Research on Geophysical Exploration Methods for Karst Collapse in Typical Areas of Northern China

Zhang Jiantai; Zhao Hui; Li Zhaoying; Jiang Guoqing; Liu Xiao; Hu Anshun; Hu Ziyuan; Geng Xiangfeng

doi:10.3969/j.issn.1003-1375.2025.02.003

Abstract：Ordovician and Cambrian limestone is widely developed in northern Jiangsu and central and southern Shandong,which is a typical area of karst development in the northern China.Since the 1980s,with the rapid development of urbanization,the over-exploitation of groundwater the significant changes in the groundwater level couple with human activities,mechanical activities and many other reasons,the problem of karst collapse geological disasters has become increasingly prominent,which has become an im-portant factor restricting urban development.kKarst collapse has become an important factor restricting urban development.How to detect karst in a complex urban environment become an urgent problem to be solved at this stage,so a variety of geophysical methods have been studied in Jinan,Tai'an,Linyi,Xuzhou and other places to analyze suitable methods for karst detection in northern Jiangsu and central and southern Luzhou.The results show that compared with the surrounding rock,karst in northern Jiangsu and central and southern Lu has the physical characteristics of low density and low speed,and the karst filled with water or clay also has low resistivity characteristics.The shallow seismic method has a large de-tection depth and sensitive karst response,but the karst boundary is difficult to determine.The high-density electric method has good karst effect on water-filled or filled clay,and the resolution of micro-motion and transient electromagnetic method is high,which can depict karst boundaries,cross-hole CT accuracy is high,and the boundary is clearly described,but the detection cost is high.At the same time,the multi-solution of a single detection method is high,and multiple geophysical methods are mutually re-stricted,which can reduce the multi-solution of interpretation,realize the fine detection of karst,and provide technical support for karst evaluation and treatment.