强震作用下地下水对砂质边坡的动力响应和破坏模式的影响分析
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摘要
基于砂质边坡的有限元模型研究地下水位上升对边坡的地震动力响应和破坏模式的影响规律,并开展砂质边坡的振动台试验。研究结果表明,在近远场地震作用下,随着地下水位的升高,边坡的最大水平加速度出现减小的趋势;坡面最大水平位移明显比无水时偏大,近场地震作用下表现更为明显,坡面处的最大水平位移均表现出增大的趋势,远场地震作用对坡脚位置位移影响最大,而近场地震作用对坡顶位置位移影响较大。地震作用下坡脚处超孔隙水压力骤然上升,并出现最大的超孔隙水压力值,使得坡脚成为最易的剪切滑出位置;随着地下水位的升高边坡的自振周期呈现增加趋势,且最高水位时的自振周期是无水时的2.88倍。无地下水时,在地震和自重联合作用下坡顶首先发生拉裂破坏,表现出明显的鞭梢效应,有地下水时边坡的破坏首先出现在坡脚,并随着超孔隙水压的累积出现剪切破坏。最后通过振动台试验对数值模拟结果进行验证,确定了数值模拟结果的准确性。
Based on the finite element model of sandy slope, the laws of seismic dynamic response and failure mode influenced by underground water are studied and the shaking table test is carried out. The research results show with the increase of groundwater, the maximum horizontal acceleration of slope shows decreasing trend under near-field and far-field earthquakes; The maximum horizontal displacements of slope are greater than that without groundwater, which is more apparent under near-field earthquake, and the maximum horizontal displacements of slope show increasing trend with the increase of groundwater; The influence of far field earthquake on the maximum horizontal displacements at the slope toe are greatest, while the influence of near field earthquake on the maximum horizontal displacements at the top of the slope are greatest; Excess pore water pressure rises abruptly which shows the maximum value and makes the slope shear sliding at the slope toe easily; Natural vibration period shows increasing trend with the increasing of groundwater and the natural vibration period of the highest water depth increases 2.88 times than that without water. Without considering the groundwater, the slope firstly shows tensile rupture on the top of slop which shows obvious whipping effect, while the destruction of slope is mainly the shearing damage through the slope toe with the accumulation of excess pore water pressure; Finally, based on the comparison of shaking table test and the numerical simulation, the accuracy of numerical simulation results of this paper are verified.
Based on the finite element model of sandy slope, the laws of seismic dynamic response and failure mode influenced by underground water are studied and the shaking table test is carried out. The research results show with the increase of groundwater, the maximum horizontal acceleration of slope shows decreasing trend under near-field and far-field earthquakes; The maximum horizontal displacements of slope are greater than that without groundwater, which is more apparent under near-field earthquake, and the maximum horizontal displacements of slope show increasing trend with the increase of groundwater; The influence of far field earthquake on the maximum horizontal displacements at the slope toe are greatest, while the influence of near field earthquake on the maximum horizontal displacements at the top of the slope are greatest; Excess pore water pressure rises abruptly which shows the maximum value and makes the slope shear sliding at the slope toe easily; Natural vibration period shows increasing trend with the increasing of groundwater and the natural vibration period of the highest water depth increases 2.88 times than that without water. Without considering the groundwater, the slope firstly shows tensile rupture on the top of slop which shows obvious whipping effect, while the destruction of slope is mainly the shearing damage through the slope toe with the accumulation of excess pore water pressure; Finally, based on the comparison of shaking table test and the numerical simulation, the accuracy of numerical simulation results of this paper are verified.
引文
[1]何峰,王来贵,王振伟,等.煤岩蠕变-渗流耦合规律实验研究[J].煤炭学报,2011,36(6):930-933(He Feng,Wang Laigui,Wang Zhenwei,et al.Experimental study on creepseepage coupling law of coal(rock)[J].Journal of China Coal Society,2011,36(6):930-933(in Chinese))
[2]Lo Grasso A S,Maugeri M,Recalcati P.Seismic behaviour of geosynthetic-reinforced slopes with overload by shaking table tests[C]//Slopes and Retaining Structures Under Seismic and Static Conditions,ASCE:1-14
[3]Wartman J,Seed R B,Bray J D.Shaking table modeling of seismically induced deformations in slopes[J].Journal of Geotechnical and Geoenvironmental Engineering,2005,131(5):610-622
[4]Kokusho T,Ishizawa T.Energy approach to earthquakeinduced slope failures and its implications[J].Journal of Geotechnical and Geoenvironmental Engineering,2007,133(7):828-840
[5]林宇亮,杨果林,钟正.不同压实度铁路路堤边坡地震响应振动台试验研究[J].岩土力学,2012,33(11):3285-3291(Lin Yuliang,Yang Guolin,Zhong Zheng.Shaking table test on seismic response of railway embankment slopes with different compaction degrees[J].Rock and Soil Mechanics,2012,33(11):3285-3291(in Chinese))
[6]叶海林,郑颖人,杜修力,等.边坡动力破坏特征的振动台模型试验与数值分析[J].土木工程学报,2012,45(9):129-135(Ye Hailin,Zheng Yingren,Du Xiuli,et al.Shaking table model test and numerical analysis on dynamic failure characteristics of slope[J].China Civil Engineering Journal,2012,45(9):129-135(in Chinese))
[2]Lo Grasso A S,Maugeri M,Recalcati P.Seismic behaviour of geosynthetic-reinforced slopes with overload by shaking table tests[C]//Slopes and Retaining Structures Under Seismic and Static Conditions,ASCE:1-14
[3]Wartman J,Seed R B,Bray J D.Shaking table modeling of seismically induced deformations in slopes[J].Journal of Geotechnical and Geoenvironmental Engineering,2005,131(5):610-622
[4]Kokusho T,Ishizawa T.Energy approach to earthquakeinduced slope failures and its implications[J].Journal of Geotechnical and Geoenvironmental Engineering,2007,133(7):828-840
[5]林宇亮,杨果林,钟正.不同压实度铁路路堤边坡地震响应振动台试验研究[J].岩土力学,2012,33(11):3285-3291(Lin Yuliang,Yang Guolin,Zhong Zheng.Shaking table test on seismic response of railway embankment slopes with different compaction degrees[J].Rock and Soil Mechanics,2012,33(11):3285-3291(in Chinese))
[6]叶海林,郑颖人,杜修力,等.边坡动力破坏特征的振动台模型试验与数值分析[J].土木工程学报,2012,45(9):129-135(Ye Hailin,Zheng Yingren,Du Xiuli,et al.Shaking table model test and numerical analysis on dynamic failure characteristics of slope[J].China Civil Engineering Journal,2012,45(9):129-135(in Chinese))
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