Research method of comprehensive geophysical exploration for urban covered karst

Abstract

During engineering investigation of covered karst in cities via conventional drilling and geophysical exploration techniques, detection accuracy is highly affected by environmental conditions. In this paper, a karst investigation on an important municipal project in Wuhan is taken as example and the clue to study geophysical exploration of municipal covered karst is proposed: engineering investigation - choose of proper geophysical exploration method - geophysical exploration - drilling confirmation. In this clue, previous geotechnical investigation data should be fully used and based on the geological conditions, petro physical parameters and investigation purpose, comparison experiment was carried out among many geophysical exploration methods and then effective geophysical exploration method was selected to reduce unnecessary work load. Moreover, drilling holes were randomly chosen for verification. It proves that the result of karst study done by geophysical exploration method from experiment comparison is relatively in accordance with the actual karst development situation. The result can provide accurate and reliable basis for engineering designs.