Deformation Assessment of Deep Excavations Retaining Structure in Collapsible Loess Areas

Abstract In this study, the deformation characteristics of deep excavations retaining structure in loess areas are investigated statistically by analyzing filed measurements in three typical loess areas of Shaanxi, Shanxi, and Gansu. Generally, the study results showed that the maximum lateral displacement of the retaining structure ranges between 0.277‰H to 3.712‰H, with an average of 0.1029%H (H is the final excavation depth of excavations). The maximum lateral displacement is approximately located at 2/3 of the excavation depth. In addition, a quantitative analysis is carried out on the influencing factors for the lateral deformation of the retaining structure, such as the insertion ratio of retaining piles (walls), the length-wide ratio of the excavation plane, synthetical stiffness of the support system, heave-resistant safety factor, and the set depth of support in the first tunnel.