PROBABILISTIC ANALYSIS OF SEISMIC HAZARD IN SOUTHWEST INDIANA REGARDING HIGHWAY EMBANKMENTS

Indiana is one of 7 states in central U. S most vulnerable to earthquakes. Interest in seismicity for SW Indiana has increased due to recent, moderate earthquakes and local vulnerability to earthquake damage. In this study, probabilistic seismic hazard analysis (PSHA) was conducted as it allows for uncertainties in size, location and rate of recurrence of earthquakes and in variations of ground motion characteristics with earthquake size and location. This can be explicitly considered when evaluating seismic hazards. Seismic risk in SW Indiana is associated with the seismic zones of central U. S.: New Madrid Seismic Zone (NWSZ), Lower Wabash Valley Seismic Zone (LWVSZ), Gile County Seismic Zone (GCSZ), and Eastern Tennessee Seismic Zone (ETSZ). Seismic hazard curves at sites of interest were developed for each source zone, based on seismicity distribution of earthquake recurrence in each zone, distance probability distribution, and conditional probability of ground motion exceedence. Seismic hazard maps for SW Indiana were developed from seismic hazard curves. Results suggest that seismic hazards are mainly related to earthquakes in the New Madrid Seismic Zone and the Wabash Valley Seismic Zone. Both are capable of producing large and damaging earthquakes. Analysis will be applied to large highway embankments in SW Indiana.