A simple approach to predict settlement due to constant rate loading in clays

Abstract

Classical theory of consolidation was conceived considering loads instantaneously applied. Since then, researchers have addressed this issue by suggesting graphical and/or analytical solutions to incorporate different time-depending load schemes. The simplest alternative is to assume a linearly increasing load. Another approach to predict the average degree of consolidation caused by a constant rate loading is based on instantaneous excess pore pressures during and at the end of construction. This technical note explains why and how this approach leads to substantial errors after the end of construction. A corrected solution is then proposed, based on the concept of superposition of effects. The final set of equations agree with the theoretical ones. A new simple approximate methodology is also presented. Numerical examples using the proposed approach showed an excellent agreement with the analytical solution. The validity of this new approach was also proven by reproducing oedometer test results with a good agreement.

Keywords
Consolidation; Settlement prediction; Soft clays; Linearly increasing load