The accurate analysis of the seismic response of isolated structures requires incorporation of the flexibility of supporting soil. However, it is often customary to idealize the soil as rigid during the analysis of su...The accurate analysis of the seismic response of isolated structures requires incorporation of the flexibility of supporting soil. However, it is often customary to idealize the soil as rigid during the analysis of such structures. In this paper, seismic response time history analyses of base-isolated buildings modelled as linear single degree-of-freedom （SDOF） and multi degree-of-freedom （MDOF） systems with linear and nonlinear base models considering and ignoring the flexibility of supporting soil are conducted. The flexibility of supporting soil is modelled through a lumped parameter model consisting of swaying and rocking spring-dashpots. In the analysis, a large number of parametric studies for different earthquake excitations with three different peak ground acceleration （PGA） levels, different natural periods of the building models, and different shear wave velocities in the soil are considered. For the isolation system, laminated rubber bearings （LRBs） as well as high damping rubber bearings （HDRBs） are used. Responses of the isolated buildings with and without SSI are compared under different ground motions leading to the following conclusions： （1） soil flexibility may considerably influence the stiff superstructure response and may only slightly influence the response of the flexible structures; （2） the use of HDRBs for the isolation system induces higher structural peak responses with SSI compared to the system with LRBs; （3） although the peak response is affected by the incorporation of soil flexibility, it appears insensitive to the variation of shear wave velocity in the soil; （4） the response amplifications of the SDOF system become closer to unit with the increase in the natural period of the building, indicating an inverse relationship between SSI effects and natural periods for all the considered ground motions, base isolations and shear wave velocities; （5） the incorporation of SSI increases the number of significant cycles of large amplitude accelerati展开更多
首先讨论了近断层脉冲型地震动的特点,并以台湾集集地震实际脉冲型近震记录为地震动输入,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的隔震器参数和上部结构构件截面几何尺寸进行一体化优...首先讨论了近断层脉冲型地震动的特点,并以台湾集集地震实际脉冲型近震记录为地震动输入,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的隔震器参数和上部结构构件截面几何尺寸进行一体化优化设计,然后输入E l Centro(1940)、Taft(1952)地震波对优化后的隔震结构进行地震反应分析。计算结果表明,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。展开更多
文摘The accurate analysis of the seismic response of isolated structures requires incorporation of the flexibility of supporting soil. However, it is often customary to idealize the soil as rigid during the analysis of such structures. In this paper, seismic response time history analyses of base-isolated buildings modelled as linear single degree-of-freedom （SDOF） and multi degree-of-freedom （MDOF） systems with linear and nonlinear base models considering and ignoring the flexibility of supporting soil are conducted. The flexibility of supporting soil is modelled through a lumped parameter model consisting of swaying and rocking spring-dashpots. In the analysis, a large number of parametric studies for different earthquake excitations with three different peak ground acceleration （PGA） levels, different natural periods of the building models, and different shear wave velocities in the soil are considered. For the isolation system, laminated rubber bearings （LRBs） as well as high damping rubber bearings （HDRBs） are used. Responses of the isolated buildings with and without SSI are compared under different ground motions leading to the following conclusions： （1） soil flexibility may considerably influence the stiff superstructure response and may only slightly influence the response of the flexible structures; （2） the use of HDRBs for the isolation system induces higher structural peak responses with SSI compared to the system with LRBs; （3） although the peak response is affected by the incorporation of soil flexibility, it appears insensitive to the variation of shear wave velocity in the soil; （4） the response amplifications of the SDOF system become closer to unit with the increase in the natural period of the building, indicating an inverse relationship between SSI effects and natural periods for all the considered ground motions, base isolations and shear wave velocities; （5） the incorporation of SSI increases the number of significant cycles of large amplitude accelerati
文摘首先讨论了近断层脉冲型地震动的特点,并以台湾集集地震实际脉冲型近震记录为地震动输入,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的隔震器参数和上部结构构件截面几何尺寸进行一体化优化设计,然后输入E l Centro(1940)、Taft(1952)地震波对优化后的隔震结构进行地震反应分析。计算结果表明,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。
