环向预应力钢绞线加固RC拱肋力学性能试验
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摘要
通过RC方柱偏压试验和RC拱肋面内受力全过程试验,对环向预应力钢绞线(LPSW)加固拱桥方法进行研究。对相对偏心距分别为0,0.25,0.5的3类RC方柱进行偏心受压试验,偏心试验表明:RC方柱加固后,预应力钢绞线先于箍筋约束混凝土,有效抑制了混凝土裂缝的纵向开展,预应力钢绞线及箍筋之间具有良好的变形协调性;LPSW加固柱承载力提高了3%～34%,LPSW加固技术适合于小偏心受压结构,偏心距越小,增强效果越明显。在偏压试验基础上,拓展了LPSW加固RC拱肋的模型试验,对LPSW加固模型拱荷载-挠度曲线、截面应变和结构破坏模式等方面进行分析。拱肋试验表明:LPSW拱肋受力过程和破坏模式与RC拱肋相似,分为弹性阶段、裂缝开展阶段和钢筋屈服阶段,最终因出现5个塑性铰形成机构而呈塑性破坏。由于环向预应力钢绞线约束,使RC拱肋提前处于3向受压应力状态,横向膨胀受到约束,避免拱肋出现拉应力,加固拱肋的初裂荷载、钢筋屈服荷载和极限荷载为未加固拱的2倍、1.6倍和1.47倍。基于偏压柱及拱肋试验结果,利用弹塑性失稳理论的等效梁柱法,建立LPSW加固拱肋极限承载力的计算公式,计算值与试验值吻合较好,且偏于安全,可用于评估实际加固拱桥的承载能力。
A technique for reinforcing arch ribs with lateral prestressed steel wire(LPSW) was studied by f testing the process behaviors of RC arch ribs under in-plane load and RC square columns under eccentric load. The eccentric compression tests of the RC square columns were performed with relative eccentricities of 0, 0.25 and 0.5. Results show that prestressed steel wire prior to stirrup restrained concrete, which effectively inhibits the development of longitudinal cracks in the concrete, and has a good deformation coordination with the stirrup after reinforcement of RC square column. The ultimate bearing capacity of the strengthened columns are 3% and 34% greater than those of the contrast columns. Using LPSW increases the strength in small eccentrically loaded columns, an effect which strengthens as the eccentricity decreases. Based on the eccentric compression test, a test was carried out on an RC rib to analyze the load deflection curve of the arch, the strain of the section and the failure mode of the structure of the LPSW reinforcement model. The result of the arch rib test shows that the defect propagation of LPSW arches are similar to RC arches. The process can be divided into the elastic stage, crack development stage and reinforcement yield stage. The LPSW arches also fail because of the mechanism formed by five plastic hinges caused by cracks in tensile areas. The effects of LPSW confinement mean that the RC arches first go under triaxial compression, constraining the lateral expansion to avoid the tensile stress of the arch rib. The initial crack load, yield load, and ultimate load of the reinforced arches are 2, 1.6, and 1.47 times that of the unreinforced arches, respectively. Utilizing the equivalent beam-column method based on the elastoplastic instability theory, the formula for calculating the ultimate bearing capacity of LPSW reinforced arches is established on the basis of the test results of the eccentric columns and arches. The calculated results are shown to be in reasonable agreement with test results and can be used to evaluate the actual bearing capacity of a reinforced arch bridge.
A technique for reinforcing arch ribs with lateral prestressed steel wire(LPSW) was studied by f testing the process behaviors of RC arch ribs under in-plane load and RC square columns under eccentric load. The eccentric compression tests of the RC square columns were performed with relative eccentricities of 0, 0.25 and 0.5. Results show that prestressed steel wire prior to stirrup restrained concrete, which effectively inhibits the development of longitudinal cracks in the concrete, and has a good deformation coordination with the stirrup after reinforcement of RC square column. The ultimate bearing capacity of the strengthened columns are 3% and 34% greater than those of the contrast columns. Using LPSW increases the strength in small eccentrically loaded columns, an effect which strengthens as the eccentricity decreases. Based on the eccentric compression test, a test was carried out on an RC rib to analyze the load deflection curve of the arch, the strain of the section and the failure mode of the structure of the LPSW reinforcement model. The result of the arch rib test shows that the defect propagation of LPSW arches are similar to RC arches. The process can be divided into the elastic stage, crack development stage and reinforcement yield stage. The LPSW arches also fail because of the mechanism formed by five plastic hinges caused by cracks in tensile areas. The effects of LPSW confinement mean that the RC arches first go under triaxial compression, constraining the lateral expansion to avoid the tensile stress of the arch rib. The initial crack load, yield load, and ultimate load of the reinforced arches are 2, 1.6, and 1.47 times that of the unreinforced arches, respectively. Utilizing the equivalent beam-column method based on the elastoplastic instability theory, the formula for calculating the ultimate bearing capacity of LPSW reinforced arches is established on the basis of the test results of the eccentric columns and arches. The calculated results are shown to be in reasonable agreement with test results and can be used to evaluate the actual bearing capacity of a reinforced arch bridge.
