Determining Casagrande Liquid Limit Values from Cone

Abstract

The liquid limit (LL) is one of the essential geotechnical parameter for fine-grained soils. Commonly, two approaches, named Casagrande apparatus and cone penetrometer methods are used to determine the liquid limit of soils. The liquid limits of 41 soil samples in Erbil province, Kurdistan region, Iraq, were found based on cone penetrometer (30°/80g cone, using 20 mm penetration) and Casagrande apparatus methods. The study compares the liquid limit values determined by both methods. The results indicated that the liquid limits obtained by the Casagrande cup method (LLcup) are lower than those from fall cone method (LLcone). Finally, an equation for determining LLcup was proposed based on LLcone values and it compared to the previously suggested equations.

Keywords

• Liquid limit; Casagrande apparatus; Cone penetration.