内置锚盘扩大头锚杆承载特性模型试验研究  

Experimental Study on Model of Bearing Characteristics of Under-reamed Anchor with Built-in Anchor Plate

作　　者：曹海莹[1,2] 穆壮尉 郑凯林 刘亮 CAO Hai-ying;MU Zhuang-wei;ZHENG Kai-lin;LIU Liang(Key Lab of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province,Yanshan University,Qinhuangdao Hebei 066004,China;School of Civil Engineering and Mechanics,Yanshan University,Qinhuangdao Hebei 066004,China;Ninth Construction Branch Company of CCCC Fourth Highway Engineering Co.,Ltd.,Wuhu Anhui 241000,China;The Eighth Geological Brigade,Hebei Bureau of Geology and Mineral Resources Exploration,Qinhuangdao Hebei 066001,China)

机构地区：[1]燕山大学河北省土木工程绿色建造与智能运维重点实验室,河北秦皇岛066004 [2]燕山大学建筑工程与力学学院,河北秦皇岛066004 [3]中交四公局第九工程有限公司,安徽芜湖241000 [4]河北省地质矿产勘查开发局第八地质大队,河北秦皇岛066001

出　　处：《公路交通科技》2023年第3期25-32,共8页Journal of Highway and Transportation Research and Development

基　　金：河北省自然科学基金项目(E2020203168);河北省高等学校科学技术研究项目(ZD2020330);河北省研究生创新资助项目(CXZZSS2020042)。

摘　　要：为揭示扩大头锚杆体系的力学性能和破坏征兆,以内置锚盘扩大头锚杆为研究对象,借助研发的一套扩大头锚杆力学性能试验装置,采用室内缩尺模型试验的方法,研究了扩大头锚固体直径、长度、内置锚盘数量对锚杆承载力的影响,获得了扩大头锚杆拉力-相对土体位移曲线、锚固体侧摩阻力与端阻力数据、杆体与锚固体的应力-应变关系曲线以及土体及锚固体破坏模式。结果表明:锚杆拉力-相对土体位移曲线具有3阶段特征,即缓慢上升段、陡然增长段及趋于平缓段;内置锚盘扩大头锚杆的抗拉承载力主要由锚固体的侧阻力与端阻力提供,侧阻力在加载初期发挥主要作用,而端阻力在加载的中后期对锚杆极限承载力的贡献率大;在加载末期,锚杆体系表现为土体整体剪切破坏和锚固体劈裂破坏两种征兆,随着锚固体直径的增加,破坏征兆由土体整体剪切破坏演化为锚固体劈裂破坏;锚固体的直径、长度和内置锚盘数量对锚杆极限承载力的影响大小排序为:锚固体直径大于锚固体长度,大于内置锚盘数量;锚杆杆体处于非均匀分布受力状态,杆体可采用变截面设计方式;在拉力作用下,锚固体处于压缩膨胀状态,内置锚盘数量的增加可有效降低锚固体膨胀劈裂的发生概率。In order to reveal the mechanical behaviors and destruction signs of under-reamed anchor system,taking the under-reamed anchor with built-in anchor plate as the research object,with the help of a set of mechanical property test device for under-reamed anchor,the influence of diameter and length of underreamed anchor and the number of built-in anchor plates on anchor bearing capacity is researched by using the indoor scale model test.The curves of tension vs.displacement relative to soil of under-reamed anchor,data of side friction and end resistance of anchorage,stress-strain relationship curves of anchor rod and anchorage,and destruction modes of soil and anchorage.The result shows that(1)The curves of tension vs.displacement of anchor relative to soil have 3-stage characteristics,which are slow rising stage,steep growth stage and flat stage.(2)The tensile bearing capacity of under-reamed anchor with built-in anchor plate is mainly provided by the side friction and end resistance of anchorage,and the side friction plays a major role in the initial stage of loading,while the contribution rate of end resistance to the ultimate bearing capacity of anchor is large in the middle and late stages of loading.(3)At the end of loading,the anchor system shows 2 signs,which are overall shear destruction of the soil and splitting destruction of the anchorage.With the increase of the diameter of anchorage,the destruction sign evolves from the overall shear destruction of the soil to the splitting destruction of the anchorage.(4)The influences of the diameter and length of the anchorage and the number of built-in anchor plates on the ultimate bearing capacity of the anchor are in descending order,which are diameter of the anchorage,length of the anchorage and number of built-in anchor plates.(5)The anchor rod body is in the state of non-uniform stress distribution,the variable section design method can be adopted.(6)Under the action of tension,the anchorage is in the state of compression and expansion,and the increase of the n

关 键 词：道路工程 承载特性 模型试验 扩大头锚杆 内置锚盘 

分 类 号：U415.6[交通运输工程—道路与铁道工程]