Sheetpile-induced vibrations at the lurie excavation project

Ground surface vibrations and their effects on the adjacent ground were monitored during installation of a 20 m deep, sheet-pile wall at the excavation for the Lurie Research Center in Chicago, IL. The subsurface conditions consisted of 9 m of loose to medium dense granular soils and fill over a sequence of increasingly stiff glacial clays. The sheets were installed with two different vibratory hammers, and velocity transducers were placed at varying distances from sheets to record transient responses during the operation. The permanent deformation caused by installation of the sheeting was recorded with optical survey methods at 198 points. The results of the observations show that larger vibrations occurred during the start-up and shutdown phases of hammer operation than during its steady-state operation. Minor settlements occurred within about 12 meters of the sheet pile wall. The settlements were consistent with magnitude of the peak ground acceleration, about 0.1 g, that was computed from the time histories of the velocity traces. No damage to adjacent utilities was noted.