Feasibility of Biopolymer in Enhancing the Load Capacity and De-formation of the Granular Pile

Abstract

This paper presents an innovative concept to improve the load carrying capacity, settlement, and the lateral deformation characteristics of the granular-pile by incorporating biopolymer as a binder to the fill materials of the granular pile. This natural biopolymer is sustainable and eco-friendly substitute binder to the conventional binder ( cement, lime), which have sever impacts on the environment. A series of loading tests using large scale models was performed considering different biopolymer contents, various ratio of footing diameter to pile diameter df/Dp, and fiber content. Results revealed that the incorporating biopolymerresulted in stiffening granular pile and eliminate the common bulging failure. Therefore, load carrying capacityincreased significantly, corresponding with clear restraint against the lateral deformation. For ground reinforced with ordinary granular pile considering df/Dp of 1.5, 1.25, 1.0, 0.75 and 0.5, the bearing pressure increased from 60 kN/m2 for the native ground to 65, 110, 157, 185 and 230 kN/m2 respectively. Compared with 230 kN/m2 for the ordinary granular pile with  df/Dp = 0.5, bearing pressure increased to 245, 304, 525, 638 and 649 kN/m2 when 1, 2, 4, 6 and 8% of biopolymer was incorporated with the granular material of the pile, respectively. However, with increasing df/Dp  to 1.5, the capacity increased from 65 kN/m2 for the ordinary granular pile to 74, 107, 144, 442, and 495 kN/m2 for biopolymer-granular pile considering the aforementioned contents of the biopolymer respectively.