Strength Reduction Method Based on Suction Stress

doi:10.3969/j.issn.1674-0696.2017.03.13

Abstract

Abstract: The deficiency of strength reduction method for unsaturated soil based on Fredlund formula was analyzed； and then the suction stress theory considering physicochemical force and matric suction was introduced.A strength reduction method for unsaturated soil based on suction stress theory was proposed； and the effect of the unsaturated soil strength reduction method based on the Fredlund formula and the suction stress theory was compared and analyzed respectively by using the finite difference software FLAC3D，the reasonableness and accuracy of strength reduction method based on soil suction stress were verified.The results show that the reduction factor based on the suction stress theory is basically the same with one based on Fredlund formula in the range of common matrix suction and slope angle； moreover，the unsaturated soil shear strength reduction method based on the suction stress theory is more in line with the definition of strength reduction，which has a more clear physical meaning.

Key words: geotechnical engineering, suction stress, SWCC, strength reduction, finite difference

摘要： 分析了基于Fredlund公式的非饱和土强度折减法的不足；介绍了考虑物理化学力、基质吸力的吸应力理论；基于吸应力理论提出一种非饱和土强度折减法运用FLAC3D有限差分计算程序，对比分析了分别基于吸应力理论与基于Fredlund公式的非饱和土强度折减法的效果，验证了基于土体吸应力的强度折减法的合理性和准确性。研究结果表明：在常用基质吸力和坡角范围内，基于吸应力理论的土体强度折减系数与基于Fredlund公式所求的折减系数基本相等，且基于吸应力理论的非饱和土抗剪强度折减法更符合强度折减的定义，具有更加清晰的物理意义。

关键词: 岩土工程, 吸应力, 土水特征曲线, 强度折减, 有限差分

CLC Number:

TU433

DENG Yousheng, LIU Huafei, YAO Zhigang, XU Wentao, WU Peng. Strength Reduction Method Based on Suction Stress[J]. Journal of Chongqing Jiaotong University(Natural Science), 2017, 36(3): 79-83.

邓友生，刘华飞，姚志刚，许文涛，吴鹏. 基于土体吸应力的强度折减法[J]. 重庆交通大学学报（自然科学版）, 2017, 36(3): 79-83.

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