基于核磁共振技术的软土三轴剪切微观孔隙特征研究

doi:10.13722/j.cnki.jrme.2018.0118

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Abstract In order to investigate the microscopic shear mechanisms of soft soil(muck)，the nuclear magnetic resonance test are conducted on the undisturbed and disturbed Nansha muck before and after triaxial test. The evolutions of size，distribution，and structural characteristic of pore under true triaxial consolidated-undrained shearing are analyzed. The results show that the pores of muck are mainly concentrated in the range of 1 μm to 20 μm，and the main peak amplitude of T2 spectrum is more than 99%，indicating that the pores of muck are of small size and narrow distributed. The water content decreases by 8.79%–17.73%，and the porosity decreases after triaxial test. The percentage of small pore decreases and the medium and large pore rises with the increasing of the strain rate. The percentage of small pore rises and the large pore decreases with the increasing of the strain when the vertical strain is less than the threshold of vertical strain(about 4%). This behavior reverses after the threshold. The pore size and pore structure parameters( ) can be directly measured with NMR，so the relationship between the microstructure parameters and macroscopic mechanical properties (generalized shear stress and generalized shear strain ) can be analyzed.

Key words： soil mechanics soft soil triaxial shearing relaxation time micro-pore structure nuclear magnetic resonance technique

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	LIU Yongjian
	LI Zhangming
	GUO Lingfeng
	KANG Wenwu
	ZHOU Yaoyao

Cite this article:

LIU Yongjian,LI Zhangming,GUO Lingfeng, et al. Pore characteristics of soft soil under triaxial shearing measured with NMR[J]. , 2018, 37(8): 1924-1932.

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http://www.rockmech.org/EN/10.13722/j.cnki.jrme.2018.0118 OR http://www.rockmech.org/EN/Y2018/V37/I8/1924

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