Calculating method of structural robustness of double-tower cable-stayed bridge with steel truss girder
-
摘要: 为了确保双塔钢桁斜拉桥的结构强健性, 依托新疆果子沟大桥, 基于现场结构试验, 开发了全方位多点温度补偿系统, 测量了特定加载工况下钢桁主梁应变、挠度与斜拉索索力增量, 确定了钢桁主梁与斜拉索重要构件的具体位置; 基于试验结果, 借鉴广义结构刚度理论, 采用桥梁结构有限元模型分析了斜拉桥弦杆与斜拉索的重要性系数, 研究了桥梁最不利破坏模型。研究结果表明: 各工况下钢桁主梁应变实测数据规律性较好, 钢桁主梁应变与挠度的实测值与理论计算值的比值小于1.0, 表明主梁承载能力与抗变形能力符合设计要求, 具有足够的安全储备; 主梁在各工况下的最大挠度均发生在中跨跨中, 达到237mm, 具有较强抗变形能力; 斜拉索索力增量实测值与理论计算值的比值小于1.0, 表明斜拉索具有一定的安全储备; 钢桁主梁控制截面处弦杆与特定斜拉索为重要性系数较高的构件, 斜拉索的重要性系数大于弦杆的重要性系数, 其中弦杆的重要性系数分布集中于主塔附近与中跨跨中; 通过斜拉索重要性系数的分布可知单根斜拉索的破损不会造成整体结构的坍塌, 但多于2根斜拉索失效可能会导致整体结构的连续倒塌; 主跨最长斜拉索和中跨跨中、边跨支座处与靠近主塔处弦杆失效对于整体结构较为不利。Abstract: In order to ensure the structural robustness of double-tower cable-stayed bridge with steel truss girder, all-round multipoint temperature compensation system was developed based on the Xinjiang Guozigou Bridge and field structure test.The strain, deflection and cable force increment of steel truss girder were measured under specific loading conditions, and the specific locations of important components of steel truss girder and stay cables were determined.Based on the experimental result and the generalized structural stiffness theory, the robustness importance factors of cables and chords were analyzed by using the finite element model of bridge structure, and the most critical failure model of cable-stayed bridge was studied.Study result shows that the regularities of the measured data of steel truss girder strain under various working conditions are good, and the ratios of measured and theoretical values of strain and deflection are less than 1.0, so the bearing capacity and anti-deformability of steel truss girder meet the design requirements, and the girder has sufficient safety reserve.The maximum deflection of the girder under eachloading case is at the middle of main span and can reach to 237 mm, so the girder has strong antideformability.Because the ratios of the measured increments of cable force and theoretical values are less than 1.0, the stay cables have safety reserve to a certain extent.The chords at control sections and the specific stay cables of the girder have higher importance factors, the factors of stay cables are larger than the values of the chords, and the importance factor distributions of the chords concentrate in the middle of main span and nearby areas of main pylons.According to the distributions of importance factors of stay cables, the damage of single stay cable can causes the collapse of overall structure, and the failures of more than two stay cables will result in the progressive collapse of entire structure.The failures of the longest stay cable of main span and the chords at its middle, as well as the chords at the supports of side spans and near the main towers, are more adverse to the entire bridge.
