A method for estimating coefficient of lateral earth pressure based on cone penetration tests

The coefficient of lateral earth pressure at rest (K₀) is a key state soil variable for the design of foundations and underground structures, characterizes in-situ stress state and soil condition. In this study, a method for the in-situ estimation of K₀ using the cone penetration test (CPT) is proposed considering vertical and inclined cone resistances (q_c). For this purpose, a series of laboratory CPTs in a soil chamber were conducted to obtain and characterize vertical and inclined q_c values at various inclination angles (θ) and relative densities (D_R). It was observed that the values of q_c increased as θ increased, which was more pronounced at higher D_R. Coupled Eulerian-Lagrangian (CEL) finite element analyses were performed to quantify the values of inclined q_c at various cone penetration and soil conditions. Based on results from laboratory CPTs and CEL analyses, a CPT-based K₀ correlation model was established, which was given as a function of vertical and inclined q_c values. The model parameter for the proposed method was evaluated and quantified. The validity of the proposed method was confirmed from the comparison with case examples.