不同颗粒级配尾砂稳态强度特性试验研究
|
摘要
颗粒级配是影响土体剪切强度的主要因素之一。通过配置三组不同级配尾砂试样,每组均在100kPa、200kPa、300kPa围压下分别进行不同初始孔隙比的固结不排水剪切试验,研究不同级配下尾砂的剪切特性及稳态强度特性,求出三种级配尾砂的稳态线及稳态内摩擦角。试验结果表明:在低围压时,各级配下饱和松散尾砂的应力-应变曲线呈软化型,且随着围压增高,软化越不明显。平均粒径越小的尾砂,其峰值强度与稳态强度越小,稳态线越靠近e-q坐标系的原点,即在同一荷载作用下,发生液化的可能性越大。为此,有必要加强细粒尾砂堆筑坝体液化势的评估,以防液化溃坝灾难的发生。
Grain size distribution is one of the main factors affecting the soil shear strength. By configuring three groups tailings sand samples with different gradations and initial void ratio,the consolidated undrained shear tests were conducted to study the shear properties and steady strength characteristics,and obtain three steady-state lines and steady-state internal friction angles. The test results showed that the stress-strain curves of saturated loose tailings sand are softening at low confining pressure,with higher confining pressure,the softening is less obvious.When the average particle size is smaller,the peak intensity and the steady state intensity are smaller. The steady state lines are closer to the origin of the e-q coordinate system,i. e.,under the same load,the occurrence likelihood of the liquefaction is greater. For this reason,it is necessary to strengthen liquefaction potential evaluation for the fine tailings dam,in order to prevent the occurrence of liquefaction and dam disaster.
Grain size distribution is one of the main factors affecting the soil shear strength. By configuring three groups tailings sand samples with different gradations and initial void ratio,the consolidated undrained shear tests were conducted to study the shear properties and steady strength characteristics,and obtain three steady-state lines and steady-state internal friction angles. The test results showed that the stress-strain curves of saturated loose tailings sand are softening at low confining pressure,with higher confining pressure,the softening is less obvious.When the average particle size is smaller,the peak intensity and the steady state intensity are smaller. The steady state lines are closer to the origin of the e-q coordinate system,i. e.,under the same load,the occurrence likelihood of the liquefaction is greater. For this reason,it is necessary to strengthen liquefaction potential evaluation for the fine tailings dam,in order to prevent the occurrence of liquefaction and dam disaster.
引文
[1]朱建群,孔令伟,钟方杰.南京砂强度特征与静态液化现象分析[J].岩土力学,2008,29(6):1461-1465ZHU Jian-qun,KONG Ling-wei,ZHONG Fang-jie.Analysis of strength characteristics of Nanjing sand mechanism of static liquefaction[J].Rock and Soil Mechanics,2008,29(6):1461-1465
[2]朱建群,孔令伟,高文华,等.南京砂的稳态特征研究[J].岩土工程学报,2012,34(5):931-935ZHU Jian-qun,KONG Ling-wei,GAO Wen-hua,et al.Steady-state properties of Nanjing sand[J].Chinese Journal of Geotechnical Engineering,2012,34(5):931-935
[3]余湘娟,房震,严蕴,等.震后饱和砂土的液化及边坡稳定问题述评[J].河海大学学报(自然科学版),2003,31(1):72-75YU Xiang-juan,FANG Zhen,YAN Yun,et al.Earthquake-induced liquefaction of saturated sand and slope stability analysis[J].Journal of Hohai University(Natural Sciences),2003,31(1):72-75
[4]蒋明镜,郑敏,刘芳,等.颗粒级配对火山灰力学特性影响的试验研究[J].扬州大学学报(自然科学版),2010,13(1):57-60JIANG Ming-jing,ZHENG Min,LIU Fang,et al.Experiment research on influence of grain size distribution on mechanical properties of volcanic ash in northeast China[J].Journal of Yangzhou University(Natural Science Edition),2010,13(1):57-60
[5]衡朝阳,裘以惠.颗粒级配对含蒙脱石砂土抗液化性能的影响[J].中国矿业大学学报,2002,31(2):138-141HENG Chao-yang,QIU Yi-hui.Experimental research on influence of grain size gradation on anti-liquefaction characteristics of clayey sand with montmorillonite[J].Journal of China University of Mining&Technology,2002,31(2):138-141
[6]刘飞禹,林旭,王军.砂土颗粒级配对筋土界面抗剪特性的影响[J].岩石力学与工程学报,2013,32(12):2575-2582LIU Fei-yu,LIN Xu,WANG Jun.Influence of particlesize gradation on shear behavior of geosynthetics and sand interface[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2575-2582
[7]Esma M K,Mourad M,Nabil A.Contribution of Particles Size Ranges to Sand Friction[J].Engineering,Technology&Applied Science Research,2013,3(4):497-501
[8]Mohammad S P,Ali S M.Effect of Sand Gradation on The Behavior of Sand-Clay Mixtures[J].International Journal of GEOMATE,2012,3(1):325-331
