The curved bridge with small radius and long span in rail transit system has the characteristics such as the complex stress, high traffic load and great design difficulties, etc. Due to factors like the coupling with axial deformation and bend in-plane, vertical flexure and reverse, cross section distortion and reverse, the construction of a curved bridge may meet challenges including the large displacement in horizontal radius direction, bridge beam warping, fixed position crazing in pier-beam, and support escaping, etc. With a case study of the curved bridge in Dalian, the pre-stressed concrete project of small radius and large span, the forces with FEM software are analyzed, the coupling of deformation is taken into consideration. Then some measures are taken with application of key technologies, such as the cross-section design, the distribution of pre-stressed tendons and steel bars. In order to solve problems of the over-loading on outer beams and lower loading on inner beams of the curved bridge, some key indexes of the bearing forms and partiality are studied. This research shows that the engineering problems could be solved effectively by a-dopting the single-cell box girder cross-section, reasonable installation of steel bars, the pre-stressing force restriction and support partiality.%轨道交通大跨度小半径曲线梁桥具有受力复杂、车辆荷载大、设计难度高等特点.曲线梁桥由于轴向变形与平面内弯曲耦合,竖向挠曲与扭转耦合,以及弯曲、扭转与截面畸变耦合等因素,易发生梁体水平径向位移过大、梁体翘曲、墩梁固结处开裂、支座脱空等工程问题.依托大连轻轨某小半径大跨度预应力混凝土曲线梁桥工程,通过对曲线桥梁受力情况的分析,考虑变形耦合效应,确定了截面、钢筋及预应力钢束设置等关键技术参数,并针对曲线梁存在的“外梁超载,内梁卸载”问题,对支承形式及偏心等关键参数进行了讨论.研究表明,采用单箱单室截面、合理设置钢筋、预应力约束、支座等措施能有效解决此类工程问题.
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