树脂锚固剂中添加不同钢质骨料对锚固力的影响
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摘要
本次实验研究对钢质骨料添加剂的外形、粒径和浓度进行了优化,以提高树脂锚固剂在破坏界面的抗剪能力和改变原锚固剂的直剪破坏方式来直接改善整个锚固系统的加固效果,进一步提高了钢质骨料对试件锚固力的增强程度。试验通过向散装慢速树脂锚固剂中分别添加粒径为1. 5,2. 0,2. 8 mm的钢砂和1. 4,2. 0,2. 5 mm的钢丸,每种粒径的钢质骨料又分为30,40,50共3种数量;使用矿业20 mm右旋螺纹钢锚杆和长度100 mm、内径30 mm、壁厚7. 0 mm的钢套筒制作锚固试样;然后使用电液伺服万能试验机,加载方式为2 mm/min进行拉拔试验采集数据,并结合销栓作用相关理论分析不同钢质骨料添加剂对平均锚固力的影响。试验数据表明:与无添加钢质骨料的锚固试件相比,向树脂锚固剂中添加钢砂和钢丸对锚固试件的平均锚固力分别为125. 6,129. 0 kN,提高了6. 4%和9. 4%;其中,添加粒径为1. 4～1. 5,2. 0～2. 0和2. 5～2. 8 mm的试件平均锚固力分别为127. 6,124. 7和129. 6 k N,提高了8. 1%,5. 7%和9. 8%,呈现先减小而后增大的趋势;而添加钢质骨料的数量增加对锚固力的提升程度呈现逐渐减小的趋势,即添加骨料数量为30,40,50的试件平均锚固力分别为128. 5,127. 2和126. 2 k N,提升约8. 9%,7. 8%和6. 9%。本次实验中最大锚固力提升来自添加数量为30、粒径为1. 4 mm的钢丸,平均锚固力为135. 1 kN,增加了14. 5%。试验中的锚固剂破坏方式为剪切破坏,且钢质骨料产生的销栓作用对锚固剂破坏表面造成划痕,并根据锚固段破坏机理分析,进一步讨论了锚固剂抗剪强度及残余抗剪强度参数对锚固效果产生的重要影响。
In this experimental study,the shape,particle size and concentration of the steel aggregate additive were optimized to directly improve the strengthening effect of the anchorage system by increasing the shear resistance of the resin anchoring agent at the failure interface and changing the original direct shear failure mode of the anchoring agent.Furthermore,the study enhanced the degree of reinforcement of the steel ag-gregate to the anchoring force of the specimen.The test was conducted by adding steel grit with a particle size of 1.5,2.0,and 2.8 mm and steel shot of 1. 4,2. 0,and 2.5 mm to the bulk slow resin anchoring agent,and each particle size was further divided into 30,40 and 50 kinds in total.A 20 mm right-lateral rebar and steel sleeve with length of 100 mm,inner diameter of 30 mm and wall thickness of 7.0 mm were used to make anchoring specimens. Then,an electro-hydraulic servo universal testing machine with 2 mm/min of loading mode was used to collect data for the pullout test,and the effects of different steel aggregate additives on the average anchoring force were analyzed based on the theory of doweling effect. The test data showed that the average anchoring force of the anchoring specimens with the steel grit and steel shot is 125.6 and 129.0 kN,respectively,increasing by 6.4% and 9.4%,comparing with the specimens without adding steel aggregate.Among them,the average anchoring force of specimens with particle sizes of 1.4-1.5,2.0-2.0 and 2.5-2.8 mm is 127.6,124.7 and 129.6 kN,respectively,which increased by 8.1%,5.7% and 9.8%,showing a trend of decreasing first and then increasing.While the increase in the amount of adding steel aggregates presents a gradual decrease in the degree of improvement of anchorage force,i.e.,the average anchoring force of the specimens with the aggregate amount of 30,40,50 is 128.5,127.2 and 126.2 k N,respectively,with an increase of about 8.9%,7.8% and 6. 9%.In this experiment,the maximum anchorage force is increased by 14.5%,with an average anchorage force of 135.1 k N,from steel shot with an added quantity of 30 and a particle size of 1.4 mm.The failure mode of the anchoring agent in the test is shear failure,and the doweling effect produced by steel aggregate causes scratches on the failure surface of the anchoring agent.According to the analysis of the failure mechanism of the anchorage section,the important effects of shear strength and residual shear strength parameters of the anchoring agent on the anchoring effect are further discussed.
