Coupled Analysis Method for Asymmetrical Excavation Based on a Modified MSD Method and a Horizontal Displacement Method

The effect of asymmetric loading on the excavation deformation and force cannot be ignored. Therefore, this paper proposes a coupled analysis method for asymmetrical excavation based on a mobilizable strength design (MSD) method and horizontal displacement method, further considering the effect of actual excavation boundary conditions, layered soil, and realistic plastic deformation mechanism. The accuracy of the modified MSD method is validated through engineering examples. Also, the effect of the size of overloading, distance from the edge of the excavation, distribution range, and timing of application on asymmetric excavation deformation are discussed. The results show that the coupled analysis method aligns more closely with measured excavation deformation, showing a 23%–27% improvement in accuracy compared with the normative method. Deformation caused by existing overloading is primarily concentrated at shallow excavation depths, whereas temporary overloading results in more pronounced asymmetric deformation. The excavation deformation under overloading correlates positively with excavation depth but exhibits a negative growth rate with increasing depth. The size of the overloading and the distance from the excavation edge are the predominant factors influencing asymmetric deformation. These results offer valuable insights and guidance for the design and calculation of asymmetrical excavation.