非一致氯离子侵蚀下近海桥梁时变地震易损性研究
|
摘要
近海桥梁往往处于氯离子空间分布不均匀的复杂环境,在服役过程中往往会遭受非一致氯离子侵蚀,导致材料及结构性能不断退化,降低桥梁抵御地震的能力。为研究非一致氯离子侵蚀下桥梁地震损伤风险变化规律,文章以氯离子扩散规律及钢筋锈蚀机理为基础,基于Duracrete模型及以往试验结果,确定不同环境参数及锈蚀参数的概率分布类型及统计特征,建立钢筋及混凝土材料退化规律。结合地震易损性分析理论,建立非一致氯离子侵蚀环境下桥梁时变地震易损性评估流程。随后,以一座多跨连续梁桥为例,分析退化桥梁抗震能力变化特征,研究不同构件的地震损伤时变规律。研究结果表明,氯离子侵蚀下的桥墩截面抗弯承载力和曲率延性均表现出明显的退化,并且曲率延性退化程度高于抗弯承载力。非一致氯离子侵蚀会导致桥墩损伤分布发生演变,桥墩易损位置可能从墩顶、墩底转移至低水位处。随着服役时间增加,桥墩损伤概率明显增大,而支座、挡块及桥台的损伤概率略有降低。
Numerous offshore bridges are located in the complex environment with the non-uniform spatial distribution of chloride ions. During the service life, the non-uniform chloride-induced corrosion often leads to the performance degradation of material and structure as well as the reduction in the seismic resistance of the bridge to earthquake. In order to investigate the variation of seismic damage risk of bridges subject to the non-uniform chloride-induced corrosion, the probability distribution type and statistical characteristics of different environmental parameters and corrosion parameters are determined, and the degradation laws of reinforcement and concrete are established combine the Duracrete model, the previous test results, the diffusion law of chloride ions and the corrosion mechanism of reinforcement. According to the analysis theory of seismic fragility, the evaluation process of the time-dependent seismic fragility of bridges subject to non-uniform chloride-induced corrosion is established. Then, a multi-span girder bridge is taken as an example, the variation characteristics of seismic capability of degenerated bridges are analyzed and the time-dependent seismic damages of various components are investigated. The results show that the flexural capacity and curvature ductility of the cross-section of the piers degrade obviously due to corrosion of the chloride ion, and the degradation of curvature ductility is more significant than that of the flexural capacity. Non-uniform chloride-induced corrosion may change the damage distribution of the pier, and the vulnerable position of the pier may be shifted from the top and the bottom of the piers to the position at low water level. With the increase of service time, the damage probability of the pier maybe increased obviously, and the damage probabilities of the bearing, shear keys and the abutment may be decreased slightly.
Numerous offshore bridges are located in the complex environment with the non-uniform spatial distribution of chloride ions. During the service life, the non-uniform chloride-induced corrosion often leads to the performance degradation of material and structure as well as the reduction in the seismic resistance of the bridge to earthquake. In order to investigate the variation of seismic damage risk of bridges subject to the non-uniform chloride-induced corrosion, the probability distribution type and statistical characteristics of different environmental parameters and corrosion parameters are determined, and the degradation laws of reinforcement and concrete are established combine the Duracrete model, the previous test results, the diffusion law of chloride ions and the corrosion mechanism of reinforcement. According to the analysis theory of seismic fragility, the evaluation process of the time-dependent seismic fragility of bridges subject to non-uniform chloride-induced corrosion is established. Then, a multi-span girder bridge is taken as an example, the variation characteristics of seismic capability of degenerated bridges are analyzed and the time-dependent seismic damages of various components are investigated. The results show that the flexural capacity and curvature ductility of the cross-section of the piers degrade obviously due to corrosion of the chloride ion, and the degradation of curvature ductility is more significant than that of the flexural capacity. Non-uniform chloride-induced corrosion may change the damage distribution of the pier, and the vulnerable position of the pier may be shifted from the top and the bottom of the piers to the position at low water level. With the increase of service time, the damage probability of the pier maybe increased obviously, and the damage probabilities of the bearing, shear keys and the abutment may be decreased slightly.
