多级边坡平台宽度对边坡地震动力响应及破坏机制的影响
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摘要
以典型工程边坡为原型,利用FLAC3D有限差分软件建立一个三维土坡模型,分析地震作用下多级边坡平台宽度对边坡动力响应特性和动力失稳机制的影响。计算结果表明,边坡设置平台可以有效地提高地震动力条件下边坡的稳定性,且平台宽度越大则稳定性越显著;PGA放大系数随着平台宽度的增大而减小。结合频谱分析得到第一级边坡坡顶的动力响应较第二级边坡坡脚的大,边坡岩土体剪应变增量和位移响应也减小;地震作用下边坡塑性区从坡脚部位向坡体内部发展,随地震持时的增加,坡顶出现拉张变形,坡面及其浅表层发生拉张剪切变形,坡体内部一定部位发生剪切变形;坡面监测点位移时程曲线表明,地震作用下边坡坡脚位移向上,发生剪出变形或破坏,坡脚和变坡点均为薄弱部位,应加强支护。研究结果对多级土质边坡抗震设计具有一定指导意义。
Regarding the typical engineering as the prototype,we utilize the FLAC3D finite difference software to build the model of a three-dimensional slope,and analyze the impact on slope dynamic response characteristics and dynamic instability mechanism which are influenced by stepped slope platform width.The results show that the slope platform can effectively improve the slope stability under seismic dynamic conditions;the slope with greater platform width will be more stable;and the PGA amplification factor decreases with the increase of platform width;moreover,the first step dynamic response of a slope on the top of the hill is more outstanding than the second step toe with the combination of spectrum analysis.The slope's rock and soil shear strain increment and the displacement response is also reduced.Plastic zone of slope under earthquake develops from the toe area to inner slope increasing with the earthquake duration;at the same time hill will be tensile deformation;slope and shallow surface layer will be tensile shear deformation,and certain parts of the slope will present a shear deformation.Displacement curves of slope monitoring points show that slope toe displacement is upward under earthquake;and the cut deformatiobn will occur;the slope slope toe and the point of gradient change become weak parts;so it should be protected tightly.The results have a guiding significance to the seismic design of earth slopes.
Regarding the typical engineering as the prototype,we utilize the FLAC3D finite difference software to build the model of a three-dimensional slope,and analyze the impact on slope dynamic response characteristics and dynamic instability mechanism which are influenced by stepped slope platform width.The results show that the slope platform can effectively improve the slope stability under seismic dynamic conditions;the slope with greater platform width will be more stable;and the PGA amplification factor decreases with the increase of platform width;moreover,the first step dynamic response of a slope on the top of the hill is more outstanding than the second step toe with the combination of spectrum analysis.The slope's rock and soil shear strain increment and the displacement response is also reduced.Plastic zone of slope under earthquake develops from the toe area to inner slope increasing with the earthquake duration;at the same time hill will be tensile deformation;slope and shallow surface layer will be tensile shear deformation,and certain parts of the slope will present a shear deformation.Displacement curves of slope monitoring points show that slope toe displacement is upward under earthquake;and the cut deformatiobn will occur;the slope slope toe and the point of gradient change become weak parts;so it should be protected tightly.The results have a guiding significance to the seismic design of earth slopes.
引文
[1]郑颖人,叶海林,黄润秋,等.边坡地震稳定性分析探讨[J].地震工程与工程振动,2010,30(2):173-180.ZHENG Ying-ren,YE Hai-lin,HUANG Run-qiu,et al.Study on the seismic stability analysis of a slope[J].Journal of Earthquake Engineering and Engineering Vibration,2010,30(2):173-180.
[2]殷跃平.汶川八级地震地质灾害研究[J].工程地质学报,2008,16(4):433-444.YIN Yue-ping.Researches on the geo-hazards triggered by Wenchuan earthquake,Sichuan[J].Journal of Engineering Geology,2008,16(4):433-444.
[3]薄景山,徐国栋,景立平.土边坡地震反应及其动力稳定性分析[J].地震工程与工程振动,2001,21(2):116-120.BO Jing-shan,XU Guo-dong,JING Li-ping.Seismic response and dynamic stability analysis of soil slopes[J].Earthquake Engineering and Engineering Vibration,2001,21(2):116-120.
