Deformation analysis of cement modified soft clay soil using finite element method (FEM)

Engineers are facing problems in infrastructure construction in soft clay areas due to excessive soil settlement and low bearing capacity that leads to treacherous problems in the structure to damages and collapse. Therefore, this study aims to investigate the deformation characteristics of cement modified soft clay soilusing finite element method. Soil samples collected were conducted to determine grain size analysis, free swell, specific gravity, index property, unconfined compressive strength, one-dimensional consolidation and triaxial test. From the test results the soil of study area is classified as inorganic clay of high plasticity (CH). Deformation characteristics of cement-modified soft clay soil was analyzed by PLAXIS 2D finite element software. In the finite element analysis, a constitutive soil model, hardening soil model is used. Triaxial test and one-dimensional consolidation conducted on 9, 12 and 15 percent of soil- cement stabilization. From the laboratory result the pre-consolidation pressure increased with increasing stabilizer content. This is due to of a pozzolanic reaction taking place with cement. The pre-consolidation pressure of soft clay when soil modified for 9%, 12%, and 15% of cement is 190 kPa, 290 kPa, 320 kPa, and 340 kPa, respectively. From numerical analysis, the vertical deformation values of soft clay soil increased as the cement percentage increased. It is observed that the optimum percentage of cement stabilization is 15%, at this percentage of cement the highest shear strength parameters and, the lowest deformation occurred as compared to the amount of 9% and 12% of cement.