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Use Of Engineering Geophysics To Investigate A Site For A Bridge Foundation, Paul Michaels

CGISS Publications and Presentations

The Idaho Transportation Department (ITD) commissioned a geophysical study to aid in the design of a replacement for an existing concrete span bridge. Because the river current was too swift to place geophones in the river, the solution was to shoot p-wave profiles in a reciprocal geometry (phones on land, shots in the river). In addition to the refraction work, a down-hole seismic profile was acquired to calibrate the surface data. Geotechnical boreholes drilled on the north and south river banks detected a laterally varying soil profile. The south-bank hole encountered 9.1 m of granular overburden, followed by 8.5 m …