Geotechnical and Economic Analysis of Cantilever Walls on Clayey Sand with Gravel Stabilised with Drywall Gypsum, Glass, Brick, and Recycled Marble

In civil engineering, the clay soils in urban areas of Junín have low bearing capacity and high deformability, which increases the cost of constructing retaining walls. This research analysed the structural design of cantilever walls stabilising soils with recycled waste such as plaster, glass, marble, and brick to improve their properties and optimise structural and economic performance. The specific weight, cohesion, angle of internal friction, and bearing capacity were evaluated, determining the optimal doses for each addition. Based on the experimental results, the walls were designed, and a comparative analysis of costs and dimensions was carried out. Glass powder at 15% was the most efficient and economical alternative, increasing the bearing capacity and allowing the wall base width and total cost to be reduced by more than 20%. Recycled gypsum at 12.5% showed the best technical balance, increasing cohesion and bearing capacity, as well as reducing footing thickness and optimising structural expenditure. In contrast, marble powder generated moderate improvements with less economic impact, while brick powder showed no benefits and reduced these properties. Overall, the stabilisation of clay soils with recycled waste proved to be a technicall y, economically, and environmentally viable alternative, improving soil properties, reducing structural dimensions, and lowering costs. In contrast, marble dust produced moderate improvements with less economic impact, while brick dust showed no benefits and reduced these properties. Overall, the stabilisation of clay soils with recycled waste proved to be a technically, economically, and environmentally viable alternative, improving soil properties, reducing structural dimensions, and lowering construction costs. The results consolidate glass powder and recycled gypsum as high-value sustainable additions to civil infrastructure.