[4]祁生文.单面边坡的两种动力反应形式及其临界高度[J].地球物理学报,2006,49(2):518-523.QI Sheng-wen.Two patterns of dynamic responses of single free surface slopes and their threshold height[J].Chinese Journal of Geophysics,2006,49(2):518-523
[5]祁生文,伍法权.边坡动力响应规律研究[J].中国科学E辑,2003,33(增刊):28-32.QI Sheng-wen,WU Fa-quan.Study on the regularity of dynamic response for slope[J].Science in China Series E,2003,33(Supp.):28-40.
[6]祁生文,伍法权,刘春玲,等.地震边坡稳定性的工程地质分析[J].岩石力学与工程学报.2004,23(16):2792-2797.QI Sheng-wen,WU Fa-quan,LIU Chun-ling,et al.Engineering geology analysis on stability of slope under earthquake[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(16):2792-2797.
[7]张林,林从谋.爆破震动对土质边坡动力稳定性影响研究[J].岩土力学,2005,26(9):1499-1501.ZHANG Lin,LIN Cong-mou.Study about soil slope dynamic stability due to blasting vibration[J].Rock and Soil Mechanics,2005,26(9):1499-1501.
[8]郑颖人,叶海林,黄润秋.地震边坡破坏机制及其破裂面的分析探讨[J].岩石力学与工程学报.2009,28(8):1715-1720.ZHENG Ying-ren,YE Hai-lin,HUANG Run-qiu.Analysis and discussion of failure mechanism and fracture surface of slope under earthquake[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(8):1714-1723.
[9]徐光兴,姚令侃,李朝红,等.边坡地震动力响应规律及地震动参数影响研究[J].岩土工程学报.2008,30(6):918-923.XU Guang-xing,YAO Ling-kan,LI Zhao-hong,et al.Dynamic response of slopes under earthquakes and influence of ground motion parameters[J].Chinese Journal of Geotechnical Engineering,2008,30(6):918-923.
[10]徐光兴,姚令侃,高召宁,等.边坡动力特性与动力响应的大型振动台模型试验研究[J].岩石力学与工程学报.2008,27(3):624-632.XU Guang-xing,YAO Ling-kan,GAO Zhao-ning,et al.Large-scale shaking table model test on the dynamic characteristics and seismic responses of slope[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(3):624-632.
[11]谷天峰,王家鼎,任权,等.循环荷载作用下黄土边坡变形研究[J].岩石力学与工程学报,2009,28(增刊1):3156-3162.GU Tian-feng,WANG Jia-ding,REN Quan,et al.Study on derormation of loess slope under cyclic load[J].Chinese Journal of Rock Mechanics and Engineering.2009,28(Supp.1):3156-3162.
[12]龚成明,程谦恭,刘争平.强夯激励下黄土边坡动力响应模型试验研究[J].岩土力学,2011,32(7):2001-2006.GONG Cheng-ming,CHENG Qian-gong,LIU Zheng-ping.Model test study of dynamic responses of loess slope by dynamic compaction[J].Rock and Soil Mechanics,2011,32(7):2001-2006.
[13]陈育民,徐鼎平.FLAC/FLAC3D基础与工程实例[J].北京:中国水利水电出版社,2008.
[14]王建,姚令侃,蒋良潍.地震作用下土体变形破坏模式与机理[J].西南交通大学学报,2012,45(2):196-202.WANG Jian,YAO Ling-kan,JIANG Liang-wei.Seismic deformation and falure modes and mechanism of soilMass[J].Journal of Southwest Jiaotong University,2012,45(2):196-202.
[15]YAN Z X,CAI H C,WANG Q M,et al.Finite difference numerical simulation of guided wave propagation in the full grouted rock bolt[J].Science China Technological Sciences,2011,54:1-8.
[2]殷跃平.汶川八级地震地质灾害研究[J].工程地质学报,2008,16(4):433-444.YIN Yue-ping.Researches on the geo-hazards triggered by Wenchuan earthquake,Sichuan[J].Journal of Engineering Geology,2008,16(4):433-444.
