Natural and anthropogenic rock collapse over open caves

Abstract

Abstract Natural rock collapse that reaches the ground surface to form a collapse doline is relatively rare in limestone karst. The anthropogenic karst geohazard is posed by the possibility of rock collapse when additional loading is imposed by engineering works directly over a known or unknown cave. An intact rock-cover thickness that exceeds half the cave width appears to be safe in most karst terrains formed in strong limestone. Guidelines suggest that drilling or probing prior to construction should prove sound rock to depths ranging between 3 and 7 m in most of the various types of karst.