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| DETERMINATION METHOD OF MODULUS OF UNSATURATED SUBGRADE SOIL |
| HU Mengling1，YU Xianghong2，YAO Hailin1，LIU Jie1，WU Wanping2 |
| (1. State Key Laboratory of Geomechanics and Geomechanical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；2. CCCC Second Highway Consultants Co.，Ltd.，Wuhan，Hubei 430056，China) |
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Abstract Based on the basic variation characteristics of void ratio and water content with net stress and matric suction，the relationships of void ratio and water content with net stress and matric suction are established. Combined with constitutive relation of unsaturated soil，elastic moduli and ，and volumetric moduli and in the form of net stress and matric suction，as well as water content are obtained. Then void ratio-net stress-matric suction 3D surface and volumetric water content-net stress-matric suction 3D surface are fitted with experiment data；and the parameters in the relationships of elastic moduli and ，and volumetric moduli and with net stress and water content are obtained. The influences of net stress and water content on the four moduli are analyzed. The analysis results are as follows：Under a certain net stress，modulus E decreases with the increase of mass water content；the larger the net stress，the more significant the decrease of modulus E with the increase of mass water content；under a certain mass water content，the larger the net stress，the larger the modulus E. Modulus H decreases monotonously with the increase of mass water content and increases monotonously with the increase of net stress. With the increase of net stress，volumetric water content increases at low mass water content and decreases after the mass water content increases to a certain degree. Under a certain net stress，volumetric water content decreases with the increase of suction；under a certain mass water content，the influence of suction on volumetric water content is weakened by increasing net stress.
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Received: 17 November 2011
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2012, Vol. 31 