引文
[1] 孙昊,钱永久.套箍加固拱肋力学性能模型试验研究[J].铁道科学与工程学报,2014,11(5):18-23.SUN Hao,QIAN Yong-jiu.Model Test on Mechanical Performance of Hooping Strengthening Arch Rib [J].Journal of Railway Science and Engineering,2014,11 (5):18-23.
[2] 张晶,钱永久.套箍法加固石拱桥主拱圈的正截面承载力的理论分析[J].公路交通科技,2008,25(6):76-80.ZHANG Jin,QIAN Yong-jiu.Theoretical Analysis of Normal Section Bearing Capacity of Stone Main Arch Ring Strengthened by Reinforced Concrete [J].Journal of Highway and Transportation Research and Development,2008,25 (6):76-80.
[3] 周长东,白晓彬,赵锋,等.预应力纤维布加固混凝土圆形截面短柱轴压性能试验[J].建筑结构学报,2013,34(2):131-140.ZHOU Chang-dong,BAI Xiao-bin,ZHAO Feng,et al.Experimental Study on Circular Concrete Short Columns Strengthened with Pre-stressed FRP Under Axial Compression [J].Journal of Building Structures,2013,34 (2):131-140.
[4] IRSHIDAT M R,AL-SALEH M H,AL-SHOUBAKI M.Using Carbon Nanotubes to Improve Strengthening Efficiency of Carbon Fiber/Epoxy Composites Confined RC Columns [J].Composite Structures,2015,134 (6):523-532.
[5] HUANG H,XI K,ZHANG Y,et al.Calculation of Axial Compression Capacity for Square Columns Strengthened with HPFL and BSP [J].Advances in Materials Science and Engineering,2016 (2):123-133.
[6] 吴刚,吴智深,魏洋,等.预应力高强钢丝绳抗弯加固钢筋混凝土梁的理论分析[J].土木工程学报,2007,40(12):28-37.WU Gang,WU Zhi-shen,WEI Yang,et al.Theoretical Analysis of the Flexural Behavior of RC Beams Strengthened with Prestressed High Strength Steel Wire Ropes [J].China Civil Engineering Journal,2007,40 (12):28-37.
[7] 郭彤,李爱群,姚秋来,等.钢绞线网片-聚合物砂浆加固钢筋混凝土箱梁试验[J].中国公路学报,2010,23(2):36-42.GUO Tong,LI Ai-qun,YAO Qiu-lai,et al.Experiment on Reinforced Concrete Box-girder Strengthened by Steel Stranded Wire Mesh and Polymer Mortar [J].China Journal of Highway and Transport,2010,23 (2):36-42.
[8] 郭蓉,杜力峰,郭娇,等.预应力碳纤维板加固钢筋混凝土梁的受弯性能[J].土木建筑与环境工程,2017,39(6):61-67.GUO Rong,DU Li-feng,GUO Jiao,et al.Flexural Property of Reinforced Concrete Beams Strengthened with Perstressed Carb on Fiber Reinforced Polymer Plate [J].Journal of Civil Architectural Engineering,2017,39 (6):61-67.
[9] 郭俊平,邓宗才,林劲松,等.预应力钢绞线网加固混凝土圆柱的轴压性能[J].工程力学,2014,31(3):129-137.GUO Jun-pin,DENG Zong-cai,LIN Jin-song,et al.Axial Compression Performance of Concrete Columns Strengthened with Prestressed High Strength Steel Wire Mesh [J].Engineering Mechanics,2014,31 (3):129-137.
[10] 郭俊平,邓宗才,卢海波,等.预应力高强钢绞线网抗剪加固钢筋混凝土梁试验[J].吉林大学学报:工学版,2014,44(4):968-977.GUO Jun-pin,DENG Zong-cai,LU Hai-bo,et al.Experiment on Shear Behavior of Reinforced Concrete Beams Strengthened with Prestressed High Strength Steel Wire Mesh [J].Journal of Jilin University:Engineering and Technology Edition,2014,44 (4):968-977.
[11] MEDA A,MOSTOSI S,RINALDI Z,et al.Corroded RC Columns Repair and Strengthening with High Performance Fiber Reinforced Concrete Jacket [J].Materials and Structures,2016,49 (5):1967-1978.
[12] KIM S Y,YANG K H,BYUN H Y,et al.Tests of Reinforced Concrete Beams Strengthened with Wire Rope Units [J].Engineering Structures,2007,29(10):2711-2722.
