Back analysis on deep excavations

Abstract

ABSTRACT:

Back analysis is necessary for further design and construction of deep basement projects in urban areas. This paper is to present two case studies that include 3 basements excavated up-to15m below current street level. Both Hardening Soil model (HSM) and Mohr Coulomb model (MCM) were applied for the analyses of geotechnical aspects. Inclinometers were installed to record diaphragm wall’s deflections before construction. The analysis points out that the horizontal displacement results of the diaphragm wall as indicated by the HSM are closer to the observed data than those given by the calculation using the MCM in both cases. Therefore, using the HSM in analysis of deep excavations is more reliable than the MCM. Furthermore, a correlation between soil stiffness and SPT is strongly recommended for further designs.

Keywords: back analysis; deflection; deep excavations; HSM,;MCM