<p>The deep cement mixing (DCM) method is widely used for ground improvement, and current design codes primarily rely on analytical equations that do not account for the pre-peak nonlinear stiffness characteristics and post-peak plastic strain softening of DCM materials. Moreover, these analytical equations do not adequately consider the interaction between DCM and surrounding soils. This study employs a bounding surface plasticity model to compute the bearing capacity and settlement of DCM-improved ground, and compares the results with those from analytical equations. Based on comprehensive parametric studies, the key and governing parameters are identified. The bearing capacity increases significantly not only with the area replacement ratio and the unconfined compressive strength of DCM, but also with the stiffness of the surrounding untreated soils. Analytical equations underestimate the bearing capacity, as they overlook the contribution of untreated soils. Hence, new design charts were developed, integrating the effects of these three factors. On the other hand, ground reaction modulus and settlement are primarily governed by the DCM stiffness characteristics, area replacement ratio, and loading level. When the applied load is relatively low (i.e. a high factor of safety), the analytical solution generally overestimates ground settlement because it underestimates the small-strain stiffness of DCM. In contrast, when the applied load is relatively high (i.e. a low factor of safety), the analytical equations tend to underestimate ground settlement, as they are unable to account for the plasticity of DCM.</p>