广吸力范围内非饱和粉土动力变形特性
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摘要
以非饱和粉土为研究对象,利用饱和盐溶液蒸汽平衡法和吸力可控的动三轴仪进行动力变形试验,得到了广吸力范围内非饱和粉土试样在净围压和吸力基本不变条件下的骨架曲线、动弹性模量和阻尼比,研究了吸力对非饱和粉土动力变形特性的影响。结果表明,在同一净围压下,非饱和粉土试样的骨架曲线和动弹性模量随着吸力增大而提高,而阻尼比随着吸力增大而减小。此外,随着试样的水力状态从边界效应区到过渡区再到残余区的变化,非饱和粉土试样的骨架曲线和动弹性模量的提高幅度逐渐减小,而阻尼比减小的趋势显著,动弹性模量随应变的衰减率随着吸力的增大而减小。
By using a suction-controllable dynamic triaxial testing apparatus, a series of dynamic deformation tests are carried out on a unsaturated silt subjected to wide suctions imposed by the axial translation technique and vapor equilibrium method with saturated salt solution. The skeleton curves, dynamic elastic moduli and damping ratios are obtained over a wide suction range under almost constant net confining stress and suction. The effect of suction on dynamic deformation characteristics of unsaturated silt is studied. The test results show that at the same net confining pressure, the skeleton curves and dynamic elastic moduli increase with increasing suction, but the damping ratios decrease with increasing suction. As the hydraulic state of specimens changes from the boundary effect zone to the transition zone and then to the residual zone, the increase rates in the skeleton curves and dynamic elastic moduli decrease gradually, the decrease rate in the damping ratios is still obvious, and the decay rate of the dynamic elastic moduli with strain decreases with the increasing suction.
By using a suction-controllable dynamic triaxial testing apparatus, a series of dynamic deformation tests are carried out on a unsaturated silt subjected to wide suctions imposed by the axial translation technique and vapor equilibrium method with saturated salt solution. The skeleton curves, dynamic elastic moduli and damping ratios are obtained over a wide suction range under almost constant net confining stress and suction. The effect of suction on dynamic deformation characteristics of unsaturated silt is studied. The test results show that at the same net confining pressure, the skeleton curves and dynamic elastic moduli increase with increasing suction, but the damping ratios decrease with increasing suction. As the hydraulic state of specimens changes from the boundary effect zone to the transition zone and then to the residual zone, the increase rates in the skeleton curves and dynamic elastic moduli decrease gradually, the decrease rate in the damping ratios is still obvious, and the decay rate of the dynamic elastic moduli with strain decreases with the increasing suction.
引文
[1]谢定义.土动力学[M].北京:高等教育出版社,2011.(XIEJing-yi.Soil dynamic[M].Beijing:Higher Education Press,2011.(in Chinese))
[2]LU N,LIKOS W J.Unsaturated soil mechanics[M].韦昌富,侯龙,简文星,译.北京:高等教育出版社,2012.(LU N,LIKOS W J.Unsaturated soil mechanics[M].WEI Chang-fu,HOU Long,JIAN Wen-xing,trans.Beijing:Higher Education Press,2012.(in Chinese))
[3]WU S M,GRAY D H,RICHART F E.Capillary effects on dynamic modulus of sands and silts[J].Journal of Geotechnical Engineering,ASCE,1984,110(9):1188-1203.
[4]QIAN X D,GRAY D H,WOODS R D.Voids and granulometry:effects on shear modulus of unsaturated sands[J].Journal of Geotechnical Engineering,ASCE,1993,119(2):295-314.
[5]田堪良,张慧莉,张伯平,等.动扭剪荷载作用下非饱和黄土动力特性试验研究[J].岩石力学与工程学报,2004,23(24):4151-4155.(TIAN Kan-liang,ZHANG Hui-li,ZHANG Bo-ping et al.An experimental study on dynamic properties of unsaturated loess under dynamic torsional shear[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(24):4151-4155.(in Chinese))
[6]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 Ya-sheng,TIANKan-liang.Dynamic shear modulus and damping ratio of unsaturated loess[J].Journal of Hydraulic Engineering,2005,36(7):830-834.(in Chinese))
[7]李又云,谢永利,刘保健.路基压实黄土动力特性的试验研究[J].岩石力学与工程学报,2009,28(5):1037-1046.(LI You-yun,XIE Yong-li,LIU Bao-jian.Experimental research on dynamic charateristics of roadbed compaction loess[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(5):1037-1046.(in Chinese))
[8]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,2003.(LUO Ya-sheng.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,2003.(in Chinese))
[9]孙德安,吴波.非饱和粉土的动弹性模量和阻尼比研究[J].水利学报,2012,43(9):1108-1113.(SUN De-an,WUBo.Study on dynamic modulus and damping ratio of unsaturated silt[J].Journal of Hydraulic Engineering,2012,43(9):1108-1113.(in Chinese))
[10]MANCUSO C,VASSALLO R,d’ONOFRIO A.Small strain behavior of a silty sand in controlled-suction resonant column-torsional shear tests[J].Canadian Geotechnical Journal,2002,39:22-31.
[11]VASSALLO R,MANCUSO C,VINALE F.Effects of net stress and suction history on the small strain stiffness of a compacted clayey silt[J].Canadian Geotechnical Journal,2007,44:447-462.
