CONTROL OF SWELLING OF SOIL UNDER CANAL LINING BY WETTING AND DRYING CYCLES

In the present research, the effects of cyclic wetting and drying on the swelling potential of clayey soils were investigated. For this purpose, three different clayey samples were collected from three irrigation project sites in Iran. The swelling tests were conducted in oedometer cells, where percent swell was measured in five wetting and drying cycles. To investigate the effects of initial moisture content of the soil on swell potential, the samples were tested at moisture contents at, below and above the shrinkage limit. The results of the experiments showed that for all samples, no matter at what the initial moisture content tested, swelling potential was considerably reduced as a result of the wetting and drying cycles. For some samples, maximum reduction in swelling was observed in the second cycle, while for others it occurred in the third or fourth cycle. Copyright (C) 2012 John Wiley & Sons, Ltd.