高层基础隔震结构高宽比限值分析

Analysis on limit of height-width ratio of high-rise base-isolated structure

研究了橡胶支座高层基础隔震结构的高宽比限值。考虑到高阶振型对结构高宽比限值的影响,采用3质点模型推导了高层隔震结构高宽比限值的显式,给出各种建筑类别、设防烈度、场地条件和结构阻尼比的高宽比限值,并按简便、安全的原则对各种工况下的高宽比限值进行了归并,与采用单质点模型的计算结果对比后发现相差不大,说明高阶振型对高层基础隔震结构高宽比限值的影响不大。还进一步讨论了当隔震周期不等于临界周期时高宽比限值的变化情况,发现当隔震周期小于临界周期时高宽比限值的降低并不明显,当隔震周期大于临界周期时高宽比限值的降低比较明显。

The limit of height-width ratio of high-rise base-isolated structure with rubber bearings was investigated.With 3-particle model being adopted,the limit ratio formulas were derived and the results were presented corresponding to various kinds of building categories,earthquake fortification intensities,site classifications,and damping ratios of structure.In conformity to the principle of simplicity and safety,the calculated limit ratios were summarized.By comparing the results with those of single-particle model,it is shown that there is little difference between them,which indicates that high-order modes have little effect on the limit of height-width ratio of high-rise base-isolated structure.The changes of the limit of height-width ratio were further discussed when the basic period is not equal to the critical period,and it is found that when the basic period is less than the critical period,the limit of height-width ratio dose not significantly reduce,and when the basic period is greater than critical period,the limit of height-width ratio reduces obviously.