岩石锚杆界面滑移破坏的DEM数值模拟
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摘要
锚固体与岩体之间界面滑移破坏是锚固系统失效的主要形式之一,开展岩石锚杆界面力学特性和破坏机制研究具有重要意义。基于岩石微观胶结接触模型,采用颗粒离散元(DEM)模拟了岩石锚杆的拉拔试验。首先分析了荷载-位移关系、轴力分布和界面剪应力分布规律,然后通过胶结破坏点的数目和组构研究了锚固段界面的微观破坏机制。主要结论有:模拟的荷载-位移曲线与室内试验结果基本一致;拉拔峰值荷载随锚固长度的增加而增大,界面平均粘结强度随着锚固长度的增加而减小;拉拔荷载值达到峰值后,锚固段界面产生渐进破坏;锚固段破坏在宏观上表现为界面滑移,在微观上主要表现为界面处的胶结拉伸破坏和沿轴力方向的微裂纹扩展。研究成果对开展岩石粘结锚杆的界面力学特性和破坏机制研究以及正确指导工程实践具有重要意义。
Researching the mechanical properties and failure mechanism of rock-bolt interface is of great significance since sliding between bolt and rock is a major failure form of anchorage system. With the microscopic bond model proposed by one of the authors previously,the pull-out test of rock bolts was simulated using discrete element method( DEM). The complete load-displacement curves,the distribution of axial force and the interfacial shear stress were investigated,respectively. Furthermore,the microscopic failure mechanism of bolt-rock interface was analyzed according to the type and fabric of broken bonds. Research results are concluded as follows: 1) the simulated load-displacement curves were consistent with those from laboratory tests; 2) with the increase of anchor length,peak load value increased while average cohesive strength of anchor interface decreased; 3) progressive failure occurred in the anchor interface after pull load reached peak; 4) on macroscopic level,the failure of anchored segment exhibited as interface sliding; whereas on microscopic level,the failure manifested as the tensile failure of bonds near interface and the propagation of micro-cracks along the direction of axial force.
Researching the mechanical properties and failure mechanism of rock-bolt interface is of great significance since sliding between bolt and rock is a major failure form of anchorage system. With the microscopic bond model proposed by one of the authors previously,the pull-out test of rock bolts was simulated using discrete element method( DEM). The complete load-displacement curves,the distribution of axial force and the interfacial shear stress were investigated,respectively. Furthermore,the microscopic failure mechanism of bolt-rock interface was analyzed according to the type and fabric of broken bonds. Research results are concluded as follows: 1) the simulated load-displacement curves were consistent with those from laboratory tests; 2) with the increase of anchor length,peak load value increased while average cohesive strength of anchor interface decreased; 3) progressive failure occurred in the anchor interface after pull load reached peak; 4) on macroscopic level,the failure of anchored segment exhibited as interface sliding; whereas on microscopic level,the failure manifested as the tensile failure of bonds near interface and the propagation of micro-cracks along the direction of axial force.
引文
[1]徐祯祥,闫莫明,苏自约.岩土锚固技术与西部开发[M].北京:人民交通出版社,2002.
[2]尤春安,战玉宝.预应力锚索锚固段界面滑移的细观力学分析[J].岩石力学与工程学报,2009,28(10):1976-1985.
[3]HOBST L,ZAJIC J.Anchoring in Rock and Soil[M].New York:Elsevier Scientific Publishing Company,1983.
[4]ELIGEHAUSEN R,LEHR B,MESZAROS J,et al.Behavior and Design of Anchorage with Bonded Anchors under Tension Load[C]∥Anchoring&Grouting—Proceedings of International Conference on Anchoring&Grouting Towards the New Century,Guangzhou,October 9,1999.Guangzhou:Zhongshan University Publishing House,1999:103-115.
[5]张永兴,饶枭宇,唐树名,等.压花锚锚固性能的试验研究与数值分析[J].岩石力学与工程学报,2008,27(3):607-614.
[6]FARMER I W.Stress Distribution Along a Resin Grouted Rock Anchor[J].International Journal of Rock Mechanics and Mining Science&Geomechanics Abstracts,1975,12(11):347-351.
[7]杨松林,荣冠,朱焕春.混凝土中锚杆荷载传递机理的理论分析和现场实验[J].岩土力学,2001,22(1):71-74.
[8]陈妙峰,唐德高,周早生,等.锚杆锚固机理试验研究[J].建筑技术开发,2003,30(4):21-23.
[9]张发明,陈祖煜,刘宁.岩体与锚固体间粘结强度的确定[J].岩土力学,2001,22(4):470-473.
[10]朱焕春,荣冠,肖明,等.张拉荷载下全长黏结锚杆工作机理试验研究[J].岩石力学与工程学报,2002,21(3):379-384.
[11]ZHANG B R,BENMOKRANE B,CHENNOUF A.Prediction of Tensile Capacity of Bond Anchorages for FRP Tendons[J].Journal of Composites for Construction,2000,4(2):39-47.
[12]江文武,徐国元,马长年.FLAC-3D的锚杆拉拔数值模拟试验[J].哈尔滨工业大学学报,2009,41(10):129-133.
[13]张凯,杨庆,蒋景彩,等.全长粘结岩石锚杆拉拔数值模拟[J].大连理工大学学报,2013,53(5):710-714.
[14]POTYONDY D O,CUNDALL P A.A Bonded-particle Model for Rock[J].International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1329-1364.
[15]赵同彬,尹延春,谭云亮,等.锚杆界面力学试验及剪应力传递规律细观模拟分析[J].采矿与安全工程学报,2011,28(2):220-224.
