Development of Rapid Consolidation Equipment for Cohesive Soil

In this study, rapid consolidation cell equipment (RACE) was developed as an alternative device to the conventional consolidation test using Oedometer to determine the consolidation characteristic of cohesive soil. RACE operates based on the constant rate of strain (CRS) consolidation theory, which is a continuous loading method of testing and could accelerate the consolidation process for cohesive soil, shortening the time consumption from 1 week (when using Oedometer and Rowe cell tests) to only a few hours. A slightly modification has been made on the normal CRS test by proposing a direct back pressure system to the specimen using a tube to saturate the soil sample. Four types of sample were tested with different rates of strain using the RACE equipment and their results were compared with those conducted using the Oedometer on the same soil type, from which fairly good agreements were evident in many specimens. It was found that, the RACE equipment is capable to determine the consolidation characteristic of the cohesive soil. In this study, the acceptable strain rates were proposed as compared with the Liquidity Indices for cohesive soil. It was found that the range of strain rate of CRS test for LI < 15 % was between 0.01 and 0.3, while for LI closed to 25 %, the range was between 0.01 and 0.1.