[13] HAMED E,CHANG Z,RABINOVITCH O.Strengthening of Reinforced Concrete Arches with Externally Bonded Composite Materials:Testing and Analysis [J].Journal of Composites for Construction,2015,19 (1):4011-4031.
[14] 杜任远,陈宝春.活性粉末混凝土拱极限承载力试验研究[J].工程力学,2013,30(5):42-48.DU Ren-yuan,CHEN Bao-chun.Experimental Research on the Ultimate Load Capacity of Reactive Powder Concrete Arches [J].Engineering Mechanics,2013,30 (5):42-48.
[15] 郭子雄,曾建宇,黄群贤,等.预应力钢板箍加固RC柱轴压性能试验研究[J].建筑结构学报,2012,33(11):124-131.GUO Zi-xiong,ZENG Jian-yu,HUANG Qun-xian,et al.Experimental Study on Axial Compression Behavior of RC Columns Retrofitted by Prestressed Steel Jackets [J].Journal of Building Structures,2012,33 (11):124-131.
[16] 林上顺,陈宝春.等效梁柱法计算钢筋混凝土拱承载力[J].福州大学学报:自然科学版,2016,44(1):110-114.LIN Shang-xun,CHEN Bao-chun.Calculation of Load-carrying Capacity of Reinforced Concrete Arch Basing on Equivalent Beam-column Method [J].Journal of Fuzhou University:Natural of Edition,2014,44 (1):110-114.
[17] 陈宝春,林上顺.钢筋混凝土拱极限承载力研究综述[J].福州大学学报:自然科学版,2014,42(2):282-289.CHEN Bao-chun,LIN Shang-xun.A State-of-the-art on the Ultimate Load-carrying Capacity of Reinforced Concrete Arches [J].Journal of Fuzhou University:Natural of Edition,2014,42 (2):282-289.
[18] JTG D62—2004,公路钢筋混凝土及预应力混凝土桥涵设计规范[S].JTG D62—2004,Code for Design of Reinforced Concrete and Prestressed Concrete Bridges and Culverts for Highways [S].
[19] Japan Road Association,Specifications for Highway Bridges,PartⅢ:Concrete Bridges [S].
[20] MANDER J B,PRIESTLEY M J N,PARK R.Theoretical Stress-strain Model for Confined Concrete [J].Journal of Structural Engineering,1988,114 (8):1804-1826.
[21] 李应根.预应力钢绞线网加固RC肋拱桥承载能力研究[D].重庆:重庆交通大学,2017.LI Ying-gen.Research on Bearing Capacity of RC Rib Arch Bridge Strengthened by Prestressed Steel Stranded Wire Mesh [D].Chongqing:Chongqing Jiaotong University,2017.
[2] 张晶,钱永久.套箍法加固石拱桥主拱圈的正截面承载力的理论分析[J].公路交通科技,2008,25(6):76-80.ZHANG Jin,QIAN Yong-jiu.Theoretical Analysis of Normal Section Bearing Capacity of Stone Main Arch Ring Strengthened by Reinforced Concrete [J].Journal of Highway and Transportation Research and Development,2008,25 (6):76-80.
[3] 周长东,白晓彬,赵锋,等.预应力纤维布加固混凝土圆形截面短柱轴压性能试验[J].建筑结构学报,2013,34(2):131-140.ZHOU Chang-dong,BAI Xiao-bin,ZHAO Feng,et al.Experimental Study on Circular Concrete Short Columns Strengthened with Pre-stressed FRP Under Axial Compression [J].Journal of Building Structures,2013,34 (2):131-140.
[4] IRSHIDAT M R,AL-SALEH M H,AL-SHOUBAKI M.Using Carbon Nanotubes to Improve Strengthening Efficiency of Carbon Fiber/Epoxy Composites Confined RC Columns [J].Composite Structures,2015,134 (6):523-532.
[5] HUANG H,XI K,ZHANG Y,et al.Calculation of Axial Compression Capacity for Square Columns Strengthened with HPFL and BSP [J].Advances in Materials Science and Engineering,2016 (2):123-133.
[6] 吴刚,吴智深,魏洋,等.预应力高强钢丝绳抗弯加固钢筋混凝土梁的理论分析[J].土木工程学报,2007,40(12):28-37.WU Gang,WU Zhi-shen,WEI Yang,et al.Theoretical Analysis of the Flexural Behavior of RC Beams Strengthened with Prestressed High Strength Steel Wire Ropes [J].China Civil Engineering Journal,2007,40 (12):28-37.
