Cost-effectiveness analysis of stiffened deep cement mixing column-supported embankment

Abstract

This article aims to study the behavior of stiffened deep cement mixing column (SDCM) under embankment loads over soft soil. The performances and construction cost of embankments supported by SDCM columns were compared with that supported by conventional deep cement mixing columns (DCM). A parametric sensitivity study based on a three-dimensional symmetry finite element (3D-symmetry FE) was employed to simulate the embankment system. There are three types of column in this study, consisting of DCM column, concrete-core SDCM column, and wooden-core SDCM column. The DCM columns and SDCM columns were investigated based on equal construction cost. Moreover, the wooden core was also compared with similar dimension of a concrete core. Regarding the performance of DCM and SDCM columns-supported embankments, the results imply that the SDCM column has a higher efficiency for improving the performance of embankment over soft soil than DCM column in total settlement, lateral movement, and differential settlement. Furthermore, the wooden core-SDCM column exhibits insignificantly different performances when compared with concrete core. In addition, a higher stiffness of inner core can be induced more bending moment that occurs from embankment loading. When performing the relation between the construction cost and performance of DCM and SDCM columns under embankment loading, the column performance was greatly enhanced when construction costs increased up to a certain level.