Multi-objective optimization of bermed embankments for reduced earthwork volume and ensured stability

Optimal utilization of natural resources, especially soil, is vital due to the slow rate of soil formation and the environmental impacts of excessive soil extraction. Besides the economic benefits, the optimal design of embankments is also important for environmental conservation and sustainable development. This article presents a decision-oriented multi-objective approach for embankment earthwork operations, where the placement of the berm is treated as a controllable geometric parameter to minimize the volume of the embankment and ensure stability. Several preliminary designs of the embankment were generated and optimized using the Multi-Objective Particle Swarm Optimization algorithm. The optimized designs were obtained with the desired number of near-optimal solutions, ranging from one to four berms. The stability of the embankment was evaluated using Spencer’s method for limit equilibrium analysis and was also verified with the SLOPE/W program. The volume of the embankment was also evaluated for the optimized designs. An initial population clustering technique was used to avoid the risk of the algorithm converging to a local optimum. The effectiveness of the proposed approach was demonstrated through four case studies with different embankment heights: 15 m, 35 m, 60 m, and 100 m. The proposed approach is effective for designing embankments with a desired volume reduction of up to 13.63% for a short homogeneous embankment and up to 9.33% for a larger embankment with cohesionless shells.