引文
[1]Mehta P K.Durability of concrete-fifty years of progress[J].Special Publication,1991,126:1-32
[2]洪定海.混凝土中钢筋的腐蚀与保护[M].北京:中国铁道出版社,1998(Hong Dinghai.Corrosion and protection of steel bars in concrete[M].Beijing:China Railway Publishing House,1998(in Chinese))
[3]Padgett J E,Ghosh J,Ataei N.Sensitivity of dynamic response of bridges under multiple hazards to aging parameters[J].American Society of Civil Engineers,2010,(370):1-12
[4]Ghosh J,Padgett J E.Aging considerations in the development of time-dependent seismic fragility curves[J].Journal of Structural Engineering-ASCE,2010,136(12):1497-1511
[5]赵珺,牛荻涛.在役钢筋混凝土连续刚构桥梁抗震性能评估[J].中国公路学报,2014,27(9):74-81(Zhao Jun,Niu Ditao.Seismic performance evaluation for reinforced concrete continuous rigid frame bridge in service[J].China Journal of Highway and Transport,2014,27(9):74-81(in Chinese))
[6]李超,李宏男.考虑氯离子腐蚀作用的近海桥梁结构全寿命抗震性能评价[J].振动与冲击,2014,33(11):70-77(Li Chao,Li Hongnan.Life-cycle aseismic performance evaluation of offshore bridge structures considering chloride ions corrosion effect[J].Journal of Vibration and Shock,2014,33(11):70-77(in Chinese))
[7]李立峰,吴文朋,胡思聪,等.考虑氯离子侵蚀的高墩桥梁时变地震易损性分析[J].工程力学,2016,33(1):163-170(Li Lifeng,Wu Wenpeng,Hu Sicong,et al.Time-dependent seismic fragility analysis of high pier bridge based on chloride ion induced corrosion[J].Engineering Mechanics,2016,33(1):163-170(in Chinese))
[8]Onyejekwe O O,Reddy N.A numerical approach to the study of chloride ion penetration into concrete[J].Magazine of Concrete Research,2000,52(4):243-250
[9]Shin C B,Kim E K.Modeling of chloride ion ingress in coastal concrete[J].Cement and Concrete Research,2002,32(5):757-762
[10]Duracrete.Statistical quantification of the variables in the limit state functions[M].Whangarei,Newzealend:DuraCrete,2000
[11]Stewart M G,Al-Harthy A.Pitting corrosion and structural reliability of corroding RC structures:Experimental data and probabilistic analysis[J].Reliability Engineering&System Safety,2008,93(3):373-382
[12]Val D V,Melchers R E.Reliability of deteriorating RCslab bridges[J].Journal of Structural Engineering,1997,123(12):1638-1644
[13]Du Y G,Clark L A,Chan A H C.Residual capacity of corroded reinforcing bars[J].Magazine of Concrete Research,2005,57(3):135-147
[14]Coronelli D,Gambarova P.Structural assessment of corroded reinforced concrete beams:Modeling guidelines[J].Journal of Structural Engineering,2004,130(8):1214-1224
[15]Choi E S,Desroches R,Nielson B.Seismic fragility of typical bridges in moderate seismic zones[J].Engineering Structures,2004,26(2):187-199
[16]Mazzoni S,Mckenna F,Scott M H,et al.OpenSees command language manual[M].Berkeley:Pacific Earthquake Engineering Research Center,University of California,2006
[17]徐略勤,李建中.挡块对规则连续梁桥横向地震反应的影响[J].公路交通科技,2013,30(4):53-59(Xu Lueqin,Li Jianzhong.Effects of retainer on simplified seismic analytical methods for regular continuous girder bridge[J].Journal of Highway and Transportation Research and Development,2013,30(4):53-59(in Chinese))
[18]Wilson P,Elgamal A.Large-scale passive earth pressure load-displacement tests and numerical simulation[J].Journal of Geotechnical and Geoenvironmental Engineering,2010,136(12):1634-1643
[19]Shome N,Cornell C A,Bazzurro P,et al.Earthquakes,records,and nonlinear responses[J].Earthquake Spectra,1998,14(3):469-500
[20]Pacific Earthquake Engineering Research Center.PEERground motion database[DB/OL].California,Berkeley:Pacific Earthquake Engineering Research Center,2012.https://ngawest2.berkeley.edu/site
[21]HAZUS-MH MR4.Earthquake model technical manual[M].Washington,D.C.:Federal Emergency Management Agency,2003
[22]李立峰,吴文朋,黄佳梅,等.地震作用下中等跨径RC连续梁桥系统易损性研究[J].土木工程学报,2012,45(10):152-160(Li Lifeng,Wu Wenpeng,Huang Jiamei,et al.Study on system vulnerability of medium span reinforced concrete continuous girder bridge under earthquake excitation[J].Civil Engineering Journal,2012,45(10):152-160(in Chinese))
[23]汤虎,李建中,邵长宇.中小跨径板式橡胶支座梁桥横向抗震性能[J].中国公路学报,2016,29(3):55-65(Tang Hu,Li Jianzhong,Shao Changyu.Seismic performance of small and medium span girder bridges with plate type elastomeric pad bearings in the transverse direction[J].China Journal of Highway and Transport,2016,29(3):55-65(in Chinese))
