微动与高密度电法在城市岩溶地质勘察中的应用

Application of Microtremor Survey Method and High Density Resistivity Method in Karst Geological Investigation of Urban Buildings

灰岩地区易出现岩溶发育,而岩溶会给城市建设和基础设施带来地质灾害,产生安全隐患。因此在地质勘察阶段有必要探测地下岩溶发育情况。微动探测技术是一种天然源面波地球物理勘探方法,其可从各种自然振动数据中提取面波频散信息,并推断地下介质速度结构;高密度电法是一种采用阵列式采集系统的直流电法,通过观测不同介质电性信息,分析地下介质电阻率特征。为提高探测精度,本文采用微动探测技术和高密度电法在城市岩溶地质勘察中进行综合探测。结果表明,在城市建筑复制环境条件下,微动探测技术和高密度电法能互相补充与验证,取长补短,可高效探测地下介质中的异常体,很好地揭示岩溶发育规模和分布规律,具有良好应用前景。

Karst development is easy to occur in limestone areas,and karst will bring geological disasters and potential safety hazards to urban construction and infrastructure.Therefore,it is necessary to detect the development of underground karst in the geological survey stage.Microtremor survey method is a geophysical exploration method of natural source surface wave,which extracts the dispersion information of surface wave from various natural vibration data and infers the velocity structure of underground medium.High density electrical method is a DC electrical method using array acquisition system.It can analyze the resistivity characteristics of underground media by observing the electrical information of different media.In this paper,the microtremor survey method and high density electrical method are used to detect karst in urban karst exploration for improving the detection accuracy.The results show that under the conditions of urban building replication environment,the microtremor survey method and high density resistivity method are complementary and can be mutually verified,they can find the abnormal bodies of underground media effectively,and well reveal the karst development scale and distribution law,with good application effect.