地震作用下微型桩支挡结构振动台试验研究
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摘要
运用大型振动台试验,通过加载EI地震波,研究地震作用下"人"字型和平形微型桩支挡结构的动力学响应并对比了二者的抗震承载能力,目的是通过对比试验研究提出抗震承载能力和抗变形能力更强的结构,为边坡工程和微型桩支挡结构抗震设计提供借鉴。研究结果表明,在EI地震波作用下:微型桩支挡结构山侧土压力滑面以上呈现"K"型分布,滑面附近土压力最大;两类微型桩河侧土压力分布特征不同;微型桩在双向耦合地震作用下土压力大于单向地震作用下的土压力;滑面处"人"字型微型桩支挡结构承担的滑坡推力为平形微型桩的2～5倍,平形微型桩桩顶横梁较"人"字型微型桩向前错动2.2 cm,"人"字型微型桩较平行微型桩支挡结构抗震承载能力和抗变形能力更强;微型桩支挡结构地震动土压力峰值存在响应滞后效应,滑动面附近土压力在整个地震时间段波动幅度较大,地震动峰值土压力响应滞后效应更明显;坡体内加速度沿桩身呈现放大特征,地震作用越强加速度放大效应越显著,边坡坡面附近加速度放大效应最强。
This paper aims to study dynamic responses and compare aseismic bearing capacity of herringbone micro-pile and parallel micro-pile retaining structures under EI earthquake action through large-scale shaking table tests. The objective of this research is to propose the structure which shows good aseismic bearing capacity and strong deformation resisting capability under earthquake condition. The results may be as a good reference for seismic design of slope engineering and micro-pile retaining structure. It is indicated that,under EI earthquake condition:The hillside soil pressure of two kinds of micro-pile retaining structures shows"K"shape distribution above sliding surface,and the earth pressure is the largest around sliding surface. The riverside soil pressure distribution characteristics of two kinds of micro-pile structures show different performance. In addition,the earth pressure of micro-pile under the action of bidirectional coupled earthquake is higher than that of unidirectional earthquake. At the sliding surface,the landslide thrust force of herringbone micro-pile bearing is twice to five times as strong as that of parallel micro-pile. The top beam displacement of parallel micro-pile is 2.2 cm more than that of herringbone micro-pile. Compared with parallel micro-pile,the aseismic bearing capacity and deformation resisting capability of herringbone micro-pile is stronger. Besides,there is hysteresis effect in the micro-pile peak value of seismic dynamic earth pressure,and the earth pressure near the sliding surface is undulating over whole time period of earthquake. The hysteresis effect of the earth pressure at the sliding surface is more significant than others. Lastly,the acceleration of the slope is magnified along the pile body,meanwhile the acceleration magnified effect is prominent when the earthquake action is greater,and the acceleration magnified effect reaches the peak near the slope surface.
This paper aims to study dynamic responses and compare aseismic bearing capacity of herringbone micro-pile and parallel micro-pile retaining structures under EI earthquake action through large-scale shaking table tests. The objective of this research is to propose the structure which shows good aseismic bearing capacity and strong deformation resisting capability under earthquake condition. The results may be as a good reference for seismic design of slope engineering and micro-pile retaining structure. It is indicated that,under EI earthquake condition:The hillside soil pressure of two kinds of micro-pile retaining structures shows"K"shape distribution above sliding surface,and the earth pressure is the largest around sliding surface. The riverside soil pressure distribution characteristics of two kinds of micro-pile structures show different performance. In addition,the earth pressure of micro-pile under the action of bidirectional coupled earthquake is higher than that of unidirectional earthquake. At the sliding surface,the landslide thrust force of herringbone micro-pile bearing is twice to five times as strong as that of parallel micro-pile. The top beam displacement of parallel micro-pile is 2.2 cm more than that of herringbone micro-pile. Compared with parallel micro-pile,the aseismic bearing capacity and deformation resisting capability of herringbone micro-pile is stronger. Besides,there is hysteresis effect in the micro-pile peak value of seismic dynamic earth pressure,and the earth pressure near the sliding surface is undulating over whole time period of earthquake. The hysteresis effect of the earth pressure at the sliding surface is more significant than others. Lastly,the acceleration of the slope is magnified along the pile body,meanwhile the acceleration magnified effect is prominent when the earthquake action is greater,and the acceleration magnified effect reaches the peak near the slope surface.
