冻融循环作用下石灰改性黄土的力学特性试验研究
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摘要
对石灰改性黄土进行击实试验,得到改性黄土的石灰掺量分别与最优含水量和最大干密度的变化规律。同时在冻融循环作用下,利用三轴剪切仪对石灰改性黄土进行固结排水剪切试验,以此研究冻融循环下石灰改性黄土的力学特性。结果表明:随石灰掺量增大,最优含水量也逐渐增大,最大干密度却呈减小的趋势。不同石灰掺量下,冻融循环后改性黄土的应力应变关系曲线随冻融循环次数的增加由弱硬化型向弱软化型过渡,最后趋于强软化型。随冻融循环次数的增加,破坏强度呈下降趋势,石灰掺量为6%且冻融次数10次时,围压越大,破坏强度衰减率越小;石灰改性黄土的黏聚力随冻融循环次数的增加而降低,最终趋于稳定,而内摩擦角几乎保持不变。石灰掺量一定时,随冻融循环次数增加,结构性参数减小,且变化趋势不大;冻融循环次数一定时,随石灰掺量的增加,结构性参数呈减小的趋势;同时,随着围压不断地增大,结构性参数也呈减小趋势,结构性参数与轴向应变关系曲线随着围压的增大由强软化型向弱软化型过渡。
The compaction test of lime modified loess was carried out, and the change rules of lime content,optimal water content and maximum dry density of modified loess were obtained. At the same time, the consolidation and drainage shear tests of lime-modified loess were carried out with triaxial shear apparatus under freeze-thaw cycle, so as to study the mechanical properties of lime-modified loess under freeze-thaw cycle. The results show that the optimal water content increases with the increase of lime content, but the maximum dry density decreases. Under different lime content, the stress-strain curve of modified loess after freeze-thaw cycle changes from weak hardening type to weak softening type with the increase of freeze-thaw cycle times, and finally tends to strong softening type. With the increase of freeze-thaw cycle times, the failure strength showed a downward trend. When the lime content was 6% and the freeze-thaw times were 10 times, the higher the confining pressure was, the smaller the failure strength attenuation rate was. The cohesive force of lime-modified loess decreases with the increase of freeze-thaw cycle times, and finally tends to be stable, while the internal friction Angle remains almost unchanged. When lime content is constant, with the increase of freeze-thaw cycle times, the structural parameters decrease and the change trend is small. With a certain number of freeze-thaw cycles, the structural parameters tend to decrease with the increase of lime content. At the same time, with the increase of confining pressure, structural parameters also show a decreasing trend, and the relationship curve between structural parameters and axial strain changes from strong softening type to weak softening type with the increase of confining pressure.
The compaction test of lime modified loess was carried out, and the change rules of lime content,optimal water content and maximum dry density of modified loess were obtained. At the same time, the consolidation and drainage shear tests of lime-modified loess were carried out with triaxial shear apparatus under freeze-thaw cycle, so as to study the mechanical properties of lime-modified loess under freeze-thaw cycle. The results show that the optimal water content increases with the increase of lime content, but the maximum dry density decreases. Under different lime content, the stress-strain curve of modified loess after freeze-thaw cycle changes from weak hardening type to weak softening type with the increase of freeze-thaw cycle times, and finally tends to strong softening type. With the increase of freeze-thaw cycle times, the failure strength showed a downward trend. When the lime content was 6% and the freeze-thaw times were 10 times, the higher the confining pressure was, the smaller the failure strength attenuation rate was. The cohesive force of lime-modified loess decreases with the increase of freeze-thaw cycle times, and finally tends to be stable, while the internal friction Angle remains almost unchanged. When lime content is constant, with the increase of freeze-thaw cycle times, the structural parameters decrease and the change trend is small. With a certain number of freeze-thaw cycles, the structural parameters tend to decrease with the increase of lime content. At the same time, with the increase of confining pressure, structural parameters also show a decreasing trend, and the relationship curve between structural parameters and axial strain changes from strong softening type to weak softening type with the increase of confining pressure.
