Abstract:The basalt fiber reinforced polymer(BFRP) anchor rod has advantages such as lightweight,high tensile strength and excellent corrosion resistance. This study pioneers the application of BFRP anchor rods in the basement anti-floating of a coastal hospital. The ultimate pull-out tests were conducted on five full-threaded BFRP anti-floating anchor rods with different anchorage lengths and diameters. The failure modes of the anti-floating anchor rods were analyzed,and the load-displacement relationship of the anchor rod and the anchor body was determined. The distribution of the axial force and the shear stress along the depth of the BFRP anchor rod was investigated,and the failure mechanism of BFRP anchor rods was discussed. The research reveals that:(1) The ultimate pull-out capacity of both groups of BFRP anti-floating anchor rods exceeds 400 kN,fully satisfying the anti-floating requirements of the project. (2) With the increase in the anchorage length and the rod diameter,the ultimate pull-out capacity of the anti-floating anchor rods slightly increases,but the displacement of the rod also increases accordingly. (3) The axial stress of BFRP anchor rod is maximum at the hole opening and decreases with increasing the depth. The area of stress transfer extends approximately two-thirds of the anchorage length. It is limited to improve the pull-out bearing capacity of the anti-floating anchor road through increasing the anchorage length. (4) The shear stress in the BFRP anchor rod initially increases rapidly along the depth of the anchorage,and then gradually decreases after reaching a peak near the anchorage depth of 0.75 m. The peak shear stress increases with increasing the load level. The results of the study provide a foundation for the application of BFRP anti-floating anchor rods.
[1] 匡 政,张明义,白晓宇,等. 风化岩地基GFRP抗浮锚杆力学与变形特性现场试验[J]. 岩土工程学报,2019,41(10):1 882–1 892. (KUANG Zheng,ZHANG Mingyi,BAI Xiaoyu,et al. Field tests on mechanics and deformation properties of GFRP anti-floating anchors in decomposed rock foundation[J]. Chinese Journal of Geotechnical Engineering,2019,41(10):1 882–1 892.(in Chinese))
[2] 曹 洪,潘 泓,骆冠勇. 地下结构截排减压抗浮概念及应用[J]. 岩石力学与工程学报,2016,35(12):2 542–2 548.(CAO Hong,PAN Hong,LUO Guanyong. A new anti-floatation method by drainage:concept and application[J]. Chinese Journal of Rock Mechanics and Engineering,2016,35(12):2 542–2 548.(in Chinese))
[3] SUN G,YAN N,BAI X,et al. Laboratory full-scale test on the bond property of GFRP anchor to concrete[J]. Construction and Building Materials,2023,396:132216.
[4] 胡成超,高 奎,涂建维,等. GFRP筋与箍筋约束混凝土之间粘结性能的试验研究[J]. 复合材料科学与工程,2020,(10):13–20.(HU Chengchao,GAO Kui,TU Jianwei,et al. Experimental research on bond behavior between GFRP bars and stirrups-confined concrete[J]. Composites Science and Engineering,2020,(10):13–20.(in Chinese))
[5] CHENG Y M,AU S K,YEUNG A T. Laboratory and field evaluation of several types of soil nails for different geological conditions[J]. Canadian Geotechnical Journal,2016,53(4):634–645.
[6] 井德胜,白晓宇,冯志威,等. 玄武岩纤维增强聚合物锚杆用于地下结构抗浮的可行性研究[J]. 材料导报,2021,35(19):19 223–19 229. (JING Desheng,BAI Xiaoyu,FENG Zhiwei. Feasibility study of BFRP anchor used in anti?floating of underground structure[J]. Materials Reports,2021,35(19):19 223–19 229.(in Chinese))
[7] 霍宝荣,张向东. BFRP筋的力学性能试验[J]. 沈阳建筑大学学报:自然科学版,2011,27(4):626–630.(HUO Baorong,ZHANG Xiangdong. Experimental study of mechanical properties of the BFRP bar in different diameters[J]. Journal of Shenyang Jianzhu University:Natural Science,2011,27(4):626–630.(in Chinese))
[8] 李为民,许金余. 玄武岩纤维对混凝土的增强和增韧效应[J]. 硅酸盐学报,2008,36(4):476–481.(LI Weimin,XU Jinyu. Strengthening and toughening in basalt fiber-reinforced concrete[J]. Journal of the Chinese Ceramic Society,2008,36(4):476–481.(in Chinese))
[9] PAVLOVSKI D,MISLAVSKY B,ANTONNOV A. CNG cylinder manufacturers test basalt fiber[J]. Reinf Plas,2007,(1):36–39.
[10] FIORE V,SCALICI T,DI BELLA G,et al. A review on basalt fibre and its composites[J]. Composites Part B:Engineering,2015,74:74–94.
[11] DONG Z Q,WU G,ZHAO X L,et al. Long-term bond durability of fiber-reinforced polymer bars embedded in seawater sea-sand concrete under ocean environments[J]. Journal of Composites for Construction,2018,22(5):04018042.
