Undrained Shear Behavior of Cement Admixed Clay at High Water Content

Understanding of undrained shear behavior of cement admixed clay is of utmost importance for strength and deformation analyses in composite soft clay under short-term condition. From the critical analysis, the distinct difference in the responses of the same clay at uncemented and induced cemented states is brought out. The undrained shear behavior of uncemented clay is mainly dependent upon the clay fabric. The dismembering of the clay clusters in the fabric brings about the interlocking when the clay is in overconsolidated state. For the cement admixed clay, the clay is in meta-stable state. Hence, the strength and deformation characteristics are controlled by the clay fabric and cementation. The shear resistance is the sum of the shear resistance due to cementation qb and due to fabric qf. The term qb is practically constant with the increase in effective confining pressure at preyield state. The contribution from the clay fabric to the shear resistance qf comes into the picture at postyield state.