ISSN: 0149-6115
Published Online: 27 April 2009
Page Count: 10

Critical Evaluation of Determining Swelling Pressure by Swell-Load Method and Constant Volume Method

Nagaraj, H. B.
Assistant Professor,Department of Civil Engineering, BMS College of Engineering,

Munnas, M. Mohammed
Post Graduate Student,Department of Civil Engineering, BMS College of Engineering,

Sridharan, A.
Professor Emeritus,Department of Civil Engineering, Indian Institute of Science,

(Received 31 July 2008; accepted 25 March 2009)

Abstract

For any construction activity in expansive soils, determination of swelling pressure/heave is an essential step. Though many attempts have been made to develop laboratory procedures by using the laboratory one-dimensional oedometer to determine swelling pressure of expansive soils, they are reported to yield varying results. The main reason for these variations could be heterogeneous moisture distribution of the sample over its thickness. To overcome this variation the experimental procedure should be such that the soil gets fully saturated. Attempts were made to introduce vertical sand drains in addition to the top and bottom drains. In this study five and nine vertical sand drains were introduced to experimentally find out the variations in the swell and swelling pressure. The variations in the moisture content at middle, top, and bottom of the sample in the oedometer test are also reported. It is found that swell-load method is better as compared to zero-swell method. Further, five number of vertical sand drains are found to be sufficient to obtain uniform moisture content distribution.

Keywords:
clays, expansive soils, heave, swelling pressure, vertical drains

Paper ID: GTJ102051
DOI: 10.1520/GTJ102051
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