湖州跨南横塘河下承式单拱肋人行桥设计

Design of a Through Single-Arch-Rib Pedestrian Bridge Crossing South Hengtang River in Huzhou

摘要:

以湖州跨南横塘河人行桥项目为背景，充分考虑现场条件及景观性，通过对方案的逻辑推演和比选，创造性提出下承式单拱肋钢结构拱梁组合体系。桥梁跨径1.3 m+6.3 m+74.8 m+6.3 m+1.3 m，全宽7.2 m，拱肋跨径74.8 m，矢高13 m，高跨比为1/5.75。桥梁横断面采用单拱肋低桥面系形式，拱肋居中布置，主梁在拱肋宽度范围内高于桥面系设置，以提高结构体系刚度，并形成休憩区，避免人行交通交织。主梁采用单箱三室整体式钢箱梁，以提高抗扭性能。拱肋采用单箱单室钢箱梁，拱脚位置与主梁弧形刚接，以提高拱肋的横向稳定性，并提升桥梁整体景观性。桥墩采用两排倒三角钢墩，并采用埋入式柱脚与承台刚接。在主梁1/3跨处设置TMD，以提升桥梁人行舒适度。

Abstract:

Based on a pedestrian bridge project crossing the South Hengtang River in Huzhou, fully considering the on-site conditions and the landscape, a composite system of through single-arch-rib steel structural arch and beam is creatively proposed through the logical reasoning and comparison of the schemes. The bridge spans are 1.3 m+6.3 m+74.8 m+6.3 m+1.3 m, a full width is 7.2 m, an arch rib span is 74.8 m, a rise is 13 m, and a height-to-span ratio is 1/5.75. The cross-section of the bridge is in the type of single-arch-rib low bridge deck system. The arch rib is centrally arranged. The girder is set higher than the bridge deck system within the width of the arch rib to enhance the stiffness of the structural system and form a rest area, avoiding the interweaving of pedestrian traffic. The girder is a single-box three-chamber integral steel box girder to improve the torsional performance. The single-box single-chamber steel box beam is adopted for the arch rib. The position of the arch foot is rigidly connected to the girder in an arc shape to enhance the lateral stability of the arch rib and improve the overall landscape of the bridge. The bridge piers are two rows of inverted triangular steel piers and are rigidly connected to the base slab by the embedded type. A TMD is set at the 1/3 span of the girder to improve the pedestrian comfort of the bridge.