首页|可回收锯齿锚杆抗拔承载力计算方法

可回收锯齿锚杆抗拔承载力计算方法

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为了解决基坑可回收锚杆普遍存在的锚杆承载头不可回收、回收效率低等问题,提出一种可完全回收的锯齿锚杆新型支护结构,阐明其结构构成和工作机理,并对其承载能力进行了分析.首先根据锯齿锚杆的结构特性,建立剪叉式锚固机构的扩张模型,采用弹性力学平面问题的复变函数法及Tresca塑性屈服准则,求解了剪叉式锚固机构扩开时周围土体的弹塑性解及剪叉臂的极限转角,并推导出该新型锚杆的抗拔承载力和转动单元转角阈值计算公式.然后采用有限元法对该新型锚杆的扩张过程和抗拔特性进行了分析,并将理论解与数值解进行对比验证.结果表明:(1)剪叉式锚固机构对土体应力的影响范围为其扩开宽度的2～3倍,锚固机构周围土体的塑性变形区边界呈椭圆状,且长短轴半径比值在锚固机构扩开过程中保持不变;(2)在不超过极限转角的范围内,锚固机构转角的增大能够提升可回收锯齿锚杆的抗拔性能;(3)相比普通锚杆,锯齿锚杆具有更强的抗拔承载能力.
Calculation Method of Pullout Capacity of Recyclable Sawtooth Anchor
In order to solve the problems of unrecyclable anchor bearing head and low recovery efficiency,which are commonly found in recyclable anchor used for foundation pit,a new supporting structure of fully recyclable sawtooth anchor is proposed,its structure and working mechanism are described,and its bearing capacity are analyzed.Firstly,according to the structural characteristics of the sawtooth anchor,the expansion model of the shear fork type anchorage mechanism is established.It is solved by using the complex function method of elasticity plane problem and Tresca plastic yield criterion that the elastoplastic solution of the surrounding soil and the ultimate rotation angle of the shear fork arm when the shear fork type anchorage mechanism is expanded,and the calculation formulas of the uplift bearing capacity and the threshold value of rotation angle of the rotation element of the new type of anchor are derived.Then,the expansion process and pullout characteristics of the new anchor are analyzed by using the finite element method,and the theoretical value is compared with the simulation value.The results show that:(1)The influence range of the shear fork anchorage mechanism on the soil stress is about 2～3 times of its expanded width.The boundary of the plastic deformation zone of the soil around the anchorage mechanism is elliptical,and the ratio of the long axis to the short axis radius remains unchanged during the expansion of the anchorage mechanism;(2)Within the range not exceeding the limit rotation angle,the increase of the rotation angle of the anchoring mechanism can improve the pullout resistant property of the recyclable sawtooth anchor;(3)Compared to ordinary anchor rod,recyclable sawtooth anchor have stronger pullout capacity.

recyclable sawtooth anchorcomplex function methodtresca yield criterionfinite element analysisexpansion processpullout capacity

连博、董建华、马连生、吴晓磊

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兰州理工大学土木工程学院,甘肃兰州 730050

西部土木工程防灾减灾教育部工程研究中心,甘肃兰州 730050

兰州理工大学理学院,甘肃兰州 730050

可回收锯齿锚杆 复变函数法 Tresca屈服准则 有限元分析 扩张过程 抗拔承载力

国家自然科学基金国家自然科学基金中央引导地方科技发展资金项目水利部重大科技项目甘肃省基础研究创新群体项目教育部产学合作协同育人项目教育部产学合作协同育人项目甘肃省自然科学基金

5217833551778275YDZX20216200001739SKS-202216620JR10RA205221070310818352210703107580622JR5RA243

2024

10.16058/j.issn.1005-0930.2024.01.016

应用基础与工程科学学报
中国自然资源学会

应用基础与工程科学学报

CSTPCD北大核心
影响因子：0.895
ISSN：1005-0930
年,卷(期)：2024.32(1)
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