抗震结构最不利设计地震动研究

在结构的抗震研究和设计中,如何选择实际的地震动记录作为输入一直是地震工程中至关重要的问题之一。首先给出最不利设计地震动的概念、确定原则及方法,然后利用估计地震动潜在破坏势的综合评价法,对四种场地类型分别给出长周期、短周期和中周期结构的国外、我国台湾地区及大陆地区的最不利设计地震动,给出的最不利设计地震动适用于特别重要的结构或地震危险性较高地区结构的抗震分析和研究。另外,根据地震动的潜在破坏势,还给出适用于一般重要性结构或地震危险性较低地区抗震验算的输入地震动。最后,通过工程结构的地震反应分析,初步验证文中所确定的最不利设计地震动的可靠性和正确性。

THE SEVEREST DESIGN GROUND MOTIONS FOR SEISMIC DESIGN AND ANALYSIS OF STRUCTURES

How to choose the adequate ground motions for the seismic analysis and design of structures is an essential problem in earthquake engineering.In the paper,a new approach for solving the problem is proposed.The concept of severest design ground motion is presented and a method is developed for assessing the damage potential of the recorded ground motions.By using this method,the severest design ground motions are selected for rocks,stiff soils,medium soils and soft soils,in terms of three period ranges of structures.The selected real strong-motion records are assumed to be most suitable for seismic analysis of very important structures or structures located in very strong seismic areas.The selected severest design ground motions are likely to cause critical response of structures and thereby result in the highest damage potential.In addition,according to the damage potential levels of ground motions,the ground motions of medium and low hazard levels are also presented for seismic analysis of structures located in areas of low and medium seismicity.An example is provided to demonstrate the rationality of the concept and the reliability of the selected design motions.