铁道学报
鐵道學報
철도학보
2010年
1期
59-64
,共6页
高速铁路%钢桥%结合桥面系%面外弯曲%约束刚度
高速鐵路%鋼橋%結閤橋麵繫%麵外彎麯%約束剛度
고속철로%강교%결합교면계%면외만곡%약속강도
high-speed railway%steel bridge%composite floor system%horizontal bending%constraint stiffness
中国大跨度高速铁路钢桁梁桥大多采用钢-混凝土结合桥面,横梁的面外弯曲是设计中的关键问题之一.本文针对高速铁路混凝土板仅与纵梁结合的纵横梁体系,从结合桥面系变形协调出发,推导出横梁面外弯曲问题的计算公式,并结合算例分析各种因素对横梁面外弯曲问题的影响.桥面系的连续长度和下弦杆的轴应力越大、下弦杆结点对于横梁的约束刚度越大、纵梁与下弦杆的距离越小,横梁的面外弯矩和弯曲应力越大.在四线铁路三主桁下承式钢桁梁桥中,中桁对横梁的约束近于绝对刚性,纵梁离中桁下弦杆的距离较小,使横梁的面外弯曲应力较二主桁桥梁大得多.
中國大跨度高速鐵路鋼桁樑橋大多採用鋼-混凝土結閤橋麵,橫樑的麵外彎麯是設計中的關鍵問題之一.本文針對高速鐵路混凝土闆僅與縱樑結閤的縱橫樑體繫,從結閤橋麵繫變形協調齣髮,推導齣橫樑麵外彎麯問題的計算公式,併結閤算例分析各種因素對橫樑麵外彎麯問題的影響.橋麵繫的連續長度和下絃桿的軸應力越大、下絃桿結點對于橫樑的約束剛度越大、縱樑與下絃桿的距離越小,橫樑的麵外彎矩和彎麯應力越大.在四線鐵路三主桁下承式鋼桁樑橋中,中桁對橫樑的約束近于絕對剛性,縱樑離中桁下絃桿的距離較小,使橫樑的麵外彎麯應力較二主桁橋樑大得多.
중국대과도고속철로강항량교대다채용강-혼응토결합교면,횡량적면외만곡시설계중적관건문제지일.본문침대고속철로혼응토판부여종량결합적종횡량체계,종결합교면계변형협조출발,추도출횡량면외만곡문제적계산공식,병결합산례분석각충인소대횡량면외만곡문제적영향.교면계적련속장도화하현간적축응력월대、하현간결점대우횡량적약속강도월대、종량여하현간적거리월소,횡량적면외만구화만곡응력월대.재사선철로삼주항하승식강항량교중,중항대횡량적약속근우절대강성,종량리중항하현간적거리교소,사횡량적면외만곡응력교이주항교량대득다.
The steel-concrete composite floor system is widely used in large span high-speed railway truss bridges in China. Horizontal bending of crossbeams is a key issue in design. According to coordinated deformation of the floor system, the theoretical formulas of the horizontal bending of the crossbeams of the composite floor system where the concrete slab only combines with the stringers are deduced. In combination with numerical examples, the main factors influencing the horizontal bending of crossbeams are analyzed. The horizontal bending moment and bending stress of the crossbeams rise quickly with increasing of the constraint stiffness of the lower chord joint to the crossbeam, the axial stress of the low chords and the continuous length of the floor system and with decreasing of the distance between the stringer and the low chord. Constraint of the middle truss on the crossbeams approximates to absolute rigidity and the distance between the stringer and the middle low chord are small in the four-line through truss bridge with three main trusses, which produces much larger horizontal bending stresses of the crossbeams as compared with two-truss bridges.
