The Bill Emerson Memorial Bridge in Cape Girardeau, Missouri is located near the most seismically active region in the central and eastern United States, the New Madrid seismic zone. Due to the bridge’s importance to the regional and national transportation system, Profs. Scott Olson and Youssef Hashash at the University of Illinois, via funding from the Advanced National Seismic System (ANSS) program of the United States Geological Survey (USGS), installed new geotechnical instrumentation at the bridge to significantly augment the existing instrumentation package.

The geotechnical instrumentation includes piezometers and dense downhole accelerometer/inclinometer arrays that will measure ground response in soils that are predicted to liquefy and laterally spread during future earthquakes as well as in soils that have been remediated to prevent liquefaction. The combined geotechnical and structural instrumentation will provide unprecedented opportunities to capture strong, near-field ground motions in the central United States, observe how soils liquefy and laterally spread, and record and study soil-structure interaction for a major bridge.

Here, we describe the geotechnical instrumentation package and details of its installation, and present potential instrument responses for a number of scenario New Madrid earthquake events, including M5.5, 6.5, and 7.5 earthquakes occurring at a distance of 30 km.