Determination of radial coefficient of consolidation using log t method

Vertical drains are extensively used to accelerate the consolidation of soft clay deposits when preloading is used as a ground improvement technique. Barron's theory is widely adopted for the design of vertical drains. The important input parameter required in Barron's solution is the coefficient of radial consolidation (cr) and a rational assessment of cr is necessary for the economic design of vertical drains. Several methods are available for the determination of the coefficient of consolidation (cv) under vertical drainage. However, very few methods were developed for the determination of cr. The √t method and log t method are considered as standard methods and are commonly used in practice for the determination of cv. The utility of √t method for the determination of cr is attempted in the literature. However, no attempt has been made in the literature to use the other standard method, the log t method, for the determination of cr. In this paper, the log t method is proposed for the determination of cr from the time-compression data obtained from consolidation tests under radial drainage. The validity of the method is evaluated by matching the experimental data with the theory and comparing with the existing methods.