季节冻土场地上的地脉动特征  

Characteristics of Micro-tremor in Seasonally Frozen Ground

作　　者：齐吉琳[1] 李海鹏[1] 赖远明[1] 朱元林[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2004年第4期449-453,共5页Journal of Glaciology and Geocryology

基　　金：中国科学院知识创新工程重大项目(KZCX1 SW 04);国家自然科学基金项目(40171021)资助

摘　　要：以张掖市的一场地为研究对象,通过对不同季节地脉动的测量和分析,研究了场地的脉动频谱特性随季节的变化.对场地实测资料的分析发现,冬季随着上覆冻土层的出现,使得场地刚度发生变化,频谱形状也明显地改变,地脉动的卓越频率明显提高.In seasonally frozen regions, with the appearance and disappearance of temporary frozen soil layers, the engineering properties of ground may change and consequently is related to stability of constructions in such regions. For this reason, the ground motion in seasonally frozen regions is studied. There are two parts in the study: in-situ measurement and ground motion analysis. Undisturbed soil samples were taken at the same time of in-situ measurement. In this paper the in-situ measurement and analysis of micro-tremor in a site in seasonally frozen area are presented, and the effect on seasonally frozen layers is discussed. Taking the site in Zhangye city in Northwest China as a working site, in-situ measurement of micro-tremor was carried out in 3 orientations, U-D, EW and SN. The measurement was undertaken twice. The first measurement was taken in autumn, when there was no frozen layer at all. In order to analyze the most likely time when the site would be frozen to the maximum depth, climate data were collected from the local meteorological stations. Then the second measurement was taken in winter when the maximum frozen depth maybe appears. The measurement is analyzed and compared with each other. It is found that with the appearance of frozen layer on the top, distinguished period increases; shape of frequency spectrum also changes.

关 键 词：季节冻土 场地 脉动 

分 类 号：P642.14[天文地球—工程地质学]