Inflection Point Method to Estimate c_h From Radial Consolidation Tests with Peripheral Drain

摘要

Horizontal coefficient of consolidation c_h is a key parameter in the design of vertical drains and the following consolidation analysis of a soil layer. There are graphical and non-graphical methods available to estimate c_h, from laboratory radial consolidation tests with a central drain. Currently, the consolidation tests with peripheral drains have to be analysed through a curve fitting method for determining c_h. In this technical note, a non-graphical inflection point method is proposed for determining c_h for an oedometer test with peripheral drainage, based on the characteristic feature observed when the gradient of the theoretical U_r -log T_r relationship was plotted against T_r The proposed method is validated through a series of consolidation tests on two reconstituted dredged clay specimens, tested in an oedometer subjected to radial drainage with peripheral drains. The consolidation settlements predicted from the proposed method, for the two different clays, were in excellent agreement with those measured in the oedometer. The proposed method will be a very valuable tool in the analysis of radial consolidation data when the drains are peripheral.