Investigation on load-carrying capacity of geogrid-encased deep cement mixing piles
Raksiri Sukkarak, Pornkasem Jongpradist, Warat Kongkitkul, Pitthaya Jamsawang, Suched Likitlersuang
Abstract
This article discusses the feasibility of a geogrid-encased deep cement mixing (EDCM) pile for enhancing the load-carrying capacity (Q ult ) of a conventional deep cement mixing (DCM) pile, based on the results of experimental and numerical investigations. Firstly, physical model tests were conducted to observe the load–settlement response and load-transfer mechanism. Subsequently, a series of three-dimensional (3D) finite-element analyses was performed to investigate the effect of the stiffness and length of the geogrid encasement. The results indicated that the geogrid encasement effectively improves the Q ult of the DCM piles by a factor of two. With the additional confinement provided by the geogrid encasement, the geogrid can also provide a greater contribution to the loading transfer. The increase in Q ult became more significant with a lower strength of the DCM. For a particular amount of geogrid, the EDCM pile with a thicker geogrid provided a higher Q ult than that with a longer geogrid. The optimum length of the geogrid-EDCM pile was found to be approximately twice that of the pile diameter. Finally, a chart for estimating the efficient effect of geogrid encasements on the Q ult of EDCM piles was proposed.