ABSTRACT
Enzyme Induced Calcite Precipitation (EICP) is an innovative bio-inspired ground improvement technique that promotes calcite (CaCO3) precipitation. This helps in the clogging of pore spaces and increases the strength of the soil. In this paper, a series of consolidated drained triaxial tests were carried out to investigate the effect of EICP treatment on the strength characteristics of soil. Two urease enzymes were adopted for the EICP treatment with different activity rates of 3g/l (5000 Units/g and 3500 Units/g) and mixed with cementation solution (1M Urea and 0.67M CaCl2). The stress-strain curves after a curing of 7 days are presented herein. The volumetric strain response curve demonstrated a more dilative tendency in the EICP-treated specimens than in the untreated. Mohr-Coulomb failure criteria were adopted to determine the shear strength parameters at peak and residual stages. Finally, acid digestion was performed on the specimens to evaluate the calcite precipitation.