[2]洪定海.混凝土中钢筋的腐蚀与保护[M].北京:中国铁道出版社,1998(Hong Dinghai.Corrosion and protection of steel bars in concrete[M].Beijing:China Railway Publishing House,1998(in Chinese))
[3]Padgett J E,Ghosh J,Ataei N.Sensitivity of dynamic response of bridges under multiple hazards to aging parameters[J].American Society of Civil Engineers,2010,(370):1-12
[4]Ghosh J,Padgett J E.Aging considerations in the development of time-dependent seismic fragility curves[J].Journal of Structural Engineering-ASCE,2010,136(12):1497-1511
[5]赵珺,牛荻涛.在役钢筋混凝土连续刚构桥梁抗震性能评估[J].中国公路学报,2014,27(9):74-81(Zhao Jun,Niu Ditao.Seismic performance evaluation for reinforced concrete continuous rigid frame bridge in service[J].China Journal of Highway and Transport,2014,27(9):74-81(in Chinese))
[6]李超,李宏男.考虑氯离子腐蚀作用的近海桥梁结构全寿命抗震性能评价[J].振动与冲击,2014,33(11):70-77(Li Chao,Li Hongnan.Life-cycle aseismic performance evaluation of offshore bridge structures considering chloride ions corrosion effect[J].Journal of Vibration and Shock,2014,33(11):70-77(in Chinese))
[7]李立峰,吴文朋,胡思聪,等.考虑氯离子侵蚀的高墩桥梁时变地震易损性分析[J].工程力学,2016,33(1):163-170(Li Lifeng,Wu Wenpeng,Hu Sicong,et al.Time-dependent seismic fragility analysis of high pier bridge based on chloride ion induced corrosion[J].Engineering Mechanics,2016,33(1):163-170(in Chinese))
[8]Onyejekwe O O,Reddy N.A numerical approach to the study of chloride ion penetration into concrete[J].Magazine of Concrete Research,2000,52(4):243-250
[9]Shin C B,Kim E K.Modeling of chloride ion ingress in coastal concrete[J].Cement and Concrete Research,2002,32(5):757-762
[10]Duracrete.Statistical quantification of the variables in the limit state functions[M].Whangarei,Newzealend:DuraCrete,2000
[11]Stewart M G,Al-Harthy A.Pitting corrosion and structural reliability of corroding RC structures:Experimental data and probabilistic analysis[J].Reliability Engineering&System Safety,2008,93(3):373-382
[12]Val D V,Melchers R E.Reliability of deteriorating RCslab bridges[J].Journal of Structural Engineering,1997,123(12):1638-1644
[13]Du Y G,Clark L A,Chan A H C.Residual capacity of corroded reinforcing bars[J].Magazine of Concrete Research,2005,57(3):135-147
[14]Coronelli D,Gambarova P.Structural assessment of corroded reinforced concrete beams:Modeling guidelines[J].Journal of Structural Engineering,2004,130(8):1214-1224
[15]Choi E S,Desroches R,Nielson B.Seismic fragility of typical bridges in moderate seismic zones[J].Engineering Structures,2004,26(2):187-199
[16]Mazzoni S,Mckenna F,Scott M H,et al.OpenSees command language manual[M].Berkeley:Pacific Earthquake Engineering Research Center,University of California,2006
[17]徐略勤,李建中.挡块对规则连续梁桥横向地震反应的影响[J].公路交通科技,2013,30(4):53-59(Xu Lueqin,Li Jianzhong.Effects of retainer on simplified seismic analytical methods for regular continuous girder bridge[J].Journal of Highway and Transportation Research and Development,2013,30(4):53-59(in Chinese))
[18]Wilson P,Elgamal A.Large-scale passive earth pressure load-displacement tests and numerical simulation[J].Journal of Geotechnical and Geoenvironmental Engineering,2010,136(12):1634-1643
[19]Shome N,Cornell C A,Bazzurro P,et al.Earthquakes,records,and nonlinear responses[J].Earthquake Spectra,1998,14(3):469-500
[20]Pacific Earthquake Engineering Research Center.PEERground motion database[DB/OL].California,Berkeley:Pacific Earthquake Engineering Research Center,2012.https://ngawest2.berkeley.edu/site
[21]HAZUS-MH MR4.Earthquake model technical manual[M].Washington,D.C.:Federal Emergency Management Agency,2003
[22]李立峰,吴文朋,黄佳梅,等.地震作用下中等跨径RC连续梁桥系统易损性研究[J].土木工程学报,2012,45(10):152-160(Li Lifeng,Wu Wenpeng,Huang Jiamei,et al.Study on system vulnerability of medium span reinforced concrete continuous girder bridge under earthquake excitation[J].Civil Engineering Journal,2012,45(10):152-160(in Chinese))
[23]汤虎,李建中,邵长宇.中小跨径板式橡胶支座梁桥横向抗震性能[J].中国公路学报,2016,29(3):55-65(Tang Hu,Li Jianzhong,Shao Changyu.Seismic performance of small and medium span girder bridges with plate type elastomeric pad bearings in the transverse direction[J].China Journal of Highway and Transport,2016,29(3):55-65(in Chinese))