A Simplified Approach for Axial Response of Single Precast Concrete Piles in Cement-Treated Soil

Abstract

Precast concrete (PC) piles reinforced with cement-treated soil have been successfully applied to soft ground improvement in China’s coastal regions. However, very few analytical approaches have been proposed to predict their responses to axial loading. This paper presents a simple analytical approach for the prediction of the axial response of a single PC pile in cement-treated soil based on the shear displacement approach. The analysis considers the pile–treated soil-surrounding soil interaction and the non-homogeneity of subsoil shear modulus. The closed-form solutions for the axial force and displacement along the pile shaft as well as the load–displacement response are quickly deduced. A comparison with the measured response of a single PC pile with cement-treated soil reinforcement is performed to verify the effectiveness and accuracy of the proposed approach. Finally, using this approach, a parametric study was further conducted to clarify the influence of the related parameters on the axial response of the reinforced PC pile. The results show that increasing the subsoil shear modulus can significantly improve the bearing performance of the reinforced PC piles that are subjected to axial loading. The ultimate bearing capacity of the reinforced PC pile increases by approximately 20% for every 100 mm increase in the diameter of outer cement-treated soil. Moreover, the pile-head displacement reduction is generally proportional to the increase in the elastic modulus and the diameter of the inner PC pile.