桥台是桥梁两端的支承结构，在地震中对主梁有一定约束作用。震害调查表明，桥台在地震中出现不同程度的震害，近断层地区桥台震害尤为严重。然而，目前对桥台结构抗震性能的研究尚不完善。本文以多跨简支梁桥为对象，研究桥台构造对桥梁地震易损性的影响，主要研究内容如下： （1）建立桥台及台后填土的二维有限元模型，通过与缩尺模型试验对比，验证了有限元模型的准确性。基于前人研究和模型试验，确定了桥台损伤等级和判别标准。统计了国内部分中小跨径桥梁的相关参数，确定桥台构造参数范围，并通过数值模拟，确定了桥台的损伤指标，轻微、中等、严重、完全损伤对应的位移界限值分别是10mm、32mm、85mm、124mm。 （2）以一座3×40m简支T梁桥为背景，分析了忽略桥台对桥梁地震易损性的影响，结果表明：忽略桥台对桥梁轻微损伤的地震易损性影响较小。对桥梁中等、严重和完全损伤的地震易损性均值偏差在28%以上，影响不容忽视。 （3）分析桥台背墙厚度变化对不同跨数简支梁桥地震易损性的影响，对比各构件损伤曲线，结果表明：背墙厚度的改变对4跨以内的简支梁桥各构件能够显著降低损伤概率，在一定地震强度下对构件的损伤概率差值能够达到50%以上；超过4跨简支梁跨数范围，各构件损伤概率差值趋于平缓，改变背墙厚度对降低损伤概率效果不太明显。建议对4跨以内简支梁桥，可采取桥台构造优化设计提高桥梁抗震性能。

         The bridge abutment is a supporting structure at both ends of the bridge, which has a certain restraining effect on the main girder in an earthquake. Seismic damage investigation shows that bridge abutments have different degrees of damage in earthquakes, and the damage of bridge abutments in near-fault areas is particularly serious. However, the current research on the seismic performance of bridge abutment structure is not perfect. In this paper, we take multi-span simply supported girder bridge as the object to study the influence of bridge abutment structure on the seismic vulnerability of bridges, and the main research contents are as follows:

       (1) A two-dimensional finite element model of the bridge abutment and the fill behind the abutment was established, and the accuracy of the finite element model was verified by comparing with the scaled-down model test. Based on the previous research and model test, the damage level of bridge abutment and judgment standard were determined. The relevant parameters of some domestic small and medium-span bridges were counted to determine the range of bridge abutment construction parameters, and through numerical simulation, the damage indexes of bridge abutments were determined, and the displacement thresholds corresponding to slight, moderate, severe, and complete damages were 10mm, 32mm, 85mm, and 124mm, respectively.

          (2) The effect of ignoring abutments on the seismic vulnerability of bridges is analyzed in the context of a 3×40m simply supported T-beam bridge, and the results show that ignoring abutments has a small effect on the seismic vulnerability of bridges with minor damage. The average deviation of the seismic vulnerability for moderate, severe and complete damage of the bridge is more than 28%, which should not be neglected.

        (3) Analyze the effect of the change of backwall thickness on the seismic vulnerability of simply supported girder bridges with different number of spans, and compare the damage curves of each member, the results show that: the change of backwall thickness can significantly reduce the damage probability of each member of simply supported girder bridges with 4 spans or less, and the difference of damage probability of the members can reach more than 50% under a certain seismic intensity; the damage probability of the members tends to be flat beyond the range of the number of 4 spans of simply supported girder bridges and the effect of the change of backwall thickness in reducing the damage probability is not so obvious. The effect of changing the thickness of the back wall on reducing the damage probability is not obvious. It is suggested that for simply supported girder bridges within 4 spans, the bridge deck structure optimization design can be adopted to improve the seismic performance of the bridge.

[1]陈乐生. 汶川地震公路震害调查 [M]. 北京: 人民交通出版社, 2012.

[2]Jia Hongyu et al. Dynamic response analyses of long-span cable-stayed bridges subjected to pulse-type ground motions [J]. Soil Dynamics and Earthquake Engineering, 2023, 164.

[3]李明,开永旺. 近、远场地震作用下深水高墩桥梁水动力效应研究 [J]. 中国铁路, 2024(01): 57-66.

[4]Ma H ,Zhuo W ,Lavorato D , et al.Probabilistic Seismic Response Analysis on Continuous Bridges Under Near-Fault Ground Motions [J]. Iranian Journal of Science and Technology, Transactions of Civil Engineering, 2019,43(3): 491-500.

[5]李亮亮. 近断层地震动作用下大跨钢管混凝土拱桥地震响应分析 [D]. 兰州交通大学, 2022.

[6]Soltanmohammadi H ,Mashayekhi M ,Memarpour M M , et al.Exploring the Effect of Near-Field Ground Motions on the Fragility Curves of Multi-Span Simply Supported Concrete Girder Bridges [J]. Infrastructures, 2024,9(2).

