Intermittent cyclic load induced 1D consolidation settlement

Based on theoretical reasoning and finite element analyses, a simple method for calculating intermittent cyclic load induced one-dimensional (1D) consolidation settlement has been proposed. For an intermittent cyclic load with a period of T, loading time increment Δtl, and a maximum load of q, in most domain, its consolidation induced compression can be calculated in the same way as a static load of qs = q∙Δtl/T. While in a zone near the drainage boundary, the consolidation stress is larger than qs, and is assumed to vary linearly from q, at the drainage boundary, to qs, at a distance (hd) from the drainage boundary. hd can be evaluated by Terzaghi's 1D consolidation theory using a time factor calculated by T. Further it is proposed that the total settlement will be the summation of the consolidation and creep deformations. To verify the proposed method, laboratory 1D consolidation tests with intermittent cyclic loads were conducted and the proposed method was applied to predict the settlement curves. Comparison between the measured and the predicted settlement curves indicates a fair good agreement. It is concluded that the method can be a useful design tool for estimating the consolidation effect of intermittent cyclic loads.