In this experimental study,the shape,particle size and concentration of the steel aggregate additive were optimized to directly improve the strengthening effect of the anchorage system by increasing the shear resistance of the resin anchoring agent at the failure interface and changing the original direct shear failure mode of the anchoring agent.Furthermore,the study enhanced the degree of reinforcement of the steel ag-gregate to the anchoring force of the specimen.The test was conducted by adding steel grit with a particle size of 1.5,2.0,and 2.8 mm and steel shot of 1. 4,2. 0,and 2.5 mm to the bulk slow resin anchoring agent,and each particle size was further divided into 30,40 and 50 kinds in total.A 20 mm right-lateral rebar and steel sleeve with length of 100 mm,inner diameter of 30 mm and wall thickness of 7.0 mm were used to make anchoring specimens. Then,an electro-hydraulic servo universal testing machine with 2 mm/min of loading mode was used to collect data for the pullout test,and the effects of different steel aggregate additives on the average anchoring force were analyzed based on the theory of doweling effect. The test data showed that the average anchoring force of the anchoring specimens with the steel grit and steel shot is 125.6 and 129.0 kN,respectively,increasing by 6.4% and 9.4%,comparing with the specimens without adding steel aggregate.Among them,the average anchoring force of specimens with particle sizes of 1.4-1.5,2.0-2.0 and 2.5-2.8 mm is 127.6,124.7 and 129.6 kN,respectively,which increased by 8.1%,5.7% and 9.8%,showing a trend of decreasing first and then increasing.While the increase in the amount of adding steel aggregates presents a gradual decrease in the degree of improvement of anchorage force,i.e.,the average anchoring force of the specimens with the aggregate amount of 30,40,50 is 128.5,127.2 and 126.2 k N,respectively,with an increase of about 8.9%,7.8% and 6. 9%.In this experiment,the maximum anchorage force is increased by 14.5%,with an average anchorage force of 135.1 k N,from steel shot with an added quantity of 30 and a particle size of 1.4 mm.The failure mode of the anchoring agent in the test is shear failure,and the doweling effect produced by steel aggregate causes scratches on the failure surface of the anchoring agent.According to the analysis of the failure mechanism of the anchorage section,the important effects of shear strength and residual shear strength parameters of the anchoring agent on the anchoring effect are further discussed.
引文
[1]赵象卓,张宏伟,CAO C,等.不同围岩条件下锚杆肋间距与锚固力优化研究[J].岩土力学,2018,39(4):1263-1270,1280.ZHAO Xiangzhuo,ZHANG Hongwei,CAO C,et al. Optimization of bolt rib spacing and anchoring force under different conditions of surrounding rock[J]. Rock and Soil Mechanics,2018,39(4):1263-1270,1280.
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[3] GHADIMI M.Effect of profile bolt in bond strength fully grouted rock bolts using analytical and experimental methods[J]. International Journal of Mining&Mineral Engineering,2017,8(2):156.
[4] MA S,AZIZ N,NEMCIK J,et al.The effects of installation procedure on bond characteristics of fully grouted rock bolts[J]. Geotechnical Testing Journal,2017,40(5):20160239.
[5]康红普,崔千里,胡滨,等.树脂锚杆锚固性能及影响因素分析[J].煤炭学报,2014,39(1):1-10.KANG Hongpu,CUI Qianli,HU Bin,et al. Analysis on anchorage performances and affecting factors of resin bolts[J].Journal of China Coal Society,2014,39(1):1-10.
[6]林健,任硕,杨景贺.树脂全长锚固锚杆外形尺寸优化实验室研究[J].煤炭学报,2014,39(6):1009-1015.LIN Jian,REN Shuo,YANG Jinghe.Laboratory research of resin fulllength anchoring bolts dimension optimization[J]. Journal of China Coal Society,2014,39(6):1009-1015.
[7] CAO C,REN T,COOK C,et al. Analytical approach in optimising selection of rebar bolts in preventing rock bolting failure[J].International Journal of Rock Mechanics&Mining Sciences,2014,72:16-25.
[8]徐有邻,沈文都.钢筋外形对粘结性能的影响[J].工业建筑,1987,17(3):28-32.XU Youling,SHEN Wendu.Effect of steel bar shape on bonding performance[J].Industrial Constrution,1987,17(3):28-32.
[9] HOEK E,WOOD D F. Rock support[J]. Mining Magazine,1988,159(4):282-287.
[10]李东印,王伸.螺纹钢横肋作用下锚固体应力分布与破坏规律[J].煤炭学报,2015,40(9):2026-2032.LI Dongyin,WANG Shen.Research on load distribution and failure of fully grouted bolt under thread steel rib[J]. Journal of China Coal Society,2015,40(9):2026-2032.
