Performance of Embankments Supported by Deep Cement Mixing Piles and Wooden Core Stiffened Deep Cement Mixing Piles

Abstract

Ground improvement is necessary to mitigate the excessive settlements, large lateral deformation, and stability in highway embankments overlying the low bearing capacity and high compressibility foundation soil. From the recent study, the dominant performances of stiffened deep cement mixing (SDCM) pile over the conventional deep cement mixing (DCM) pile to support embankment has been confirmed. Although a less stiffness material such as Eucalyptus wood can also be used as stiffened core and provide indifferent axial bearing capacity compared to concrete core SDCM pile, performances of wooden core SDCM pile-supported embankment have not been investigated. Therefore, this article aims to analyses the performances of embankments supported by DCM piles and wooden core SDCM piles by finite element analyses. Selected case study is highway embankment No.3117 (Bangbo-Klongdan), which is constructed over Bangkok soft clay and supported by conventional DCM piles. Field measurements are adopted to validate the analysis results. The influences of key design parameters on the embankment performances are investigated. The results indicate the superior performances of wooden core SDCM piles over conventional DCM piles under embankment loading. Increasing of the pile strength and cross-section area can enhance the embankment performances for embankments supported by DCM and wooden core SDCM piles. For the wooden core SDCM piles, the influence of stiffened core length on the embankment performance is significantly higher than the stiffened core cross-section area.