| Title |
Evaluation of Seismic Risk of the Building with Different Building Heights |
| Abstract |
Most provisions in the current seismic desgin codes of standards have been developed based on the experience of the structrual performances under historic earthquakes. Thus, it is hard to expect the consistent structrual performances of the buildings with different sizes or different systems. In this study, the implied seismic risk level of current seismic design provisions are evaluated. The seismic risks can be represented by seismic reliabilities (Limit state probabilities). Limit state is defined as the state of undesirable performance of a structrue(e.g., yielding, buckling, large displacement, collapse, etc.). Three buildings (5 stroy, 9story, and 12 story) having specially moment resisting steel frames (SMRSF) are designed according to current seismic design provision. The structures are assumed to be located at strong seismic zone. Los Angeles site and Imperial Valley site are selected for this purpose. The future ground motions on these sites are generated based on the characteristic parameters of historical earthquakes at these sites (zero crossing, distribution of seismic intensity, relationship between attenuation and source distance, etc.) using nonstationary random process. The characteristic parameters of earthquakes are estimated by nonlinear programming solution procedure. Using these generated earthquakes as inputs, the linear or nonlinear responses of three representative structures are evaluated by dynamic response analyses. These responses are then used to evaluate the seismic risk in terms of reliability of various limit states. The risk levels of three buildings are compared by which the implied risks and consistency of current seismic design provisions are discussed. |