主应力轴旋转对压实黄土动变形特性的影响
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摘要
实际工程中的地基或路基的土体往往处于复杂初始应力状态,在地震或其他动荷载的作用下会出现变形和沉降,而常规的室内土工试验无法真实再现这种固结应力条件下土的动力特性。通过对原有的DTC-199型周期扭转荷载三轴仪进行简单的改造后可进行土体在主应力轴发生旋转时的压实黄土动变形的试验研究。结果表明,在其他固结条件不变的情况下,初始主应力方向角α对压实黄土的动剪切模量有一定的影响,随着α的增加,动剪切模量有减小的趋势,最大动剪应力也逐渐减小,但是α对最大动剪切模量的影响不太显著。初始主应力方向角α对压实黄土的阻尼比基本没有影响,在λ-lgγd的半对数坐标图中,阻尼比随动剪应变的增加有逐渐增大的趋势,并且表现出较好的相关性。
In real projects,soils under foundations or roadbeds are usually in complex initial stress state,deformation and settlement happens under earthquakes or other dynamic loadings.Conventional laboratory experiments of soils cannot authentically reproduce dynamic behaviors of soils under this kind of consolidation stress conditions.After having reformed the DTC-199 torsional cyclic load triaxial apparatus,dynamic deformation of compacted loess can be tested when the initial principal stress axis is rotated.Results show that the initial angle α of the principal stress has an influence on the dynamic shear modulus of the compacted loess when other consolidation conditions are fixed.As α increases,the dynamic shear modulus shows a decreasing trend,and the maximum dynamic shear stress reduces gradually.But α does not considerably influence the maximum dynamic shear modulus.The initial angle α of the principal stress has basically no influence on the damping ratio of compacted loess.The damping ratio has an increasing trend with the increase of dynamic shear strain in the semilog plot of λ-lgγd,and they show good relativity.
In real projects,soils under foundations or roadbeds are usually in complex initial stress state,deformation and settlement happens under earthquakes or other dynamic loadings.Conventional laboratory experiments of soils cannot authentically reproduce dynamic behaviors of soils under this kind of consolidation stress conditions.After having reformed the DTC-199 torsional cyclic load triaxial apparatus,dynamic deformation of compacted loess can be tested when the initial principal stress axis is rotated.Results show that the initial angle α of the principal stress has an influence on the dynamic shear modulus of the compacted loess when other consolidation conditions are fixed.As α increases,the dynamic shear modulus shows a decreasing trend,and the maximum dynamic shear stress reduces gradually.But α does not considerably influence the maximum dynamic shear modulus.The initial angle α of the principal stress has basically no influence on the damping ratio of compacted loess.The damping ratio has an increasing trend with the increase of dynamic shear strain in the semilog plot of λ-lgγd,and they show good relativity.
引文
[1]王兰民等.黄土动力学[M].北京:地震出版社,2003.Wang Lanmin,et al.Loess dynamics[M].Beijing:Earthquake Press,2003.
[2]吕立强,邵生俊,龙吉勇.对黄土基本动力特性的认识[J].地下水,2007,29(6):109～111.LüLiqiang,Shao Shengjun,Long Jiyong.The basic dynamics properties of loess[J].Ground Water,2007,29(6):109～111.
[3]郭莹,栾茂田,史旦达,等.初始应力条件对松砂动力变形特性影响的试验研究[J].岩土力学,2005,26(8):1195～1200.Guo Ying,Luan Maotian,Shi Danda,et al.Experimental study on effect of initial stress condition on dynamic behavior and deforma-tion parameters of loose sands[J].Rock and Soil Mechanics,2005,26(8):1195～1200.
[4]郭莹,张小玲,栾茂田,等.初始中主应力系数对中密粉煤灰动模量阻尼比影响的实验研究[J].岩土力学,2008,29(3):591～595.Guo Ying,Zhang Xiaoling,Luan Maotian,et al.Experimental stud-y on effect of initial intermediate principal stress coefficient on dy-namic shear modulus and damping ratio of medium-dense fly ash[J].Rock and Soil Mechanics,2008,29(3):591～595.
