2018 Volume 74 Issue 2 Pages 164-176
It is pointed out that the shear strength of cemented soil improved with calcium carbonate (CaCO3) crystal is enhanced by decrease in saturation degree during precipitation. In this study, improvement efficiency of liquefaction resistance enhanced through controlling saturation degree (from 20 to 100%) and CaCO3 content (from 0 to 1%) was investigated by undrained cyclic triaxial tests for coarse and fine sand specimens. Enzymatically Mediated Calcite Precipitation (EMCP) technique was employed to precipitate CaCO3. SEM-EDX was utilized to observe calcium carbonate crystal on the sand grain surface and to identify the crystal. It was found that, in EMCP with controlling saturation degree during precipitation, high efficiency in liquefaction mitigation was provided to finer sand including larger crystal.