变刚度悬臂式双排抗滑桩水平推桩模型试验研究
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摘要
双排抗滑桩常用于加固大型滑坡,其中悬臂式双排抗滑桩由于施工便利,受到工程界广泛重视。已有研究表明,后排桩承受的滑坡推力大于前排桩,是困扰设计的重要问题。文章借鉴变刚度调平设计原理,通过改变前后排桩间距实现前后排桩刚度的调整,设计了变刚度悬臂式双排抗滑桩支护形式,并进行了室内水平推桩模型试验,得到桩顶及坡顶位移、桩身弯矩以及滑体内土压力分布。结果表明:水平推桩模式下,桩顶位移和桩身弯矩随荷载增大而增大,模型边坡沿着滑动面破坏,根据桩顶的荷载-位移曲线,双排桩在推力作用下的发展过程被划分为三个阶段;适度增大前排桩的桩间距并不会明显降低双排抗滑桩的临界荷载;采用变刚度调平设计悬臂式双排抗滑桩,前排作用被充分调动,前后排最大弯矩差值变小;双排抗滑桩存在明显的三维土拱效应,在推力方向上被划分为后排桩后土拱效应、桩排间土拱效应、前排桩前土拱效应,在深度方向上,滑体中部土拱效应与滑体下部有所不同;适度扩大前排桩的间距,桩排间土体保持稳定,未见土体绕流现象,桩排间土拱效应作用明显。
Double-row anti-slide piles are usually used to reinforce large-scale landslides, and the cantilever-type are popular by engineers for the convenience in construction. The key step of design is to determine the landslide thrust acting on the front and back row piles. However, the research showed that the landslide thrust on the back-row piles is greater than that on the front-row piles. In order to solve the problem, a model test was designed by adjusting the stiffness of front and back row piles. The testing results showed that the pile head displacement and bending moment increased with the loading. The model slope destroyed along the sliding surface under the horizontal load. The development process of double-row piles under the thrust could be divided into three stages. The ultimate resistance of double-row anti-slide piles would not be significantly reduced when the pile spacing of front-row pile increased. By adjusting the stiffness between the front and back row piles,function of the front-row piles was fully motivated, the maximum bending moment between front and rear rows was reduced. The test also showed that there was obvious soil arching effect between piles, which could be divided into three zones, the back-row one, the front-row one and the one between the pile rows. Enlarging the spacing of the front row piles enhanced the soil arching effect between the piles. The distribution of soil pressure has spatial characteristics.
Double-row anti-slide piles are usually used to reinforce large-scale landslides, and the cantilever-type are popular by engineers for the convenience in construction. The key step of design is to determine the landslide thrust acting on the front and back row piles. However, the research showed that the landslide thrust on the back-row piles is greater than that on the front-row piles. In order to solve the problem, a model test was designed by adjusting the stiffness of front and back row piles. The testing results showed that the pile head displacement and bending moment increased with the loading. The model slope destroyed along the sliding surface under the horizontal load. The development process of double-row piles under the thrust could be divided into three stages. The ultimate resistance of double-row anti-slide piles would not be significantly reduced when the pile spacing of front-row pile increased. By adjusting the stiffness between the front and back row piles,function of the front-row piles was fully motivated, the maximum bending moment between front and rear rows was reduced. The test also showed that there was obvious soil arching effect between piles, which could be divided into three zones, the back-row one, the front-row one and the one between the pile rows. Enlarging the spacing of the front row piles enhanced the soil arching effect between the piles. The distribution of soil pressure has spatial characteristics.
