软土地基上土-高层建筑群体系对高层建筑影响的试验研究

Tests of effect of soil on high-rise buildings built on a soft soil foundation

在软土地基上,城市密集的高层建筑群间通过场地土将产生动力相互影响。为研究土与高层建筑群间动力相互作用对高层建筑动力响应的影响,设计了两组对比试验,一组为建筑群振动台试验,另一组为单个建筑振动台试验。试验结果表明:在软土地基上,土与高层建筑群间存在明显的动力相互作用,建筑群间的动力相互作用加剧了建筑物的破坏,并使得高层建筑的加速度减小,且影响程度与输入的地震波特性有关;在两种波的激励作用下,相互作用对速度的影响是一致的,减少了短周期结构的速度,对长周期结构的影响则与输入的地震峰值相关;相互作用对短周期结构的位移影响很小,而对长周期结构的位移影响较大。

A large number of dense urban high-rise buildings built on a soft soil foundation each have a dynamic effect on each other through the site＇s soil.To study the effect of the dynamic interaction of soil and high-rise buildings on the response of the high-rise buildings,two comparative tests of a soil-structure system were designed.One test is a shake-table test with multiple structures,and the other one is a shake-table test with only one structure.The experimental results show that there is significant dynamic interaction among the structures built on a soft-soil foundation through the site soil. The interaction increases the destruction of buildings and decreases the acceleration of the structures.Furthermore,the degree of influence has something to do with the characteristics of the inputs.Under the two kinds of wave excitation,the effects of interaction on the velocity are consistent：they decrease the velocity of the short-period structure.However,the effect on the long-period structure has something to do with the peak value of the inputs.Interaction has little effect on the displacement of the short-period structure,but it has a significant effect on the displacement of the long-period structure.