Evaluation of improved MSD method based on centrifugal model tests on in-flight excavation of foundation pits

A set of novel device for the centrifugal model tests on the whole process of excavation is developed to investigate the influences of excavation on wall displacement and ground settlement. The test data of excavation-induced ground settlement behind the retaining wall and wall deformation are compared with the published research results, and it is determined that the device can effectively simulate the excavation process under high centrifugal force field test conditions. Based on the centrifugal test data, the deformation mechanism of the foundation pit system is modified and the improved mobilizable strength design (MSD) is proposed. The improved MSD method is used to calculate the deformation curves of retaining walls for multi-pillar excavation, and the calculated results are compared with the field monitoring data. It is shown that the predicted results by the improved MSD method are consistent with the measured data, and the applicability of the improved MSD is demonstrated. © 2024 Chinese Society of Civil Engineering. All rights reserved.