SUMMARYThe need to investigate the level of seismic pounding risk of buildings is apparent in future building code calibrations. In order to provide further insight into the pounding risk of adjacent buildings, this study develops a numerical simulation approach to estimate the seismic pounding risk of adjacent buildings separated by a minimum code-speciÿed separation distance during a certain period of time. It has been demonstrated that the period ratio of adjacent buildings is an important parameter that a ects the pounding risk of adjacent buildings. However, there is no speciÿc consideration for the period ratio in the related seismic pounding provisions of the 1997 Uniform Building Code. Results also reveal that, for two adjacent buildings, the probability distribution of required distance to avoid seismic pounding ÿts very well with the type I extreme value distribution.

This study investigates the seismic pounding probability of buildings in the Taipei metropolitan area. Detailed procedures of the analytical method are presented. The results indicate that the building separation specified in the Seismic Provisions of the 1997 Taiwan Building Code (TBC'97) generally provides a relatively conservative estimate compared to that specified in the 1994 Uniform Building Code (UBC'94) for the required distance to avoid pounding. This observation is demonstrated by comparing both the separation distance and/or the pounding probability of adjacent buildings based on the TBC'97 with those based on the UBC'94. The comparison results also reveal that the building separation distance specified by the TBC'97 is 1.6 times that specified by the UBC'94 for the same building and site soil condition. If a reduction coefficient of 0.375 is adopted instead of the 0.6 specified in the TBC'97 to consider the effect of vibration phase difference of adjacent buildings, the critical pounding risk of the TBC'97 and the UBC'94 will be similar.

No abstract

A seismic fragility analysis of structures is essential to prediction of the building behavior that is likely to occur during earthquakes. Normally, the probability of failure of a structure over a specified period of time is obtained through a convolution of the fragility curve with the seismic hazard curve for the structure site. The fragility models and damage states probabilities serve as a basis for improving the structural codes and performance-based design. Thus, there is a need for relatively simple procedures for evaluating fragility data for decision-making. In this study, the peak story drifts of a building structure during earthquakes are used as an indicator of structural demands. An analytical solution for evaluating the statistical characteristics of peak story drifts of frame structures during earthquakes is proposed. Based on it, an approximate approach to constructing the seismic fragility curves for various states of damage for frame structures is developed.

No abstract