Bearing capacity and deformations of geosynthetic-reinforced stone column using recycled aggregates

Encapsulating stone columns with geosynthetic encasement is an effective technique to enhance bearing capacity and reduce deformation in soft soils. However, this approach typically requires large quantities of virgin aggregates from local quarries, which may cause significant environmental impacts on fragile ecosystems. In this study, recycled aggregates (RAs) derived from concrete debris were employed as a full replacement for natural aggregates in the construction of stone columns. A comprehensive series of laboratory model tests was conducted to evaluate the bearing capacity and deformation performance of geosynthetic-reinforced stone columns constructed with RAs under different reinforcement configurations. A hybrid geosynthetic reinforcement scheme (combining geogrid encasement with horizontal reinforcement discs) was introduced to restrict lateral displacement and enhance the interlocking effect of RAs near the geogrid. Key parameters including load–displacement response, lateral earth pressure distribution, load transfer mechanisms, excess pore water pressure, and geogrid strain were systematically measured and analysed. Results indicate that recycled aggregate columns (RACs) with hybrid reinforcement can achieve up to 94% of the bearing capacity of natural aggregate columns. The RACs represent a sustainable and environmentally resilient alternative to conventional stone columns in ground improvement practice, promoting both resource conservation and ecological protection.