中主应力对压实黄土动变形特性的影响
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摘要
常规的三轴试验通常无法真实模拟实际工程中土体所受的应力状态,因而就不能准确地评价土体的变形特性,尤其是中主应力对土体变形的影响。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,可进行中主应力对压实黄土动变形影响的试验研究。中主应力的大小σ2通过中主应力系数b(b=(σ2-σ3)/(σ1-σ3))来反映,在其它固结条件不变的前提下,初始中主应力系数b对压实黄土的动剪切模量有一定的影响,随着b的增大,动剪切模量有减小的趋势,最大剪应力也逐渐减小;b对最大动剪切模量基本没有影响。初始中主应力系数b对压实黄土的阻尼比λ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。
Conventional triaxial test cannot authentically simulate the stress conditions of soils in real projects,and it cannot evaluate deformations of soils exactly,especially for the effect of intermediate principal stress on the deformations of soils.After reforming the DTC-199 torsional cyclic load triaxial apparatus,dynamic deformation of compacted loess can be tested under intermediate principal stress.Magnitude of intermediate principal stress is reflected by intermediate principal stress coefficient b(b=(σ2-σ3)/(σ1-σ3)),the initial intermediate principal stress coefficient b has some influence on the dynamic shear modulus of compacted loess when other consolidation conditions are fixed.With b increasing,the dynamic shear modulus shows a decreasing trend,and the maximum dynamic shear stress reduces gradually,but b does not considerably influence the maximum dynamic shear modulus.The initial intermediate principal stress coefficient b has basically no influence on the damping ratio of compacted loess,and 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 correlation.
Conventional triaxial test cannot authentically simulate the stress conditions of soils in real projects,and it cannot evaluate deformations of soils exactly,especially for the effect of intermediate principal stress on the deformations of soils.After reforming the DTC-199 torsional cyclic load triaxial apparatus,dynamic deformation of compacted loess can be tested under intermediate principal stress.Magnitude of intermediate principal stress is reflected by intermediate principal stress coefficient b(b=(σ2-σ3)/(σ1-σ3)),the initial intermediate principal stress coefficient b has some influence on the dynamic shear modulus of compacted loess when other consolidation conditions are fixed.With b increasing,the dynamic shear modulus shows a decreasing trend,and the maximum dynamic shear stress reduces gradually,but b does not considerably influence the maximum dynamic shear modulus.The initial intermediate principal stress coefficient b has basically no influence on the damping ratio of compacted loess,and 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 correlation.
引文
[1]王兰民,石玉成,刘旭,等.黄土动力学[M].北京:地震出版社,2003.Wang Lanmin,Shi Yucheng,Liu Xu,et al.Loess Dynamics[M].Beijing:Earthquake Press,2003.
[2]贾革续,孔宪京.土工三轴试验方法-静动耦合试验[J].世界地震工程,2005,21(2):1-6.Jia Gexu,Kong Xianjing.Triaxial test method-the couping static-dynamic test[J].World Earthquake Engineering,2005,21(2):1-6.
[3]孙静,袁晓铭.土的动模量和阻尼比研究述评[J].2003,19(1):88-95.Sun Jing,Yuan Xiaoming.A state-of-art of research on dynamic modulus and damping ratio of soils[J].World Earthquake Engineering.2003,19(1):88-95.
[4]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].Chinese Journalof Geotechnical Engineering.2000,22(4):435-440.
[5]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 damping ration of unsaturated loess[J].Journal of Hydraulic Engineering,2005,36(7):830-834.
[6]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.
[7]巫志辉,谢定义,余雄飞.洛川黄土动变形强度特性的研究[J].水利学报,1994,12:67-71.Wu Zhihui,Xie Dingyi,Yu Xiongfei.Study on dynamic deformation and strength characteristics of Luochuan loess[J].Journal of Hydraulic En-gineerin,1994,12:67-71.
[8]谢定义.土动力学[M].西安:西安交通大学出版社,1988.Xie Dingyi.Soil Dynamics[M].Xi’an:Press of Xi’an Jiao Tong University,1988.
[9]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 deformation parame-ters of loose sands[J].Rock and Soil Mechanics,2005,26(8):1195-1200.
[10]Yang W,Zhong Z,Hwang K C.Meso-deformation and constitutive relations of sliding polycrystal[A].IUTAMSymposium on Constitutive Rela-tions for Finite Deformation of Polycrystalline Metals[C]∥Beijing:Springer-Verlag and Peking Unibrtdity Press,1991:136-150.
[2]贾革续,孔宪京.土工三轴试验方法-静动耦合试验[J].世界地震工程,2005,21(2):1-6.Jia Gexu,Kong Xianjing.Triaxial test method-the couping static-dynamic test[J].World Earthquake Engineering,2005,21(2):1-6.
[3]孙静,袁晓铭.土的动模量和阻尼比研究述评[J].2003,19(1):88-95.Sun Jing,Yuan Xiaoming.A state-of-art of research on dynamic modulus and damping ratio of soils[J].World Earthquake Engineering.2003,19(1):88-95.
[4]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].Chinese Journalof Geotechnical Engineering.2000,22(4):435-440.
[5]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 damping ration of unsaturated loess[J].Journal of Hydraulic Engineering,2005,36(7):830-834.
[6]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.
[7]巫志辉,谢定义,余雄飞.洛川黄土动变形强度特性的研究[J].水利学报,1994,12:67-71.Wu Zhihui,Xie Dingyi,Yu Xiongfei.Study on dynamic deformation and strength characteristics of Luochuan loess[J].Journal of Hydraulic En-gineerin,1994,12:67-71.
[8]谢定义.土动力学[M].西安:西安交通大学出版社,1988.Xie Dingyi.Soil Dynamics[M].Xi’an:Press of Xi’an Jiao Tong University,1988.
[9]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 deformation parame-ters of loose sands[J].Rock and Soil Mechanics,2005,26(8):1195-1200.
[10]Yang W,Zhong Z,Hwang K C.Meso-deformation and constitutive relations of sliding polycrystal[A].IUTAMSymposium on Constitutive Rela-tions for Finite Deformation of Polycrystalline Metals[C]∥Beijing:Springer-Verlag and Peking Unibrtdity Press,1991:136-150.
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