Caveins

A cave-in is the sudden collapse of part or all of a subsurface cavity, such as a natural cave, a mining chamber, or a tunnel, resulting in debris fall and partial or complete blockage of the opening and possible entrapment.

Cave-ins can occur in natural karst environments as the ceiling or walls underground collapse after dissolution of soluble rock or prolonged weathering, as well as in mining or civil engineering contexts where ground support fails.

Causes include structural instability due to rock mass properties, weathering, and water infiltration that reduces strength; seismic shaking; frost and freeze-thaw cycles; and, in mine sites, pillar collapse, overloading, poor ground control, or sudden excavation-induced stress changes. Carried out near or above significant voids, such collapses can propagate quickly and may generate air or water inflows.

Impacts range from minor debris showers to complete entombment of workers, blocking routes, and damage to surface structures. Cave-ins pose ongoing risks of secondary collapses and gas buildup, and rescue operations are hazardous.

Prevention and mitigation focus on ground control and monitoring. Engineering measures include proper site characterization, safe excavation sequencing, rockbolts or wire meshes, shotcrete, timber or steel supports, cross-pieces, and backfilling; drainage and groundwater control; and regular inspections and maintenance. In natural caves, understanding rock mass, karst activity, and hydrology informs risk assessment and access decisions.

Response involves stabilizing the site, avoiding unprotected entries, and conducting careful, staged rescues guided by geotechnical experts.