A combined geotechnical/geophysical method for the prediction of liquefaction, with particular reference to the Fraser River Delta, British Columbia

Abstract

Abstract Over the past decade or so, much work has been undertaken into the development of various techniques for the measurement of seismic shear wave velocity, offshore, onshore and in the laboratory. Previous research has suggested that the shear wave velocity of an uncemented sand may be a useful index to its liquefaction potential. The research described in this paper has combined the concepts of critical/steady-state soil mechanics and the measurement of shear wave velocity in order to provide a new index of sand consolidation state, enabling the prediction of flow liquefaction in laboratory-prepared samples. Results obtained from the laboratory are then applied to the field situation, in this case, the Fraser River Delta, British Columbia, which is an example of a site currently undergoing a major earthquake stability evaluation. A preliminary analysis of the data indicates that the sediments around Roberts Bank, on the southwestern portion of the delta, are potentially liquefiable. This conclusion is confirmed by other, more conventional, investigative techniques.