Variation of Matric Suction as a Function of Gypseous Soil Dry Density
Engineering and Technology Journal,
2020, Volume 38, Issue 6, Pages 861-868
AbstractGypseous soil is one of the most problematic types of collapsible soils which is affected by many geotechnical factors. The most important factors are the effect of loading and wetting and their relation to soil density, especially when the soil at unsaturation condition. Suction pressure is the main criteria in determining the deformation behaviour of unsaturated collapsible soil when these soils distributed in arid or semi-arid region. In this study, disturbed sample of sandy soil of more than 70% gypsum content is taken from Al-Ramadi city western of Iraq. This study interested to investigate the variation of matric suction with the dry density and their effects on deformation of gypseous soil. For this purpose, a soil-model device provided with high accurate Tensiometers and Time Domain Reflectometry sensors in addition to data logger is designed and manufactured. Tensiometer sensor is used to monitor and measure the matric suction, while the Time Domain Reflectometry is used to monitor and measure the volumetric water content in the soil mass. The results of the tests showed that there is a significant effect of soil dry density on the relationship between the matric suction and water content.
 D. G. Fredlund and H. Rahardjo, “Soil mechanics for unsaturated soils,” New York: John Wiley, 1993.
 C. Ng and B. Menzies, “Advanced unsaturated soil mechanics and engineering,” Taylor & Francis, 2007.
.E. Murray and V. Sivakumar, “Unsaturated Soils,” Wiley-Blackwell, 2010.
 Q. A. J. Al-obaidi, “Hydro-mechanical behaviour of collapsible soils,” PhD. thesis, Ruhr- Universität Bochum, Germany, 2014.
 I. H. Nashat,”Engineering characteristiec of some gypseous soils in Iraq,” PhD. thesis, Civil Engineering Department, University of Baghdad, Iraq, 1990.
 A. A. Al-Mufty “Effect of gypsum dissolution on the mechanical behaviour of gypseous soils,” PhD thesis, Department of Civil Engineering, University of Baghdad, Iraq, 1997.
 Q. A. J. Al-obaidi, “Studies in geotehnical and collapsible characteristics of gypseous soil,” MSc thesis, AL-Mustansiria University, Baghdad, Iraq 2003.
 M. Y. Fattah, A. Y. Yahya, M. Th. Al-Hadidi, B. A. Ahmed, , “Effect of Salt content on total and matric suction of unsaturated soils,"European Scientific Journal, Vol. 9, No. 9, pp. 228-245,2013.
 M. Y. Fattah, M. M. Al-ani, and M. T. A. Al-lamy, “Studying collapse potential of gypseous soil treated by grouting,” Soils Found., vol. 54, no. 3, pp. 396–404, 2014.
 A. A. H. Al-Obaidi, M. Y. Fattah, M. Kh. Al-Dorry, “Variation of suction during wetting of unsaturated collapsible gypseous soils,” International Journal of Engineering & Technology, Vol. 7(4.37), pp. 79 – 85, 2018.
 T. Schanz and H. H. Karim, “Geotechnical characteristics of some Iraqi gypseous soils,” MATEC Web Conf., vol. 162, no. May, 2018.
 FAO Report 1990, “Food and Agricultural Organization of the United Nations,” Bulletin No.62, Rome.
 A. Al-Mufty & I. Nashat, "Gypsum content determination in gypseous soils and rocks," in `Third International Jordanian Conference on Mining, Vol. 2, Amman, Jordan, pp. 485-492, 2000.
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