Impacts of spatial variations in permeability of liquefiable deposits on seismic performance

Sand deposits are often stratified with thin layers of low-permeability silt. In this study, which will be published by the Journal of Geotechnical and Geoenvironmental Engineering, Dr. Balaji Paramasivam and his coauthors present the results of dynamic centrifuge tests that evaluate the response of 3- and 9-story inelastic steel structures (A and B) founded on layered liquefiable deposits with and without a silt cap. The thin silt layer is also evaluated in terms of its influence on the effectiveness of prefabricated vertical drains (PVDs) as mitigation. The results indicate that a thin silt cap may have beneficial or detrimental effects on a structure’s performance, particularly when evaluated in terms of foundation’s permanent rotation (or tilt). . These results point to the importance of identifying and characterizing thin interlayers in the soil profile, together with the key properties of structure, foundation, and ground motion, when assessing and mitigating the consequences of liquefaction.

A link to the manuscript pre-publication: here.