Cover- collapse sinkholes are forming with increasing frequency under buildings. Analyses of sinkhole distribution in Beacon Woods, Florida, preliminarily indicate their occurrence is an order of magnitude greater in urban versus undeveloped areas, suggesting the structures themselves are enhancing the collapse process. The most likely causes are induced recharge via at least one of two sources. First, runoff and drainage from roads, structures, and impoundments that is not adequately dispersed will promote sinkhole development. Second, leaking water, sewer, and septic systems beneath or adjacent to a structure will also promote collapse. The process of cover-collapse from induced recharge is well understood. However, building codes generally do not require drainage and structural engineering practices that would reduce induced recharge and thus reduce the risk of collapse. This paper proposes engineering practices that measurably restrict the accidental discharge of municipal water through leaking subgrade drainage systems or the deliberate discharge of stormwater runoff, induced shallow groundwater recharge from retention ponds and septic drainfields, or heavily-irrigated land use. We recommend these practices be incorporated into building codes and ordinances to reduce induced sinkhole development in areas prone to cover-collapse.
展开▼
