【作者】 乔磊； 袁昶； 章建平； 翟恩地；

【Author】 Lei Qiao~1,Chang Yuan~1,Jianping Zhang~1 and Endi Zhai~2 1 Geo-Engineering Investigation Institute of Jiangsu Province,China. 2 Kleinfelder West,Inc.,USA;

【机构】 江苏省地质工程勘察院； 美国Kleinfelder West,Inc.公司；

【摘要】 本文通过振动台试验和非线性有效应力数值分析探讨了饱和土液化引起的边坡侧向移动与沉降机理及边坡移动对土中埋设管线的破坏。振动台试验采用了长1.8米,宽0.6米,高0.8米的砂箱。模型边坡高度为0.2米,坡度为2H:1V。边坡下有0.4米厚的饱和砂。坡顶设在砂箱正中。模型管直径为0.025米,埋在坡顶下0.1米处。水位设在与坡脚处等高。采用的砂土为5号硅砂。试验在日本金泽大学振动台进行。上述试验经多次重复,采用0.1g到0.25g不同振幅的正弦波输入。量测结果包括地表和埋设管反应加速度,边坡下不同深处的间隙水压和边坡变形。针对以上试验结果,我们用FLAC程序建立了二维非线性有效应力模型。其中土液化模块由FISH语言编成,建立在Seed和Idriss的往返应力波理论基础之上,已经在美国加州广为应用。振动间隙水压力升高和消散采用土中应力波和渗流混合运算。数值计算结果与试验结果进行了对比,对吻合与不吻合处进行了分析。更多还原

【Abstract】 This paper presents Shake-Table testing and FLAC numerical modeling of liquefaction-induced large ground lateral movement and settlement,and pipeline behavior induced by soil movement.A series of laboratory Shake-Table experiments were performed using a model slope ground and model pipe buried under the crest of the slope in a box 1,800 mm long by 600 mm wide by 800 mm high.A typical 2H:1V slope was prepared with its crest at the center of the box.The model pipe had an outside diameter of 25 mm and was buried crossing the full box width and 100 mm below the crest.The above model ground was repeated for different amplitudes of input sine waves varying from 0.1 g to 0.25g.Observed and recorded ground failures included lateral spreading and settlement,sand boiling,time histories of excess pore water pressure buildup,input acceleration and model pipe responded acceleration.The above experimental cases were modeled using a nonlinear effective-stress modeling approach with computer code FLAC coupled with a practical-oriented pore pressure model based on cyclic stress method by Seed and co-workers(Seed,1979).Pore water pressure buildup and dissipation were modeled using alternative stepping of fluid flow-mechanical interaction.The computed ground failures reasonably agree with the observations in the Shake-Table test.The FLAC modeling further revealed the soil liquefaction mechanism and induced ground deformation and pipe deflection.更多还原