Groundpenetrating Radar And High-Resolution Reflection Seismic Surveys Of Subsidence Features Along Interstate 44 Springfield, Missouri

Abstract

In May of 1997, the Department of Geology and Geophysics at the University of Missouri-Rolla conducted a reflection seismic survey and a ground penetrating radar (GPR) survey for the Missouri Department of Transportation (MoDOT) along and adjacent to a 300 meter section of Interstate 44 in Springfield, Missouri. In October of 1997, a second GPR survey was conducted along the same section of interstate. The site was located approximately 1.5 kilometers west of Missouri Highway 266. The section of interstate studied overlies an active sinkhole and has experienced continued, localized subsidence. Seven 12-fold reflection seismic profiles were acquired along or near Interstate 44, using a Bison 24- channel seismograph and an EWG weight drop source. Forty-live GPR profiles were acquired along paved sections of Interstate 44 during the first survey. During the second GPR survey, the survey area was expanded to include a total of seventy ground penetrating radar profiles. A GSSI SIR-S GPR unit equipped with a 500 MHZ (megahertz) monostatic antenna/receiver was used to acquire the data. The geophysical surveys were successful. The reflection seismic data established that sinkholes, both active and nonactive are prevalent in the area. The seismic data also supports the interpretation that a sinkhole lies immediately beneath the interstate. The ground-penetrating radar data also proved to be of significant utility. Anomalous areas interpreted as voids on the GPR data were drilled and significant volumes of grout were injected. The second GPR survey established the success of the grouting program.