引文
[1]刘祖典.黄土力学与工程[M].西安:陕西科学技术出版社,1997
[2]Janoo V C,Firicano A J,Barna L A,et al.Field testing of stabilized soil[J].Journal of Cold Regions Engineering,1999,13(1):37-53
[3]Sauer E K,Weimer N F.Deformation of lime modified clay after freeze-thaw[J].Transportation Engineering Journal,1978,104(2):201-212
[4]Lee C J,Sheu S F.The stiffness degradation and damping ratio evolution of Taipei silty clay under cyclic straining[J].Soil Dynamics and Earthquake Engineering,2007,27(8):730-740
[5]Yarbasi N,Kalkan E,Akbulut S.Modification of the geotechnical properties,as influenced by freeze-thaw of granular soils with waste additives[J].Cold Regions Science and Technology,2007,48(1):44-54
[6]王天亮,刘建坤,田亚护.水泥及石灰改良土冻融循环后的动力特性研究[J].岩土工程学报,2010,32(11):1733-1737(Wang Tianliang,Liu Jiankun,Tian Yahu.Dynamic properties of cement-and lime-improved soil subjected to freeze-thaw cycles[J].Chinese Journal of Geotechnical Engineering,2010,32(11):1733-1737(in Chinese))
[7]王天亮,刘建坤,田亚护.冻融作用下水泥及石灰改良土静力特性研究[J].岩土力学,2011,32(1):193-198(Wang Tianliang,Liu Jiankun,Tian Yahu.Static properties of cement and lime-modified soil subjected to freeze-thaw cycles[J].Rock and Soil Mechanics,2011,32(1):193-198(in Chinese))
[8]张立新,张虎元,冯珂,等.水泥黄土反复冻融条件下的强度衰减机理[J].冰川冻土,1993,15(1):175-181(Zhang Lixin,Zhang Huyuan,Feng Ke,et al.Mechanism of the attenuation of strength for loess-cement under cyclical freezing and thawing[J].Journal of Glaciology and Geocryology,1993,15(1):175-181(in Chinese))
[9]张立新,王家澄.石灰土冻胀特性试验研究[J].岩土工程学报,2002,24(3):336-339(Zhang Lixin,Wang Jiacheng.Experimental study on frost heaving behaviors of lime soil[J].Chinese Journal of Geotechnical Engineering,2002,24(3):336-339(in Chinese))
[10]韩春鹏,贾艳敏,何东坡,等.冻融循环作用下石灰改良粘土抗剪强度衰减规律[J].中外公路,2013,33(3):256-260(Han Chunpeng,Jia Yanmin,He Dongpo,et al.The attenuation law of shear strength of lime improved clay under freeze-thaw cycle[J].Journal of China&Foreign Highway,2013,33(3):256-260(in Chinese))
[11]Terzaghi K.Theoretical Soil Mechanics[M].New York:Wiley,1943
[12]沈珠江.关于黄土力学的研究途径[C]//中加非饱和土学术研讨会论文集,武汉,1994(Shen Zhujisng.On the way of development of loess mechanics[C]//Sino Canadian Seminar on unsaturated soils,Wuhan,1994(in Chinese))
[13]沈珠江.土体结构性的数学模型-21世纪土力学的核心问题[J].岩土工程学报,1996,18(1):95-97
[14]谢定义,齐吉琳,张振中.考虑土结构性的本构关系[J].土木工程学报,2000,33(4):35-41(Xie Dingyi,Qi Jilin,Zhang Zhenzhong.A constitutive laws considering soil structural properties[J].China Civil Engineering Journal,2000,33(4):35-41(in Chinese))
[15]胡再强,沈珠江,谢定义.结构性黄土的本构模型[J].岩石力学与工程学报,2005,24(4):565-569(Hu Zaiqiang,Shen Zhujiang,Xie Dingyi.Constitutive model of structural loess[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(4):565-569(in Chinese))
[16]骆亚生.非饱和黄土在动?静复杂应力条件下的结构变化特性及结构性本构关系研究[D].西安:西安理工大学,2005(Luo Yasheng.Variation characteristics of soil structure and structural constitutive relation of unsaturated loess under static and dynamic complex stress conditions[D].Xi'an:Xi'an University of Technology,2005(in Chinese))
[17]陈存礼,何军芳,杨鹏.考虑结构性影响的原状黄土本构关系[J].岩土力学,2007,28(11):2284-2290(Chen Cunli,He Junfang,Yang Peng.Constitutive relationship of intact loess considering structural effect[J].Rock and Soil Mechanics,2007,28(11):2284-2290(in Chinese))
[18]邵生俊,龙吉勇,于清高,等.湿陷性黄土的结构性参数本构模型[J].水利学报,2006,37(11):1315-1322(Shao Shengjun,Long Jiyong,Yu Qinggao,et al.Aconstitutive model of collapsible loess with structural parameter[J].Journal of Hydraulic Engineering,2006,37(11):1315-1322(in Chinese))
