Geopolymers as Sustainable Additives for Reducing Liquefaction Potential in Geotechnical Engineering

Soil liquefaction poses a significant geotechnical hazard in seismic-prone regions, leading to catastrophic infrastructure failures during earthquakes. Traditional mitigation techniques, such as cement-based stabilization, effectively enhance soil resistance but also contribute substantially to carbon emissions and environmental degradation due to the high energy consumption of cement production. This paper explores the application of geopolymers as sustainable, low-carbon additives to reduce the liquefaction potential of loose saturated soils, particularly sandy deposits. Geopolymers are aluminosilicate-based materials activated by alkaline solutions, formed from industrial by-products such as fly ash, slag, or metakaolin. They offer mechanical performance comparable to or superior to Portland cement while significantly reducing CO۲ emissions–often by ۶۰-۸۰%–making them an environmentally friendly alternative. Recent studies demonstrate that geopolymer stabilization increases shear strength, reduces excess pore-water pressure generation under cyclic loading, and improves the cyclic resistance ratio (CRR) in liquefiable soils. Key mechanisms include the formation of a strong three-dimensional aluminosilicate network that binds soil particles, enhances inter-particle bonding, and reduces permeability. Laboratory investigations, including cyclic triaxial tests, resonant column tests, and bending element tests, reveal that geopolymer-treated sands exhibit higher liquefaction resistance, with triggering strains delayed and damping ratios optimized at low additive contents (typically ۵-۱۵%). Field-scale applications and numerical simulations further validate these findings, showing reduced settlement and lateral spreading risks. This review synthesizes over ۵۰ recent studies (۲۰۲۰-۲۰۲۵) on geopolymer compositions, curing conditions, and performance in liquefaction mitigation. The results highlight geopolymers' potential as a green solution for sustainable geotechnical engineering, addressing both seismic safety and climate change concerns. Future research directions include long-term durability, scalability, and standardization for widespread adoption.

کلیدواژه ها:

Geopolymers ، Soil Liquefaction ، Sustainable Additives ، Cyclic Shear Strength ، Environmental Impact ، Geotechnical Engineering