Practical Investigation into Two Types of Analyses in Predicting Ground Displacements Due to Dewatering and Excavation

Abstract

To reduce ground displacements induced by dewatering and excavation in foundation engineering, it is crucial to predict the ground displacements before construction. Two types of analyses, i.e., transient analysis (TA) and steady state analysis (SSA), are often used to predict ground displacements. To facilitate appropriate use of the two analyses in this study, both TA and SSA are carried out for a large-scale excavation in Shanghai, China. The calculations include groundwater table, ground settlement, and horizontal displacement. Comparisons between the calculated results and the measured results are made. Both the calculated and the measured results suggest that the deep mixing soil walls and diaphragm walls play an important part in preventing groundwater seepage and constraining soil movement. The calculated results show similar tendencies to the measured results, although the magnitudes were different. The comparisons indicate that TA is more accurate, and it is appropriate for detailed analysis of construction processes. SSA requires less calculation and is suitable for preliminary evaluation.