龙湖地区地面脉动特性分析

ANALYSIS OF MICROTREMOR OBSERVED IN LONGHU AREA

本文对龙湖地区地面脉动的测试结果,结合该地区的土层剪切波速度Vs,第四纪复盖层厚度H,进行分析研究。求得了本地区地面脉动卓越周期T的统计计算式:T=1.8H/Vs。应用这个计算式,根据实测的地面脉动卓越周期,剪切波速度的数据,推算第四纪复盖层厚度,得到了比较满意的结果。 本文的统计计算式与日本学者金井清提出的计算公式T=4H/Vs,有相同的比例关系,但有明显差别的比例常数。文中对此及一些有关问题进行了简要的定性讨论。 综合分析结果,我们认为,地面脉动的卓越周期与场地土的动力特性密切相关,而且有可能反应小区域范围场地土层的动力性质。

This paper analysis microtremor observed in Longhu area by means of relating them to the shear-wave velocities ( Vs ) and the thicknesses (H) of soil layers deposited in Quaternary, and gives a statistic , formula about the prominent period of microtremor in the area as follow;T=l,8H/Vs.Then by the formula, thicknesses of soil layers of Quaternary can be predicted according to the prominent periods of microtremors (T) and the shear-wave velocities ( Vs ) The result is very satifacting. The above formula has the same expression with T=4H/Vs (which has been given by K.Kanai).But their statistic constants are obviously different. Through being synthesizely, analysised, it is censidered that the prominent period of microtremor is closely relating to the dynamic character of field soil and even to some extent, represents the dynamic character of field soil layer in the region of microzation.