Document Type : Research Paper


1 Ph.D. student, Civil Engineering Department, University of Technology, Baghdad.

2 Civil Engineering Department, University of Technology, Baghdad

3 civil engineering department, university of technology, Baghdad, Iraq


There are many methods to measure the suction and saturation point of any soil and the most used is Tensiometer. The objective of this research is to investigate a new trend to measure the saturation point and suction by using soil moisture content sensors (SMCS) and compare the procedure with tensiometer for the granular soil. The soil in this study has been prepared at three relative densities (5%, 35% and 75%) used. The results show that the readings of SMCS become stable when the water content is more than 20% with different relative densities. The relative density did not affect the SMCS reading when approximately reaching the saturation point.


[1]  W.R. Gardner (1968). Availability and measurement of soil water. Water Deficits and Plant 524 Growth, 1: 107-135.
[2]   M. Y. Fattah, A. Al-Obaidi, and M. K. Al-Dorri, (2018), Determinationof the Water Characteristic Curve for Unsaturated Gypseous Soil from Model Tests, Journal of Applied Sciences, Vol. 9, pp. 544-551.
[3]   M. Y. Fattah, A. Al-Obaidi, and M. K. Al-Dorri, (2018), Variation of Suction during Wetting of Unsaturated Collapsible Gypseous Soils, International Journal of Engineering & Technology Sciences, Vol. 7, pp. 79-85.
[4]  N. Ganjian, Y.P.Pisheh, S.M.M.M.Hosseini, (2007), Prediction of Soil–Water Characteristic Curve Based on Soil Index Properties, Experimental Unsaturated Soil Mechanics. Springer Proceedings in Physics, vol 112. Springer, Berlin, Heidelberg.
[5]  H. Pan, Y. Qing, L. Pei-yong, (2010) Direct and Indirect Measurement of Soil Suction in the Laboratory, Electronic Journal of Geotechnical Engineering, Vol. 15, Bund A.
[6]  N. Lu, and W.J. Likos, (2004). “Unsaturated Soil Mechanics,” John Wiley & Sons, Inc., Hoboken, New Jersey, USA.
[7]  S. Sreedeep and D.N. Singh, (2011), Critical Review of the Methodologies Employedfor Soil Suction Measurement, International Journal of Geomechanics, ASCE, Vol. 11, pp. 99-104
[8]   M. Y. Fattah, A.Y. Yahya, M.Th.  Al-Hadidi, B.A. Ahmed, (2013), “Effect of Salt Content on Total and Matric Suction of Unsaturated Soils”, European Scientific Journal, Vol. 9, No. 9, pp. 228-245.
[9]  M. Y. Fattah, N.M.Salim, E.J.Irshayyid, (2017), "Influence of Soil Suction on Swelling Pressure of Bentonite-sand Mixtures", European Journal of Environmental and Civil Engineering,, Taylor & Francis.
[10]   T. Maughan, L.N. Allen, and D. Drost, “Soil Moisture Measurement and Sensors for Irrigation Management,” AG/Irrigation/2015-01pr, October, 2015.