Undrained shear strength gain with consolidation at soft and sensitive soil sites

摘要

Staged construction and ground improvement are two strategies adopted in constructing high embankments at sites underlain by soft and sensitive soils. Usually the gain in shear strengths are estimated from poorly documented local experience database and an elaborate scheme of construction monitoring is implemented to ensure the pace of construction does not lead to remolding and progressive failure. A procedure based on the well known SHANSEP approach has been proposed herein for estimation of undrained shear strength as a function of embankment height and rate of construction. To illustrate its use, the procedure was utilized in predicting the embankment response at three soft soil sites. One of these embankments performed satisfactorily while the others failed during construction. Use of the undrained shear strengths in limit equilibrium slope stability assessments was found to provide results which were in qualitative agreement with the observed embankment behavior.