下承式密布横梁体系钢桁结合梁桥受力性能分析

发布时间：2018-12-31 21:46

【摘要】：下承式钢桁结合梁桥通过桥面板与主桁结构的连接形成稳定的空间结构,使得桥梁的刚度,特别是面外抗弯刚度得到了有效提高。密布横梁体系的下承式钢桁结合梁桥则取消了纵梁,增加了节间横梁,改善了桥梁结构主桁的受力情况。本文以跨度64 m的密布横梁式钢桁结合梁桥为例,通过静、动载试验和有限元分析,研究了该结构体系的受力特性。研究结果表明:该桥一阶横向自振频率满足规范要求;且由于桥面板与下弦杆形成的整体共同承受外部荷载,在30 t轴重荷载作用下弦杆与横梁受力较小,最大应力分别为26.39,30.73 MPa,并有效减小了下弦杆挠度,实测挠跨比远小于限值;混凝土桥面板以受拉为主,顺桥向最大应力为3.53 MPa。该桥动力性能良好,跨中横、竖向振动特性均满足规范要求,满足30 t轴重重载运输要求。
[Abstract]:The through steel truss composite beam bridge forms a stable spatial structure through the connection between the deck slab and the main truss structure, which can effectively improve the stiffness of the bridge, especially the out-of-plane flexural stiffness. The through steel truss composite girder bridge of dense cross beam system cancels the longitudinal beam, increases the Internode cross beam, and improves the stress condition of the main truss of the bridge structure. Taking a 64 m span steel truss composite girder bridge as an example, the mechanical characteristics of the structure system are studied by static and dynamic load tests and finite element analysis. The results show that the first-order transverse natural vibration frequency of the bridge meets the requirements of the specifications. Because the whole bridge deck plate and the bottom chord bear the external load together, the stress of the chord and the beam is smaller under the action of 30 t axial load, the maximum stress is 26.39 MPa, and the deflection of the lower chord is reduced effectively. The measured deflection span ratio is far less than the limit value. The concrete deck slab is mainly subjected to tension, and the maximum stress is 3.53 MPa. along the bridge. The dynamic performance of the bridge is good. The vibration characteristics of the bridge meet the requirements of the code and the heavy load of 30 t axle load.
【作者单位】：中国铁道科学研究院;中国铁道科学研究院铁道建筑研究所;
【基金】：中国铁道科学研究院基金(2015YJ028)
【分类号】：U441

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