Soil Model Effects on Deep Excavations Analysis

Abstract

Nowadays, excavation is considered as one of the sensitive and important steps of urban construction that engineers are always attempting to analyze, design, and construct it by selecting various methods. The importance of this subject is conspicuous when the analysis of displacement and deformations around the excavation is necessary according to the national building regulation due to the presence of buildings in this area, which are of high sensitivity to asymmetric settlement. Therefore, in addition to the stability analysis of excavation, engineers are also dealing with the assessment and prediction of deformations and displacements of its surrounding by using geotechnical site specifications, excavation geometry, surrounding overloads, and simulating the excavations stages. The analysis of displacement and deformation is highly dependent to the constitutive soil model and the use of an appropriate model that imitates the actual behavior of the soil is of significant importance in the simulation of soil behavior in numerical software. In the present study, a comparison investigated between the results obtained from hardening-soil and Mohr-Coulomb constitutive models for a case study of a 16.5m deep excavation in Tehran city with the numerical method of finite element analysis. The results show that the soil behavior and the excavation operations induced displacements are more similar to the reality if the hardening-soil constitutive model is selected compared to the Mohr-Coulomb constitutive model.