Characteristics of Lateral Spreading in Liquefied Deposits During the 1995 Hanshin-Awaji Earthquake

Attempts were made to investigate the features of ground displacements and settlements caused by the lateral spreading of liquefied soil during the earthquake in the wharf areas along the peripheries of Port Island, Rokko Island and Fukae Island. At a number of locations, measurements were made on the width of open cracks and vertical offsets across the cracks on the ground surface along alignments in the direction perpendicular to the revetment line. By summing up the width of the crack openings successively from the datum point inland, the lateral displacement at any place was determined. Similarly, by successively summing up the vertical offsets, the distribution of settlements was obtained as a function of distance inland from the waterfront where caisson-type quay walls are installed. The results of the above ground survey disclosed that both lateral displacement and settlement tend to attenuate sharply within a zone of 30 m in proximity to the quaywall line, but they could encroach into the backland area as far back as about 150 m.