近断层地震动作用下基础隔震结构的一体化动力优化设计

首先讨论了近断层地震动的脉冲运动特征和特性参数,并以台湾集集地震实际脉冲型近震记录作为地震动输入,以上部结构最大层间位移和构件体积最小化为目标,应用含潜在约束策略的序列二次规划算法,对安装铅芯橡胶隔震支座的钢筋混凝土框架隔震结构进行一体化优化设计,同步确定隔震器参数和上部结构构件截面几何尺寸。然后输入ElCentro(1940)、Hachinohe(1968)非脉冲型近断层地震动记录进行隔震结构一体化优化设计。计算结果表明,本文隔震结构优化设计得到的结果是合理的,与其他作者通过参数分析确定的隔震器最优参数具有可比性;对考虑脉冲型近断层地震动作用的隔震结构进行参数优化设计后,该隔震结构能同时满足脉冲型和普通非脉冲型近震作用的结构设计需求。反之,对非脉冲型近断层地震动作用的隔震结构进行参数优化设计后,该隔震结构不能满足脉冲型近震作用的设计需求。

Integrated dynamic optimum design of base-isolated structure subjected to near-fault ground motions

In the present paper,the pulse-like characteristics and property parameters of near-fault ground motions are discussed firstly.Secondly,the near-fault pulse-like ground motions from the Taiwan Chi-Chi earthquake(1999,9,21) are taken as the input,and by using the sequential quadratic programming algorithm with the potential constraints strategy,the integrated optimum design of a multistory RC base-isolated frame structure with lead-core rubber bearings is conducted,in which the optimum objective is to minimize the maximum story drift and member volume of superstructure,as well as the structural member sizes and the parameters of isolation devices are modified simultaneously.Finally,the integrated base-isolated structure is optimized subjected to the non-pulse-like near-fault ground motions such as El Centro(1940) and Hachinohe(1968) earthquake records.It is concluded from the numerical results that the optimal parameters of isolators are reasonable and comparable with the results obtained by other authors using numerous parameter analyses;through the parametric optimum design of base-isolated building subjected to the pulse-like nearfault ground motions,the optimal structure can satisfy simultaneously the structural design requirement under both the pulse-like and the non-pulse-like near-fault ground motions.However,through the parametric optimum design of base-isolated building subjected to the non-pulse-like near-fault ground motions,the optimal structure cannot satisfy the structural design requirement under the pulse-like near-fault ground motions.