Seyed Mohammad Iman Bathaeian - Department of Civil Engineering, Islamic Azad University – Central Tehran Branch
Morteza Jiryaei Sharahi - Department of Civil Engineering, Qom University of Technology

This study presents a detailed analysis of a well-documented deep excavation case history under undrained conditions with three different soil models, i.e. Mohr Coulomb, the soft soil (SS) model and thehardening soil (HS) model. Results from the application of MC model indicate over prediction in the initial stages of excavation and underprediction in the final stages, both for wall deflection and ground settlement. The SS model generally over predicts wall deflection andground settlement, moreover, the peak of settlement curves is further from the wall and also the pattern of wall deflection in the first stages isnot cantilever. The HS model under predicts both wall deflection and ground settlement in the final stages and over predicts ground settlementin the initial stages, however, in the initial stages the wall deflection is predicted with acceptable accuracy and almost the same deflectionpattern as the field observations. Furthermore, the peak of the settlement curves is similar to the field measurements. With a change in Prefparameter of the HS model in proportion to the effective stress in depth, the results become closer to those measured in the field. Therefore, it canbe inferred that among the three MC, SS and HS models. The hardening soil model can predict excavation-induced movements more accurately. Furthermore, it can be understood that limiting soil behavior to a hypothetic yield surface is the main weakness of most models.

Deep excavation, MC model, SS model, HS model, Finite element method (FEM