[5]蔡袁强,王军,徐长节.初始偏应力作用对萧山软黏土动弹模量与阻尼影响实验研究[J].岩土力学,2007,28(11):2291～2296.Cai Yuanqiang,Wang Jun,Xu Changjie.Experimental study on dynamic elastic modulus and damping ratio of Xiaoshan saturated soft clay considering initial deviator stress[J].Rock and Soil Me-chanics,2007,28(11):2291～2296.
[6]沈扬.考虑主应力方向变化的原状软黏土试验研究[D].浙江:浙江大学博士学位论文,2007.6.Shen Yang.Experimental study on effect of variation of principal stress orientation on undisturbed soft clay[D].Zhejiang:The Doctor Degree Dissertation of Zhejiang University,2007.6.
[7]李焱,骆亚生,谭东岳等.振动频率对压实黄土动强度特性的影响[J].水土保持通报,2009,8(4):130～133.Li Yan,Luo Yasheng,Tan Dongyue,et al.Effects of vibration fre-quency on dynamic strength properties of compacted loess[J].Bulletin of Soil and Water Conservation.2009,8(4):130～133.
[8]余雄飞.原状黄土的增湿结构弱化性对静动荷载下变形强度特性的影响[D],西安:陕西机械学院硕士学位论文,1986.4.Yu Xiongfei.Undisturbed loess weakening of Humidifier structure effect on deformation and strength characteristics under Static and dynamic load[D],Xi an:The Master Degree Dissertation of Shaanxi Institute of Mechanical Engineering,1986.4.
[9]付磊,王洪瑾,周景星.主应力偏角对砂砾料动力特性影响的试验研究[J].岩土工程学报,2000,22(4)::435～440.Fu Lei,Wang Hongjin,Zhou Jingxing.Effect of the initial rotation angle of principal stress on the dynamic properties of soil[J].Chi-nese Journal of Geotechnical Engineering.2000,22(4):435～440.
[10]Hardin B O,Drnevich V P.Shear modulus and damping in soils:design equations and curves[J].Journal of Soil Mechanics and Foundations,ASCE,1972,(7):667～692.
[11]谢定义.土动力学[M].西安:西安交通大学出版社,1987.Xie Dingyi.Soil dynamics[M].Xi′an:Press of Xi an Jiao tong University,1987.
[12]骆亚生,田堪良.非饱和黄土的动剪模量与阻尼比[J].水利学报,2005,36(7):830～834.Luo Yasheng,Tian Kanliang.Dynamic shear modulus and damp-ing ration of unsaturated loess[J].Journal of Hydraulic Engi-neering,2005,36(7):830～834.
[13]朱克廉,周新赞,蔡东艳.黄土动模量和阻尼比的试验研究[J].西安冶金建筑学报,1991,23(2):151～157.Zhu Kelian,Zhou Xinzan,Cai Dongyan.Experimental study on dynamic shear modulus and damping ration of loess[J].Journal of Xi an Metallurgical Construction,1991,23(2):151～157.
[14]崔文鉴,孙远茹.陕西东坡地区原状黄土动剪模量及阻尼比的试验研究[J].西北地震学报,1990,12(4):60～68.Cui Wenjian,Sun Yuanru.An experimental research on dynamic shear modulus and damping ratio of loess in Dongpo area,Shaanxi province[J].Northwestern Seismological Journal,1990,12(4):60～68.
[2]吕立强,邵生俊,龙吉勇.对黄土基本动力特性的认识[J].地下水,2007,29(6):109～111.LüLiqiang,Shao Shengjun,Long Jiyong.The basic dynamics properties of loess[J].Ground Water,2007,29(6):109～111.
[3]郭莹,栾茂田,史旦达,等.初始应力条件对松砂动力变形特性影响的试验研究[J].岩土力学,2005,26(8):1195～1200.Guo Ying,Luan Maotian,Shi Danda,et al.Experimental study on effect of initial stress condition on dynamic behavior and deforma-tion parameters of loose sands[J].Rock and Soil Mechanics,2005,26(8):1195～1200.
