泸定大渡河兴康特大桥抗震设计关键技术
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摘要
泸定大渡河兴康特大桥主桥为1 100m单跨钢桁梁悬索桥,针对该桥桥址区地震动参数高的特点,开展结构抗震设计关键技术研究。基于延性抗震设计理念提出耗能型中央扣,将防屈曲钢支撑用作中央扣杆件,防屈曲钢支撑的两端以铰接形式与缆、梁连接,只承受轴向力,不产生弯矩。基于组合设计思想提出波形钢腹板钢-混组合桥塔横梁,利用预应力混凝土顶板和底板抗弯、高强度钢腹板抗剪。对比耗能型中央扣与传统刚性、柔性中央扣对悬索桥抗震性能的影响;对比波形钢腹板钢-混组合桥塔横梁与普通钢筋混凝土、钢桥塔横梁的抗震性能,并对组合桥塔横梁进行缩尺模型试验,结果表明:铰接式耗能型中央扣能显著改善高烈度震区大跨径悬索桥的抗震性能;波形钢腹板钢-混组合桥塔横梁具有良好的综合抗震性能,连接构造安全可靠。
The main bridge of the Xingkang Dadu River Bridge in Luding is a single-span steel truss girder suspension bridge with the main span of 1 100 m.In the light of the characteristic that the ground motion parameters of the site area where the bridge is located are high,the key techniques of the seismic design of the bridge have been researched.Based on the concept of the ductile seismic design,the energy-dissipating central cable bands are proposed.The anti-buckling steel supports on the deck are used as the members of the cable bands,both ends of the supports are connected with the main cables and stiffening girder in articulation and the supports are to bear the axial load only and are not to produce the bending moment.In accordance with the combined design ideas,the steel and concrete composite cross beams with corrugated steel webs for the towers of the bridge are also proposed in order to fully utilize the bending resistance of the prestressed concrete top and bottom slabs and the shear resistance of the high-strength steel webs of the cross beams.The influences of the energy-dissipating central cable bands and the traditional rigid or flexible cable bands on the seismic performance of the long span suspension bridge are compared.The seismic performance of the composite cross beams,the ordinary reinforced concrete cross beams and the steel cross beams is compared as well and the scale-down model tests for the composite cross beams are made.The results yield that the energy-dissipating articulated central cable bands can significantly improve the seismic performance of the suspension bridge in the high-intensity seismic region.The composite cross beams for the towers have good comprehensive seismic performance and the connections of the cross beams are safe and reliable.
The main bridge of the Xingkang Dadu River Bridge in Luding is a single-span steel truss girder suspension bridge with the main span of 1 100 m.In the light of the characteristic that the ground motion parameters of the site area where the bridge is located are high,the key techniques of the seismic design of the bridge have been researched.Based on the concept of the ductile seismic design,the energy-dissipating central cable bands are proposed.The anti-buckling steel supports on the deck are used as the members of the cable bands,both ends of the supports are connected with the main cables and stiffening girder in articulation and the supports are to bear the axial load only and are not to produce the bending moment.In accordance with the combined design ideas,the steel and concrete composite cross beams with corrugated steel webs for the towers of the bridge are also proposed in order to fully utilize the bending resistance of the prestressed concrete top and bottom slabs and the shear resistance of the high-strength steel webs of the cross beams.The influences of the energy-dissipating central cable bands and the traditional rigid or flexible cable bands on the seismic performance of the long span suspension bridge are compared.The seismic performance of the composite cross beams,the ordinary reinforced concrete cross beams and the steel cross beams is compared as well and the scale-down model tests for the composite cross beams are made.The results yield that the energy-dissipating articulated central cable bands can significantly improve the seismic performance of the suspension bridge in the high-intensity seismic region.The composite cross beams for the towers have good comprehensive seismic performance and the connections of the cross beams are safe and reliable.
