GEOTECHNICAL ASPECTS OF DEEP EXCAVATION IN SOFT CLAY

Abstract

As a summary for the studies made in the previous chapters, two case studies Sukhumvit Subway Station, Bangkok, and State Street Subway, Chicago were reanalysed using the hardening soil small strain model. Then, comparisons between the results of the analysis and the site measurements were applied. The hardening soil stiffness parameter (E50ref ) was calculated using Finno and Calvello (2005). Parametric studies for the Bangkok case study were conducted to clarify the effect of the concrete thermal shrinkage due to hydration processes of the supported slabs, the wall thickness, and the wall-length on the wall deformations. Also, comparisons between different constitutive models were adopted to conclude the difference between each constitutive model on the wall deformations such as Mohr-Coulomb model, Modified Mohr-Coulomb model, Hardening soil model, Hardening soil small strain model, and soft soil model. A study of the Port-said soil from Egypt was processed to investigate the effect of the deep excavation in the soft clay soil, which is extended to depths from the ground surface. Also, the effect of numerical analysis on the two cases like Sukhumvit Subway Station, Bangkok, and Chicago-State Subway, Chicago. Then the analysis results were compared with values estimated from the semi-empirical/empirical methods. 7.2 Conclusion (1) Through the analysis of the two cases studies using the approach proposed by Finno and Calvello (2005) to determine the loading stiffness parameter (E50), the results of the wall deformations