原状黄土的压缩曲线特性
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摘要
原状黄土是一种具有结构强度的欠压密土,其侧限压缩变形特性区别于一般土。为研究原状黄土侧限压缩变形的共性,对西安、兰州6个场地不同含水率的原状Q3、Q2黄土进行了侧限压缩试验,得到了相应场地不同含水率原状黄土的压缩曲线,分析了其压缩曲线的形态,通过曲线对应的压缩屈服应力及初始孔隙比,将各黄土不同含水率下的压缩曲线归一化为同一曲线,且形成时代相同的黄土归一化曲线位置相同,并利用复合幂-指数模式分别描述了Q3、Q2黄土归一化的曲线。将文献中试验黄土的初始孔隙比与压缩屈服应力代入归一化曲线的表达式,计算得其压缩曲线和压缩性指标。经对比,与文献实测压缩曲线及压缩性指标很接近,验证了黄土压缩曲线的归一化特性并对其进行了应用。结果表明:试验黄土压缩曲线具有可被其初始孔隙比和压缩屈服应力归一化的特性,此特性为黄土侧限变形性质的分析提供了一条便捷的途径。
Undisturbed loess is a type of under-consolidated soils with structural strength, and its confined compressive deformation characteristic is distinct from those of ordinary soils. To study the general character of confined compression deformation of undisturbed loess, confined compression tests were carried out on Q3 and Q2 undisturbed loess with different water contents sampled from six fields in Xi'an and Lanzhou. The compression curves of undisturbed loess at different water contents from corresponding sites were obtained. The shape of the compression curve was analyzed. Through the compressive yield stress and the initial void ratio corresponding to the curve, the compression curves of tested loess at different water contents were normalized into a same curve, and the positions of the normalized curves of loess with the same sedimentary period were the same. The normalized curves of Q3 and Q2 loess were respectively described by composite power-exponent model. The initial void ratio and compressive yield stress of the loess in the literature were substituted into the expression of normalized curve to calculate the compression curves and compressibility indexes. It was found that the curves tested in literature was close to the compression compressibility indexes, demonstrating the normalized characteristic of loess compression curve and its application value. The test loess compression curve has the characteristics that can be normalized by its initial void ratio and compressive yield stress, which provides a convenient way for the analysis of confined deformation properties of loess.
Undisturbed loess is a type of under-consolidated soils with structural strength, and its confined compressive deformation characteristic is distinct from those of ordinary soils. To study the general character of confined compression deformation of undisturbed loess, confined compression tests were carried out on Q3 and Q2 undisturbed loess with different water contents sampled from six fields in Xi'an and Lanzhou. The compression curves of undisturbed loess at different water contents from corresponding sites were obtained. The shape of the compression curve was analyzed. Through the compressive yield stress and the initial void ratio corresponding to the curve, the compression curves of tested loess at different water contents were normalized into a same curve, and the positions of the normalized curves of loess with the same sedimentary period were the same. The normalized curves of Q3 and Q2 loess were respectively described by composite power-exponent model. The initial void ratio and compressive yield stress of the loess in the literature were substituted into the expression of normalized curve to calculate the compression curves and compressibility indexes. It was found that the curves tested in literature was close to the compression compressibility indexes, demonstrating the normalized characteristic of loess compression curve and its application value. The test loess compression curve has the characteristics that can be normalized by its initial void ratio and compressive yield stress, which provides a convenient way for the analysis of confined deformation properties of loess.
引文
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[10]王丽琴,鹿忠刚,邵生俊.岩土体复合幂-指数非线性模型[J].岩石力学与工程学报,2017,36(5):1269-1278.WANG Li-qin,LU Zhong-gang,SHAO Sheng-jun.Acomposite power exponential nonlinear model of rock and soil[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(5):1269-1278.
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[13]陈立,李靖,王俊卿,等.黄土的结构强度及其与结构屈服压力的关系[J].岩土工程学报,2008,30(6):895-899.CHEN Li,LI Jing,WANG Jun-qing,et al.Relationship between structural strength and structural yield pressure of loess[J].Chinese Journal of Geotechnical Engineering,2008,30(6):895-899.
[14]邵生俊,陶虎,许萍.黄土结构性力学特性研究与应用的探讨[J].岩土力学,2011,32(增刊2):42-50.SHAO Sheng-jun,TAO Hu,XU Ping.Discussion on research of mechanical characteristics of loess considering structural behavior and its application[J].Rock and Soil Mechanics,2011,32(Suppl.2):42-50.
[15]王丽琴,邵生俊,赵聪,等.黄土初始结构性对其压缩屈服的影响研究[J].岩土力学,2018,39(9):3223-3228+3236.WANG Li-qin,SHAO Sheng-jun,ZHAO Cong,et al.Effect of initial structural property of loess on its compressive yield[J].Rock and Soil Mechanics,2018,39(9):3223-3228+3236.
