中跨采用梁拱组合的三跨连续梁桥参数分析与结构设计  

Parametric analysis and structural design of a three‑span continuous bridge with beam‑arch combination in the mid‑span portion

作　　者：方芳 杨轩 武时宇 刘钊[2] FANG Fang;YANG Xuan;WU Shiyu;LIU Zhao(Su Yi Design Group Co.Ltd.,Nanjing 210012,China;School of Civil Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]苏邑设计集团有限公司,江苏南京210012 [2]东南大学土木工程学院,江苏南京211189

出　　处：《现代交通与冶金材料》2022年第4期31-36,共6页Modern Transportation and Metallurgical Materials

摘　　要：将三跨连续梁桥的中跨采用梁拱组合结构进行替代,可以增大结构刚度、降低梁高、增强跨越能力。以一座钢结构的三跨连续梁拱组合桥为背景,提出了针对结构总体力学性能的优化策略,分析了边中跨比、矢跨比和拱梁刚度比对结构受力的影响,研究表明:合理边中跨比取值宜为0.4~0.6,在小于0.25时边支座会出现负反力;矢跨比对拱肋弯矩和轴力影响较大,宜取1/5~1/6.5;在采用整体钢箱作为系梁时,因拱梁刚度比取值范围远小于1而对结构受力影响不大。在确定吊杆内力时,提出基于“一期恒载+0.5×中跨活载”工况并考虑边中跨弯矩均衡的修正刚性吊杆法,以此得到的成桥内力状态较为合理。Substituting the central span of a three-span continuous beam bridge with beam-arch composite structure can bring benefits like greater stiffness,lower deck height and longer span.Taking a real steel bridge of this type as benchmark structure,an optimization strategy is put forward towards its global structural behavior,and the influences of side to middle span ratio,rise-span ratio and stiffness ratio of arch to beam on the structure are analyzed.The research shows that the reasonable side-tomiddle span ratio of this type of bridge should be 0.4~0.6,and the side support will have negative reaction when it is less than 0.25.The rise-span ratio,which has great influence on the bending moment and axial force of arch rib,should be 1/5~1/6.5.When the integral steel box girder is used as the tied beam,the stiffness ratio of arch to beam is far less than 1,which has little effect on the stress values.In addition,an updated rigid-hanger method is proposed,which is based on the load case of“first phase dead load+0.5×mid-span live load”and with due regard to a balanced bending moment distribution.It is proved that the proposed method is more reasonable to determine the structural internal force of the completed bridge state.

关 键 词：梁拱组合桥 结构参数分析 边中跨比 刚性吊杆法 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]