STATIC AND DYNAMIC BEHAVIOR OF SOFT CLAY SOILS STABILIZED BY OIL PALM'S DIRTYGOLD PhD ProposalMehran Naghizadehrokni PhD Researcher at RWTH Aachen University

The construction of heavy structures on soft clay soil is a high challenging task. Oil palm fuel ash (POFA) is one of the most abundantly produced waste materials which has a strong potential to treat physical and chemical characteristics of problematic soils thanks to its high siliceous content. Utilizing of this dirty gold as full or partial substitution of conventional additives in ground improvement not only can reduce the energy consumption of these additives but also can be useful with respect to reducing the waste disposal volume of landfills. This proposed research consists of four stages. The first stage investigates the efficacy of utilizing OPFA on the basic geotechnical characteristics of soft clay soils. In the second part, behavior of OPFA stabilized soft clay soils under static and dynamic load is modeled. For this purpose, geotechnical design procedure of interaction between a strip footing model and POFA stabilized soil by column technique is evaluated. More importantly, in the third stage of this research, the constitutive model of dynamic behavior that more sophisticated for minimizing post-construction deformation will be formulated. In the final stage, by comparing the numerical analyses of behavior before and after treatment, the benefits of using this dirty gold in soil stabilization can be quantified in a rational manner, and compared to the alternative empirical relations. The outcomes of this proposed research will provide valuable information for geotechnical designers in designing cost-effective and well-performing stabilized soil to reduce the settlement of foundations, to prevent shear deformation and also to mitigate liquefaction during earthquake. Furthermore, in line towards achieving the status of green environmental policy, the innovation of using OPFA in the field of ground improvement will encourage geotechnical researchers in Malaysia to investigate usage of other agro-wastes. Hypothesis: Hypothetically, the large amount of amorphous silica in POFA potentially contributes to the pozzolanic reaction during hydration, which results in cementitious compounds called calcium aluminate hydrates (CAH) and calcium silicate hydrates (CSH). These compounds are responsible for improving the engineering characteristics of soils that increase over time as the pozzolanic reaction develops