引文
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[2]申永江,项正良,杨明.柔性双排长短组合桩滑坡推力的计算方法[J].岩土力学,2018,39(10):3597-3602(Shen Yongjiang,Xiang Zhengliang,Yang Ming.Calculation method of thrust force on the flexible double rows long-short piles[J].Rock and Soil Mechanics,2018,39(10):3597-3602(in Chinese))
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[4]Yu Yang,Shang Yuequan,Sun Hongyue.Bending behavior of double-row stabilizing piles with constructional time delay[J].Journal of Zhejiang University:Science A,2012,13(8):596-609
[5]邱志华.门架式抗滑桩土拱效应的数值分析研究[J].土工基础,2018,32(3):318-321(Qiu Zhihua.Arching effect of the pile frames and its numerical simulations[J].Soil Engineering and Foundations,2018,32(3):318-321(in Chinese))
[6]Zhao Bo,Wang Yunsheng,Wang Yu,et al.Retaining mechanism and structural characteristics of h type anti-slide pile(hTP pile)and experience with its engineering application[J].Engineering Geology,2017,222:29-37
[7]吴红刚,张乾翼,周张博.双排抗滑桩工作性能的模型试验研究[J].铁道工程学报,2015,32(9):49-54(Wu Honggang,Zhang Qianyi,Zhou Zhangbo.Model test research on the working performance of double-row anti-slide pile[J].Journal of Railway Engineering Society,2015,32(9):49-54(in Chinese))
[8]赖杰,郑颖人,刘云.双排抗滑桩抗震性能振动台试验研究及数值分析[J].中南大学学报:自然科学版,2015,46(11):4307-4315(Lai Jie,Zheng Yingren,Liu Yun.Shaking table test studies and numerical analysis of double-row anti-slide piles under earthquake[J].Journal of Central South University:Science and Technology,2015,46(11):4307-4315(in Chinese))
[9]肖世国,何洪.双排抗滑桩上滑坡推力近似解析方法[J].岩土力学,2015,36(2):376-380(Xiao Shiguo,He Hong.An approximate analytical method for calculating thrust on double-row stabilizing piles[J].Rock and Soil Mechanics,2015,36(2):376-380(in Chinese))
[10]Xiao Shiguo,Zeng Jinxiu,Yan Yuping.A rational layout of double-row stabilizing piles for large-scale landslide control[J].Bulletin of Engineering Geology&the Environment,76:309-321
[11]杨波,郑颖人,赵尚毅.双排抗滑桩在三种典型滑坡的计算与受力规律分析[J].岩土力学,2010,31(增1):237-244(Yang Bo,Zheng Yingren,Zhao Shangyi.Two-row anti-slide piles in three kinds of typical landslide computations and stress rule analysis[J].Rock and Soil Mechanics,2010,31(S1):237-244(in Chinese))
[12]谢芸菲,迟世春.桩基础变刚度调平设计研究进展[J].建筑结构,2017,47(6):91-95(Xie Yunfei,Chi Shichun.Review of variable rigidity design method for balance settlement of pile foundation[J].Building Structure,2017,47(6):91-95(in Chinese))
[13]董捷.悬臂桩三维土拱效应及嵌固段地基反力研究[D].重庆:重庆大学,2009(Dong Jie.Study on threedimensional soil arching effect of cantilever piles and ground resisting force acted on its build-in zone[D].Chongqing:Chongqing University,2009(in Chinese))
[14]赵晓坷,雷用,胡明,等.梅花型布置双排抗滑桩合理桩位研究[J].后勤工程学院学报,2015,31(2):11-16(Zhao Xiaoke,Lei Yong,Hu Ming,et al.Study on reasonable location of quincuncial layout double row anti slide pile[J].Journal of Logistical Engineering University,2015,31(2):11-16(in Chinese))
[15]孙书伟,朱本珍,马惠民.框架微型桩结构抗滑特性的模型试验研究[J].岩石力学与工程学报,2010,29(增1):3039-3044(Sun Shuwei,Zhu Benzhen,Ma Huimin.Model experimental research on anti-sliding characteristics of micropiles with cap bean[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(S1):3039-3044(in Chinese))
[16]欧孝夺,唐迎春,崔伟,等.H型抗滑桩模型试验及数值模拟[J].岩石力学与工程学报,2012,31(9):1936-1943(Ou Xiaoduo,Tang Yingchun,Cui Wei,et al.Model test and numerical simulation of h-shaped anti-sliding pile[J].Chinese Journal of Rock Mechanical and Engineering,2012,31(9):1936-1943(in Chinese))
[17]张永兴.边坡工程学[M].北京:中国建筑工业出版社,2008(Zhang Yongxing.Slope engineering[M].Beijing:China Construction Industry Press,2008(in Chinese))
[18]Robert Y L,Mohammad Y.Three dimensional finite element study of arching behavior in slope/drilled shafts system[J].International Journal for Numerical and Analytical Methods in Geomechanics,2010,34(11):1157-1168
