Characteristics and Prediction of Ground Settlement around Deep Excavation in Shanghai

Abstract:

Based on the field monitoring data of 32 deep excavations in Shanghai, the main characteristics of ground settlement have been summarized as follows. Firstly, most settlement profiles around deep excavations appear to be grooves with settling tanks. Secondly, the maximum ground settlement, , lies between 0.4 and 1.9 ( for the maximum lateral deflection), and its mean value is equal to . Thirdly, system stiffness of all deep excavations is great and its influence on is small. Fourthly, the maximum ground settlement decreases with the increase of the factor of safety against base heave (FOS), and the FOS-based settlement predictive curve is proposed at the same time. Finally, according to the character of measured settlement profiles in Shanghai, the author proposed a predictive method taking into account effect of the settling tank’s eccentricity. With the verification of the proposed method in four deep excavation cases, the results show a high degree of accuracy, which is proved to be a practical method in ground settlement prediction around deep excavation.