-
表 1 工况1下边跨主梁截面Ⅰ-Ⅰ应变比较
Table 1. Comparison of strains at girder sectionⅠ-Ⅰunder loading case 1
表 2 工况3下主梁截面Ⅱ-Ⅱ应变比较
Table 2. Comparison of strains at girder sectionⅡ-Ⅱunder loading case 3
表 3 工况4下主梁截面Ⅲ-Ⅲ应变比较
Table 3. Comparison of strains at girder sectionⅢ-Ⅲunder loading case 4
表 4 工况6下主梁截面Ⅳ-Ⅳ应变比较
Table 4. Comparison of strains at girder sectionⅣ-Ⅳunder loading case 6
表 5 中载工况下控制截面挠度比较
Table 5. Comparison of deflections at control sections under middle loading cases
表 6 偏载工况下控制截面挠度比较
Table 6. Comparison of deflections at control sections under biased loading cases
表 7 索力增量比较
Table 7. Comparison of cable force increments
表 8 钢桁主梁加载方法
Table 8. Loading methods of steel truss girder
表 9 斜拉索加载方法
Table 9. Loading methods of stay cables
-
[1] 谷音, 范立础, 叶建仁. 基于结构易损性的斜拉桥多灾害安全性能研究[J]. 福州大学学报: 自然科学版, 2010, 38 (3): 401-407. https://www.cnki.com.cn/Article/CJFDTOTAL-FZDZ201003020.htmGU Yin, FAN Li-chu, YE Jian-ren. The assessment method of safety performance of cable-stayed bridge under multihazard based on structure vulnerability[J]. Journal of Fuzhou University: Natural Science Edition, 2010, 38 (3): 401-407. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-FZDZ201003020.htm [2] ASCE. 2005report card for America's infrastructure[R]. Reston: ASCE, 2005. [3] GHOSN M, MOSES F. Redundancy in highway bridge superstructures (report 406)[R]. Washington DC: National Academy Press, 1998. [4] LIU W D, GHOSN M, MOSES F. Redundancy in highway bridge substructures (report 458)[R]. Washington DC: National Academy Press, 2001. [5] GHOSN M, YANG Jian, BEAL D, et al. Bridge system safety and redundancy[R]. Washington DC: TRB, 2014. [6] KUDSI T N, FU C C. Redundancy analysis of existing truss bridges: a system reliability-based approach[C]//IABMAS. IABMAS'02First International Conference Bridge Maintenance, Safety and Management. Stresa: IABMAS, 2002: 1-9. [7] GHARAIBEH E S, FRANGOPOL D M, ONOUFRIOU T. Reliability-based importance assessment of structural members with applications to complex structures[J]. Computers and Structures, 2002, 80 (12): 1113-1131. doi: 10.1016/S0045-7949(02)00070-6 [8] 赵煜, 贺拴海, 宋一凡. 在役索桁组合连续钢桥承载力综合评估方法[J]. 长安大学学报: 自然科学版, 2005, 25 (5): 47-50. doi: 10.3321/j.issn:1671-8879.2005.05.011ZHAO Yu, HE Shuan-hai, SONG Yi-fan. Evaluation methodology for existing truss cable composite continuous steel bridge[J]. Journal of Chang'an University: Natural Science Edition, 2005, 25 (5): 47-50. (in Chinese). doi: 10.3321/j.issn:1671-8879.2005.05.011 [9] ZHU Ben-jin, FRANGOPOL D M. Risk-based approach for optimum maintenance of bridges under traffic and earthquake loads[J]. Journal of Structural Engineering, 2013, 139 (3): 422-434. doi: 10.1061/(ASCE)ST.1943-541X.0000671 [10] GHOSN M, DUEÑAS-OSORIO L, FRANGOPOL D M, et al. Performance indicators for structural systems and infrastructure networks[J]. Journal of Structural Engineering, 2016, 142 (9): F4016003-1-18. doi: 10.1061/(ASCE)ST.1943-541X.0001542 [11] 李源, 贺拴海. 基于吊杆损伤失效的飞燕式拱桥鲁棒性研究[J]. 合肥工业大学学报: 自然科学版, 2014, 37 (10): 1254-1258. doi: 10.3969/j.issn.1003-5060.2014.10.020LI Yuan, HE Shuan-hai. Research on robustness performance of swallow type arch bridge based on suspender damage[J]. Journal of Hefei University of Technology: Natural Science, 2014, 37 (10): 1254-1258. (in Chinese). doi: 10.3969/j.issn.1003-5060.2014.10.020 [12] YANG Jian. Structural redundancy and system reliability of highway bridges[D]. New York: City University of New York, 2015. [13] MIAO Feng, GHOSN M. Reliability-based progressive collapse analysis of highway bridges[J]. Structural Safety, 2016, 63: 33-46. doi: 10.1016/j.strusafe.2016.05.004 [14] GHOSN M, FRANGOPOL D M, MCALLISTER T P, et al. Reliability-based performance indicators for structural members[J]. Journal of Structural Engineering, 2016, 142 (9): F4016002-1-13. doi: 10.1061/(ASCE)ST.1943-541X.0001546 [15] 张岗, 贺拴海, 王翠娟. 