Consolidation for Radial Drainage under Time-Dependent Loading

This paper presents the investigation of consolidation for radial drainage under linear time-dependent loading with varying loading-dependent coefficients of radial consolidation by using a viscoelastic approach. By extending Barron’s solution for radial consolidation of small strain sustained constant load, the convolution integral with time as the variable was used to analyze the consolidation under time-dependent loading. Four different loading rates were applied in the consolidation tests on three types of remolded clay with various plasticity indices to study the behavior of radial consolidation. The variation of the coefficient of radial consolidation versus effective stress was determined by explicitly performing falling head radial permeability tests at various loading stages in a modified consolidometer through a series of radial consolidation tests. The aforementioned relationship was converted to the coefficient of radial consolidation with the loading time of the corresponding pressure applied to the specimen for each specific loading rate test. The convolution integral of the viscoelastic theory was then applied for the prediction of consolidation settlement versus time for each loading rate test. The findings indicated that the viscoelastic settlement prediction, in terms of the average degree of radial consolidation using the loading-dependent coefficients of radial consolidation, is more consistent with the experimental results compared with those when assuming a constant coefficient of radial consolidation.