基础隔震结构的楼面设计反应谱研究

Floor design response spectrum of base-isolated structure

依据基础隔震结构楼面反应谱的谱形特点,将谱曲线分段进行回归分析,确定各段谱曲线的形状,得到一种双峰值的基础隔震结构楼面设计反应谱。考虑影响基础隔震结构楼面反应谱的各主要因素,如结构动力参数、场地特性、地震动强度、结构与设备的相互作用和设备阻尼等,用正交试验法,分析基础隔震结构-设备组合体系的楼面反应谱,以拟合优度最大为目标,分段标定楼面设计反应谱的各特征参数并统计拟合出各特征参数的计算公式。通过三个实际的基础隔震工程-设备实例验证,结果表明:建立的标准化的楼面设计反应谱,能忠实地反映楼面反应谱的频谱特性,还原楼面反应谱的曲线变化,各段曲线的谱值可基本包络楼面反应谱;与时程分析法的结果相比,用该楼面设计反应谱求得各设备的地震作用,误差均在10%以内,说明该楼面设计反应谱具有较高的精度和较好的工程实用性。

Here,according to spectral shape characteristics of floor response spectrum of base-isolated structure,spectral curve was divided in segments to do regressive analysis,determine shapes of various spectral curve segments,and obtain a double-peak floor design response spectrum of the structure.Considering main factors affecting floor response spectrum,such as,structural dynamic parameters,site characteristics,ground motion intensity,interaction between structure and equipment,and equipment damping,etc.,the floor response spectrum of a base-isolated structure and equipment combined system was analyzed by using the orthogonal test method.Taking the goodness of fit being maximized as the goal,each characteristic parameter of floor design response spectrum was calibrated in segments and the calculation formula of each characteristic parameter was statistically fitted.Through verification with 3 actual base isolation engineering-equipment examples,the results showed that the standardized floor design response spectrum established here can faithfully reflect spectral characteristics of floor response spectrum,and restore curve changes of floor response spectrum;spectral values of various curve segments can basically envelope floor response spectrum;compared with the results of the time history analysis method,the error for seismic action of each equipment calculated using this floor design response spectrum is within 10%,so this floor design response spectrum has higher accuracy and better engineering practicability.