The description of an effective sinkhole investigation approach: A case study of two sites in Greene County, Missouri.

摘要

Karst topographies pose danger to the environment. The associated gradual subsidence or sudden collapse of the ground can lead to loss of lives and damage to property. A sinkhole is the subsidence or collapse of the overburden into subsurface cavities. Sinkholes develop in different sizes, shapes and rates all over the world especially in areas where the bedrock can be dissolved by percolating slightly acidic surface water.;Different methods have been used to investigate sinkholes. Boring is the most common of these methods. But the boring technique is quite inefficient; it only provides information of the subsurface conditions at the boring location thereby requiring multiple borings to more accurately characterize a sinkhole. Geophysical methods have also been used to investigate sinkholes including Gravity, Electromagnetic, Multichannel Analysis of Surface Waves (MASW), Electrical Resistivity Tomography and Ground Penetrating Radar (GPR). But these methods work best in appropriate geological environments in mapping sinkholes.;This project describes a framework for an efficient investigation of sinkholes. The study uses the combination of Aerial photographs, Topographic maps, geological maps and cross sections which are categorized as preliminary studies; appropriate geophysical methods (MASW and ERT) and a few borings to effectively characterize sinkholes. This approach was successfully applied in two case study sites located in Greene County, Missouri and is recommended for future sinkhole investigations where applicable.