低应力及拉应力条件下非饱和土强度及剪胀特性

doi:10.13722/j.cnki.jrme.2017.1465

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Abstract The strength and dilation behavior of unsaturated compacted soils was investigated via low-stress direct shear and direct tensile tests over a wide range of water contents. The results show that the unsaturated soils with the water content below the plastic limit exhibit the characteristics of strain softening and shear dilation. The peak shear strength，the minimum dilation rate and the uniaxial tensile strength of unsaturated soils over a wide range of water contents increase and then decrease with the increasing of water content similarly. A modified Mohr-Coulomb strength envelope in tensile stress regime for unsaturated soils is proposed based on the test results. It is verified that the revised Bishop's shear strength model predicts the effect of suction on the shear strength poorly，and the reason why this model is popular is analyzed. Finally，it is suggested that the contribution of suction on the peak shear strength can be described in terms of the effect of suction on interparticle tensile stress and shear dilation，in which the suction is the sum of capillary and adsorptive processes，and the interparticle tensile stress is approximated by the uniaxial tensile strength.

Key words： soil mechanics unsaturated soil low stress tensile stress shear strength dilatancy

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	Articles by authors
	XU Xiao1
	2
	CAI Guoqing1
	2
	LI Jian1
	2
	ZHAO Chengang2
	3

Cite this article:

XU Xiao1,2,CAI Guoqing1, et al. The strength and dilatancy characteristics of unsaturated soil at low and tensile stresses[J]. , 2018, 37(8): 1933-1942.

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http://www.rockmech.org/EN/10.13722/j.cnki.jrme.2017.1465 OR http://www.rockmech.org/EN/Y2018/V37/I8/1933

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