Prof. D. N. Singh

VIKAS KUMAR SINGH THAKUR

M.Tech.
Indian Institute of Technology Bombay, Powai, India vksthakur@rediffmail.com

INSTRUMENTATION FOR MEASURING EXTREMELY HIGH SOIL SUCTION AND ITS APPLICATION

The present study deals with development of a methodology, which helps in measuring extremely high soil suction (?90 MPa) with the help of a Dew point potentiameter and a pressure plate apparatus. Locally available silty soil and commercially available white clay have been used in the study. Based on the obtained results soil water characteristic curve, SWCC, for these soils have been developed and the obtained trends are compared vis-?-vis those obtained by using SoilVision 3.14, a knowledge-based database, which utilizes volume-mass properties and the grain-size distribution of the soil. The study reveals that the dry unit weight of the soil, practically, does not influence its suction parameters such as the air entry value and the residual water content. It has been noted that only Fredlund et al. PTF (Pedo-transfer function) is the most generalized PTF and can be employed to estimate SWCC of all types of soils. Further, to demonstrate usefulness of the study, conventional free swelling and one-dimensional swelling pressure experiments have been conducted to develop a relationship between the swelling pressure and suction of Montmorillonite and Bentonite minerals. The obtained results have been validated using the data reported in the literature. It is believed that such a relationship would be very helpful to field engineers in obtaining swelling pressure of a soil quite easily and in a short duration.