Estimation of Settlement in Loess-Filled Subgrade with Consideration of Lateral Deformation.

The effect of lateral deformation on subgrade settlement is often ignored. This paper discusses this effect under different constraint conditions. Compression tests of typical Q2 remoulded loess from Shaanxi Province, China, were conducted under different confining pressures using a self-developed three-dimensional loading test device. The vertical and lateral deformation characteristics of loess samples were analysed, and a model of lateral strain in subgrade soil was derived. Then, a model of total subgrade settlement with consideration of lateral deformation was established based on the equal volume concept. The stratified summation calculation formula was also revised, and correction coefficients under different constraints are given. The results show that the accuracy of the revised method is positively correlated with the number of lateral constraints. The correction coefficient can reflect the influence of different subgrade constraints. Importantly, the modified model was verified by field measurements and found to be more accurate than the stratified summation method. These results help to understand the influence of lateral deformation on total settlement and the mechanism of subgrade settlement. [ABSTRACT FROM AUTHOR]