两种应力路径下非饱和污染土强度与微观结构研究
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摘要
以非饱和CH_3COOH污染黏土为研究对象,完成不同基质吸力下加压和减压两种应力路径的三轴试验,得到了强度参数和强度公式,并利用扫描电镜(SEM)观测污染黏土微观结构,分析污染黏土微观结构的变化特征.发现非饱和土的基质吸力可增大土体内聚力和内摩擦角;常规三轴试验与减压三轴试验的应力-应变曲线呈现出不同的强度变化规律;基质吸力由小变大,黏土颗粒分布的均匀性变差,孔隙尺寸从大孔向中孔再向小孔逐渐过渡,说明基质吸力可促进土体固结;基质吸力的增加对减压路径下土体抗剪强度的提高效果优于对加压路径下的影响.
This paper takes the CH_3COOH polluted clay as the research object,three axis test in the two stress paths of compression and decompression under different matrix suction was carried.And scanning electron microscope(SEM) was used to observe the microstructure of contaminated clay,the change characteristics of the microstructure of contaminated clay were analyzed.Research results showed that:The suction strength of unsaturated soil can be increased by increasing the cohesion and internal friction angle of soil;The stress-strain curves of the conventional three axial test and the decompression three axial test have different strength variation law;Matrix suction decreases,the uniformity of the clay particle distribution changes weaker,total pore becomes less,the size changes gradually from big hole to median hole to small hole;Suction can promote soil consolidation;The increase of matrix suction on the shear strength of soil under the decompression path is better than that under the pressure path.
This paper takes the CH_3COOH polluted clay as the research object,three axis test in the two stress paths of compression and decompression under different matrix suction was carried.And scanning electron microscope(SEM) was used to observe the microstructure of contaminated clay,the change characteristics of the microstructure of contaminated clay were analyzed.Research results showed that:The suction strength of unsaturated soil can be increased by increasing the cohesion and internal friction angle of soil;The stress-strain curves of the conventional three axial test and the decompression three axial test have different strength variation law;Matrix suction decreases,the uniformity of the clay particle distribution changes weaker,total pore becomes less,the size changes gradually from big hole to median hole to small hole;Suction can promote soil consolidation;The increase of matrix suction on the shear strength of soil under the decompression path is better than that under the pressure path.
引文
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[2] Fredlund D G,Rahardjo H.Soil mechanics for unsaturated soils[M].New York:John Wiley and Sons,1993
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[4] Saadi Z,Maslouhi A.Modeling nitrogen dynamics in unsaturated soils for evaluating nitrate contamination of the Mnasra groundwater[J].Advances in Environmental Research,2003,7(4):803-823
[5] Wong R C K.Effects of clay content and temperature on crude oil (nonvolatile components) transport in unsaturated soils:Centrifuge study[J].Journal of Environmental Engineering,2005,131(10):1473-1478
[6] Romero E,Simms P H.Microstructure investigation in unsaturated soils:A review with special attention to contribution of mercury intrusion porosimetry and environmental scanning electron microscopy[J].Geotechnical and Geological Engineering,2008,26(6):705-727
[7] 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):201-272 Chen Zhenghan.On basic theories of unsaturated soils and special soils[J].Chinese Journal of Geotechnical Engineering,2014,36(2):201-272
[8] 黄勇,刘干斌,祁良,等.不同温度下饱和软黏土应力路径试验研究[J].水文地质工程地质,2016,43(2):83-87 Huang Yong,Liu Ganbin,Qi Liang,et al.Experimental study of the stress path of saturated soft clay under different temperatures[J].Hydrogeology & Engineering Geology,2016,43(2):83-87