[16]王丽琴,鹿忠刚,邵生俊.黄土非线性应力-应变新模型及对比研究[J].岩土工程学报,2017,39(9):1724-1730.WANG Li-qin,LU Zhong-gang,SHAO Sheng-jun.New nonlinear stress-strain model for loess and its comparative research[J].Chinese Journal of Geotechnical Engineering,2017,39(9):1724-1730.
[17]胡再强,沈珠江,谢定义.非饱和黄土的结构性研究[J].岩石力学与工程学报,2000,19(6):775-779.HU Zai-qiang,SHEN Zhu-jiang,XIE Ding-yi.Research on structural behavior of unsaturated loess[J].Chinese Journal of Rock Mechanics and Engineering,2000,19(6):775-779.
[18]陈存礼,高鹏,胡再强.黄土的增湿变形特性及其与结构性的关系[J].岩石力学与工程学报,2006,25(7):1352-1360.CHEN Cun-li,GAO Peng,HU Zai-qiang.Moistening deformation characteristic of loess and its relation to structure[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(7):1352-1360.
[19]罗宇生.湿陷性黄土地基评价[J].岩土工程学报,1998,20(4):87-92.LUO Yu-sheng.Assessment of collapsibility of collapsible loess foundation[J].Chinese Journal of Geotechnical Engineering,1998,20(4):87-92.
[20]王丽琴,邵生俊.黄土构度与物理指标之间的定量关系[J].岩石力学与工程学报,2015,34(增刊2):4380-4386.WANG Li-qin,SHAO Sheng-jun.Combined Influence of physical properties on the initial structure of loess[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(Suppl.2):4380-4386.
[21]王丽琴,邵生俊,鹿忠刚.物理性质对黄土初始结构性的综合影响研究[J].岩土力学,2017,38(12):3484-3490.WANG Li-qin,SHAO Sheng-jun,LU Zhong-gang.Combined influence of physical properties on the initial structure of loess[J].Rock and Soil Mechanics,2017,38(12):3484-3490.
[22]李大展,何颐华,隋国秀.Q2黄土大面积浸水试验研究[J].岩土工程学报,1993,15(2):1-11.LI Da-zhan,HE Yi-hua,SUI Guo-xiu.Study and test on immersion of Q2 loess in large area[J].Chinese Journal Geotechnical Engineering,1993,15(2):1-11.
[23]刘宁.关中地区某场地自重湿陷性黄土的试验研究[D].西安:长安大学,2007.LIU Ning.Study and test on collapsible loess under overburden pressure in a field of Guanzhong area[D].Xi’an:Chang’an University,2007.
[2]陈存礼,曹程明,王晋婷,等.湿载耦合条件下结构性黄土的压缩变形模式研究[J].岩土力学,2010,31(1):39-45+50.CHEN Cun-li,CAO Cheng-ming,WANG Jin-ting,et al.Modeling compression of structural loess under coupling of stress and moisture[J].Rock and Soil Mechanics,2010,31(1):39-45+50.
[3]张茂花,谢永利,刘保健.增(减)湿时黄土的压缩变形特性分析[J].湖南科技大学学报(自然科学版),2007,22(3):50-55.ZHANG Mao-hua,XIE Yong-li,LIU Bao-jian.Analysis of compression deformation characteristics of loess during moistening and demoistening process[J].Journal of Hunan University of Science&Technology(Natural Science Edition),2007,22(3):50-55.
[4]张苏民,张炜.减湿和增湿时黄土的湿陷性[J].岩土工程学报,1992,14(1):57-61.ZHANG Su-min,ZHANG Wei.The collapsibility of loess during demoistening and moistening process[J].Chinese Journal of Geotechnical Engineering,1992,14(1):57-61.
[5]刘祖典.黄土力学与工程[M].西安:陕西科学技术出版社,1996:19-20.LIU Zu-dian.Mechanics and engineering of loess[M].Xi’an:Shaanxi Science and Technology Press,1996:19-20.
[6]李作勤.有结构强度的欠压密土的力学特性[J].岩土工程学报,1982,4(1):34-45.LI Zuo-qin.Mechanical characteristics of underconsolidated clay soils with structural strength[J].Chinese Journal of Geotechnical Engineering,1982,4(1):34-45.
[7]李作勤.关于黏土压密类型的鉴别问题[J].岩土工程学报,1984,6(1):67-78.LI Zuo-qin.Identification of consolidated types in clays[J].Chinese Journal of Geotechnical Engineering,1984,6(1):67-78.
[8]张炜.黄土力学性质试验中的若干问题[J].工程勘察,1995,23(3):6-12.ZHANG Wei.Certain problems during the test of mechanical property of loess[J].Geotechnical Investigation and Surveying,1995,23(3):6-12.
