非饱和土的强度准则及其吸力摩擦角
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摘要
为揭示非饱和土的强度特征和吸力作用机理,根据水气状态和联通特点对非饱和土进行了重新分类。在此基础上,基于球形颗粒数学上的理想排列方式建立了理想非饱和土模型的强度准则。该强度模型以莫尔—库仑准则为基础,与理想排列方式不同饱和阶段的强度特征匹配良好。考虑土颗粒并不是大小一致的球形,且颗粒的级配具有多样性和复杂性等特点后,建立了以基质吸力为参数的连续可导的强度公式,并进一步给出了与非饱和性相关的吸力摩擦角及其发展规律。研究表明,吸力摩擦角随吸力的增加而增加并逐渐趋近于其渐近线。
In order to discover strength character and suction effect,unsaturated soils are reclassified according to water & air state and connectivity features.Furthermore,the strength model of ideal unsaturated soils is established based on ideal spherical particles arranged in a particular way. It bases on the Mohr Coulomb criterion and corresponds to the various stages of saturation for ideal unsaturated soils,Considering the nonuniformity of the actual soil particle size,the irregularities of particle shape,the diversity of the particle size distribution and the complexity of the particle mineralcomposition,a continuous and differentiable strength equation of unsaturated soils is set up with matric suction as parameters. And further,the suction friction angle that is related to unsaturated characteristics and its law of development are given. The researchers indicated that suction friction angle increases with the increase of the suction and gradually approaches its horizontal asymptote.
In order to discover strength character and suction effect,unsaturated soils are reclassified according to water & air state and connectivity features.Furthermore,the strength model of ideal unsaturated soils is established based on ideal spherical particles arranged in a particular way. It bases on the Mohr Coulomb criterion and corresponds to the various stages of saturation for ideal unsaturated soils,Considering the nonuniformity of the actual soil particle size,the irregularities of particle shape,the diversity of the particle size distribution and the complexity of the particle mineralcomposition,a continuous and differentiable strength equation of unsaturated soils is set up with matric suction as parameters. And further,the suction friction angle that is related to unsaturated characteristics and its law of development are given. The researchers indicated that suction friction angle increases with the increase of the suction and gradually approaches its horizontal asymptote.
引文
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[2] FREDLUND D G,MORGENSTERN N R,WILDGER R A. The shear strength of unsaturated soils[J]. Can Geotech J,1978,15(3):313-321.
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[4]赵成刚,蔡国庆.非饱和土广义有效应力原理[J].岩土力学,2009,30(11):3232-3236.
[5]刘艳,韦昌富,房倩,等.非饱和土水—力本构模型及其隐式积分算法.岩土力学,2014,35(2):365-406.
[6]龚壁卫,周小文,周武华.干—湿循环过程中吸力与强度关系研究[J].岩土工程学报,2006,28(2):207-209.
[7]吴丽君,蒋关鲁,李安洪,等.控制基质吸力的非饱和粉质粘土固结试验研究[J].水文地质工程地质,2009,36(4):66-70.
[8]卢肇钧,吴肖茗,孙玉珍,等.膨胀力在非饱和土强度理论中的应用[J].岩土工程学报,1997,19(5):20-27.
[9]缪林昌,殷宗泽.非饱和土的剪切强度[J].岩土力学,1999,20(3):1-6.
[10]党进谦,李靖.非饱和黄土的强度特征[J].岩土工程学报,1997,19(2):56-61.
[11]汤连生.从粒间吸力特性再认识非饱和土抗剪强度理论[J].岩土工程学报,2001,23(4):412-417.
[12]姚志华,连杰,陈正汉,等.考虑细观结构演化的非饱和Q3原状黄土弹塑性本构模型[J].岩土力学,2018,39(5):1553-1562.
[13]栾茂田,李顺群,杨庆.非饱和土的基质吸力和张力吸力[J].岩土工程学报,2006,28(7):863-868.
[14] FREDLUND D G,RAHARDJO H.非饱和土土力学[M].陈仲颐,张在明,陈愈炯,等译.北京:中国建筑工业出版社,1997.
[15]俞培基,陈愈炯.非饱和土的水气形态及其力学性质的关系[J].水利学报,1965(1):16-23.
[16]包承纲.非饱和土的性状及膨胀土边坡稳定问题[J].岩土工程学报,2004,26(1):1-15.
[17] BARDEN L. Consolidation of compacted and unsaturated clays[J]. Geotechnique,1965,15(3):267-286.
[2] FREDLUND D G,MORGENSTERN N R,WILDGER R A. The shear strength of unsaturated soils[J]. Can Geotech J,1978,15(3):313-321.
[3]陈正汉.非饱和土与特殊土力学的基本理论研究[J].岩土工程学报,2014,36(2):201-271.
[4]赵成刚,蔡国庆.非饱和土广义有效应力原理[J].岩土力学,2009,30(11):3232-3236.
[5]刘艳,韦昌富,房倩,等.非饱和土水—力本构模型及其隐式积分算法.岩土力学,2014,35(2):365-406.
[6]龚壁卫,周小文,周武华.干—湿循环过程中吸力与强度关系研究[J].岩土工程学报,2006,28(2):207-209.
[7]吴丽君,蒋关鲁,李安洪,等.控制基质吸力的非饱和粉质粘土固结试验研究[J].水文地质工程地质,2009,36(4):66-70.
[8]卢肇钧,吴肖茗,孙玉珍,等.膨胀力在非饱和土强度理论中的应用[J].岩土工程学报,1997,19(5):20-27.
[9]缪林昌,殷宗泽.非饱和土的剪切强度[J].岩土力学,1999,20(3):1-6.
[10]党进谦,李靖.非饱和黄土的强度特征[J].岩土工程学报,1997,19(2):56-61.
[11]汤连生.从粒间吸力特性再认识非饱和土抗剪强度理论[J].岩土工程学报,2001,23(4):412-417.
[12]姚志华,连杰,陈正汉,等.考虑细观结构演化的非饱和Q3原状黄土弹塑性本构模型[J].岩土力学,2018,39(5):1553-1562.
[13]栾茂田,李顺群,杨庆.非饱和土的基质吸力和张力吸力[J].岩土工程学报,2006,28(7):863-868.
[14] FREDLUND D G,RAHARDJO H.非饱和土土力学[M].陈仲颐,张在明,陈愈炯,等译.北京:中国建筑工业出版社,1997.
[15]俞培基,陈愈炯.非饱和土的水气形态及其力学性质的关系[J].水利学报,1965(1):16-23.
[16]包承纲.非饱和土的性状及膨胀土边坡稳定问题[J].岩土工程学报,2004,26(1):1-15.
[17] BARDEN L. Consolidation of compacted and unsaturated clays[J]. Geotechnique,1965,15(3):267-286.