摘要
建于山区台地上的多台阶爬山式横向错层框架是多见的一种结构形式,但以往对其抗震性能的研究还很少。利用二次开发后的ANSYS对台地框架在E1-Centro波作用下的抗震性能进行了上下部共同作用分析,对台地框架与普通框架的自振频率进行了对比,探讨了台地框架最大加速度及最大层间位移角沿高度分布规律。有两个因素对台地框架的频率变化产生影响:一个是徒坎本身随着高度的增加而自振频率降低的趋势;另一个因素是由于位于徒坎上部的那部分框架层数减少,框架本身变刚而产生的自振频率增加的变化趋势。当徒坎弹性模量较大时,第二个影响因素占主导地位,当徒坎弹性模量较小时,第一个影响因素占主导地位。徒坎高度越高、位于徒坎下部的框架跨数越少,则台地框架与对应普通框架的地震反应差异越大。但这种差异既可能是台地框架的地震反应大于对应的普通框架,也可能小于对应的普通框架。当输入的地震动高频成分较多、徒坎弹性模量较小时,则趋向增大地震反应,而输入地震动的高频成分较小、徒坎弹性模量较大时,则趋向减小地震反应。
Based on multi-transmitting boundary and taking use of the ANSYS software after secondary development,the effect of earthquake response on the frame connected with ground by not only the first floor is analysed,in analysis,the soil-structure interraction is considered.The elastic modulus of the bank will greatly affect the dynamical characters of the frame.There are two influencial factors on the natural frequencies:there is a trend to lower the frequencies of the system when the bank becomes high and there is a trend to raise the frequencies when the frame consists of less number of floors.The second influencial factor becomes the main when the elastic modulus of bank is large,and the first influencial factor becomes the main when the elastic modulus of bank is small.Much difference will appear between the frame connected with ground by not only the first floor and the general frame when the bank becomes higher or the number of spans below the bank becomes fewer.But the response of the frame can be bigger or smaller than that of the general frame.It is bigger when the higher order frequency in the input earthquake wave are abundant or when the elastic modulus of the bank is smaller and it is smaller when the higher order frequency components in the input earthquake motion are fewer or when the elastic modulus of the bank is bigger.
出处
《振动与冲击》
EI
CSCD
北大核心
2007年第6期36-40,51,共6页
Journal of Vibration and Shock
基金
重庆市建委资助(200437)
关键词
台地框架
多次透射边界
土与结构相互作用
frame connected with ground by not only the first floor,multi-transmitting boundary,soil-structure interraction
