Shear strength and constant rate of strain consolidation behaviour of cement-treated slurry-consolidated soft soil

This article focuses on the compressibility and shear strength behaviour of cement-treated soft soil at different cement content and curing time. The soil was found to be too soft (SPT N = 1) to collect the undisturbed samples from soil site. Therefore, a pneumatic slurry consolidation set-up has been developed in the laboratory to produce remoulded specimens of soft soil with same in situ density and water content. These representative slurry-consolidated remoulded specimens were tested using unconfined compression (UC) and constant rate of strain (CRS) set-up to evaluate the shear strength and compressibility behaviour of soil before and after cement treatment. The conventional 1D consolidation set-up (oedometer) was found to be unsuitable to determine the compressibility behaviour of cement-treated soft soil due to its long testing duration (~10 days), which caused major discrepancy in compressibility results of treated soft soil at the chosen curing time. Thus, the CRS set-up has been developed in the laboratory to accelerate the consolidation process for cement-treated soft soil. A wide range of cement contents (2%, 4%, 6% and 8%) and curing periods (1, 3, 7 and 28 days) were explored to study the compressibility and shear strength parameters of highly compressible soft soil with respect to the cement content and curing time used for its treatment.