On Detection of the Near-Surface Cavities in Earth with the Help of the Light Rock Drill.

This article describes the importance and usefulness of a light rock drill in the detection of some near-to-surface cavities. In Karst regions, these cavities are frequent and hidden. The light rock drill with an acoustic probe proved to be very useful in explaining why and how a one-family house sustained sudden, serious damages by the subsidence of its cellar. The probe detected a cavity in the ground which caused sudden subsidence in the foundation soil and subsequently damaged the house. Geomechanical analysis was used in the decision on how to fill the cavity with concrete to stop further subsidence and to restore the house.