针对锚杆拉拔过程锚固界面的承载特性问题,本文基于锚杆的受力破坏机理,建立了能描述锚杆杆体-砂浆界面历经弹性、塑性软化及开裂滑移的三段非线性函数模型。采用荷载传递理论,对拉拔荷载下锚杆的全历程承载特性进行了分析,并通过与现场试验对比分析验证了模型的合理性。结果表明:(1) 弹性区侧阻力沿深度方向呈双曲函数分布,塑性软化区侧阻力非线性软化至残余剪切强度;滑移区侧阻力均匀分布;(2)拉拔过程中,随着拉拔荷载的增大,P-s关系图由直线向曲线转变,相同荷载增量下,位移增量变大,理论预测与实测结果较吻合。
In view of the bearing characteristics of the anchorage interface in the process of anchor drawing, a three-stage nonlinear function model is established to describe the three stages of elastic, plastic softening and cracking sliding of the anchorage interface based on the mechanical failure mechanism of anchor. Adopting the load transfer theory, the bearing characteristics of anchor under the pull-out load are analyzed, and the rationality of the model is verified by comparing with the field test. The results show that: (1) The lateral resistance in the elastic zone is hyperbolic along the depth direction; The lateral resistance in the plastic soft zone is nonlinear softened to the residual shear strength; the lateral resistance in the sliding zone is evenly distributed. (2) In the process of drawing, with the increase of drawing load, the P-s curve changes from a straight line to a curve. Under the same load increment, the displacement increment becomes larger. The theoretical prediction is in good agreement with the measured results.
[1] 张乐文, 汪淰. 岩土锚固理论研究之现状[J].岩土力学, 2002, 23(5): 627-631.
[2] 汪班桥, 门玉明, 沈星. 土层锚杆的常见病害及防治对策研究[J]. 安全与环境学报, 2010, 10(1): 154-159.
[3] 宋洋, 祝百茹. 动荷载作用下端锚杆力学响应试验研究[J].安全与环境学报, 2014, 14(3): 58-62.
[4] 程良奎, 范景伦, 韩军, 等. 岩土锚固[M]. 北京:中国建筑工业出版社, 2002.
[5] 程良奎, 张培文.岩土锚固工程的若干力学概念问题[J]. 岩石力学与工程学报, 2015, 34(4): 668-682.
[6] 杨庆, 朱训国, 栾茂田. 全长注浆岩土锚杆双曲线模型的建立及锚固效应的参数分析[J]. 岩石力学与工程学报, 2007, 26(4): 692-698.
[7] Ren F F, Yang Z J, Chen J F, et al. An analytical analysis of the full-range behaviour of grouted rockbolts based on a tri-linear bond-slip model[J]. Construction and Building Materials, 2010, 24(3): 361-370.
[8] 雷勇, 尹君凡, 陈秋南, 等. 基于荷载传递法的嵌岩锚杆抗拔承载特性[J]. 水利水电科技进展, 2017, 37(4): 70-76.
[9] Ma S Q, Nemcik J, Aziz N. An analytical model offully grouted rock bolts subjected to tensile load[J]. Construction and Building Materials, 2013, 49: 519-526.
[10] Dai J, Ueda T, Sato Y. Development of the nonlinearbond stress-slip model of fiber reinforced plastics sheet-concrete interfaces with a simple method[J]. Journal of Composites for Construction, 2005, 9(1): 52-62.
[11] Zhou Y W, Wu Y F, Yun Y. Analytical modeling ofthe bond-slip relationship at FRP-concrete interfaces for adhesively-bonded joints[J]. Composites Part B: Engineering, 2010, 41(6): 423-433.
[12] 张季如, 唐保付. 锚杆荷载传递机理分析的双曲函数模型[J].岩土工程学报, 2002, 24(2): 188-192.
[13] 黄明华, 周智, 欧进萍. 拉力型锚杆锚固段拉拔受力的非线性全历程分析[J]. 岩石力学与工程学报, 2014, 33(11): 2190-2199.
[14] 何思明, 田金昌, 周建庭. 胶结式预应力锚索锚固段荷载传递特性研究[J]. 岩石力学与工程学报, 2006, 25(1): 117-121.
[15] Farmer I W. Stress distribution along a resin grouted rock anchor[J]. International Journal of Rock Mechanics Mining Science & Geomechanics Abstract, 1975, 12(11): 347-351.
[16] 黄明华, 赵明华, 陈昌富. 基于非线性界面模型的锚杆拉拔受力变形特性研究[J]. 安全与环境学报, 2019, 19(4): 1196-1203.
[17] 徐前卫, 朱合华, 金方方, 等. 软弱破碎岩体中锚杆抗拔受力机理及试验研究[J]. 地下空间与工程学报, 2011, 7(5): 830-835.
[18] 张传庆, 崔国建, 周辉, 等.锚杆杆体-砂浆界面剪切力学特性试验研究[J]. 岩石力学与工程学报, 2018, 37(4): 820-828.
[19] Jonston I W, Lam T S K, Williams A F. Constant normal stiffness direct shear testing for socketed piledesign in weak rock[J]. Geotechnique, 1987, 37 (1): 83-89.
[20] Seed H B, Reese L C. The action of soft clay along friction piles[J].Transactions of the American Society of Civil Engineers, 1957, 122(1): 31-754.
[21] 刘波, 李东阳, 段艳芳, 等. 锚杆-砂浆界面黏结滑移关系的试验研究与破坏过程解析[J]. 岩石力学与工程学报, 2011, 30(增1): 2790-2797.