[9]尹光志,张千贵,魏作安,等.尾矿细微观力学与变形观测试验装置的研制与应用[J].岩石力学与工程学报,2011,30(5):926-934YIN Guang-zhi,ZHANG Qian-gui,WEI Zuo-an,et al.Development and application of observation testing apparatus for micromechanics and deformation of tailings[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(5):926-934
[10]Ishihara K.Liquefaction and flow failure during earthquakes[J].Geotechnique,1993,43(3):351-415
[11]甘霖,袁光国.大型高压三轴试验测试及粗粒土的强度特性[J].大坝观测与土工测试,1997,21(3):9-12GAN Lin,YUAN Guang-guo.High pressure large triaxial tests and strength characteristics of coarse-grained soil[J].Dam Observation and Geotechnical Tests,1997,21(3):9-12
[12]赵成刚,尤昌龙.饱和砂土液化与稳态强度[J].土木工程学报,2001,34(3):90-95ZHAO Cheng-gang,YOU Chang-long.Liquefaction and steady strength[J].China Civil Engineering Journal,2001,34(3):90-95
[13]潘建平,孔宪京,邹德高.尾矿坝地震液化稳定的简化分析[J].水利学报,2006,37(10):1224-1229PAN Jian-ping,KONG Xian-jing,ZOU De-gao.Simplified analysis of liquefaction and stability of tailing dam during earthquake[J].Shuili Xuebao,2006,37(10):1224-1229
[14]潘建平,刘湘平,朱洪威,等.尾矿坝地震液化评价可靠度模型及应用[J].中国安全生产科学技术,2013,9(2):23-28PAN Jian-ping,LIU Xiang-ping,ZHU Hong-wei,et al.Reliability model of seismic liquefaction evaluation for tailings dam and its application[J].Journal of Safety Science and Technology,2013,9(2):23-28
[2]朱建群,孔令伟,高文华,等.南京砂的稳态特征研究[J].岩土工程学报,2012,34(5):931-935ZHU Jian-qun,KONG Ling-wei,GAO Wen-hua,et al.Steady-state properties of Nanjing sand[J].Chinese Journal of Geotechnical Engineering,2012,34(5):931-935
[3]余湘娟,房震,严蕴,等.震后饱和砂土的液化及边坡稳定问题述评[J].河海大学学报(自然科学版),2003,31(1):72-75YU Xiang-juan,FANG Zhen,YAN Yun,et al.Earthquake-induced liquefaction of saturated sand and slope stability analysis[J].Journal of Hohai University(Natural Sciences),2003,31(1):72-75
[4]蒋明镜,郑敏,刘芳,等.颗粒级配对火山灰力学特性影响的试验研究[J].扬州大学学报(自然科学版),2010,13(1):57-60JIANG Ming-jing,ZHENG Min,LIU Fang,et al.Experiment research on influence of grain size distribution on mechanical properties of volcanic ash in northeast China[J].Journal of Yangzhou University(Natural Science Edition),2010,13(1):57-60
[5]衡朝阳,裘以惠.颗粒级配对含蒙脱石砂土抗液化性能的影响[J].中国矿业大学学报,2002,31(2):138-141HENG Chao-yang,QIU Yi-hui.Experimental research on influence of grain size gradation on anti-liquefaction characteristics of clayey sand with montmorillonite[J].Journal of China University of Mining&Technology,2002,31(2):138-141
[6]刘飞禹,林旭,王军.砂土颗粒级配对筋土界面抗剪特性的影响[J].岩石力学与工程学报,2013,32(12):2575-2582LIU Fei-yu,LIN Xu,WANG Jun.Influence of particlesize gradation on shear behavior of geosynthetics and sand interface[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2575-2582
[7]Esma M K,Mourad M,Nabil A.Contribution of Particles Size Ranges to Sand Friction[J].Engineering,Technology&Applied Science Research,2013,3(4):497-501
[8]Mohammad S P,Ali S M.Effect of Sand Gradation on The Behavior of Sand-Clay Mixtures[J].International Journal of GEOMATE,2012,3(1):325-331
[9]尹光志,张千贵,魏作安,等.尾矿细微观力学与变形观测试验装置的研制与应用[J].岩石力学与工程学报,2011,30(5):926-934YIN Guang-zhi,ZHANG Qian-gui,WEI Zuo-an,et al.Development and application of observation testing apparatus for micromechanics and deformation of tailings[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(5):926-934
[10]Ishihara K.Liquefaction and flow failure during earthquakes[J].Geotechnique,1993,43(3):351-415
[11]甘霖,袁光国.大型高压三轴试验测试及粗粒土的强度特性[J].大坝观测与土工测试,1997,21(3):9-12GAN Lin,YUAN Guang-guo.High pressure large triaxial tests and strength characteristics of coarse-grained soil[J].Dam Observation and Geotechnical Tests,1997,21(3):9-12
[12]赵成刚,尤昌龙.饱和砂土液化与稳态强度[J].土木工程学报,2001,34(3):90-95ZHAO Cheng-gang,YOU Chang-long.Liquefaction and steady strength[J].China Civil Engineering Journal,2001,34(3):90-95
[13]潘建平,孔宪京,邹德高.尾矿坝地震液化稳定的简化分析[J].水利学报,2006,37(10):1224-1229PAN Jian-ping,KONG Xian-jing,ZOU De-gao.Simplified analysis of liquefaction and stability of tailing dam during earthquake[J].Shuili Xuebao,2006,37(10):1224-1229
[14]潘建平,刘湘平,朱洪威,等.尾矿坝地震液化评价可靠度模型及应用[J].中国安全生产科学技术,2013,9(2):23-28PAN Jian-ping,LIU Xiang-ping,ZHU Hong-wei,et al.Reliability model of seismic liquefaction evaluation for tailings dam and its application[J].Journal of Safety Science and Technology,2013,9(2):23-28