引文
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[6]孙书伟,朱本珍,郑静.基于极限抗力分析的微型桩群加固土质边坡设计方法[J].岩土工程学报,2010,32(11):1 671-1 677.(SUNShuwei,ZHU Benzhen,ZHENG Jing.Design Method of micropile group for soil slope stabilization based on ultimate resistance of analysis[J].Chinese Journal of Geotechnical Engineering,2010,32(11):1 671-1 677.(in Chinese))
[7]沈龙运,余云燕.独立微型桩加固边坡的内力计算[J].兰州交通大学学报:自然科学版,2007,26(4):81-83.(SHEN Longyun,YUYunyan.Calculation of internal force of independent micropile to reinforce slope[J].Journal of Lanzhou Jiaotong University:Natural Sciences,2007,26(4):81-83.(in Chinese))
[8]王唤龙,周德培.边坡工程中受压微型桩的屈曲分析[J].中国铁道科学,2010,31(6):21-25.(WANG Huanlong,ZHOU Depei.The buckling analysis of the pressed micro-pile in slope project[J].China Railway Science,2010,31(6):21-25.(in Chinese))
[9]朱本珍,孙书伟,郑静.微型桩群加固堆积层滑坡原位试验研究[J].岩石力学与工程学报,2011,30(增1):2 858-2 864.(ZHUBenzhen,SUN Shuwei,ZHENG Jing.In-situ testing study of accumulative formation landslide reinforced by micropile group[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(Supp.1):2 858-2 864.(in Chinese))
[10]朱宝龙,陈强,巫锡勇.微型桩群加固边坡受力特性离心模型试验研究[J].四川大学学报:工程科学版,2012,44(2):1-8.(ZHUBaolong,CHEN Qiang,WU Xiyong.Centrifugal mode test research on mechanical characteristics micropile groups reinforcing slope[J].Journal of Sichuan University:Engineering Science Edition,2012,44(2):1-8.(in Chinese))
[11]韩金平.液化场地微型桩基地震响应数值仿真研究[硕士学位论文][D].合肥:合肥工业大学,2007.(HAN Jinping.Numerical simulation experiments of micropile foundations in liquefiable soils[M.S.Thesis][D].Hefei:Hefei University of Technology,2007.(in Chinese))
[12]王栋.微型桩抗滑结构地震反应分析[硕士学位论文][D].成都:西南交通大学,2014.(WANG Dong.Research on micropiles to earthquake load[M.S.Thesis][D].Chengdu:Southwest Jiao tong University,2014.(in Chinese))
[13]杨静.微型桩加固边坡的动力响应特征及抗震计算方法研究[硕士学位论文][D].成都:西南交通大学,2012.(YANG Jing.Study on dynamic response characteristics of reinforced slope with micropiles and the aseismic analysis method[M.S.Thesis][D].Chengdu:Southwest Jiao tong University,2012.(in Chinese))
[14]牛文庆.微型桩支挡结构地震动力特性试验研究[硕士学位论文][D].北京:中国铁道科学研究院,2016.(NIU Wenqing.Research on earthquake dynamic experiment of micropiles supporting structure[M.S.Thesis][D].Beijing:China Academy of Railway Sciences,2016.(in Chinese))
[15]郑静,牛文庆,吴红刚,等.微型桩大型振动台试验-坡体及桩动力特性研究[J].铁道工程学报,2017,34(9):22-28.(ZHENGJing,NIU Wenqing,WU Honggang,et al.Research on the characteristics of large-scale shaking table experiment slope and dynamy of micropiles[J].Journal of Railway Engineering Society,2017,34(9):22-28.(in Chinese))
[16]ANG E C.Numerical investigation of load transfer mechanisms in slopes reinforced with piles[Ph.D.Thesis][D].Columbia:University of Missouri-Columbia,2005.
[2]SCHERER S D,WALTON W H,JOHNSON R.Chicago?s micropile debut[J].Civil Engineering,1996,66(8):51-53.
[3]MACKLIN P R,BERGER D,ZIETLOW W,et al.Case history:Micropile use for temporary excavation support[C]//Proceedings of Sessions of the Geosupport Conference:Innovation and Cooperation in Geo.Reston:Geotechnical Special Publication,ASCE,2004:653-661.
