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| STUDY OF EQUIVALENT SUCTION OF UNSATURATED LOESS |
| (Institute of Water Resources and Hydroelectric Engineering，Xi¢an University of Technology，Xi¢an，Shaanxi 710048，China) |
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Abstract As an essential portion of basic framework of soil mechanics，strength theory of saturated soils has been well developed and widely used in geotechnical engineering. However，unsaturated soils have a wide distribution and display more complex behaviours compared with saturated soils in engineering practice. Until now the research activities in the field of unsaturated soils have been still in the academic stage because of the difficulty of suction measurement. To solve this problem，the equivalent suction has been proposed and validated recently. Based on the principle of equivalence of deformation and the stress-strain curves obtained from triaxial compression tests of intact saturated and unsaturated loess，a determination method of equivalent suction is proposed. The nonlinear relationship formula between equivalent suction and degree of saturation is proposed；and the correctness of this exponential function relationship is verified. Based on testing results，the influence of water content on shear strength is analyzed；and shear strength formula of unsaturated soils is established. It provides a new feasible method for application of unsaturated soil theory to engineering practice.
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Received: 02 April 2010
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2010, Vol. 29 