[9] 章峻豪,陈正汉,赵娜,等.非饱和土的新非线性模型及其应用[J].岩土力学,2016,37(3):616-624 Zhang Junhao,Chen Zhenghan,Zhao Na,et al.A new nonlinear model of unsaturated soils and its application[J].Rock and Soil Mechanics,2016,37(3):616-624
[10] 黄润秋,吴礼舟.非饱和土抗剪强度的研究[J].成都理工大学学报(自然科学版),2007,34(3):221-224 Huang Runqiu,Wu Lizhou.Study on the shear strength of unsaturated expansive soils[J].Journal of Chengdu University of Technology(Science & Technology Edition),2007,34(3):221-224
[11] 胡波,汪稔,王钊,等.非饱和土强度公式的比较研究[J].岩土力学与工程学报,2008,27(增1):3005-3009 Hu Bo,Wang Ren,Wang Zhao,et al.Research on comparison of strength equations of unsaturated soil[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(S1):3005-3009
[12] 李万双,孙德安,高游.土水特征曲线预测非饱和黏土的抗剪强度[J].上海大学学报(自然科学版),2016,22(5):648-655 Li Wanshuang,Sun Dean,Gao You.Predicting shear strength of unsaturated clay using soil-water characteristic curve[J].Journal of Shanghai University(Natural Science),2016,22(5):648-655
[13] 叶为民,陈宝,卞祚庥,等.上海软土的非饱和三轴强度[J].岩土工程学报,2006,23(3):317-321 Ye Weimin,Chen Bao,Bian Zuoxiu,et al.Tri-axial shear strength of Shanghai unsaturated soft clay[J].Chinese Journal of Geotechnical Engineering,2006,23(3):317-321
[14] 宋友建,胡新丽,郭利娜,等.吸力路径对非饱和土力学性质的影响[J].水文地质工程地质,2013,40(5):64-68 Song Youjian,Hu Xinli,Guo Lina,et al.Effect of suction path on mechanical behaviors of unsaturated soils[J].Hydrogeology & Engineering Geology,2013,40(5):64-68
[15] 秦立科,李云璋,胡伟.非饱和黄土结构性定量试验研究[J].岩土力学,2011,32(增1):265-269 Qin Like,Li Yunzhang,Hu Wei.Experimental study of the structural parameter of unsaturated loess[J].Rock and Soil Mechanics,2011,32(S1):265-269
[16] 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 Dang Jinqian,Li Jing.Strength characteristics of unsaturated loess[J].Chinese Journal of Geotechnical Engineering,1997,19(2):56-61
[17] 党进谦,李靖.非饱和黄土的结构强度与剪切强度[J].水利学报,2001,(7):79-90 Dang Jinqian,Li Jing.The structural strength and shear strength of unsaturated loess[J].Shuili Xuebao,2001,(7):79-90
[18] 刘小文,叶云雪.不同影响因素下非饱和红土土-水特征曲线的试验研究[J].水文地质工程地质,2015,42(2):97-104 Liu Xiaowen,Ye Yunxue.Experimental study of the soil-water characteristic curve of unsaturated laterite under different affecting factors[J].Hydrogeology & Engineering Geology,2015,42(2):97-104
[19] 陈伟,李文平,刘强强,等.陕北非饱和红土-水特征曲线试验研究[J].工程地质学报,2014,22(2):341-347 Chen Wei,Li Wenping,Liu Qianqiang,et al.Experimental research on soil-water characteristics curves of unsaturated laterite in northern shaanxi province[J].Journal of Engineering Geology,2014,22(2):341-347
[20] 孔令伟,周葆春,白颢,等.荆门非饱和膨胀土的变形与强度特性试验研究[J].岩土力学,2010,31(10):3036-3042 Kong Lingwei,Zhou Baochun,Bai Hao,et al.Experimental study of deformation and strength characteristics of Jingmen unsaturated expansive soil[J].Rock and Soil Mechanics,2010,31(10):3036-3042
[21] 汪明武,朱其坤,朱宇,等.基于非对称联系云的膨胀土和改良土胀缩性评价[J].应用基础与工程科学学报,2017,25(1):162-170 Wang Mingwu,Zhu Qikun,Zhu Yu,et al.Shrinkage-swelling evaluation of untreated and lime-treated expansive clays based on the asymmetric connection cloud model[J].Journal of Basic Science and Engineering,2017,25(1):162-170
[22] 陈振新,孙德安.非饱和上海软土的土-水和变形特性[J].上海大学学报(自然科学版),2012,18(1):98-103 Chen Zhenxin,Sun Dean.Soil- water and deformation characteristics of unsaturated shanghai soft clays[J].Journal of Shanghai University(Natural Science),2012,18(1):98-103
[23] 叶为民,朱悦铭,陈宝,等.上海软土非饱和压缩特征[J].同济大学学报(自然科学版),2011,39(10):1458-1462 Ye Weimin,Zhu Yueming,Chen Bao,et al.Compressibility of shanghai unsaturated soft soil[J].Journal of Tongji University(Natural Science),2011,39(10):1458-1462
