Modelling Random Construction Deviation and Spatial Variability of Lime-Cement Treated Ground

Lime cement columns are widely used to improve unfavorable grounds as they are effective, flexible and versatile. However, this method is usually used with great conservativeness because high uncertainties in both material properties and geometries have significant impact on the global behavior of the treated ground. The material properties vary due to uneven distribution of binder (and therefore local mix ratio). The geometries deviate from the idealized case where the columns are perfectly vertical cylinders due to inevitable inclinations and random variations of diameters. Therefore, a relatively low strength is usually assumed regardless of the average strength. An effective simulation method that quantifies the effect of both uncertainties is highly demanded. The geometric imperfections are tiny as compared to the scale of the whole treated ground, and considering those geometric imperfections in three-dimensional models is very time consuming. In this study, a novel simulation method is proposed to effectively simulate both uncertainties. It saves computation costs and has high potential for further upgrading.

Keywords: Spatial variability, Geometric imperfection, Numerical simulation, Random finite element method.