Abstract:Using the continuous and uniform micro-tremor test, data are collected in Chengxian. We analyze the spectrum characteristics of micro-tremor test data using a single point of spectrum ratio method, then the recommended value of the site predominant period is obtained according to the classification of the spectrum type results. Based on existing drilling data, the correlation between site predominant period and the thickness of the overlay is established. Using the actual engineering data to verify the accuracy and the universality of the relationship. Due to its economy, simplicity and speed, the micro-tremor test provides basic data for the seismic safety evaluation of region engineering sites, earthquake seismic micro-zoning, the categories of site classification, site selection and evaluation.