A formula to predict the effect of the variable discharge capacity of prefabricated vertical drains Available to Purchase

ABSTRACT: An empirical formula that relates the discharge capacity of prefabricated vertical drains to the consolidation time and the confining pressure around the drains is proposed in this paper. Firstly, the performance of the formula is analysed based on laboratory and field data published previously. The proposed formula is included in a three-dimensional code, which is used to analyse the behaviour of an embankment built on a soft soil improved with prefabricated vertical drains and to consider the hypotheses of infinite, reduced and variable discharge capacity of the vertical drains. The results of the numerical predictions are compared with field data, in terms of settlement, horizontal displacement and excess pore pressure. In general, the results show that the use of the formula proposed (with suitable parameters) improves the numerical predictions of the settlement and the excess pore pressure during the intermediate phases of consolidation. In terms of the horizontal displacement, the effect of the discharge capacity of the vertical drains appears negligible. The results also reveal some consistency of the parameters in the formula, as the parameters evaluated from experimental data provide the best numerical predictions.