A parametric study on the use of construction wastes in stone columns placed in peaty soil

Disposing of demolition waste materials has become a global challenging issue due to expanding construction projects and the cost required to discard them. Re-using these materials particularly satisfies the sustainable development goals. Thus, in this study the recycled concrete aggregate (RCA) has been selected in two soil improvement techniques: stone columns and soil replacement to treat peaty soil. The study aims to investigate numerically the potential of using RCA-made stone columns to reduce the settlement and enhance the bearing capacity in highly compressible soil using Plaxis 3D software. The replaced soil (t) thickness varies from 0.25, 0.5, and 0.75 to 1.0m. The depth and diameter of stone columns are 0.4, 0.6 and, 0.8 and 10, 12, and 14m, respectively. The results indicate that the method of stone columns is better than the replacement technique in reducing foundation settlement. Furthermore, the maximum improvement in bearing capacity was achieved when 16 RCA-made columns with 0.8m diameter and 14m long were used; then the bearing improvement ratio (BIR) and settlement reduction ratio (SSR) were found to be 1000% and 0.18 respectively.