Cover‐Subsidence Sinkhole Evaluation of State Road 434, Longwood, Florida

Abstract

This paper presents the results of a cover‐subsidence sinkhole evaluation. In this case, the sinkhole activity caused a slow, gradual settlement of the State Road 434/Harbour Isle Way intersection, in Longwood, Florida. The subsoil conditions were explored with numerous cone penetrometer tests and permanent piezometers. The study indicated that the settlement was caused by internal soil erosion and raveling. Piezometric elevation contour maps revealed a well‐defined depression that coincided with the observed surface settlement. The piezometer monitoring results suggest this may be an effective technique for economically identifying potential sinkhole locations.