冻融作用下裂隙岩体锚固效应研究  

LABORATORY RESEARCH ON ANCHORAGE EFFECT OF FRACTURED ROCK MASS UNDER FREEZING AND THAWING

作　　者：赵建军[1] 严浩元 杨昌鑫 步凡 李涛 ZHAO Jianjun;YAN Haoyuan;YANG Changxin;BU Fan;LI Tao(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059;China Tower Corporation Chengdu Branch,Chengdu 610041;Shanghai Municipal Engineering Design and Research Institute(Group)Co.,Ltd.,Shanghai 200092)

机构地区：[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),成都610059 [2]中国铁塔股份有限公司成都市分公司,成都610041 [3]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《工程地质学报》2018年第5期1257-1264,共8页Journal of Engineering Geology

基　　金：国家科技支撑计划(2015BAK09B01);国家创新研究群体科学基金(41521002);中国华能集团科技项目(HNKJ16-H15)资助

摘　　要：用相似材料制作含预制裂隙岩体无锚和加锚试样,以锚杆与裂隙呈45°、90°打入锚杆制作3组试样,进行60次冻融循环,对冻融过程中裂隙进行应变监测并对冻融循环60次后的试样进行单轴压缩试验,探讨冻融循环作用下不同角度的锚杆支护对裂隙岩体的裂隙扩展规律、锚固效应及破坏模式的影响。研究结果表明:裂隙岩体在经历30次冻融循环之前,两种支护方式对裂隙的控制效果相当,随着冻融循环的进行,锚杆支护角度会对作用于锚杆的摩阻力产生一定影响,锚杆与裂隙夹角越大,作用于裂隙的摩阻力越大;天然状况下一个冻融循环周期内裂隙的应变大致经历了冷缩→冻胀→冻胀稳定→融缩→回弹→稳定6个阶段,两种支护工况均未出现明显的融缩阶段和回弹阶段,且90°支护工况效果比45°支护工况效果更加明显;对裂隙岩体采用水泥浆进行压力灌浆,由于水泥浆的保护作用可以对整个锚固系统起到一定的修复作用;锚杆增强了裂隙岩体抵制裂隙扩展的能力,降低了裂隙岩体劈裂破坏的突然性,且破坏模式由张拉破坏转换为张剪复合破坏。This paper uses similar materials and makes rock specimens with unanchored and/or anchored prefabricated fissures.Bolts and cracks at 45°and 90°are made into the anchor rods in the rock specimens.It discusses the regulation of propagation rules,anchorage effects and failure modes of rock samples through uniaxial compression tests after 60 cycles of freeze-thaw cycles with strain monitoring.The test results show the follows.(1)Two types of anchorages have equal effect in cracks supporting before 30 cycles of freeze-thaw cycles.The higher angle between bolts and cracks would have the larger power of anchorage to the cracks.(2)There is a regular form including six stages,cold shrinkage,frost heaving,frost heaving stability,melt-thaw,and rebound stability under natural conditions.Two supporting conditions do not show obvious stages of contraction and rebound.The 90°supporting condition is more effective than the 45°supporting condition.(3)The cement slurry is applied to fractured rock mass by hydraulic grout.It can repair the whole anchoring system.(4)The anchor rod enhances the ability of the fractured rock mass to resist the expansion of the fracture,reduces the suddenness of the fractured rock mass in the fractured rock mass.The failure mode is transformed from tensile damage to tensile shear complex damage.

关 键 词：冻融循环 裂隙岩体 摩阻力 锚固效应 

分 类 号：P642.3[天文地球—工程地质学]