引文
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[7]陈磊,巢斯.防屈曲支撑应用现状研究[J].佳木斯大学学报(自然科学版),2015,33(5):665-670.(CHEN Lei,CHAO Si.The Application Condition and Research Progress of Buckling-Restrained Braces[J].Journal of Jiamusi University(Natural Science Edition),2015,33(5):665-670.in Chinese)
[8]高尔新,王永贵.防屈曲支撑滞回性能试验研究[J].四川建筑科学研究,2013,39(2):201-205.(GAO Er-xin,WANG Yong-gui.Test Study of Hysteretic Performance of Buckling-Restrained Brace[J].Sichuan Building Science,2013,39(2):201-205.in Chinese)
[9]李杰,武海鹏,陈淮.波形钢腹板变截面连续体系梁桥钢腹板承剪分析[J].桥梁建设,2015,45(1):79-84.(LI Jie,WU Hai-peng,CHEN Huai.Analysis of Steel Web Shear Capacity of Variable Section Continuous System Composite Box Beam Bridge with Corrugated Steel Webs[J].Bridge Construction,2015,45(1):79-84.in Chinese)
[10]聂建国,朱力,唐亮.波形钢腹板的抗剪强度[J].土木工程学报,2013,46(6):97-109.(NIE Jian-guo,ZHU Li,TANG Liang.Shear Strength of Trapezoidal Corrugated Steel Webs[J].China Civil Engineering Journal,2013,46(6):97-109.in Chinese)
[2]胡腾飞,华旭刚,温青,等.中央扣对大跨悬索桥模态特性的影响[J].公路交通科技,2015,32(6):89-94.(HU Teng-fei,HUA Xu-gang,WEN Qing,et al.Influence of Central Buckles on Modal Characteristics of Long-Span Suspension Bridge[J].Journal of Highway and Transportation Research and Development,2015,32(6):89-94.in Chinese)
[3]张新军,张超.大跨度悬索桥合理抗震结构体系研究[J].世界桥梁,2017,45(1):39-43.(ZHANG Xin-jun,ZHANG Chao.Study of Rational Anti-Seismic Structural System for Long-Span Suspension Bridge[J].World Bridges,2017,45(1):39-43.in Chinese)
[4]于德恩,李建中.中央扣对大跨悬索桥地震响应的影响研究[J].结构工程师,2016,32(1):112-118.(YU De-en,LI Jian-zhong.Influence of Central Buckles on Seismic Responses of Long-Span Suspension Bridges[J].Structural Engineers,2016,32(1):112-118.in Chinese)
[5]单宏伟,韩大章,吕立人.润扬长江公路大桥悬索桥中央扣设计[J].公路,2004(8):58-61.(SHAN Hong-wei,HAN Da-zhang,LU Li-ren.Design of Central Cable Bands of Suspension Bridge of Runyang Yangtze River Highway Bridge[J].Highway,2004(8):58-61.in Chinese)
[6]曹永睿,柴增铧.悬索桥柔性中央扣锚固系统对比研究[J].公路,2013,12(12):73-79.(CAO Yong-rui,CHAI Zeng-hua.Comparison and Study of Anchor Systems for Flexible Central Cable Bands of Suspension Bridge[J].Highway,2013,12(12):73-79.in Chinese)
[7]陈磊,巢斯.防屈曲支撑应用现状研究[J].佳木斯大学学报(自然科学版),2015,33(5):665-670.(CHEN Lei,CHAO Si.The Application Condition and Research Progress of Buckling-Restrained Braces[J].Journal of Jiamusi University(Natural Science Edition),2015,33(5):665-670.in Chinese)
[8]高尔新,王永贵.防屈曲支撑滞回性能试验研究[J].四川建筑科学研究,2013,39(2):201-205.(GAO Er-xin,WANG Yong-gui.Test Study of Hysteretic Performance of Buckling-Restrained Brace[J].Sichuan Building Science,2013,39(2):201-205.in Chinese)
[9]李杰,武海鹏,陈淮.波形钢腹板变截面连续体系梁桥钢腹板承剪分析[J].桥梁建设,2015,45(1):79-84.(LI Jie,WU Hai-peng,CHEN Huai.Analysis of Steel Web Shear Capacity of Variable Section Continuous System Composite Box Beam Bridge with Corrugated Steel Webs[J].Bridge Construction,2015,45(1):79-84.in Chinese)
[10]聂建国,朱力,唐亮.波形钢腹板的抗剪强度[J].土木工程学报,2013,46(6):97-109.(NIE Jian-guo,ZHU Li,TANG Liang.Shear Strength of Trapezoidal Corrugated Steel Webs[J].China Civil Engineering Journal,2013,46(6):97-109.in Chinese)