[4]郭莹,张小玲,栾茂田,等.初始中主应力系数对中密粉煤灰动模量阻尼比影响的实验研究[J].岩土力学,2008,29(3):591～595.Guo Ying,Zhang Xiaoling,Luan Maotian,et al.Experimental stud-y on effect of initial intermediate principal stress coefficient on dy-namic shear modulus and damping ratio of medium-dense fly ash[J].Rock and Soil Mechanics,2008,29(3):591～595.
[5]蔡袁强,王军,徐长节.初始偏应力作用对萧山软黏土动弹模量与阻尼影响实验研究[J].岩土力学,2007,28(11):2291～2296.Cai Yuanqiang,Wang Jun,Xu Changjie.Experimental study on dynamic elastic modulus and damping ratio of Xiaoshan saturated soft clay considering initial deviator stress[J].Rock and Soil Me-chanics,2007,28(11):2291～2296.
[6]沈扬.考虑主应力方向变化的原状软黏土试验研究[D].浙江:浙江大学博士学位论文,2007.6.Shen Yang.Experimental study on effect of variation of principal stress orientation on undisturbed soft clay[D].Zhejiang:The Doctor Degree Dissertation of Zhejiang University,2007.6.
[7]李焱,骆亚生,谭东岳等.振动频率对压实黄土动强度特性的影响[J].水土保持通报,2009,8(4):130～133.Li Yan,Luo Yasheng,Tan Dongyue,et al.Effects of vibration fre-quency on dynamic strength properties of compacted loess[J].Bulletin of Soil and Water Conservation.2009,8(4):130～133.
[8]余雄飞.原状黄土的增湿结构弱化性对静动荷载下变形强度特性的影响[D],西安:陕西机械学院硕士学位论文,1986.4.Yu Xiongfei.Undisturbed loess weakening of Humidifier structure effect on deformation and strength characteristics under Static and dynamic load[D],Xi an:The Master Degree Dissertation of Shaanxi Institute of Mechanical Engineering,1986.4.
[9]付磊,王洪瑾,周景星.主应力偏角对砂砾料动力特性影响的试验研究[J].岩土工程学报,2000,22(4)::435～440.Fu Lei,Wang Hongjin,Zhou Jingxing.Effect of the initial rotation angle of principal stress on the dynamic properties of soil[J].Chi-nese Journal of Geotechnical Engineering.2000,22(4):435～440.
[10]Hardin B O,Drnevich V P.Shear modulus and damping in soils:design equations and curves[J].Journal of Soil Mechanics and Foundations,ASCE,1972,(7):667～692.
[11]谢定义.土动力学[M].西安:西安交通大学出版社,1987.Xie Dingyi.Soil dynamics[M].Xi′an:Press of Xi an Jiao tong University,1987.
[12]骆亚生,田堪良.非饱和黄土的动剪模量与阻尼比[J].水利学报,2005,36(7):830～834.Luo Yasheng,Tian Kanliang.Dynamic shear modulus and damp-ing ration of unsaturated loess[J].Journal of Hydraulic Engi-neering,2005,36(7):830～834.
[13]朱克廉,周新赞,蔡东艳.黄土动模量和阻尼比的试验研究[J].西安冶金建筑学报,1991,23(2):151～157.Zhu Kelian,Zhou Xinzan,Cai Dongyan.Experimental study on dynamic shear modulus and damping ration of loess[J].Journal of Xi an Metallurgical Construction,1991,23(2):151～157.
[14]崔文鉴,孙远茹.陕西东坡地区原状黄土动剪模量及阻尼比的试验研究[J].西北地震学报,1990,12(4):60～68.Cui Wenjian,Sun Yuanru.An experimental research on dynamic shear modulus and damping ratio of loess in Dongpo area,Shaanxi province[J].Northwestern Seismological Journal,1990,12(4):60～68.
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