[2]Janoo V C,Firicano A J,Barna L A,et al.Field testing of stabilized soil[J].Journal of Cold Regions Engineering,1999,13(1):37-53
[3]Sauer E K,Weimer N F.Deformation of lime modified clay after freeze-thaw[J].Transportation Engineering Journal,1978,104(2):201-212
[4]Lee C J,Sheu S F.The stiffness degradation and damping ratio evolution of Taipei silty clay under cyclic straining[J].Soil Dynamics and Earthquake Engineering,2007,27(8):730-740
[5]Yarbasi N,Kalkan E,Akbulut S.Modification of the geotechnical properties,as influenced by freeze-thaw of granular soils with waste additives[J].Cold Regions Science and Technology,2007,48(1):44-54
[6]王天亮,刘建坤,田亚护.水泥及石灰改良土冻融循环后的动力特性研究[J].岩土工程学报,2010,32(11):1733-1737(Wang Tianliang,Liu Jiankun,Tian Yahu.Dynamic properties of cement-and lime-improved soil subjected to freeze-thaw cycles[J].Chinese Journal of Geotechnical Engineering,2010,32(11):1733-1737(in Chinese))
[7]王天亮,刘建坤,田亚护.冻融作用下水泥及石灰改良土静力特性研究[J].岩土力学,2011,32(1):193-198(Wang Tianliang,Liu Jiankun,Tian Yahu.Static properties of cement and lime-modified soil subjected to freeze-thaw cycles[J].Rock and Soil Mechanics,2011,32(1):193-198(in Chinese))
[8]张立新,张虎元,冯珂,等.水泥黄土反复冻融条件下的强度衰减机理[J].冰川冻土,1993,15(1):175-181(Zhang Lixin,Zhang Huyuan,Feng Ke,et al.Mechanism of the attenuation of strength for loess-cement under cyclical freezing and thawing[J].Journal of Glaciology and Geocryology,1993,15(1):175-181(in Chinese))
[9]张立新,王家澄.石灰土冻胀特性试验研究[J].岩土工程学报,2002,24(3):336-339(Zhang Lixin,Wang Jiacheng.Experimental study on frost heaving behaviors of lime soil[J].Chinese Journal of Geotechnical Engineering,2002,24(3):336-339(in Chinese))
[10]韩春鹏,贾艳敏,何东坡,等.冻融循环作用下石灰改良粘土抗剪强度衰减规律[J].中外公路,2013,33(3):256-260(Han Chunpeng,Jia Yanmin,He Dongpo,et al.The attenuation law of shear strength of lime improved clay under freeze-thaw cycle[J].Journal of China&Foreign Highway,2013,33(3):256-260(in Chinese))
[11]Terzaghi K.Theoretical Soil Mechanics[M].New York:Wiley,1943
[12]沈珠江.关于黄土力学的研究途径[C]//中加非饱和土学术研讨会论文集,武汉,1994(Shen Zhujisng.On the way of development of loess mechanics[C]//Sino Canadian Seminar on unsaturated soils,Wuhan,1994(in Chinese))
[13]沈珠江.土体结构性的数学模型-21世纪土力学的核心问题[J].岩土工程学报,1996,18(1):95-97
[14]谢定义,齐吉琳,张振中.考虑土结构性的本构关系[J].土木工程学报,2000,33(4):35-41(Xie Dingyi,Qi Jilin,Zhang Zhenzhong.A constitutive laws considering soil structural properties[J].China Civil Engineering Journal,2000,33(4):35-41(in Chinese))
[15]胡再强,沈珠江,谢定义.结构性黄土的本构模型[J].岩石力学与工程学报,2005,24(4):565-569(Hu Zaiqiang,Shen Zhujiang,Xie Dingyi.Constitutive model of structural loess[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(4):565-569(in Chinese))
[16]骆亚生.非饱和黄土在动?静复杂应力条件下的结构变化特性及结构性本构关系研究[D].西安:西安理工大学,2005(Luo Yasheng.Variation characteristics of soil structure and structural constitutive relation of unsaturated loess under static and dynamic complex stress conditions[D].Xi'an:Xi'an University of Technology,2005(in Chinese))
[17]陈存礼,何军芳,杨鹏.考虑结构性影响的原状黄土本构关系[J].岩土力学,2007,28(11):2284-2290(Chen Cunli,He Junfang,Yang Peng.Constitutive relationship of intact loess considering structural effect[J].Rock and Soil Mechanics,2007,28(11):2284-2290(in Chinese))
[18]邵生俊,龙吉勇,于清高,等.湿陷性黄土的结构性参数本构模型[J].水利学报,2006,37(11):1315-1322(Shao Shengjun,Long Jiyong,Yu Qinggao,et al.Aconstitutive model of collapsible loess with structural parameter[J].Journal of Hydraulic Engineering,2006,37(11):1315-1322(in Chinese))