[9]郑林春.不同黄土的压缩变形特性分析[J].西南交通大学学报,2012,47(增刊):115-117.ZHENG Lin-chun.Compression deformation property analysis of different loesses[J].Journal of Southwest Jiaotong University,2012,47(Suppl.):115-117.
[10]王丽琴,鹿忠刚,邵生俊.岩土体复合幂-指数非线性模型[J].岩石力学与工程学报,2017,36(5):1269-1278.WANG Li-qin,LU Zhong-gang,SHAO Sheng-jun.Acomposite power exponential nonlinear model of rock and soil[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(5):1269-1278.
[11]中华人民共和国水利部.GB/T50123―1999土工试验方法标准[S].北京:中国计划出版社,1999.The Ministry of Water Resources of the People’s Republic of China.GB/T50123―1999 Standard for soil test method[S].Beijing:China Planning Press,1999.
[12]陈仲颐,周景星,王洪瑾.土力学[M].北京:清华大学出版社,1994:116-118.CHEN Zhong-yi,ZHOU Jing-xing,WANG Hong-jin.Soil mechanics[M].Beijing:Tsinghua University Press,1994:116-118.
[13]陈立,李靖,王俊卿,等.黄土的结构强度及其与结构屈服压力的关系[J].岩土工程学报,2008,30(6):895-899.CHEN Li,LI Jing,WANG Jun-qing,et al.Relationship between structural strength and structural yield pressure of loess[J].Chinese Journal of Geotechnical Engineering,2008,30(6):895-899.
[14]邵生俊,陶虎,许萍.黄土结构性力学特性研究与应用的探讨[J].岩土力学,2011,32(增刊2):42-50.SHAO Sheng-jun,TAO Hu,XU Ping.Discussion on research of mechanical characteristics of loess considering structural behavior and its application[J].Rock and Soil Mechanics,2011,32(Suppl.2):42-50.
[15]王丽琴,邵生俊,赵聪,等.黄土初始结构性对其压缩屈服的影响研究[J].岩土力学,2018,39(9):3223-3228+3236.WANG Li-qin,SHAO Sheng-jun,ZHAO Cong,et al.Effect of initial structural property of loess on its compressive yield[J].Rock and Soil Mechanics,2018,39(9):3223-3228+3236.
[16]王丽琴,鹿忠刚,邵生俊.黄土非线性应力-应变新模型及对比研究[J].岩土工程学报,2017,39(9):1724-1730.WANG Li-qin,LU Zhong-gang,SHAO Sheng-jun.New nonlinear stress-strain model for loess and its comparative research[J].Chinese Journal of Geotechnical Engineering,2017,39(9):1724-1730.
[17]胡再强,沈珠江,谢定义.非饱和黄土的结构性研究[J].岩石力学与工程学报,2000,19(6):775-779.HU Zai-qiang,SHEN Zhu-jiang,XIE Ding-yi.Research on structural behavior of unsaturated loess[J].Chinese Journal of Rock Mechanics and Engineering,2000,19(6):775-779.
[18]陈存礼,高鹏,胡再强.黄土的增湿变形特性及其与结构性的关系[J].岩石力学与工程学报,2006,25(7):1352-1360.CHEN Cun-li,GAO Peng,HU Zai-qiang.Moistening deformation characteristic of loess and its relation to structure[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(7):1352-1360.
[19]罗宇生.湿陷性黄土地基评价[J].岩土工程学报,1998,20(4):87-92.LUO Yu-sheng.Assessment of collapsibility of collapsible loess foundation[J].Chinese Journal of Geotechnical Engineering,1998,20(4):87-92.
[20]王丽琴,邵生俊.黄土构度与物理指标之间的定量关系[J].岩石力学与工程学报,2015,34(增刊2):4380-4386.WANG Li-qin,SHAO Sheng-jun.Combined Influence of physical properties on the initial structure of loess[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(Suppl.2):4380-4386.
[21]王丽琴,邵生俊,鹿忠刚.物理性质对黄土初始结构性的综合影响研究[J].岩土力学,2017,38(12):3484-3490.WANG Li-qin,SHAO Sheng-jun,LU Zhong-gang.Combined influence of physical properties on the initial structure of loess[J].Rock and Soil Mechanics,2017,38(12):3484-3490.
[22]李大展,何颐华,隋国秀.Q2黄土大面积浸水试验研究[J].岩土工程学报,1993,15(2):1-11.LI Da-zhan,HE Yi-hua,SUI Guo-xiu.Study and test on immersion of Q2 loess in large area[J].Chinese Journal Geotechnical Engineering,1993,15(2):1-11.
[23]刘宁.关中地区某场地自重湿陷性黄土的试验研究[D].西安:长安大学,2007.LIU Ning.Study and test on collapsible loess under overburden pressure in a field of Guanzhong area[D].Xi’an:Chang’an University,2007.