[2]申永江,项正良,杨明.柔性双排长短组合桩滑坡推力的计算方法[J].岩土力学,2018,39(10):3597-3602(Shen Yongjiang,Xiang Zhengliang,Yang Ming.Calculation method of thrust force on the flexible double rows long-short piles[J].Rock and Soil Mechanics,2018,39(10):3597-3602(in Chinese))
[3]温祥虎,叶四桥,毛晓光.悬臂式双排桩与承台式双排桩的对比研究[J].公路工程,2016,41(2):251-255(Wen Xianghu,Ye Siqiao,Mao Xiaoguang.Comparative study of cantilever double-row piles and cushion cap double-row piles[J].Highway Engineering,2016,41(2):251-255(in Chinese))
[4]Yu Yang,Shang Yuequan,Sun Hongyue.Bending behavior of double-row stabilizing piles with constructional time delay[J].Journal of Zhejiang University:Science A,2012,13(8):596-609
[5]邱志华.门架式抗滑桩土拱效应的数值分析研究[J].土工基础,2018,32(3):318-321(Qiu Zhihua.Arching effect of the pile frames and its numerical simulations[J].Soil Engineering and Foundations,2018,32(3):318-321(in Chinese))
[6]Zhao Bo,Wang Yunsheng,Wang Yu,et al.Retaining mechanism and structural characteristics of h type anti-slide pile(hTP pile)and experience with its engineering application[J].Engineering Geology,2017,222:29-37
[7]吴红刚,张乾翼,周张博.双排抗滑桩工作性能的模型试验研究[J].铁道工程学报,2015,32(9):49-54(Wu Honggang,Zhang Qianyi,Zhou Zhangbo.Model test research on the working performance of double-row anti-slide pile[J].Journal of Railway Engineering Society,2015,32(9):49-54(in Chinese))
[8]赖杰,郑颖人,刘云.双排抗滑桩抗震性能振动台试验研究及数值分析[J].中南大学学报:自然科学版,2015,46(11):4307-4315(Lai Jie,Zheng Yingren,Liu Yun.Shaking table test studies and numerical analysis of double-row anti-slide piles under earthquake[J].Journal of Central South University:Science and Technology,2015,46(11):4307-4315(in Chinese))
[9]肖世国,何洪.双排抗滑桩上滑坡推力近似解析方法[J].岩土力学,2015,36(2):376-380(Xiao Shiguo,He Hong.An approximate analytical method for calculating thrust on double-row stabilizing piles[J].Rock and Soil Mechanics,2015,36(2):376-380(in Chinese))
[10]Xiao Shiguo,Zeng Jinxiu,Yan Yuping.A rational layout of double-row stabilizing piles for large-scale landslide control[J].Bulletin of Engineering Geology&the Environment,76:309-321
[11]杨波,郑颖人,赵尚毅.双排抗滑桩在三种典型滑坡的计算与受力规律分析[J].岩土力学,2010,31(增1):237-244(Yang Bo,Zheng Yingren,Zhao Shangyi.Two-row anti-slide piles in three kinds of typical landslide computations and stress rule analysis[J].Rock and Soil Mechanics,2010,31(S1):237-244(in Chinese))
[12]谢芸菲,迟世春.桩基础变刚度调平设计研究进展[J].建筑结构,2017,47(6):91-95(Xie Yunfei,Chi Shichun.Review of variable rigidity design method for balance settlement of pile foundation[J].Building Structure,2017,47(6):91-95(in Chinese))
[13]董捷.悬臂桩三维土拱效应及嵌固段地基反力研究[D].重庆:重庆大学,2009(Dong Jie.Study on threedimensional soil arching effect of cantilever piles and ground resisting force acted on its build-in zone[D].Chongqing:Chongqing University,2009(in Chinese))
[14]赵晓坷,雷用,胡明,等.梅花型布置双排抗滑桩合理桩位研究[J].后勤工程学院学报,2015,31(2):11-16(Zhao Xiaoke,Lei Yong,Hu Ming,et al.Study on reasonable location of quincuncial layout double row anti slide pile[J].Journal of Logistical Engineering University,2015,31(2):11-16(in Chinese))
[15]孙书伟,朱本珍,马惠民.框架微型桩结构抗滑特性的模型试验研究[J].岩石力学与工程学报,2010,29(增1):3039-3044(Sun Shuwei,Zhu Benzhen,Ma Huimin.Model experimental research on anti-sliding characteristics of micropiles with cap bean[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(S1):3039-3044(in Chinese))
[16]欧孝夺,唐迎春,崔伟,等.H型抗滑桩模型试验及数值模拟[J].岩石力学与工程学报,2012,31(9):1936-1943(Ou Xiaoduo,Tang Yingchun,Cui Wei,et al.Model test and numerical simulation of h-shaped anti-sliding pile[J].Chinese Journal of Rock Mechanical and Engineering,2012,31(9):1936-1943(in Chinese))
[17]张永兴.边坡工程学[M].北京:中国建筑工业出版社,2008(Zhang Yongxing.Slope engineering[M].Beijing:China Construction Industry Press,2008(in Chinese))
[18]Robert Y L,Mohammad Y.Three dimensional finite element study of arching behavior in slope/drilled shafts system[J].International Journal for Numerical and Analytical Methods in Geomechanics,2010,34(11):1157-1168