[24] 吴礼舟,许强,黄润秋.非饱和黏土的冻胀融沉过程分析[J].岩土力学,2011,32(4):1025-1028 Wu Lizhou,Xu Qiang,Huang Runqiu.Analysis of freezing-thawing test process of unsaturated clay[J].Rock and Soil Mechanics,2011,32(4):1025-1028
[25] 王勇.压实非饱和粘土层生活源污染质运移及其效应[D].徐州:中国矿业大学,2014:1-156 Wang Yong.Life source pollutant migration and its inducing effects in unsaturated compacted clay layer[D].Xuzhou:China University of Mining and Technology,2014:1-156
[26] 霍攀.两种应力路径的非饱和CH3COOH污染土强度与变形研究[D].徐州:中国矿业大学,2015:1-76 Huo Pan.Study on the strength and deformation of unsaturated CH3COOH polluted clay under two stress paths[D].Xuzhou:China University of Mining and Technology,2015:1-76
[27] 蒋引珊,金为群,权新君,等.粘土矿物酸溶解反应特征[J].长春科技大学学报,1999,29(1):97-100 Jiang Yinshan,Jin Weiqun,Quan Xinjun,et al.The characteristic of acid dissolution reaction on clay minerals[J].Journal of Changchun University of Science and Technology,1999,29(1):97-100
[28] 伍三民.粘土矿物在稀硫酸和碳酸钠浸出中的行为[J].铀矿冶,1990,9(2):1-8 Wu Sanmin.Behaviors of clay minerals in dilute sulphuric acid and sodium carbonate leaching[J].Uranium Mining and Metallurgy,1990,9(2):1-8
[2] Fredlund D G,Rahardjo H.Soil mechanics for unsaturated soils[M].New York:John Wiley and Sons,1993
[3] Stephens D B.Hydraulic conductivity assessment of unsaturated soils[C].Tbe Symposium on Hydraulic Conductivity and Waste Contaminant Transport in Soil.San Antonio,TX,USA:ASTM,Jam 21-22,1993
[4] Saadi Z,Maslouhi A.Modeling nitrogen dynamics in unsaturated soils for evaluating nitrate contamination of the Mnasra groundwater[J].Advances in Environmental Research,2003,7(4):803-823
[5] Wong R C K.Effects of clay content and temperature on crude oil (nonvolatile components) transport in unsaturated soils:Centrifuge study[J].Journal of Environmental Engineering,2005,131(10):1473-1478
[6] Romero E,Simms P H.Microstructure investigation in unsaturated soils:A review with special attention to contribution of mercury intrusion porosimetry and environmental scanning electron microscopy[J].Geotechnical and Geological Engineering,2008,26(6):705-727
[7] 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):201-272 Chen Zhenghan.On basic theories of unsaturated soils and special soils[J].Chinese Journal of Geotechnical Engineering,2014,36(2):201-272
[8] 黄勇,刘干斌,祁良,等.不同温度下饱和软黏土应力路径试验研究[J].水文地质工程地质,2016,43(2):83-87 Huang Yong,Liu Ganbin,Qi Liang,et al.Experimental study of the stress path of saturated soft clay under different temperatures[J].Hydrogeology & Engineering Geology,2016,43(2):83-87
[9] 章峻豪,陈正汉,赵娜,等.非饱和土的新非线性模型及其应用[J].岩土力学,2016,37(3):616-624 Zhang Junhao,Chen Zhenghan,Zhao Na,et al.A new nonlinear model of unsaturated soils and its application[J].Rock and Soil Mechanics,2016,37(3):616-624
[10] 黄润秋,吴礼舟.非饱和土抗剪强度的研究[J].成都理工大学学报(自然科学版),2007,34(3):221-224 Huang Runqiu,Wu Lizhou.Study on the shear strength of unsaturated expansive soils[J].Journal of Chengdu University of Technology(Science & Technology Edition),2007,34(3):221-224
[11] 胡波,汪稔,王钊,等.非饱和土强度公式的比较研究[J].岩土力学与工程学报,2008,27(增1):3005-3009 Hu Bo,Wang Ren,Wang Zhao,et al.Research on comparison of strength equations of unsaturated soil[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(S1):3005-3009
[12] 李万双,孙德安,高游.土水特征曲线预测非饱和黏土的抗剪强度[J].上海大学学报(自然科学版),2016,22(5):648-655 Li Wanshuang,Sun Dean,Gao You.Predicting shear strength of unsaturated clay using soil-water characteristic curve[J].Journal of Shanghai University(Natural Science),2016,22(5):648-655
