Chemistry, sensitivity and quick-clay landslide amelioration

Abstract

Quick clay’s combination of sufficient undisturbed shear strength to be stable in situ and liquefaction upon structural failure derives from chemical factors that act during and after sediment accumulation. Flocculation of silt and clay particles in marine water produces an interlinked, random structure with a water content that approximates its high-salinity liquid limit. Co-sedimentation of cementing agents may augment its strength. Upon uplift above sea level, fresh water displacement of the high-salinity pore water decreases the liquid limit while the structure and water content remain almost constant, yielding a liquidity index in the range of about 1.5–4. The central premise of this paper is that development of solutions begins with consideration of how problems have arisen. Specifically, chemistry’s dominating role in quick clay development provides insights into approaches that can be applied to amelioration of the quick clay landslide problem.