悬臂式抗滑桩加固黏土边坡地震永久位移算法
|
摘要
为了有效地确定悬臂式抗滑桩加固的黏土边坡地震永久位移,基于极限分析上限定理,针对圆弧滑动式土坡破坏模式,通过对设置抗滑桩条件下土坡进行外力功率和内能耗散率的计算,按严格力学定义推导出坡体在地震作用下的安全系数,进而导出与安全系数相对应的边坡地震屈服加速度计算公式,并结合Newmark滑块位移法对边坡产生的转动加速度进行二次积分,推导出与边坡设计安全系数密切相关的坡体地震永久位移的详细计算公式。以5.12汶川地震卧龙测站东向地震波为例,通过对一算例边坡进行分析,给出了边坡永久位移时程曲线以及不同设计安全系数与永久位移的关系,分析了算法与Ambraseys算法的结果,验证了所提计算方法的有效性,并得到不同设计安全系数时边坡土体黏聚力和内摩擦角对坡体永久位移的影响规律。研究结果表明,坡体永久位移随着设计安全系数的增加逐渐呈指数函数式减小变化,在较低设计安全系数下,坡体永久位移受土体抗剪强度参数影响较为敏感,随着设计安全系数的提高,这种敏感性则逐渐降低。
In order to get the seismic permanent displacement of clay slope reinforced with cantilever stabilizing piles effectively,based on the upper bound theorem of limit analysis and circular failure mode of soil slope,factor of safety and the corresponding yield acceleration of slope with stabilizing piles under the earthquake can be derived through calculating the rate of work done by external loads and the energy dissipation rate.Then,combined with the Newmark’s sliding block method,the expression for the seismic permanent displacement related to design safety factor can be deducted by the double integrals of the rotational acceleration of slope.The paper takes a clay slope reinforced with cantilever stabilizing piles under the 5.12 Wenchuan Earthquake for example,the validity of the proposed method is verified by comparison with Ambraseys’s method.In Addition,the permanent displacement time history of the reinforced slope is given,and the relationship between the permanent displacement and factor of safety of the slope is also shown.The laws that the permanent displacement affected by the cohesion and internal friction angle of soil under different safety conditions are obtained.The research results show that the permanent displacement exponentially decreases with design safety factor of the slope increasing.In the case of lower design safety factor,the permanent displacement is more sensitive to soil shear strength parameters.However,the sensitivity is gradually reduced with the increase of the design safety factor.
In order to get the seismic permanent displacement of clay slope reinforced with cantilever stabilizing piles effectively,based on the upper bound theorem of limit analysis and circular failure mode of soil slope,factor of safety and the corresponding yield acceleration of slope with stabilizing piles under the earthquake can be derived through calculating the rate of work done by external loads and the energy dissipation rate.Then,combined with the Newmark’s sliding block method,the expression for the seismic permanent displacement related to design safety factor can be deducted by the double integrals of the rotational acceleration of slope.The paper takes a clay slope reinforced with cantilever stabilizing piles under the 5.12 Wenchuan Earthquake for example,the validity of the proposed method is verified by comparison with Ambraseys’s method.In Addition,the permanent displacement time history of the reinforced slope is given,and the relationship between the permanent displacement and factor of safety of the slope is also shown.The laws that the permanent displacement affected by the cohesion and internal friction angle of soil under different safety conditions are obtained.The research results show that the permanent displacement exponentially decreases with design safety factor of the slope increasing.In the case of lower design safety factor,the permanent displacement is more sensitive to soil shear strength parameters.However,the sensitivity is gradually reduced with the increase of the design safety factor.
引文
[1]NEWMARK N M.Effects of earthquakes on dams andembankments[J].Geotechnique,1965,15(2):139-159.
[2]CHANG C J,CHEN W F,YAO J T P.Seismicdisplacements in slopes by limit analysis[J].Journal ofGeotechnical and Geoenvironmental Engineering,1984,110(7):860-874.
[3]LING H I,LESHCHINSKY D,PERRY E B.Seismicdesign and performance of geosynthetic-reinforced soilstructures[J].Geotechnique,1997,47(5):933-952.
[4]LING H I,LESHCHINSKY D.Effects of verticalacceleration on seismic design of geosynthetic-reinforcedsoil structures[J].Geotechnique,1998,48(3):347-373.
[5]AUSILIO E,CONTE E,DENTE G.Seismic stabilityanalysis of reinforced slopes[J].Soil Dynamics andEarthquake Engineering,2000,19(3):159-172.
[6]AUSILIO E,CONTE E,DENTE G.Stability analysis ofslopes reinforced with piles[J].Computers andGeotechnics,2001,28(8):591-611.
[7]李红军,迟世春,林皋.考虑时程竖向加速度的Newmark滑块位移法[J].岩土力学,2007,28(11):2385-2390.LI Hong-jun,CHI Shi-chun,LIN Gao.Effects of verticalacceleration-time histories on Newmark sliding blockanalyses[J].Rock and Soil Mechanics,2007,28(11):2385-2390.
[8]李红军,迟世春,林皋.高心墙堆石坝坝坡加筋抗震稳定分析[J].岩土工程学报,2007,29(12):1881-1887.LI Hong-jun,CHI Shi-chun,LIN Gao.Aseismic stabilityanalysis for reinforced slopes of high core rock-filldams[J].Chinese Journal of Geotechnical Engineering,2007,29(12):1881-1887.
[9]LI X P,HE S M,WU Y.Seismic displacement of slopesreinforced with piles[J].Journal of Geotechnical andGeoenvironmental Engineering,2010,136(6):880-884.
