abstract |
The inelastic demand caused by earthquake load is related to the natural period, displacement ductility ratio, coefficient of hysteretic characteristics and soil types. Hysteretic characteristics, which govern the behavior of structural performance, are second slope (bilinear), strength deterioration, stiffness degradation and pinching. The objective of this study is to evaluate a determination method for the inelastic demand in consideration of soil conditions. Five different hysteretic models are used in this study, which are elastic perfectly plastic, bilinear, strength deterioration, stiffness degradation and pinching model. Used soil profile types in this study are generally classified into three categories: rock sites (S1), stiff soil sites (S2) and soft soil sites (S3). For a given target ductility ratio, inelastic demand is evaluated by using nonlinear time history analysis with earthquake ground motions for each soil sites. To determine the ductility factor, the proposed method of Lee, Han and Oh (1999) was reviewed. By two-stage regression analysis, a functional equation was derived from ductility factor, characteristics of hysteretic models and soil conditions. This result will be used to determine the performance point of buildings by capacity spectrum method. |