焰流效应下混凝土空心薄壁墩火温时变分布[J]. 交通运输工程学报, 2014, 14 (1): 26-34. http://transport.chd.edu.cn/article/id/201401004ZHANG Gang, HE Shuan-hai, WANG Cui-juan. Timedependent variation distribution of fire temperature for concrete hollow thin-walled pier affected by flame fluid[J]. Journal of Traffic and Transportation Engineering, 2014, 14 (1): 26-34. (in Chinese). http://transport.chd.edu.cn/article/id/201401004 [16] 张岗, 朱美春, 贺拴海, 等. 火灾下预应力混凝土T形截面梁破坏模式研究[J]. 中国公路学报, 2017, 30 (2): 77-85. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL201702010.htmZHANG Gang, ZHU Mei-chun, HE Shuan-hai, et al. Failure model analysis of prestressed concrete T girder exposed to fire[J]. China Journal of Highway and Transport, 2017, 30 (2): 77-85. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL201702010.htm [17] 赵煜, 周勇军, 周敉, 等. G30线连霍高速公路赛里木湖至果子沟口段果子沟大桥桥梁静动载试验报告[R]. 西安: 长安大学, 2016.ZHAO Yu, ZHOU Yong-jun, ZHOU Mi, et al. Static and dynamic load test report on Sailimu Lake to Guozigou Bridge of Guozigou section of G30Lianhuo Expressway[R]. Xi'an: Chang'an University, 2016. (in Chinese). [18] 王新敏. 基于ANSYS的舰船设备抗冲击之DDAM研究[J]. 国防交通工程与技术, 2013 (1): 1-5, 59. https://www.cnki.com.cn/Article/CJFDTOTAL-GFJT201301002.htmWANG Xin-min. ANSYS-DDAM study for the shock response of shipboard equipments[J]. Traffic Engineering and Technology for National Defense, 2013 (1): 1-5, 59. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GFJT201301002.htm [19] CHEN Chien-Chou, WU Wen-Hwa, LIU Chun-Yan, et al. Diagnosis of instant and long-term damages in cable-stayed bridges based on the variation of cable forces[J]. Structure and Infrastructure Engineering, 2017: 1-15. [20] ZHOU Yu-fen, CHEN Su-ren. Framework of nonlinear dynamic simulation of long-span cable-stayed bridge and traffic system subjected to cable-loss incidents[J]. Journal of Structural Engineering, 2016, 142 (3): 04015160-1-17. doi: 10.1061/(ASCE)ST.1943-541X.0001440 [21] 刘坤. 关头坝大桥应变监测系统研究[D]. 西安: 长安大学, 2013.LIU Kun. Researches on the strain monitoring system of Guantouba Bridge[D]. Xi'an: Chang'an University, 2013. (in Chinese). [22] HUNLEY C T, HARIK I E. Structural redundancy evaluation of steel tub girder bridges[J]. Journal of Bridge Engineering, 2012, 17 (3): 481-489. doi: 10.1061/(ASCE)BE.1943-5592.0000266 [23] 叶列平, 林旭川, 曲哲, 等. 基于广义结构刚度的构件重要性评价方法[J]. 建筑科学与工程学报, 2010, 27 (1): 1-6. https://www.cnki.com.cn/Article/CJFDTOTAL-XBJG201001003.htmYE Lie-ping, LIN Xu-chuan, QU Zhe, et al. Evaluating method of element importance of structural system based on generalized structural stiffness[J]. Journal of Architecture and Civil Engineering, 2010, 27 (1): 1-6. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-XBJG201001003.htm [24] GB 50153—2008, 公路工程结构可靠度设计统一标准[S].GB 50153—2008, unified standard for reliability design of engineering structures[S]. (in Chinese). [25] ZHOU Yu-fen, CHEN Su-ren. Dynamic simulation of a longspan bridge-traffic system subjected to combined service and extreme loads[J]. Journal of Structural Engineering, 2015, 141 (9): 04014215-1-18.