新型吊杆布置系杆拱桥结构受力分析

Analysis on Structural Stress of Bowstring Arch Bridge with New Arrangement of Suspenders

随着对城市桥梁景观需求地不断增强,系杆拱的建造越来越多,而吊杆布置直接影响着拱桥景观。系统总结了吊杆布置的常用形式,研究了矢跨比和合理拱轴线的工程现状,并提出了扇形吊杆布置拱桥的概念。针对新型吊杆布置形式的关键参数——吊杆圆心角α,比较分析了其拱肋内力影响线、推力影响线、系梁弯矩卸荷比等结构特性。结合工程实例说明吊杆圆心角α决定了扇形吊杆布置系杆拱的吊杆锚固,吊杆的集中布置、以及倾斜吊杆与拱肋间夹角减小会极大地增加设计难度,实际工程应结合具体的锚固形式,确定合适的吊杆锚固间距。

With the increasing landscape demand of urban bridges,more and more bowstring arches are built,and the arrangement of suspenders directly affects the landscape of arch bridges.The common type of suspender arrangement is systematically summarized.The current engineering status of rise-span ratio and optimum arch axis are studied.And the concept of arch bridge with fan-shaped arrangement of suspender is proposed.Aiming at the key parameter-the central angleαof suspender for the new type of suspender arrangement,the structural characteristics of arch rib internal force influence line,thrust influence line,tie beam moment unloading ratio and the others are compared and analyzed.Combined with the engineering cases,it is explained that the central angleαof suspender determines the anchoring of the suspender with the tie arch.The centralized arrangement of suspender and the reduction of included angle between the inclined suspender and arch rib will greatly increase the difficulty of design.In practical engineering,the proper anchorage spacing of suspender should be determined according to the concrete anchorage form.