饱和黄土边坡的动力稳定性分析
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摘要
考虑地震荷载作用下饱和黄土的孔压增长模式及液化规律,建立了饱和黄土无限边坡的动力稳定性分析模型,并将此类边坡的破坏分为液化型破坏和滑动型破坏两种基本类型。分析结果表明,由于孔压的累积,屈服地震系数将随时间而减小,并且明显地受到有效粘聚力、初始孔压比等参数的影响。另外还证实,考虑孔压累积时的永久位移计算值要大于常规的Newmark 法分析的结果。
Based on the increasing mode of pore pressure and the liquefaction mechanism of saturated loess, a model to analyze the dynamic stability of infinite slopes of saturated loess is established. By the model, the failures of this kind of slopes are classified into two modes: one due to liquefaction and another due to sliding. The analytical results indicate that the yield seismic coefficient, which decreases with time, is strongly affected by some soil parameters, i.e. the effective cohesion and initial pore pressure ratio. In addition, it is validated that the value of permanent displacement computed by the model, in which the pore pressure build-up is considered, is greater than by the conventional Newmark method.
Based on the increasing mode of pore pressure and the liquefaction mechanism of saturated loess, a model to analyze the dynamic stability of infinite slopes of saturated loess is established. By the model, the failures of this kind of slopes are classified into two modes: one due to liquefaction and another due to sliding. The analytical results indicate that the yield seismic coefficient, which decreases with time, is strongly affected by some soil parameters, i.e. the effective cohesion and initial pore pressure ratio. In addition, it is validated that the value of permanent displacement computed by the model, in which the pore pressure build-up is considered, is greater than by the conventional Newmark method.
引文
[1]黄建梁,王威中,薛宏交.坡体地震稳定性的动态分析[J].地震工程与工程振动,1997,17(4):113-122.HUANG Jian-liang,WANG Wei-zhong,XUE Hong-jiao.Dynamic analysis of seismic stability of slopes[J].EarthquakeEngineering andEngineeringVibration,1997,17(4):113-122
[2]SarmaSK.Seismic stability of earth dams and embankments[J].Geotechnique,1975,25:743-761.
[3]BiondiG,CasconeE,MaugeriM, et al.Seismic response of saturated cohesionless slopes[J].SoilDynamic andEarthquakeEngineering,2000,20:209-215.
[4]白铭学,张苏民.高烈度地震时黄土地层的液化移动[J].工程勘察,1990,(6):1-5.BAI Ming-xue,ZHANG Su-min.Landslide induced by liquefaction of loessial soil during earthquake of high intensity[J].GeotechnicalInvestigation andSurveying,1990,(6):1-5.
[5]王兰民,刘红玫,李兰,等.饱和黄土液化机理与特性的试验研究[J].岩土工程学报,2000,22(1):89-94.WANG Lan-min,LIU Hong-mei,LI Lan, et al.Laboratory study on the mechanism and behaviors of saturated loess liquefaction[J].ChineseJournal ofGeotechnicalEngineering,2000,22(1):89-94.
[6]佘跃心,刘汉龙,高玉峰.饱和黄土孔压增长模式与液化机理试验研究[J].岩土力学,2002,23(4):395-399.SHE Yue-xin,LIU Han-long,GAO Yu-feng.Study on liquefaction mechanism and pore-water pressure mode of saturated original loess[J].Rock andSoilMechanics,2002,23(4):395-399.
[7]钱家欢,殷宗泽.土工原理与计算(第二版)[M].北京:中国水利水电出版社,1996.
[2]SarmaSK.Seismic stability of earth dams and embankments[J].Geotechnique,1975,25:743-761.
[3]BiondiG,CasconeE,MaugeriM, et al.Seismic response of saturated cohesionless slopes[J].SoilDynamic andEarthquakeEngineering,2000,20:209-215.
[4]白铭学,张苏民.高烈度地震时黄土地层的液化移动[J].工程勘察,1990,(6):1-5.BAI Ming-xue,ZHANG Su-min.Landslide induced by liquefaction of loessial soil during earthquake of high intensity[J].GeotechnicalInvestigation andSurveying,1990,(6):1-5.
[5]王兰民,刘红玫,李兰,等.饱和黄土液化机理与特性的试验研究[J].岩土工程学报,2000,22(1):89-94.WANG Lan-min,LIU Hong-mei,LI Lan, et al.Laboratory study on the mechanism and behaviors of saturated loess liquefaction[J].ChineseJournal ofGeotechnicalEngineering,2000,22(1):89-94.
[6]佘跃心,刘汉龙,高玉峰.饱和黄土孔压增长模式与液化机理试验研究[J].岩土力学,2002,23(4):395-399.SHE Yue-xin,LIU Han-long,GAO Yu-feng.Study on liquefaction mechanism and pore-water pressure mode of saturated original loess[J].Rock andSoilMechanics,2002,23(4):395-399.
[7]钱家欢,殷宗泽.土工原理与计算(第二版)[M].北京:中国水利水电出版社,1996.
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