[3]薄景山,徐国栋,景立平.土边坡地震反应及其动力稳定性分析[J].地震工程与工程振动,2001,21(2):116-120.BO Jing-shan,XU Guo-dong,JING Li-ping.Seismic response and dynamic stability analysis of soil slopes[J].Earthquake Engineering and Engineering Vibration,2001,21(2):116-120.
[4]祁生文.单面边坡的两种动力反应形式及其临界高度[J].地球物理学报,2006,49(2):518-523.QI Sheng-wen.Two patterns of dynamic responses of single free surface slopes and their threshold height[J].Chinese Journal of Geophysics,2006,49(2):518-523
[5]祁生文,伍法权.边坡动力响应规律研究[J].中国科学E辑,2003,33(增刊):28-32.QI Sheng-wen,WU Fa-quan.Study on the regularity of dynamic response for slope[J].Science in China Series E,2003,33(Supp.):28-40.
[6]祁生文,伍法权,刘春玲,等.地震边坡稳定性的工程地质分析[J].岩石力学与工程学报.2004,23(16):2792-2797.QI Sheng-wen,WU Fa-quan,LIU Chun-ling,et al.Engineering geology analysis on stability of slope under earthquake[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(16):2792-2797.
[7]张林,林从谋.爆破震动对土质边坡动力稳定性影响研究[J].岩土力学,2005,26(9):1499-1501.ZHANG Lin,LIN Cong-mou.Study about soil slope dynamic stability due to blasting vibration[J].Rock and Soil Mechanics,2005,26(9):1499-1501.
[8]郑颖人,叶海林,黄润秋.地震边坡破坏机制及其破裂面的分析探讨[J].岩石力学与工程学报.2009,28(8):1715-1720.ZHENG Ying-ren,YE Hai-lin,HUANG Run-qiu.Analysis and discussion of failure mechanism and fracture surface of slope under earthquake[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(8):1714-1723.
[9]徐光兴,姚令侃,李朝红,等.边坡地震动力响应规律及地震动参数影响研究[J].岩土工程学报.2008,30(6):918-923.XU Guang-xing,YAO Ling-kan,LI Zhao-hong,et al.Dynamic response of slopes under earthquakes and influence of ground motion parameters[J].Chinese Journal of Geotechnical Engineering,2008,30(6):918-923.
[10]徐光兴,姚令侃,高召宁,等.边坡动力特性与动力响应的大型振动台模型试验研究[J].岩石力学与工程学报.2008,27(3):624-632.XU Guang-xing,YAO Ling-kan,GAO Zhao-ning,et al.Large-scale shaking table model test on the dynamic characteristics and seismic responses of slope[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(3):624-632.
[11]谷天峰,王家鼎,任权,等.循环荷载作用下黄土边坡变形研究[J].岩石力学与工程学报,2009,28(增刊1):3156-3162.GU Tian-feng,WANG Jia-ding,REN Quan,et al.Study on derormation of loess slope under cyclic load[J].Chinese Journal of Rock Mechanics and Engineering.2009,28(Supp.1):3156-3162.
[12]龚成明,程谦恭,刘争平.强夯激励下黄土边坡动力响应模型试验研究[J].岩土力学,2011,32(7):2001-2006.GONG Cheng-ming,CHENG Qian-gong,LIU Zheng-ping.Model test study of dynamic responses of loess slope by dynamic compaction[J].Rock and Soil Mechanics,2011,32(7):2001-2006.
[13]陈育民,徐鼎平.FLAC/FLAC3D基础与工程实例[J].北京:中国水利水电出版社,2008.
[14]王建,姚令侃,蒋良潍.地震作用下土体变形破坏模式与机理[J].西南交通大学学报,2012,45(2):196-202.WANG Jian,YAO Ling-kan,JIANG Liang-wei.Seismic deformation and falure modes and mechanism of soilMass[J].Journal of Southwest Jiaotong University,2012,45(2):196-202.
[15]YAN Z X,CAI H C,WANG Q M,et al.Finite difference numerical simulation of guided wave propagation in the full grouted rock bolt[J].Science China Technological Sciences,2011,54:1-8.
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