基于不同结构强度软粘土长期强度特性研究
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摘要
天然软粘土一般具有结构性,土的结构性反映其内部颗粒孔隙连结及空间组合,决定了土体的物理力学效应,是软粘土长期强度的重要内在影响因素。为研究结构性强弱不同对软粘土长期强度特性的影响,人工制备含水率相同而结构强度不同的土体,对其进行三轴不固结不排水蠕变试验。试验结果表明,软粘土由于存在结构性,其长期强度具有明显差异。通过对不同结构强度土体蠕变等时曲线进行分析,建立了考虑结构强度影响的软粘土长期强度经验模型。利用本文建立的经验模型,以结构屈服应变(1.9%)作为人工结构性软粘土蠕变变形的破坏准则,结果表明预测值与试验值较为吻合,验证了本文建立的考虑结构强度影响的土体长期强度预测关系式的合理性。
The natural soft clay generally has structure, which is one of the important internal factors affecting the long-term strength of soft clay. And the structural properties of soil can reflect its internal particle pore links and space combination, and determine the physical and mechanical effects of soil. In order to study the effect of structural strength on the long-term deformation property of soft clay, creep tests under unconsolidated-undrained conditions were done on artificial soil with the same moisture content while different structural strengths. And the results show that the long-term deformation property difference is obvious, due to different structural strength of soft clay.The hydrogeology of soil samples is analyzed and studied, and the empirical formula of long-term strength of soft clay with the effect of structural strength is obtained. Using the empirical formula proposed in this paper, the structural yield stress(1.9%) was used as the failure criterion of creep deformation of artificial structural soft clay, the results show that the predicted value was coincident with the test results, and the rationality of the long-term strength prediction formula is verified, which considering the effect of structural strength.
The natural soft clay generally has structure, which is one of the important internal factors affecting the long-term strength of soft clay. And the structural properties of soil can reflect its internal particle pore links and space combination, and determine the physical and mechanical effects of soil. In order to study the effect of structural strength on the long-term deformation property of soft clay, creep tests under unconsolidated-undrained conditions were done on artificial soil with the same moisture content while different structural strengths. And the results show that the long-term deformation property difference is obvious, due to different structural strength of soft clay.The hydrogeology of soil samples is analyzed and studied, and the empirical formula of long-term strength of soft clay with the effect of structural strength is obtained. Using the empirical formula proposed in this paper, the structural yield stress(1.9%) was used as the failure criterion of creep deformation of artificial structural soft clay, the results show that the predicted value was coincident with the test results, and the rationality of the long-term strength prediction formula is verified, which considering the effect of structural strength.
引文
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[4] 孔令伟,张先伟,郭爱国,等.湛江强结构性黏土的三轴排水蠕变特征[J].岩石力学与工程学报,2011,(2):365-372.KONG Lingwei,ZHANG Xianwei,GUO Aiguo,et al.Creep behavior of Zhanjiang strong structured clay by drained triaxial test [J].Chinese Journal of Rock Mechanics and Engineering,2011,(2):365-372.(in Chinese)
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[8] 陈存礼,蒋雪,杨炯,等.结构性对压实黄土侧限压缩特性的影响[J].岩石力学与工程学报,2014,(9):1939-1944.CHEN Cunli,JIANG Xue,YANG Jiong,et al.Influence of soil structure on confined compression behavior of compacted loess [J].Chinese Journal of Rock Mechanics and Engineering,2014,(9):1939-1944.(in Chinese)
[9] 杨爱武,闫澍旺,杜东菊.考虑结构性影响的吹填软土流变历时特性研究[J].工业建筑,2012,42(6):106-111.YANG Aiwu,YAN Shuwang,DU Dongju.Study on rheological diachronic property considering structural characteristics of soft dredger fill [J].Industrial Construction,2012,42(6):106-111.(in Chinese)
[10] 李又云,刘保健,谢永利.软土结构性对渗透及固结沉降的影响[J].岩石力学与工程学报,2006,(S2):3587-3592.LI Youyun,LIU Baojian,XIE Yongli.Influences of permeability and consolidation settlement on structure of soft clay [J].Chinese Journal of Rock Mechanics and Engineering,2006,(S2):3587-3592.(in Chinese)
[11] 沈明荣,谌洪菊.红砂岩长期强度特性的试验研究[J].岩土力学,2011,(11):3301-3305.SHEN Mingrong,CHEN Hongju.Testing study of long-term strength characteristics of red sandstone [J].Rock and Soil Mechanics,2011,(11):3301-3305.(in Chinese)
[12] 杨爱武,张兆杰,孔令伟.不同应力状态下软黏土蠕变特性试验研究[J].岩土力学,2014,(S2):53-60.YANG Aiwu,ZHANG Zhaojie,KONG Lingwei.Experimental study of creep property of soft clay under different stress conditions [J].Rock and Soil Mechanics,2014,(S2):53-60.(in Chinese)
[13] 董卫军.软土流变特性室内试验研究及长期强度的确定[D].河海大学,2007.DONG Weijun.Study on the Laboratory Test of Rheological Characteristic of Soft Clay and Long-Term Strength [D].Hohai University,2007.(in Chinese)
[14] 吴谦.软粘土的结合水对其次固结和长期强度的影响及机理研究[D].吉林大学,2015.WU Qian.Research on Influence of Bond Water on Secondary Consolidation and Long Term Strength of Soft cclay [D].Jilin University,2015.(in Chinese)
[15] 张兆楠.两种软土非线性蠕变特性与长期强度试验研究[D].吉林大学,2015.ZHANG Zhaonan.Experiment Study on Nonlinear Creep Characteristics and Long Term Strength of Two Kinds of Soft Soil [D].Jilin University,2015.(in Chinese)
[2] Leroueil S,Vaughan P R.The general and Congruent effects of structure in natural soil and weak [J].Geotechnique,1990,40(3):467-488.
