Issues and Challenges of Sustainability in Soft Ground Construction

Abstract

Soft ground construction often presents significant challenges, such as low bearing capacity, high compressibility, and a high susceptibility to settlement. These geotechnical issues can lead to instability, costly maintenance, and safety concerns if not addressed appropriately. In recent years, attention has increasingly shifted towards incorporating sustainable materials and innovative construction techniques to address these problems more effectively while minimizing environmental impacts. This paper reviews and analyzes three sustainable approaches in geotechnical applications for soft soils: the use of recycled materials, the implementation of geosynthetics, and the application of microbial-induced calcite precipitation (MICP) techniques. Recycled materials, including industrial by-products such as steel slag and fly ash, offer an eco-friendly alternative to conventional fill, reducing waste disposal while improving soil strength. Geosynthetics, including geotextiles, geogrids, and geomembranes, provide reinforcement, separation, and drainage functions, thereby enhancing stability and service life. MICP, a bio-mediated ground improvement technique, promotes calcite precipitation within soil pores, increasing stiffness and reducing permeability without relying on conventional cement-based binders. In addition to these sustainability-focused approaches, this review presents a comparative assessment of three case studies addressing embankment construction over soft ground. The first case study examines wick drains and counterweight fills at Salamanga, Mozambique, for accelerated consolidation and stability improvement. The second investigates geosynthetic reinforcement combined with floating pile walls in Egypt, highlighting settlement reduction and economic savings through optimized design. The third explores lightweight fill materials and preloading techniques for shallow soil strata in urban environments. A critical comparison of these methods is provided in terms of feasibility, applicability, cost-effectiveness, geotechnical performance, and environmental sustainability. The paper concludes with practical insights and recommendations for integrating sustainable solutions into soft ground construction, offering valuable guidance for future infrastructure projects in challenging soil conditions.