[7]闫晓宇,赵卓,王瑾. 基于振动台试验的刚构桥近断层土-结构相互作用地震响应研究 [J]. 工业建筑, 2022,52(08): 140-146.

[8]邹赐. 近断层铁路简支梁桥抗震韧性提升及评估 [D]. 重庆交通大学, 2023.

[9]Jónsson M H, Bessason B, Haflidason E. Earthquake response of a base-isolated bridge subjected to strong near-fault ground motion[J]. Soil Dynamics and Earthquake Engineering, 2010, 30(6): 447-455.

[10]Zhou T, Jiang L, ang P, et al. Effects of near-fault pulse-type ground motions on high-speed railway simply supported bridge and pulse parameter analysis [J]. Bulletin of Earthquake Engineering, 2022, 20(11): 6167-6192.

[11]陆星妤. 考虑桩土影响的高铁大跨减隔震斜拉桥近断层地震响应分析 [D]. 扬州大学, 2022.

[12]陈奕涵. 近断层地震作用下高速铁路连续刚构桥减震控制研究 [D]. 福建工程学院, 2022.

[13]张洪豪. 近断层区上承式钢筋混凝土拱桥抗震性能研究 [D]. 重庆交通大学, 2022.

[14]游四方. 近场脉冲地震下简支梁桥倒塌全过程模拟及支座参数分析 [D]. 西南交通大学, 2024.

[15]Wan H P, Su L, Frangopol D M, et al. Seismic response of a bridge crossing a canyon to near-fault acceleration-pulse ground motions [J]. Journal of Bridge Engineering, 2021, 26(6): 05021006.

[16]Basoz N I, Kiremidjian A S. Evaluation of bridge damage data from the Loma Prieta and Northridge, California earthquakes [M]//Evaluation of bridge damage data from the Loma Prieta and Northridge, California earthquakes. 1998: 167-167.

[17]Pucci A ,Eickmeier D ,Sousa S H , et al.Fragility Analysis Based on Damaged Bridges during the 2021 Flood in Germany [J]. Applied Sciences, 2023,13(18)

[18]张海燕. 基于易损性分析的公路梁式桥地震经济损失评估 [D]. 兰州交通大学, 2022.

[19]吴子燕,贾兆平,刘骁骁. 基于桥梁经验数据的理论易损性曲线校准 [J]. 应用数学和力学, 2014,35(07): 723-736.

[20]余其鑫. 基于历史震害的桥梁地震易损性研究 [D]. 中国地震局工程力学研究所, 2015.

[21]黄文涛, 熊永良,张莹等.川南地区民居建筑地震易损性研究 [J]. 华北地震科学, 2022,40(04): 40-49.

[22]彭巧威. 地震作用下不等高墩曲线桥支座布置优化与易损性分析 [D]. 湘潭大学, 2019.

[23]Wang D, Wang X, Liu H. Seismic fragility analysis of multi-span continuous beam bridge considering spatial variation of ground motions [C]//The 17th World Conference on Earthquake Engineering. Sendai: International Association for Earthquake Engineering. 2021.

[24]Wu F, Luo J, Zheng W, et al. Performance-based seismic fragility and residual seismic resistance study of a long-span suspension bridge [J]. Advances in Civil Engineering, 2020, 2020: 1-16.

[25]黄飞鸿,何沛祥,吴腾飞. 下承式钢管混凝土拱桥地震易损性分析 [J]. 合肥工业大学学报(自然科学版), 2022,45(06): 801-807.

[26]余洁歆,吴淑婧,丁传辉等. 大跨度斜拉桥地震易损性分析 [J]. 福州大学学报(自然科学版), 2023,51(06): 843-849.

[27]黄伟健. 地震作用下简支梁桥的易损性分析 [D]. 广州大学, 2021.

[28]陈龙. 简支梁桥地震灾害情景推演与易损性分析 [D]. 安徽建筑大学, 2023.

[29]Amirhossein M ,Farhad B ,Armin A , et al.Seismic Vulnerability Assessment of Stone Arch Bridges by Nonlinear Dynamic Analysis Using Discrete Element Method [J]. International Journal of Architectural Heritage, 2023,17(11): 1791-1812.

[30]李虹剑. 基于ETM考虑行波效应的高墩大跨连续刚构桥地震易损性分析 [D]. 重庆交通大学, 2023.

[31]吴靖江,丁雪航,徐景洪等. 预应力混凝土弯桥地震易损性分析 [J]. 工程抗震与加固改造, 2023,45(06): 77-85.

[32]宋帅,王帅,吴刚,等. 中小跨径梁桥地震易损性研究 [J]. 振动与冲击, 2020,39(09): 118-125.

[33]张鹏.跨断层简支梁桥的概率性地震损伤特性研究 [D]. 北京交通大学, 2018.

[34]董俊,曾永平,冷丹.九度地震区高速铁路简支梁合理减隔震体系分析 [J]. 哈尔滨工业大学学报, 2023,55(11): 115-124+134.