[7] 郭彤,李爱群,姚秋来,等.钢绞线网片-聚合物砂浆加固钢筋混凝土箱梁试验[J].中国公路学报,2010,23(2):36-42.GUO Tong,LI Ai-qun,YAO Qiu-lai,et al.Experiment on Reinforced Concrete Box-girder Strengthened by Steel Stranded Wire Mesh and Polymer Mortar [J].China Journal of Highway and Transport,2010,23 (2):36-42.
[8] 郭蓉,杜力峰,郭娇,等.预应力碳纤维板加固钢筋混凝土梁的受弯性能[J].土木建筑与环境工程,2017,39(6):61-67.GUO Rong,DU Li-feng,GUO Jiao,et al.Flexural Property of Reinforced Concrete Beams Strengthened with Perstressed Carb on Fiber Reinforced Polymer Plate [J].Journal of Civil Architectural Engineering,2017,39 (6):61-67.
[9] 郭俊平,邓宗才,林劲松,等.预应力钢绞线网加固混凝土圆柱的轴压性能[J].工程力学,2014,31(3):129-137.GUO Jun-pin,DENG Zong-cai,LIN Jin-song,et al.Axial Compression Performance of Concrete Columns Strengthened with Prestressed High Strength Steel Wire Mesh [J].Engineering Mechanics,2014,31 (3):129-137.
[10] 郭俊平,邓宗才,卢海波,等.预应力高强钢绞线网抗剪加固钢筋混凝土梁试验[J].吉林大学学报:工学版,2014,44(4):968-977.GUO Jun-pin,DENG Zong-cai,LU Hai-bo,et al.Experiment on Shear Behavior of Reinforced Concrete Beams Strengthened with Prestressed High Strength Steel Wire Mesh [J].Journal of Jilin University:Engineering and Technology Edition,2014,44 (4):968-977.
[11] MEDA A,MOSTOSI S,RINALDI Z,et al.Corroded RC Columns Repair and Strengthening with High Performance Fiber Reinforced Concrete Jacket [J].Materials and Structures,2016,49 (5):1967-1978.
[12] KIM S Y,YANG K H,BYUN H Y,et al.Tests of Reinforced Concrete Beams Strengthened with Wire Rope Units [J].Engineering Structures,2007,29(10):2711-2722.
[13] HAMED E,CHANG Z,RABINOVITCH O.Strengthening of Reinforced Concrete Arches with Externally Bonded Composite Materials:Testing and Analysis [J].Journal of Composites for Construction,2015,19 (1):4011-4031.
[14] 杜任远,陈宝春.活性粉末混凝土拱极限承载力试验研究[J].工程力学,2013,30(5):42-48.DU Ren-yuan,CHEN Bao-chun.Experimental Research on the Ultimate Load Capacity of Reactive Powder Concrete Arches [J].Engineering Mechanics,2013,30 (5):42-48.
[15] 郭子雄,曾建宇,黄群贤,等.预应力钢板箍加固RC柱轴压性能试验研究[J].建筑结构学报,2012,33(11):124-131.GUO Zi-xiong,ZENG Jian-yu,HUANG Qun-xian,et al.Experimental Study on Axial Compression Behavior of RC Columns Retrofitted by Prestressed Steel Jackets [J].Journal of Building Structures,2012,33 (11):124-131.
[16] 林上顺,陈宝春.等效梁柱法计算钢筋混凝土拱承载力[J].福州大学学报:自然科学版,2016,44(1):110-114.LIN Shang-xun,CHEN Bao-chun.Calculation of Load-carrying Capacity of Reinforced Concrete Arch Basing on Equivalent Beam-column Method [J].Journal of Fuzhou University:Natural of Edition,2014,44 (1):110-114.
[17] 陈宝春,林上顺.钢筋混凝土拱极限承载力研究综述[J].福州大学学报:自然科学版,2014,42(2):282-289.CHEN Bao-chun,LIN Shang-xun.A State-of-the-art on the Ultimate Load-carrying Capacity of Reinforced Concrete Arches [J].Journal of Fuzhou University:Natural of Edition,2014,42 (2):282-289.
[18] JTG D62—2004,公路钢筋混凝土及预应力混凝土桥涵设计规范[S].JTG D62—2004,Code for Design of Reinforced Concrete and Prestressed Concrete Bridges and Culverts for Highways [S].
[19] Japan Road Association,Specifications for Highway Bridges,PartⅢ:Concrete Bridges [S].
[20] MANDER J B,PRIESTLEY M J N,PARK R.Theoretical Stress-strain Model for Confined Concrete [J].Journal of Structural Engineering,1988,114 (8):1804-1826.
[21] 李应根.预应力钢绞线网加固RC肋拱桥承载能力研究[D].重庆:重庆交通大学,2017.LI Ying-gen.Research on Bearing Capacity of RC Rib Arch Bridge Strengthened by Prestressed Steel Stranded Wire Mesh [D].Chongqing:Chongqing Jiaotong University,2017.