Scope and field context
Project scope and field context
GeoView, Inc. a wholly owned subsidiary of Ambient Technologies, performed a geophysical investigation across the area of a planned overpass associated with the Wekiva Expressway in Orange County, FL. The purpose of the investigation was to determine the presence of any buried sinkhole (karst) related features at the site. The project site was located in-between two stabilized sinkhole-related lakes. Initial geotechnical borings indicated that additional buried karst related features were present within the planned area of construction and that these features could have an impact on the design and viability of the planned foundation system for the overpass. The investigation performed using Electrical Resistivity Imaging (ERI) and Ground Penetrating Radar (GPR). The purpose of the GPR survey was to determine the presence of any buried paleo-karst features within the surficial sediments overlying the limestone bedrock. The purpose of the ERI survey was to help establish the vertical extend of the GPR identified features and to determine areas of voids, cavities or weathered/weakened limestone rock. Results from the GPR survey identified three major and three minor buried paleo karst features across the site. There was a very good correlation between the GPR and ERI results. The ERI demonstrated that the limestone, which occurred at a depth ranging from 80 to 150 feet across the site, was generally highly weathered in the areas in areas where GPR anomalies were present. Subsequent geotechnical drill testing confirmed the geophysical survey results and allowed the design engineers to make appropriate modifications to the overpass design prior to construction. Project Services: Ground-penetrating radar Electrical Resistivity Imaging