[35]胡明亮.基于KDE的高烈度区典型简支梁桥地震易损性分析 [J]. 铁道科学与工程学报, 2022,19(01): 198-207.

[36]JGJ/T 101-2015. 建筑抗震试验规程 [S]. 北京: 中国建筑工业出版社, 2015.

[37]HAZUS-MH MR4 Earthquake model technical manual [M]. Washington, D.C.: Federal Emergency Management Agency, 2003(7): 1―93.

[38]Nielson B G,Desroches R.Seismic fragility methodology for highway bridges using a component level approach [J]. Earthquake Engineering ＆Structural Dynamics, 2007,36(6): 823−839.

[39]Eunsoo Choi. Seismic Analysis and Retrofit of Mid-America Bridges [D]. Georgia Institute of Technology, 2002.

[40]郭军军,钟剑,袁万城等. 考虑桥台性能影响的连续梁桥地震易损性分析 [J]. 哈尔滨工程大学学报, 2017,38(04): 532-537.

[41]Hose Y D, Serble F. Performance evaluation data-base for concrete bridge components and systems under simulated seismic loads, PEER Report 1999/11 [R]. Berkeley, Pacific Earthquake Engineering Research Center, College of Engineering, University of California. 1999.

[42]SEAOC Vision 2000.Performance-based seismic engineering of building [R]. California: Structural Engineering Association of California, 1995: 1-10.

[43]Kowalsky M J. A displacement-based approach for the seismic design of continuous concrete bridges [J]. Earthquake Engineering and Structural Dynamics, 2002, 31: 719―747.

[44]Calvi G M. Recent experience and innotative approaches in design and assessment of bridges [C]. 13WCEE. Canada,Reference No.5009, 2004.

[45]胡晨旭. 空心墩地震损伤评估与抗震性能指标研究 [D]. 西南交通大学, 2019.

[46]Caltrans. Seismic Design Criteria [S]. California: California Department of Transportation, 2013.

[47]Deng ,Yulin,Ge , et al. Effects of Pounding at Expansion Joints on Seismic Responses of Long-Span Deep-Water Bridge with Multiple Approach Spans [J]. Arabian Journal for Science and Engineering, 2021,47(4): 1-19.

[48]Housner G W, Hudson D E. The Port Hueneme earthquake of March 18, 1957 [J]. Bulletin of the Seismological Society of America, 1958, 48(2): 163−168.

[49]王玉石,宋卓,李小军,等. 我国Ⅰ、Ⅱ、Ⅲ类场地上PGA归一化加速度反应谱特征统计研究 [J]. 震灾防御技术, 2023,18(04): 854-863.

[50]谢俊举,李小军,温增平,等. 芦山7.0级地震近断层地震动的方向性 [J]. 地球物理学报, 2018,61(04): 1266-1280.

[51]JTG/T 2231-01-2020 公路桥梁抗震设计规范 [S], 北京: 中华人民共和国交通运输部标 准, 2020.

[52]Cornell C A, Jalayer F, Hamburger R O, et al. Probabilistic basis for 2000 SAC federal emergency management agency steel moment frame guidelines [J]. Journal of structural engineering, 2002, 128(4): 526-533.

[53]HAZUS-MH MR4 Earthquake model technical manual [M]. Washington, D.C.: Federal Emergency Management Agency, 2003(7): 1―93.

[54]Megally SH, Silva PF, Seible F. Seismic Response of Sacrificial Shear Keys in Bridge Abutments [R]. Structural Systems Research Report SSRP - 2001/23, Department of Structural Engineering, University of California, San Diego, La Jolla, California, 2001.

[55]Aviram A, Mackie K R, Stojadinovic B. Effect of abutment modeling on the seismic response of bridge structures [J]. Earthquake Engineering and Engineering Vibration, 2008, 7(4): 395-402.

[56]宋飞,李建中. 桥台模拟方法对连续梁桥地震反应的影响 [J]. 结构工程师, 2016, 32(01): 85-91.

[57]Hwang H, Jernigan J B, Lin Y W. Evaluation of seismic damage to Memphis bridges and highway systems [J]. Journal of Bridge Engineering, 2000, 5(4): 322-330.

[58]李喜梅,蒲奎,杨国俊,等. 不同地震激励方向下隔震曲线梁桥易损性分析 [J]. 地震工程学报, 2024,46(01): 26-38.

[59]张海君,董建兴. 中小跨径梁桥地震易损性分析 [J]. 建筑科学与工程学报, 2023,40(06): 118-126.

[60]Song S, e Y, Wang Y, et al. Seismic fragility and vulnerability assessment of a multi-span irregular curved bridge under spatially varying ground motions[J]. Soil Dynamics and Earthquake Engineering, 2024, 180: 108585.

[61]李正阳,雷凡. 水平位移荷载作用下桥台背墙的受力特性和参数分析 [J]. 交通科技, 2023(02): 85-89.

[62]刘传森. 考虑桥台背墙贡献的连续梁桥地震易损性研究 [D]. 西安科技大学, 2022.