[13] 叶为民,陈宝,卞祚庥,等.上海软土的非饱和三轴强度[J].岩土工程学报,2006,23(3):317-321 Ye Weimin,Chen Bao,Bian Zuoxiu,et al.Tri-axial shear strength of Shanghai unsaturated soft clay[J].Chinese Journal of Geotechnical Engineering,2006,23(3):317-321
[14] 宋友建,胡新丽,郭利娜,等.吸力路径对非饱和土力学性质的影响[J].水文地质工程地质,2013,40(5):64-68 Song Youjian,Hu Xinli,Guo Lina,et al.Effect of suction path on mechanical behaviors of unsaturated soils[J].Hydrogeology & Engineering Geology,2013,40(5):64-68
[15] 秦立科,李云璋,胡伟.非饱和黄土结构性定量试验研究[J].岩土力学,2011,32(增1):265-269 Qin Like,Li Yunzhang,Hu Wei.Experimental study of the structural parameter of unsaturated loess[J].Rock and Soil Mechanics,2011,32(S1):265-269
[16] 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 Dang Jinqian,Li Jing.Strength characteristics of unsaturated loess[J].Chinese Journal of Geotechnical Engineering,1997,19(2):56-61
[17] 党进谦,李靖.非饱和黄土的结构强度与剪切强度[J].水利学报,2001,(7):79-90 Dang Jinqian,Li Jing.The structural strength and shear strength of unsaturated loess[J].Shuili Xuebao,2001,(7):79-90
[18] 刘小文,叶云雪.不同影响因素下非饱和红土土-水特征曲线的试验研究[J].水文地质工程地质,2015,42(2):97-104 Liu Xiaowen,Ye Yunxue.Experimental study of the soil-water characteristic curve of unsaturated laterite under different affecting factors[J].Hydrogeology & Engineering Geology,2015,42(2):97-104
[19] 陈伟,李文平,刘强强,等.陕北非饱和红土-水特征曲线试验研究[J].工程地质学报,2014,22(2):341-347 Chen Wei,Li Wenping,Liu Qianqiang,et al.Experimental research on soil-water characteristics curves of unsaturated laterite in northern shaanxi province[J].Journal of Engineering Geology,2014,22(2):341-347
[20] 孔令伟,周葆春,白颢,等.荆门非饱和膨胀土的变形与强度特性试验研究[J].岩土力学,2010,31(10):3036-3042 Kong Lingwei,Zhou Baochun,Bai Hao,et al.Experimental study of deformation and strength characteristics of Jingmen unsaturated expansive soil[J].Rock and Soil Mechanics,2010,31(10):3036-3042
[21] 汪明武,朱其坤,朱宇,等.基于非对称联系云的膨胀土和改良土胀缩性评价[J].应用基础与工程科学学报,2017,25(1):162-170 Wang Mingwu,Zhu Qikun,Zhu Yu,et al.Shrinkage-swelling evaluation of untreated and lime-treated expansive clays based on the asymmetric connection cloud model[J].Journal of Basic Science and Engineering,2017,25(1):162-170
[22] 陈振新,孙德安.非饱和上海软土的土-水和变形特性[J].上海大学学报(自然科学版),2012,18(1):98-103 Chen Zhenxin,Sun Dean.Soil- water and deformation characteristics of unsaturated shanghai soft clays[J].Journal of Shanghai University(Natural Science),2012,18(1):98-103
[23] 叶为民,朱悦铭,陈宝,等.上海软土非饱和压缩特征[J].同济大学学报(自然科学版),2011,39(10):1458-1462 Ye Weimin,Zhu Yueming,Chen Bao,et al.Compressibility of shanghai unsaturated soft soil[J].Journal of Tongji University(Natural Science),2011,39(10):1458-1462
[24] 吴礼舟,许强,黄润秋.非饱和黏土的冻胀融沉过程分析[J].岩土力学,2011,32(4):1025-1028 Wu Lizhou,Xu Qiang,Huang Runqiu.Analysis of freezing-thawing test process of unsaturated clay[J].Rock and Soil Mechanics,2011,32(4):1025-1028
[25] 王勇.压实非饱和粘土层生活源污染质运移及其效应[D].徐州:中国矿业大学,2014:1-156 Wang Yong.Life source pollutant migration and its inducing effects in unsaturated compacted clay layer[D].Xuzhou:China University of Mining and Technology,2014:1-156
[26] 霍攀.两种应力路径的非饱和CH3COOH污染土强度与变形研究[D].徐州:中国矿业大学,2015:1-76 Huo Pan.Study on the strength and deformation of unsaturated CH3COOH polluted clay under two stress paths[D].Xuzhou:China University of Mining and Technology,2015:1-76
[27] 蒋引珊,金为群,权新君,等.粘土矿物酸溶解反应特征[J].长春科技大学学报,1999,29(1):97-100 Jiang Yinshan,Jin Weiqun,Quan Xinjun,et al.The characteristic of acid dissolution reaction on clay minerals[J].Journal of Changchun University of Science and Technology,1999,29(1):97-100
[28] 伍三民.粘土矿物在稀硫酸和碳酸钠浸出中的行为[J].铀矿冶,1990,9(2):1-8 Wu Sanmin.Behaviors of clay minerals in dilute sulphuric acid and sodium carbonate leaching[J].Uranium Mining and Metallurgy,1990,9(2):1-8