Calculation method of multi-stage earth pressure for foundation excavation considering excavation process

The underground structures typically require deep excavation involving multiple stages. Each stage can significantly impact excavation support structures and the surrounding environment. The combination of various influencing factors resulting from the excavation stages typically has varying and considerable effects than a single factor. The combination of supporting structure and excavation-induced deformation critically influences soil pressure, significantly impacting the surrounding environment and structures. Currently, research exploring this combined effect is limited. Accordingly, an earth pressure calculation method is developed in this study. The method considers the combined effect of the excavation process and deformation mode of underground diaphragm walls. Different excavation processes result in different deformation modes in the walls, leading to variations in earth pressure distributions. Considering these differences, the proposed method is deemed suitable for engineering practice. The method was verified and improved using five existing practical engineering and numerical simulation cases. Results indicate that the theoretical calculation method accurately reflects the actual earth pressure distribution.