[11]贺小岗,关国雄.钢筋销栓模型及其在深梁分析中的应用[J].工程力学,2001,18(1):96-102.HE Xiaogang,GUAN Guoxiong. A model for dowel action of reinforcement bars and its application to deep beam analysis[J].Engineering Mechanics,2001,18(1):96-102.
[12] HYETT A J,BAWDEN W F,REICHERT R D. The effect of rock mass confinement on the bond strength of fully grouted cable bolts[J]. International Journal of Rock Mechanics&Mining Sciences&Geomechanics Abstracts,1992,29(5):503-24.
[13] 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&Mining Science&Geomechanics Abstracts,1995,32(1):11-36.
[14] HYETT A J,MOSSAVI M,BAWDEN W F.Load distribution along fully grouted bolts,with emphasis on cable bolt reinforcement[J].International Journal for Numerical&Analytical Methods in Geomechanics,1996,20:517-44.
[15]饶枭宇.预应力岩锚内锚固段锚固性能及荷载传递机理研究[D].重庆:重庆大学,2007:43-55.RAO Xiaoyu. Study on anchorage performance and load-transfer mechanism of embedment section of prestressed rock cable bolt[D].Chongqing:Chongqing University,2007:43-55.
[16]尤春安,战玉宝.预应力锚索锚固段界面滑移的细观力学分析[J].岩石力学与工程学报,2009,28(10):1976-1985.YOU Chun’an,ZHAN Yubao. Analysis of interfacial slip mesomechanics in anchorage section of prestressed anchor cable[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(10):1976-1985.
[17] CAO C,NEMCIK J,AZIZ N,et al. Analytical study of steel bolt profile and its influence on bolt load transfer[J]. International Journal of Rock Mechanics&Mining Sciences,2013,60:188-195.
[18] KILIC A,YASAR E,ATIS C D.Effect of bar shape on the pullout capacity of fully-grouted rockbolts[J]. Tunnelling&Underground Space Technology Incorporating Trenchless Technology Research,2003,18(1):1-6.
[19] WU T,CAO C,HAN J,et al. Effect of bolt rib spacing on load transfer mechanism[J]. International Journal of Mining Science and Technology,2017,27(3):431-434.
[20] CAO C,REN T,ZHANG Y,et al.Experimental investigation of the effect of grout with additive in improving ground support[J].International Journal of Rock Mechanics&Mining Sciences,2016,85:52-59.
[21] CAO C,REN T,COOK C.Introducing aggregate into grouting material and its influence on load transfer of the rock bolting system[J].International Journal of Mining Science and Technology,2014,24(3):325-328.
[22] ZHOU F P,LYDON F D,BARR B I G.Effect of coarse aggregate on elastic modulus and compressive strength of high performance concrete[J]. Cement&Concrete Research,1995,25(1):177-186.
[23] KILIC A,ATIS C D,TEYMEN A,et al. The influence of aggregate type on the strength and abrasion resistance of high strength concrete[J]. Cement&Concrete Composites,2008,30(4):290-296.
[24] BENMOKRANE B,CHENNOUF A,MITRI H S.Laboratory evaluation of cement-based grouts and grouted rock anchors[J]. International Journal of Rock Mechanics&Mining Sciences&Geomechanics Abstracts,1995,32(7):633-642.
[25] MOOSAVI M,BAWDEN W F. Shear strength of Portland cement grout[J]. Cement&Concrete Composites,2003,25(7):729-735.
[2]吴涛,CAO C,赵象卓,等.不同肋间距锚杆锚固性能实验室试验研究[J].煤炭学报,2017,42(10):2545-2553.WU Tao,CAO C,ZHAO Xiangzhuo,et al. Laboratory study on anchorage performance in different rib spacings of bolt[J]. Journal of China Coal Society,2017,42(10):2545-2553.
[3] GHADIMI M.Effect of profile bolt in bond strength fully grouted rock bolts using analytical and experimental methods[J]. International Journal of Mining&Mineral Engineering,2017,8(2):156.
[4] MA S,AZIZ N,NEMCIK J,et al.The effects of installation procedure on bond characteristics of fully grouted rock bolts[J]. Geotechnical Testing Journal,2017,40(5):20160239.
[5]康红普,崔千里,胡滨,等.树脂锚杆锚固性能及影响因素分析[J].煤炭学报,2014,39(1):1-10.KANG Hongpu,CUI Qianli,HU Bin,et al. Analysis on anchorage performances and affecting factors of resin bolts[J].Journal of China Coal Society,2014,39(1):1-10.
