微型桩-锚组合抗滑新结构支挡效果的数值分析
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摘要
针对微型桩加固滑坡时抗弯强度不足的缺陷,在类叉形微型桩组合结构的基础上引入预应力锚索,提出了一种微型桩-锚组合抗滑新结构。为验证其加固效果,基于斜坡应力状态变化理论,利用有限差分软件FLAC3D,分析了某边坡处于临滑状态时有无微型桩-锚结构加固的变形位移及应力分布特征。结果表明:1滑动状态下,坡体下部位移、应力水平大于上部,判断为牵引式滑坡;2新结构在布设位置产生较大局部应力集中,形成了一个结构-土空间骨架结构,在复合体系作用下滑坡体位移及中下部应力集中得到有效控制,尤其是在坡脚附近,主应力差、剪应变增量明显减小;3预应力锚索可以有效改善结构的整体受荷能力并减小桩身弯矩峰值;4该新结构轻型、环保、抗弯承载力高,可较好地满足边坡病害快速治理工程的需要。
Aiming at the defects of the micropile that the bending strength is insufficient when strengthening the landslide,this paper introduces prestressed anchor on base of the fork-like micropile composite structure,and puts forward a new micropile-anchor composite anti-sliding structure.In order to verify the reinforcement effect,on the base of the theory of slope stress state,this paper uses software FLAC3 Dto analyze the deformation displacement and stress distribution characteristics of the slpoe in critical sliding state when reinforced by the new micropile-anchor composite structure or not.Comparative results show that:(1)in sliding state,displacement and stress levels of the lower part of slope are greater than those of the upper,judging for the tractive landslide;(2)larger local stress concentration occurs at the arrangement location of the new structure,forming of a structure-soil space frame structure;landslide movement and stress concentration in the middle and lower parts are controlled effectively by the composite system,especially near the slope toe,the principal stress difference and shear strain increment are obviously reduced;(3)prestressed anchorage cable can improve the bearing capacity of the overall structure and decrease the peak of the pile bending moment effectively;(4)the new structure is light,green,and of high flexural bearing capacity,can meet the need of quick treatment against slope disease.
引文
[1]孙书伟.微型桩结构加固边坡受力机制和设计计算理论研究[D].北京:中国铁道科学研究院,2009.Sun Sh W.Study on loaded mechanism and design calculation theory of micropile structures for slope stabilization[D].Beijing:China Academy of Railway Sciences,2009.
    [2]刘凯,刘小丽,苏媛媛.微型抗滑桩的应用发展研究现状[J].岩土力学,2008,28(增):675-679.Liu K,Liu X L,Su Y Y.Research on application development of anti-slide micropiles[J].Rock and Soil Mechanics,2008,28(S):675-679.
    [3]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):2858-2864.Zhu B Zh,Sun Sh W,Zheng J.In-situ testing study of accumulative formation landslide reinforced by micropile group[J].Chinese Journal of Rock Mechanics and Engineering,2011,30(S1):2858-2864.
    [4]Thompson M J,White D J.Design of slope reinforcement with small-diameter pile[C]∥Proceeding of the Geo Shanghai Conference.Reston:Geotechnical Special Publication,ASCE,2006.
    [5]闫金凯,殷跃平.滑坡微型桩群桩加固工程模型试验研究[J].土木工程学报,2011,44(4):120-128.Yan J K,Yin Y P.Model test study of landslide reinforcement wite micropile groups[J].China Civil Engineering Journal,2011,44(4):120-128.
    [6]王恭先.王恭先滑坡学与滑坡防治技术文集[M].北京:人民交通出版社,2010.Wang G X.Wang Gongxian Landslide and Landslide Prevention and Control Technology[M].Beijing:China Communications Press,2010.
    [7]孙光忠.地质工程理论与实践[M].北京:地震出版社,1996.Sun G Zh.The Theory and Practice of Geological Engineering[M].Beijing:Seismological Press,1996.
    [8]杨光华,钟志辉.根据应力场和位移场判断滑坡的破坏类型及最优加固位置确定[J].岩石力学与工程学报,2012,31(9):1879-1887.Yang G H,Zhong Zh H.Indentification of landslide type and determination of optimal reinforcement site based on stress field and displacement field[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(9):1879-1887.
    [9]肖世国,鲜飞,王唤龙.一种微型桩组合抗滑结构内力分析方法[J].岩土力学,2010,31(8):2553-2559,2564.Xiao Sh G,Xian F,Wang H L.Analytical method of internal forces of a combining micropiles structure[J].Rock and Soil Mechanics,2010,31(8):2553-2559,2564.
    [10]贾金青,郑卫锋,陈国周.预应力锚杆柔性支护技术的数值分析[J].岩石力学与工程学报,2005,24(21):3978-3982.Jia J Q,Zheng W F,Chen G Zh.Numerical analysis of prestressed anchor flexible retaining method[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(21):3978-3982.

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