[4]周德培,王唤龙,孙宏伟.微型桩组合抗滑结构及其设计理论[J].岩石力学与工程学报,2009,28(7):1 353-1 362.(ZHOU Depei,WANG Huanlong,SUN Hongwei.Micro-pile composite structure and its design theory[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(7):1 353-1 362.(in Chinese))
[5]冯君,周德培,江南,等.微型桩体系加固顺层岩质边坡的内力计算模式[J].岩石力学与工程学报,2006,25(2):284-288.(FENG Jun,ZHOU Depei,JIANG Nan,et al.A mode for calculation of internal force of micropile system to reinforce bedding rock slope[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(2):284-288.(in Chinese))
[6]孙书伟,朱本珍,郑静.基于极限抗力分析的微型桩群加固土质边坡设计方法[J].岩土工程学报,2010,32(11):1 671-1 677.(SUNShuwei,ZHU Benzhen,ZHENG Jing.Design Method of micropile group for soil slope stabilization based on ultimate resistance of analysis[J].Chinese Journal of Geotechnical Engineering,2010,32(11):1 671-1 677.(in Chinese))
[7]沈龙运,余云燕.独立微型桩加固边坡的内力计算[J].兰州交通大学学报:自然科学版,2007,26(4):81-83.(SHEN Longyun,YUYunyan.Calculation of internal force of independent micropile to reinforce slope[J].Journal of Lanzhou Jiaotong University:Natural Sciences,2007,26(4):81-83.(in Chinese))
[8]王唤龙,周德培.边坡工程中受压微型桩的屈曲分析[J].中国铁道科学,2010,31(6):21-25.(WANG Huanlong,ZHOU Depei.The buckling analysis of the pressed micro-pile in slope project[J].China Railway Science,2010,31(6):21-25.(in Chinese))
[9]朱本珍,孙书伟,郑静.微型桩群加固堆积层滑坡原位试验研究[J].岩石力学与工程学报,2011,30(增1):2 858-2 864.(ZHUBenzhen,SUN Shuwei,ZHENG Jing.In-situ testing study of accumulative formation landslide reinforced by micropile group[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(Supp.1):2 858-2 864.(in Chinese))
[10]朱宝龙,陈强,巫锡勇.微型桩群加固边坡受力特性离心模型试验研究[J].四川大学学报:工程科学版,2012,44(2):1-8.(ZHUBaolong,CHEN Qiang,WU Xiyong.Centrifugal mode test research on mechanical characteristics micropile groups reinforcing slope[J].Journal of Sichuan University:Engineering Science Edition,2012,44(2):1-8.(in Chinese))
[11]韩金平.液化场地微型桩基地震响应数值仿真研究[硕士学位论文][D].合肥:合肥工业大学,2007.(HAN Jinping.Numerical simulation experiments of micropile foundations in liquefiable soils[M.S.Thesis][D].Hefei:Hefei University of Technology,2007.(in Chinese))
[12]王栋.微型桩抗滑结构地震反应分析[硕士学位论文][D].成都:西南交通大学,2014.(WANG Dong.Research on micropiles to earthquake load[M.S.Thesis][D].Chengdu:Southwest Jiao tong University,2014.(in Chinese))
[13]杨静.微型桩加固边坡的动力响应特征及抗震计算方法研究[硕士学位论文][D].成都:西南交通大学,2012.(YANG Jing.Study on dynamic response characteristics of reinforced slope with micropiles and the aseismic analysis method[M.S.Thesis][D].Chengdu:Southwest Jiao tong University,2012.(in Chinese))
[14]牛文庆.微型桩支挡结构地震动力特性试验研究[硕士学位论文][D].北京:中国铁道科学研究院,2016.(NIU Wenqing.Research on earthquake dynamic experiment of micropiles supporting structure[M.S.Thesis][D].Beijing:China Academy of Railway Sciences,2016.(in Chinese))
[15]郑静,牛文庆,吴红刚,等.微型桩大型振动台试验-坡体及桩动力特性研究[J].铁道工程学报,2017,34(9):22-28.(ZHENGJing,NIU Wenqing,WU Honggang,et al.Research on the characteristics of large-scale shaking table experiment slope and dynamy of micropiles[J].Journal of Railway Engineering Society,2017,34(9):22-28.(in Chinese))
[16]ANG E C.Numerical investigation of load transfer mechanisms in slopes reinforced with piles[Ph.D.Thesis][D].Columbia:University of Missouri-Columbia,2005.