Performances of Two Inverse Sequencing Excavations in Anisotropic Clay

Site soil shows anisotropic behavior due to its structural characteristics, formed in the prolonged sedimentation process. For more efficient utilization of underground space, reasonable and proper description of soil anisotropy is a crucial step in simulating complex geological conditions, which is helpful in assessing the excavation safety and its impact on the surrounding environment. This study analyzed a well-recorded excavation case through finite element analysis, adopting an advanced soil constitutive model simulating the anisotropy behavior of clay. The necessity of restoring the natural soil characteristics was highlighted, due to the underestimated deformation prediction resulted from soil isotropic hypothesis. In more detail, this study also analyzed the features of excavation and supporting between two different construction sequences, namely top-down and bottom-up methods. Differences of retaining structures’ deformation modes and the influences on adjacent infrastructures were also identified. Suggestions were proposed for the sake of safe construction and reasonable cost.