Sinkhole Case Studies—Is It or Isn't It a Sinkhole?

Three sinkhole case studies are discussed to show the precarious nature of determining if a sinkhole is present based on commonly used investigative techniques in west-central Florida. Conclusions reached in sinkhole investigations are generally based on site conditions determined from study of essentially: (1) site geologic history, (2) GPR (Ground Penetrating Radar) survey, (3) SPT (Standard Penetration Test) borings, (4) an evaluation of building distress and (5) shallow test pits excavated around the building. Three case studies are presented that show how sensitive the data obtained are to the location of the tests and the interpretation of the data. In most studies different investigators have reached different conclusions at the same site.