[12]HOYOS L R,SUESCUN-FLOREZ E A,PUPPALA A J.Stiffness of intermediate unsaturated soil from simultaneous suction-controlled resonant column and bender element testing[J].Engineering Geology,2015,188:10-28.
[13]GREENSPAN L.Humidity fixed points of binary saturated aqueous solutions[J].Journal of Research of the National Bureau of Standards,1977,81(1):89-96.
[14]ABE H,HATAYAMA M.The results of unconfined and triaxial compression tests on unsaturated soil conducted simultaneously[C]//Proc Symposium on the Investigation,Design and Construction of Unsaturated Soil Engineering.Tokyo,1993.(in Japanese)
[15]SALAGER S,El YOUSSOUFI M S,SAIX C.Definition and experimental determination of a soil-water retention surface[J].Canadian Geotechnical Journal,2010,47(6):609-622.
[16]吴世明.非饱和无黏性土的动剪切模量[J].岩土工程学报,1985,7(6):33-41.(WU Shi-ming.Dynamic shear modulus of partly saturated cohesionless soils[J].Chinese Journal of Geotechnical Engineering,1985,7(6):33-41.(in Chinese))
[17]SUN D A,SUN W J,XIANG L.Effect of degree of saturation on mechanical behaviour of unsaturated soils and its elastoplastic simulation[J].Computers and Geotechnics,2010,37(5):678-688.
[2]LU N,LIKOS W J.Unsaturated soil mechanics[M].韦昌富,侯龙,简文星,译.北京:高等教育出版社,2012.(LU N,LIKOS W J.Unsaturated soil mechanics[M].WEI Chang-fu,HOU Long,JIAN Wen-xing,trans.Beijing:Higher Education Press,2012.(in Chinese))
[3]WU S M,GRAY D H,RICHART F E.Capillary effects on dynamic modulus of sands and silts[J].Journal of Geotechnical Engineering,ASCE,1984,110(9):1188-1203.
[4]QIAN X D,GRAY D H,WOODS R D.Voids and granulometry:effects on shear modulus of unsaturated sands[J].Journal of Geotechnical Engineering,ASCE,1993,119(2):295-314.
[5]田堪良,张慧莉,张伯平,等.动扭剪荷载作用下非饱和黄土动力特性试验研究[J].岩石力学与工程学报,2004,23(24):4151-4155.(TIAN Kan-liang,ZHANG Hui-li,ZHANG Bo-ping et al.An experimental study on dynamic properties of unsaturated loess under dynamic torsional shear[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(24):4151-4155.(in Chinese))
[6]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 Ya-sheng,TIANKan-liang.Dynamic shear modulus and damping ratio of unsaturated loess[J].Journal of Hydraulic Engineering,2005,36(7):830-834.(in Chinese))
[7]李又云,谢永利,刘保健.路基压实黄土动力特性的试验研究[J].岩石力学与工程学报,2009,28(5):1037-1046.(LI You-yun,XIE Yong-li,LIU Bao-jian.Experimental research on dynamic charateristics of roadbed compaction loess[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(5):1037-1046.(in Chinese))
[8]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,2003.(LUO Ya-sheng.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,2003.(in Chinese))
[9]孙德安,吴波.非饱和粉土的动弹性模量和阻尼比研究[J].水利学报,2012,43(9):1108-1113.(SUN De-an,WUBo.Study on dynamic modulus and damping ratio of unsaturated silt[J].Journal of Hydraulic Engineering,2012,43(9):1108-1113.(in Chinese))
[10]MANCUSO C,VASSALLO R,d’ONOFRIO A.Small strain behavior of a silty sand in controlled-suction resonant column-torsional shear tests[J].Canadian Geotechnical Journal,2002,39:22-31.
[11]VASSALLO R,MANCUSO C,VINALE F.Effects of net stress and suction history on the small strain stiffness of a compacted clayey silt[J].Canadian Geotechnical Journal,2007,44:447-462.
[12]HOYOS L R,SUESCUN-FLOREZ E A,PUPPALA A J.Stiffness of intermediate unsaturated soil from simultaneous suction-controlled resonant column and bender element testing[J].Engineering Geology,2015,188:10-28.
[13]GREENSPAN L.Humidity fixed points of binary saturated aqueous solutions[J].Journal of Research of the National Bureau of Standards,1977,81(1):89-96.
[14]ABE H,HATAYAMA M.The results of unconfined and triaxial compression tests on unsaturated soil conducted simultaneously[C]//Proc Symposium on the Investigation,Design and Construction of Unsaturated Soil Engineering.Tokyo,1993.(in Japanese)
[15]SALAGER S,El YOUSSOUFI M S,SAIX C.Definition and experimental determination of a soil-water retention surface[J].Canadian Geotechnical Journal,2010,47(6):609-622.
[16]吴世明.非饱和无黏性土的动剪切模量[J].岩土工程学报,1985,7(6):33-41.(WU Shi-ming.Dynamic shear modulus of partly saturated cohesionless soils[J].Chinese Journal of Geotechnical Engineering,1985,7(6):33-41.(in Chinese))
[17]SUN D A,SUN W J,XIANG L.Effect of degree of saturation on mechanical behaviour of unsaturated soils and its elastoplastic simulation[J].Computers and Geotechnics,2010,37(5):678-688.