Prediction of Ground Surface Settlements Caused by Deep Excavations in Sands

Abstract

The objective of this paper is to evaluate the applicability of a simple method for predicting movements, especially the ground surface settlements, caused by deep excavations in sands. A case history of deep excavation in thick layers of sand in Kaohsiung, Taiwan was adopted as a basis for numerical analyses. In order to improve the inconsistence in prediction of ground surface settlements induced by the deep excavation, the analysis using the simple constitutive model but with additional two factors, α and β is applied. The factor α defines the width of primary strain zone behind the retaining wall, and β indicates the difference of soil stiffness in two zones of the primary strain zone and small strain zone. It is concluded that changing α seems not to induce significant change, and values of β from 3 to 5 shall be taken once such approach intends to be adopted for predicting ground surface settlements caused by deep excavations in sands.