[16]张思峰.预应力内锚固段作用机理及其耐久性研究[D].上海:同济大学,2007.
[17]蒋明镜,方威,司马军.模拟岩石的平行粘结模型微观参数标定[J].山东大学学报(工学版),2015,45(4):50-56.
[18]蒋明镜,陈贺,刘芳.岩石微观胶结模型及离散元数值仿真方法初探[J].岩石力学与工程学报,2013,32(1):15-23.
[19]JIANG M J,KONRAD J M,LEROUEIL S.An Efficient Technique for Generating Homogeneous Specimens for DEM Studies[J].Computers and Geotechnics,2003,30(7):579-597.
[20]JIANG M J,CHEN H,CROSTA G B.Numerical Modeling of Rock Mechanical Behavior and Fracture Propagation by a New Bond Contact Model[J].International Journal of Rock Mechanics and Mining Sciences,2015,78:175-189.
[21]陈贺.岩石宏微观力学特性及高陡研制边坡的离散元数值模拟[D].上海:同济大学,2013.
[22]MARTIN C D.The Strength of Massive Lac du Bonnet Granite Around Underground Openings[D].Winnipeg,Canada:University of Manitoba,1993.
[23]韩军,陈强,刘元坤,等.锚杆灌浆体与岩(土)体间的粘结强度[J].岩石力学与工程学报,2005,24(19):3482-3486.
[24]尤春安,高明,张利民,等.锚固体应力分布的试验研究[J].岩土力学,2004,25(增刊):63-66.
[2]尤春安,战玉宝.预应力锚索锚固段界面滑移的细观力学分析[J].岩石力学与工程学报,2009,28(10):1976-1985.
[3]HOBST L,ZAJIC J.Anchoring in Rock and Soil[M].New York:Elsevier Scientific Publishing Company,1983.
[4]ELIGEHAUSEN R,LEHR B,MESZAROS J,et al.Behavior and Design of Anchorage with Bonded Anchors under Tension Load[C]∥Anchoring&Grouting—Proceedings of International Conference on Anchoring&Grouting Towards the New Century,Guangzhou,October 9,1999.Guangzhou:Zhongshan University Publishing House,1999:103-115.
[5]张永兴,饶枭宇,唐树名,等.压花锚锚固性能的试验研究与数值分析[J].岩石力学与工程学报,2008,27(3):607-614.
[6]FARMER I W.Stress Distribution Along a Resin Grouted Rock Anchor[J].International Journal of Rock Mechanics and Mining Science&Geomechanics Abstracts,1975,12(11):347-351.
[7]杨松林,荣冠,朱焕春.混凝土中锚杆荷载传递机理的理论分析和现场实验[J].岩土力学,2001,22(1):71-74.
[8]陈妙峰,唐德高,周早生,等.锚杆锚固机理试验研究[J].建筑技术开发,2003,30(4):21-23.
[9]张发明,陈祖煜,刘宁.岩体与锚固体间粘结强度的确定[J].岩土力学,2001,22(4):470-473.
[10]朱焕春,荣冠,肖明,等.张拉荷载下全长黏结锚杆工作机理试验研究[J].岩石力学与工程学报,2002,21(3):379-384.
[11]ZHANG B R,BENMOKRANE B,CHENNOUF A.Prediction of Tensile Capacity of Bond Anchorages for FRP Tendons[J].Journal of Composites for Construction,2000,4(2):39-47.
[12]江文武,徐国元,马长年.FLAC-3D的锚杆拉拔数值模拟试验[J].哈尔滨工业大学学报,2009,41(10):129-133.
[13]张凯,杨庆,蒋景彩,等.全长粘结岩石锚杆拉拔数值模拟[J].大连理工大学学报,2013,53(5):710-714.
[14]POTYONDY D O,CUNDALL P A.A Bonded-particle Model for Rock[J].International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1329-1364.
[15]赵同彬,尹延春,谭云亮,等.锚杆界面力学试验及剪应力传递规律细观模拟分析[J].采矿与安全工程学报,2011,28(2):220-224.
[16]张思峰.预应力内锚固段作用机理及其耐久性研究[D].上海:同济大学,2007.
[17]蒋明镜,方威,司马军.模拟岩石的平行粘结模型微观参数标定[J].山东大学学报(工学版),2015,45(4):50-56.
[18]蒋明镜,陈贺,刘芳.岩石微观胶结模型及离散元数值仿真方法初探[J].岩石力学与工程学报,2013,32(1):15-23.
[19]JIANG M J,KONRAD J M,LEROUEIL S.An Efficient Technique for Generating Homogeneous Specimens for DEM Studies[J].Computers and Geotechnics,2003,30(7):579-597.
[20]JIANG M J,CHEN H,CROSTA G B.Numerical Modeling of Rock Mechanical Behavior and Fracture Propagation by a New Bond Contact Model[J].International Journal of Rock Mechanics and Mining Sciences,2015,78:175-189.
[21]陈贺.岩石宏微观力学特性及高陡研制边坡的离散元数值模拟[D].上海:同济大学,2013.
[22]MARTIN C D.The Strength of Massive Lac du Bonnet Granite Around Underground Openings[D].Winnipeg,Canada:University of Manitoba,1993.
[23]韩军,陈强,刘元坤,等.锚杆灌浆体与岩(土)体间的粘结强度[J].岩石力学与工程学报,2005,24(19):3482-3486.
[24]尤春安,高明,张利民,等.锚固体应力分布的试验研究[J].岩土力学,2004,25(增刊):63-66.