Civil Engineering Association

RISK ASSESSMENT USING SEISMIC RISK MANAGEMENT AND RESPONSE ANALYSIS OF BASE ISOLATION STRUCTURE

For structures that receive a large earthquake it is required to apply a good technique which suppresses a danger to the minimum irrespective of existing and establishment. A technique of seismic risk management dealt with the quantitative amount of information is to obtain the anticipative amount of the earthquake damages during access peri
od,and is the support tool to select the higher expense efficiency step to reduce an earthquake damage. In this study,the method of seismic risk management is searched for
using the earthquake proof reliability assessment technique. A seismic lose function is calculated from the earthquake damage factors that are modeled by using fragility curves and event trees. The seismic hazard curve is obtained by Nankai offshore scenario earthquake. The third floor or the eighth floor steel structures on a hard or soft ground in Kochi Prefecture are taken up as SRM(Seismic Risk Management Method) study cases. Using structures from as three kinds of seismic code,costs of both initial construction and life cycle are calculated. As the results,the seismic risk reduces to half by ground conditions. Though initial investment becomes high so that earthquake resi stant construction goes up,the life cycle costs and the seismic risk become small. The seismic risk of the base isolation structure is set to zero,and excels as the earthquake resistant construction. Then,the eighth floor steel structure with the base isolation system is applied to obtain time history responses in comparison of those by the different input wave motions. The base isolation building is able to reduce a strong motion because of the long time period shake,and is efective to the short period large earthquake motion