Updating Soil Parameters Using Spreadsheet Method for Predicting Wall Deflections in Braced Excavations

Abstract

A back analysis procedure implemented in a spreadsheet environment that uses construction monitoring data for supported excavation systems to continuously recalibrate the soil parameters and thus enable updating of the lateral wall deflection predictions is presented. With this framework, the observed maximum wall deflections are used to update the soil parameters through a recently developed semi-empirical polynomial regression model. This paper demonstrates that the updated soil parameters recalibrated from the current stage of excavation can be used to predict the maximum wall deflection in the subsequent stages of excavation. The proposed framework is computationally efficient and can easily be implemented in a spreadsheet. The feasibility and effectiveness of the proposed methodology is illustrated through seven well-documented excavation case histories. The results of the case histories show that the updated soil parameters improve the accuracy of estimations of the wall deflections in braced excavations.