[10]何思明,张晓曦,欧阳朝军.超前支护桩加固高切坡的静动力响应与永久位移预测研究[J].四川大学学报(工程科学版),2010,42(5):127-133.HE Si-ming,ZHANG Xiao-xi,OUYANG Chao-jun.Static-dynamic response and permanent displacementforecast for high cutting slope pre-reinforced by pile[J].Journal of Sichuan University(Engineering ScienceEdition),2010,42(5):127-133.
[11]李乔,赵世春.汶川大地震工程震害分析[M].成都:西南交通大学出版社,2008.
[12]AMBRASEYS N N,MENU J M.Earthquake-inducedground displacements[J].Earthquake Engineering andStructural Dynamics,1988,16(7):985-1006.
[13]CHEN W F.Limit analysis and soil plasticity[M].Amsterdam:Elsevier,1975.
[14]年廷凯,栾茂田,杨庆.抗滑桩加固土坡稳定性分析与桩基的简化设计[J].岩石力学与工程学报,2005,24(19):3427-3433.NIAN Ting-kai,LUAN Mao-tian,YANG Qing.Stabilityanalysis of slopes with stabilizing piles and theirsimplified design[J].Chinese Journal of RockMechanics and Engineering,2005,24(19):3427-3433.
[15]谭捍华,赵炼恒,李亮.抗滑桩预加固边坡的能量分析方法[J].岩土力学,2011,32(增刊2):190-197.TAN Han-hua,ZHAO Lian-heng,LI Liang.Energyanalysis method for pre-reinforcing slopes with anti-slidepiles[J].Rock and Soil Mechanics,2011,32(Supp.2):190-197.
[16]交通部公路规划设计院.JTJ004-89公路工程抗震设计规范[S].北京:人民交通出版社,1999.
[17]XIAO S G,FENG W K,ZHANG J J.Analysis of theeffects of slope geometry on the dynamic response of anear-field mountain from the Wenchuan earthquake[J].Journal of Mountain Science,2010,7(4):353-360.
[2]CHANG C J,CHEN W F,YAO J T P.Seismicdisplacements in slopes by limit analysis[J].Journal ofGeotechnical and Geoenvironmental Engineering,1984,110(7):860-874.
[3]LING H I,LESHCHINSKY D,PERRY E B.Seismicdesign and performance of geosynthetic-reinforced soilstructures[J].Geotechnique,1997,47(5):933-952.
[4]LING H I,LESHCHINSKY D.Effects of verticalacceleration on seismic design of geosynthetic-reinforcedsoil structures[J].Geotechnique,1998,48(3):347-373.
[5]AUSILIO E,CONTE E,DENTE G.Seismic stabilityanalysis of reinforced slopes[J].Soil Dynamics andEarthquake Engineering,2000,19(3):159-172.
[6]AUSILIO E,CONTE E,DENTE G.Stability analysis ofslopes reinforced with piles[J].Computers andGeotechnics,2001,28(8):591-611.
[7]李红军,迟世春,林皋.考虑时程竖向加速度的Newmark滑块位移法[J].岩土力学,2007,28(11):2385-2390.LI Hong-jun,CHI Shi-chun,LIN Gao.Effects of verticalacceleration-time histories on Newmark sliding blockanalyses[J].Rock and Soil Mechanics,2007,28(11):2385-2390.
[8]李红军,迟世春,林皋.高心墙堆石坝坝坡加筋抗震稳定分析[J].岩土工程学报,2007,29(12):1881-1887.LI Hong-jun,CHI Shi-chun,LIN Gao.Aseismic stabilityanalysis for reinforced slopes of high core rock-filldams[J].Chinese Journal of Geotechnical Engineering,2007,29(12):1881-1887.
[9]LI X P,HE S M,WU Y.Seismic displacement of slopesreinforced with piles[J].Journal of Geotechnical andGeoenvironmental Engineering,2010,136(6):880-884.
[10]何思明,张晓曦,欧阳朝军.超前支护桩加固高切坡的静动力响应与永久位移预测研究[J].四川大学学报(工程科学版),2010,42(5):127-133.HE Si-ming,ZHANG Xiao-xi,OUYANG Chao-jun.Static-dynamic response and permanent displacementforecast for high cutting slope pre-reinforced by pile[J].Journal of Sichuan University(Engineering ScienceEdition),2010,42(5):127-133.
[11]李乔,赵世春.汶川大地震工程震害分析[M].成都:西南交通大学出版社,2008.
[12]AMBRASEYS N N,MENU J M.Earthquake-inducedground displacements[J].Earthquake Engineering andStructural Dynamics,1988,16(7):985-1006.
[13]CHEN W F.Limit analysis and soil plasticity[M].Amsterdam:Elsevier,1975.
[14]年廷凯,栾茂田,杨庆.抗滑桩加固土坡稳定性分析与桩基的简化设计[J].岩石力学与工程学报,2005,24(19):3427-3433.NIAN Ting-kai,LUAN Mao-tian,YANG Qing.Stabilityanalysis of slopes with stabilizing piles and theirsimplified design[J].Chinese Journal of RockMechanics and Engineering,2005,24(19):3427-3433.
[15]谭捍华,赵炼恒,李亮.抗滑桩预加固边坡的能量分析方法[J].岩土力学,2011,32(增刊2):190-197.TAN Han-hua,ZHAO Lian-heng,LI Liang.Energyanalysis method for pre-reinforcing slopes with anti-slidepiles[J].Rock and Soil Mechanics,2011,32(Supp.2):190-197.
[16]交通部公路规划设计院.JTJ004-89公路工程抗震设计规范[S].北京:人民交通出版社,1999.
[17]XIAO S G,FENG W K,ZHANG J J.Analysis of theeffects of slope geometry on the dynamic response of anear-field mountain from the Wenchuan earthquake[J].Journal of Mountain Science,2010,7(4):353-360.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心