A Method to Determine C_v Under Sinusoidal Pore Pressure Distributions

摘要

The coefficient of consolidation (c_v) is traditionally evaluated by fitting experimental settlement-time data to the theoretical percentage consolidation-time factor curve of a layer subjected to a uniform initial excess pore water pressure (u_i) distribution. Over the years, numerous curve-fitting techniques have been developed for this experimental-theoretical correlation, the most popular of which are Casagrande's logarithm-of-time method and Taylor's square-root time method. These classical curve-fitting techniques have recently been generalized to account for a variety of different u_i distributions. In this paper, basic consolidation principles have been applied in a novel fashion to both standard and tall oedometer tests on two clays to simulate a sinusoidal u_i distribution (operating under either singly or doubly drained conditions) within a laboratory setting. The settlement-time data obtained from these tests were analyzed using the modified curve-fitting procedures previously put forward by the authors to determine appropriate values for c_v, which were found to closely align with values of c_v obtained using the traditional Taylor and Casagrande methods, when the u_i, distribution is considered uniform. The most valuable feature of these modified curve-fitting techniques was found to be their ability to analyze traditionally obtained settlement-time data to supplement any conventionally obtained c_v values. This is useful in terms of validation when settlement-time data do not exhibit the usual trends and traditionally calculated values of c_v require further authentication.