高速铁路等跨连续钢桁柔性拱设计关键技术研究  

Study on Key Technology of Equal Span Continuous Steel Truss Flexible Arch in High Speed Railways

作　　者：乔雷涛[1] QIAO Leitao(China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《铁道标准设计》2023年第7期81-87,共7页Railway Standard Design

基　　金：中铁第一勘察设计院集团有限公司科研开发课题(院科16-17)。

摘　　要：钢桁梁柔性拱能充分发挥梁、拱结构各自的受力特点,具有跨越能力强、造型美观、用钢量省、施工技术成熟等优点,逐渐在铁路中得到应用。但目前关于钢桁梁柔性拱关键技术研究的成果不多,等跨连续钢桁柔性拱为首次在国内高铁桥梁中应用。在总结钢桁柔性拱设计经验的基础上,以银西高铁黄河桥3×168 m连续钢桁柔性拱为工程依托,对等跨连续钢桁柔性拱的孔跨布置、主桁、拱肋、横断面、桥面系结构形式等关键技术进行研究。结果表明,主桁采用华伦式或N形桁式均可,由于边跨加拱后桁高对结构刚度影响较小,在结构刚度满足要求的前提下,桁高满足铁路限界要求即可,斜杆与水平线夹角宜在45°~55°,节间长度宜为桁高的0.8~1.2倍;支点处设置加劲弦可减小支点及跨中弯矩,减小墩高,降低基础工程量,建议支点处设置加劲弦;钢桁柔性拱的拱轴线可采用二次抛物线或圆曲线,拱肋矢跨比宜在1/4~1/5之间;高铁连续钢桁柔性拱桥面系宜采用密布横梁正交异性板桥面系,选择人行道置于主桁内侧的方案,可提高结构横向刚度,并有利于与引桥简支梁人行道顺畅衔接。Steel truss beam flexible arch can give full play to the respective stress characteristics of beam and arch structure.It has the advantages of strong span capacity,beautiful shape,less steel consumption and mature construction technology,and is applied gradually in railway.However,there are not many research results on the key technologies of steel truss flexible arch,and the equal span continuous steel truss flexible arch is applied in high-speed railway bridges for the first time.On the basis of summarizing the design experience of steel truss flexible arch,this paper takes the Yellow River Bridge of Yinchuan-Xi’an High-speed Railway as an example based on 3×168 m continuous steel truss flexible arch to study such key design parameters of equal span continuous steel truss flexible arch as hole span layout,main truss structure,arch rib structure,cross-section structure and bridge deck system structure form.The results show that the main truss can be warren or n-shaped truss,since the influence of truss height of side span with added arch on the structural stiffness is small;on the premise that the structural stiffness meets the requirements,the truss height can meet the requirements of railway clearance,and the included angle between the inclined rod of the main truss and the horizontal line should be 45°~55°,and the internode length should be 0.8~1.2 times of the truss height.Setting stiffening chord at the fulcrum can reduce the bending moment at the fulcrum and mid span and reduce the pier height and foundation works,it is recommended to set stiffening chord at the fulcrum.The arch axis of steel truss flexible arch can adopt quadratic parabola or circular curve,and the arch rib span ratio should be between 1/4~1/5.The surface system of high-speed railway continuous steel truss flexible arch bridge should adopt the dense beam orthotropic plate bridge surface system.The scheme of placing the sidewalk inside the main truss can improve the transverse stiffness of the structure and facilitate the smooth conne

关 键 词：高速铁路 铁路桥 钢桁柔性拱 关键技术 结构形式 

分 类 号：U238[交通运输工程—道路与铁道工程] U448.22+4[建筑科学—桥梁与隧道工程]