[6]林健,任硕,杨景贺.树脂全长锚固锚杆外形尺寸优化实验室研究[J].煤炭学报,2014,39(6):1009-1015.LIN Jian,REN Shuo,YANG Jinghe.Laboratory research of resin fulllength anchoring bolts dimension optimization[J]. Journal of China Coal Society,2014,39(6):1009-1015.
[7] CAO C,REN T,COOK C,et al. Analytical approach in optimising selection of rebar bolts in preventing rock bolting failure[J].International Journal of Rock Mechanics&Mining Sciences,2014,72:16-25.
[8]徐有邻,沈文都.钢筋外形对粘结性能的影响[J].工业建筑,1987,17(3):28-32.XU Youling,SHEN Wendu.Effect of steel bar shape on bonding performance[J].Industrial Constrution,1987,17(3):28-32.
[9] HOEK E,WOOD D F. Rock support[J]. Mining Magazine,1988,159(4):282-287.
[10]李东印,王伸.螺纹钢横肋作用下锚固体应力分布与破坏规律[J].煤炭学报,2015,40(9):2026-2032.LI Dongyin,WANG Shen.Research on load distribution and failure of fully grouted bolt under thread steel rib[J]. Journal of China Coal Society,2015,40(9):2026-2032.
[11]贺小岗,关国雄.钢筋销栓模型及其在深梁分析中的应用[J].工程力学,2001,18(1):96-102.HE Xiaogang,GUAN Guoxiong. A model for dowel action of reinforcement bars and its application to deep beam analysis[J].Engineering Mechanics,2001,18(1):96-102.
[12] HYETT A J,BAWDEN W F,REICHERT R D. The effect of rock mass confinement on the bond strength of fully grouted cable bolts[J]. International Journal of Rock Mechanics&Mining Sciences&Geomechanics Abstracts,1992,29(5):503-24.
[13] 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&Mining Science&Geomechanics Abstracts,1995,32(1):11-36.
[14] HYETT A J,MOSSAVI M,BAWDEN W F.Load distribution along fully grouted bolts,with emphasis on cable bolt reinforcement[J].International Journal for Numerical&Analytical Methods in Geomechanics,1996,20:517-44.
[15]饶枭宇.预应力岩锚内锚固段锚固性能及荷载传递机理研究[D].重庆:重庆大学,2007:43-55.RAO Xiaoyu. Study on anchorage performance and load-transfer mechanism of embedment section of prestressed rock cable bolt[D].Chongqing:Chongqing University,2007:43-55.
[16]尤春安,战玉宝.预应力锚索锚固段界面滑移的细观力学分析[J].岩石力学与工程学报,2009,28(10):1976-1985.YOU Chun’an,ZHAN Yubao. Analysis of interfacial slip mesomechanics in anchorage section of prestressed anchor cable[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(10):1976-1985.
[17] CAO C,NEMCIK J,AZIZ N,et al. Analytical study of steel bolt profile and its influence on bolt load transfer[J]. International Journal of Rock Mechanics&Mining Sciences,2013,60:188-195.
[18] KILIC A,YASAR E,ATIS C D.Effect of bar shape on the pullout capacity of fully-grouted rockbolts[J]. Tunnelling&Underground Space Technology Incorporating Trenchless Technology Research,2003,18(1):1-6.
[19] WU T,CAO C,HAN J,et al. Effect of bolt rib spacing on load transfer mechanism[J]. International Journal of Mining Science and Technology,2017,27(3):431-434.
[20] CAO C,REN T,ZHANG Y,et al.Experimental investigation of the effect of grout with additive in improving ground support[J].International Journal of Rock Mechanics&Mining Sciences,2016,85:52-59.
[21] CAO C,REN T,COOK C.Introducing aggregate into grouting material and its influence on load transfer of the rock bolting system[J].International Journal of Mining Science and Technology,2014,24(3):325-328.
[22] ZHOU F P,LYDON F D,BARR B I G.Effect of coarse aggregate on elastic modulus and compressive strength of high performance concrete[J]. Cement&Concrete Research,1995,25(1):177-186.
[23] KILIC A,ATIS C D,TEYMEN A,et al. The influence of aggregate type on the strength and abrasion resistance of high strength concrete[J]. Cement&Concrete Composites,2008,30(4):290-296.
[24] BENMOKRANE B,CHENNOUF A,MITRI H S.Laboratory evaluation of cement-based grouts and grouted rock anchors[J]. International Journal of Rock Mechanics&Mining Sciences&Geomechanics Abstracts,1995,32(7):633-642.
[25] MOOSAVI M,BAWDEN W F. Shear strength of Portland cement grout[J]. Cement&Concrete Composites,2003,25(7):729-735.