Assessing deep soil mixing for excavation support in Sabkha soils: a numerical study

Abstract Excavation in Sabkha soils, found in coastal regions of Saudi Arabia, presents complex challenges in construction due to their unique geotechnical characteristics. These soils are known for their high compressibility, collapsibility, and variable sediment deposition, rendition them unsuitable for excavation without adequate support systems. As urbanization and industrial activities continue to expand into these areas, the demand for effective excavation support systems becomes gradually critical. This study investigates the feasibility of employing Deep Soil Mixing (DSM) as an excavation support system in Sabkha soils. Utilizing finite element analysis through PLAXIS 3D software, the behaviour of DSM walls in Sabkha soil under various conditions is rigorously simulated. The findings of this research establish that DSM walls can serve as an efficient excavation support system in Sabkha soils, provided that crucial factors, particularly excavation depth, are considered during the design phase. The study demonstrates that properly designed DSM walls, in combination with appropriate anchoring methods, can substantially reduce horizontal displacement and bending moments, ensuring the stability of excavations in Sabkha soils. The research highlights the need for further investigations into the cost-effectiveness of DSM walls in comparison to other excavation support options to evaluate the economic feasibility of using DSM in Sabkha soil applications.