Prevention and remediation of sinkholes

Abstract

Design and construction of buildings and infrastructure in karst terrains are influenced not only by the character of the bedrock but also by the nature and thickness of the soil cover. Voids and cavities in both the bedrock and the soil are significant as potential sites for collapse. The possibility of subsidence due to them, whether slow or rapid, therefore has to be assessed prior to the commencement of construction operations. Hence construction must involve the total environment that influences those processes that aggravate sinkhole development in karst and its overlying soils, both on-site and in the immediate environs (Sowers, 1996ref). Once an assessment has been made, it may be possible to change the layout of a site to avoid the potential hazards. Ground preparation on sites within karst terrain can include remedial work on existing sinkholes and dissolution features, and also works to prevent or minimise the impact of their future development. Landfills on karst provide a special case where the nature and behaviour of the cover soils is critical; any potential hazard of new sinkhole development beneath landfill threatens its integrity with the added risk of serious pollution of local groundwater resources.