Sinkhole Risk Evaluation: Detection of Raveled Soils in Central Florida's Karst Geology Using CPT

Florida's aquifer system is a major drinking-water source for over 80% of the population; however, this aquifer system only exists due to the weak, porous bedrock underlying most of central Florida. An area where the bedrock consists of highly weathered carbonate-soluble rock is known as a karst environment which brings along many civil engineering design concerns. The major construction risk in karst areas, especially in central Florida, is sinkholes. With high fluctuations in groundwater levels and metropolitan areas exponentially expanding, Florida is experiencing higher frequency of sinkhole occurrences. Geotechnical engineers often use subsurface exploration techniques such as standard penetration tests (SPT) and cone penetrometer tests (CPT) to estimate soil stratigraphy and soil characteristics. In this study, the authors establish techniques to differentiate between naturally low penetration strength layers, possible raveled or disturbed layers, or possible voids within the soil stratigraphy which may indicate internal erosion and sinkhole formation. Identifying, understanding, and quantifying zones of potential sinkhole anomalies using common subsurface exploration test data can be a viable way to detect, and evaluate risk of sinkhole to create the safest and most economical engineered structure.