Zeolite role in oil-polluted carbonate sand liquefaction mitigation risk – Developing a novel approach

Liquefaction, a crucial concern in geoengineering, is an imminent threat to infrastructures if the cyclic stress reduces effective stress to zero in the soil mass. This natural disaster relies on various factors. Scholars predominantly concentrate on the silica sands' liquefaction response, which contradicts that of carbonates. Few papers address contaminated carbonate sand liquefaction. Therefore, this investigation aims to study the liquefaction resistance of Bushehr carbonate sand (BCS) in clean, crude oil-contaminated, and treated conditions with eco-friendly techniques. The stabilization process uses natural zeolite, a novel material in geotechnical engineering, to stabilize oil-contaminated soils. Zeolite is a clean, safe, ample, and environmentally friendly material. The investigation uncovers that using 6 wt% zeolite has the most significant influence on the treatment of the liquefaction of BCS, yielding a 1.94-fold growth in the number of required cycles for triggering liquefaction. SEM and FTIR results verify the physical experiments, demonstrating that C-H bonds decrease sharply in zeolite-treated BCS specimens. This paper's findings reveal the significant role of zeolite's porous surface in the better adsorption of crude oil from the soil mass. This considerable adsorbing capacity causes outstanding improvement in cyclic strength, leading to a more convincing performance of this agent than other stabilization techniques suggested.