无支架施工系杆拱桥临时锚固设计与受力特性分析

摘要:

采用无支架方式施工系杆拱桥时,施工期间的水平推力依靠施加于拱脚间的临时拉索进行平衡,随着施工过程的进行,水平推力不断发生变化,相应需要不停地调整临时索的索力。依托泰东河大桥作为背景工程,详细介绍了无支架施工临时索设计方法,并建立空间实体分析模型,研究了锚固区的受力特性,结果表明：临时索的施加对锚固横梁受力影响显著,横梁呈现明显的横向弯曲效应,为此提出钢束横向不均匀张拉的施工优化措施；锚固块主拉应力较大值主要出现在临时索锚下区及与系梁交界位置,应布置加强钢筋防止施工过程中开裂,锚固块整体主拉应力较小,满足受力要求。

Abstract:

SWhen the tied arch bridge is constructed in non- falsework, the horizontal thrust during the construction period is balanced by the temporary cable applied between the arch feet. With the progress of the construction process, the horizontal thrust changes continuously, and the cable force of the temporary cable needs to be adjusted constantly. Relying on Taidong River Bridge as a background project, this paper introduces the design method of temporary cable in detail, and establishes a spatial solid analysis model. The mechanical properties of the anchorage zone are studied. The results show that the application of temporary cable has a significant impact on the stress of the anchorage beam, and the beam presents an obvious transverse bending effect. Therefore, the construction optimization measures of transverse uneven tensioning of steel tendon are put forward; The larger value of the main tensile stress of the anchor block mainly appears in the lower area of the temporary cable anchor and the junction with the tie beam. Reinforced reinforcement shall be arranged to prevent cracking during construction. The overall main tensile stress of the anchor block is small and meets the stress requirements.