S. Chaiyaput and M. Sugimoto 2021. The Boundary Condition of a 3D Continuum Model for a Quasi 2D Plane Strain Condition. Geotechnical Engineering Journal of the SEAGS & AGSSEA . 52, 2 (Jun. 2021), 24–30. DOI:https://doi.org/10.14456/seagj.2021.35.