[3] 曾玲玲.软土的结构性及不同应力路径下的力学特性试验研究[D].暨南大学,2007.ZENG Lingling.Experimental Studies on Structural Properties and Mechanical Behavior Under Different Stress Paths of Soft Soil [J].Jinan University,2007.(in Chinese)
[4] 孔令伟,张先伟,郭爱国,等.湛江强结构性黏土的三轴排水蠕变特征[J].岩石力学与工程学报,2011,(2):365-372.KONG Lingwei,ZHANG Xianwei,GUO Aiguo,et al.Creep behavior of Zhanjiang strong structured clay by drained triaxial test [J].Chinese Journal of Rock Mechanics and Engineering,2011,(2):365-372.(in Chinese)
[5] 陈盼,韦昌富,李永和,等.结构性黏土的压缩变形特性[J].岩土力学,2012,33(2):29-36.CHEN Pan,WEI Changfu,LI Yonghe,et al.Compression deformation characteristics of structural clays [J].Rock and Soil Mechanics,2012,33(2):29-36.(in Chinese)
[6] 陈波,孙德安,吕海波.海相软土压缩特性的试验研究[J].岩土力学,2013,34(2):381-388.CHEN Bo,SUN Dean,LV Haibo.Experimental study of compression behavior of marine soft clays [J].Rock and Soil Mechanics,2013,34(2):381-388.(in Chinese)
[7] 董邑宁,徐日庆,龚晓南.萧山粘土的结构性对渗透性质影响的试验研究[J].大坝观测与土工测试,2000,(6):44-46.DONG Yining,XU Riqing,GONG Xiaonan.Experimental research on effect of Xiaoshan clay structure on its permeability [J].Dam Observation and Geotechnical Tests,2000,(6):44-46.(in Chinese)
[8] 陈存礼,蒋雪,杨炯,等.结构性对压实黄土侧限压缩特性的影响[J].岩石力学与工程学报,2014,(9):1939-1944.CHEN Cunli,JIANG Xue,YANG Jiong,et al.Influence of soil structure on confined compression behavior of compacted loess [J].Chinese Journal of Rock Mechanics and Engineering,2014,(9):1939-1944.(in Chinese)
[9] 杨爱武,闫澍旺,杜东菊.考虑结构性影响的吹填软土流变历时特性研究[J].工业建筑,2012,42(6):106-111.YANG Aiwu,YAN Shuwang,DU Dongju.Study on rheological diachronic property considering structural characteristics of soft dredger fill [J].Industrial Construction,2012,42(6):106-111.(in Chinese)
[10] 李又云,刘保健,谢永利.软土结构性对渗透及固结沉降的影响[J].岩石力学与工程学报,2006,(S2):3587-3592.LI Youyun,LIU Baojian,XIE Yongli.Influences of permeability and consolidation settlement on structure of soft clay [J].Chinese Journal of Rock Mechanics and Engineering,2006,(S2):3587-3592.(in Chinese)
[11] 沈明荣,谌洪菊.红砂岩长期强度特性的试验研究[J].岩土力学,2011,(11):3301-3305.SHEN Mingrong,CHEN Hongju.Testing study of long-term strength characteristics of red sandstone [J].Rock and Soil Mechanics,2011,(11):3301-3305.(in Chinese)
[12] 杨爱武,张兆杰,孔令伟.不同应力状态下软黏土蠕变特性试验研究[J].岩土力学,2014,(S2):53-60.YANG Aiwu,ZHANG Zhaojie,KONG Lingwei.Experimental study of creep property of soft clay under different stress conditions [J].Rock and Soil Mechanics,2014,(S2):53-60.(in Chinese)
[13] 董卫军.软土流变特性室内试验研究及长期强度的确定[D].河海大学,2007.DONG Weijun.Study on the Laboratory Test of Rheological Characteristic of Soft Clay and Long-Term Strength [D].Hohai University,2007.(in Chinese)
[14] 吴谦.软粘土的结合水对其次固结和长期强度的影响及机理研究[D].吉林大学,2015.WU Qian.Research on Influence of Bond Water on Secondary Consolidation and Long Term Strength of Soft cclay [D].Jilin University,2015.(in Chinese)
[15] 张兆楠.两种软土非线性蠕变特性与长期强度试验研究[D].吉林大学,2015.ZHANG Zhaonan.Experiment Study on Nonlinear Creep Characteristics and Long Term Strength of Two Kinds of Soft Soil [D].Jilin University,2015.(in Chinese)