[12] 魏 斌. 玄武岩连续纤维及其混杂复合材料性能评价[硕士学位论文][D]. 哈尔滨:哈尔滨工业大学,2008.(WEI Bin. Evaluation of basalt fiber and its hybrid reinforced composite performance[M. S. Thesis][D]. Haerbin:Harbin Institute of Technology,2008.(in Chinese))
[13] HUSSAIN S,KHAN M Z N,KHAN H A. Bond performance of basalt FRP bar against aggressive environment in high-strength concrete with varying bar diameter and bond length[J]. Construction and Building Materials,2022,349:128779.
[14] 张书博,王长盛,王 刚,等. BFRP筋锚固节理岩体剪切行为试验研究[J]. 岩石力学与工程学报,2022,41(4):712–724.(ZHANG Shubo,WANG Changsheng,WANG Gang,et al. Experimental study on the shear behaviors of bolted rock joints reinforced with BFRP bars[J]. Chinese Journal of Rock Mechanics and Engineering,2022,41(4):712–724.(in Chinese))
[15] WANG X,SU C,DENG W,et al. Bond behavior between corrugated BFRP shell and concrete under monotonic and cyclic loads[J]. Construction and Building Materials,2019,210:596–606.
[16] SHEN D,LI C,FENG Z,et al. Influence of strain rate on bond behavior of concrete members reinforced with basalt fiber-reinforced polymer rebars[J]. Construction and Building Materials,2019,228:116755.
[17] YANG Y,LI Z,ZHANG T,et al. Bond-slip behavior of basalt fiber reinforced polymer bar in concrete subjected to simulated marine environment:effects of BFRP bar size,corrosion age,and concrete strength[J]. International Journal of Polymer Science,2017,2017:1–9.
[18] 冯 君,赖 冰,张圣亮,等. 玄武岩纤维增强锚杆加固混合土室内拉拔试验研究[J]. 西南交通大学学报,2022,57(6):1 193–1 200. (FENG Jun,LAI Bing,ZHANG Shengliang,et al. Laboratory pull-out test study of basalt fiber reinforced polymer bolt for strengthening mixed soil[J]. Journal of Southwest Jiaotong University,2022,57(6):1 193–1 200.(in Chinese))
[19] 白晓宇,井德胜,王海刚,等. GFRP抗浮锚杆界面黏结性能现场试验[J]. 岩石力学与工程学报,2022,41(4):748–763.(BAI Xiaoyu,JING Desheng,WANG Haigang,et al. Field test of interface bonding performance of GFRP anti-floating anchors[J]. Chinese Journal of Rock Mechanics and Engineering,2022,41(4):748–763.(in Chinese))
[20] HYETT A J,BAWDEN W F,MACSPORRAN G R,et al. A constitutive law for bond failure of fully-grouted cable bolts using a modified Hoek cell[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1995,32(1):11–36.
[21] 曾宪明,赵 林,李世民,等. 锚固类结构杆体临界锚固长度与判别方法试验研究[J]. 岩土工程学报,2008,30(增1):404–409. (ZENG Xianming,ZHAO Lin,LI Shimin,et al. Critical rod anchorage length and discrimination method of anchorage type structure[J]. Chinese Journal of Geotechnical Engineering,2008,30(Supp.1):404–409.(in Chinese))
[22] 张 晨,周 峰,王旭东,等. 扩底抗浮锚杆的抗拔承载特性试验研究[J]. 地下空间与工程学报,2021,17(6):1 888–1 893.(ZHANG Chen,ZHOU Feng,WANG Xudong,et al. Field tests and research on uplift capacity of expanded anchor[J]. Chinese Journal of Underground Space and Engineering,2021,17(6):1 888–1 893.(in Chinese))
[23] 赵卫平,朱彬荣. 高温后HSC粘结滑移基础参数测量与3D有限元数值模拟[J]. 工程力学,2017,34(4):177–186.(ZHAO Weiping,ZHU Binrong. Basic parameters test and 3D modelling of bond in HSC after elevated temperatures[J]. Engineering Mechanics,2017,34(4): 177–186.(in Chinese))
[24] 冯 君,王 洋,张俞峰,等. 玄武岩纤维与钢筋锚杆锚固性能现场对比试验研究[J]. 岩土力学,2019,40(11):4 185–4 193.(FENG Jun,WANG Yang,ZHANG Yufeng,et al. Experimental comparison of anchorage performance between basalt fiber and steel bars [J]. Rock and Soil Mechanics,2019,40(11):4 185–4 193.(in Chinese))
[25] 白晓宇,张明义,闫 楠. 两种不同材质抗浮锚杆锚固性能的现场对比试验研究与机制分析[J]. 土木工程学报,2015,48(8):38–46.(BAI Xiaoyu,ZHANG Mingyi,YAN Nan,et al. Field contrast test and mechanism analysis on anchorage performance of anti-floating anchors with two different materials[J]. China Civil Engineering Journal,2015,48(8):38–46.(in Chinese))