Basal Heave Stability of Braced Excavations Considering Spatial Variability in Cement-Admixed Soil Slab

This paper discusses the effect of spatial variability in strength properties of the cement-admixed soil slab on the basal heave stability for braced excavations. Deterministic and random finite element analyses are performed in Optum G2 software. In deterministic analysis, the effect of different strengths and thickness of slab on the basal heave stability are studied. For studying the effect of spatial variability in cement-admixed soil slab, the spatially correlated random fields of undrained shear strength (cuj) are simulated for varying coefficient of variation (COV) and scale of fluctuation (SOF). Results show that the mean value of the FoS decreases with the increase in COV. The mean value of FoS also tends to decrease as the value of SOF increases from 0.5 to 1.0. Finally, equivalent design strengths are computed for the varying spatial parameters to take in account of the spatial variability in strength properties of the cement-admixed soil slab.