Studies on the Mechanical Properties and Carbon Sequestration Potential of Geosynthetic-Reinforced Soil Incorporating Biochar

Abstract

This study evaluates the feasibility of using biochar-amended soil (BAS) as a sustainable backfill material in geosynthetic-reinforced earth structures, considering both mechanical performance and carbon sequestration potential. Laboratory tests, including standard Proctor compaction and consolidated drained triaxial tests, were conducted on soils with biochar contents of 0%, 1%, 3%, and 5%, while numerical simulations using PLAXIS 2D were performed to assess the deformation and reinforcement behavior of mechanically stabilized earth (MSE) walls. Results show that increasing biochar content reduces maximum dry unit weight and increases optimum moisture content. Moderate biochar addition (≤3%) enhances shear strength, whereas excessive content (5%) leads to strength reduction due to particle crushing. Numerical results indicate that using 1% biochar reduces wall displacement by approximately 36% and reinforcement tensile force by about 27.3%, demonstrating improved structural performance. Overall, BAS provides a promising nature-based solution that integrates carbon sequestration with enhanced geotechnical performance; however, its effectiveness is highly dependent on biochar content, and further research is required to determine optimal design conditions.