刚架系杆拱桥拱墩梁结合部结构受力分析及优化

Stress Analysis and Optimization of the Joint Structure of Arch Pier and Beam of Rigid Frame Tied Arch Bridge

刚架系杆拱桥拱肋与桥墩固结、与主梁分离,形成的拱墩梁结合部构造复杂,截面突变严重,加上多方向受力,应力状态极为复杂。文中以某系杆拱桥拱墩梁结合部为研究对象,建立有限元实体模型,分析该结构在恒载、恒载+活载、运营阶段等工况下的受力状态及变化规律,并据此提出结构优化建议。结果表明,拱墩梁结合部第三主应力总体水平不高,基本均在0.7^-10.4 MPa之间;结构第一主应力基本均在-4.5~7.0 MPa,剪应力基本在-3.0~4.6 MPa之间,其中应力较大位置出现在拱肋与立柱、横梁连接局部区域;建议在拉应力较大的连接部位设置圆弧倒角进行过渡,同时增加防裂钢筋。在拱肋侧面与横梁连接局部区域,应按构造要求配置箍筋、斜筋或粘贴钢板,并进行抗剪强度检算。

The arch rib of rigid frame tied arch bridge is consolidated with the pier and separated from the main beam.The structure of the joint of the arch pier and the beam is complex,the section mutation is serious,and the stress state is very complex due to multiple directions forces.In this paper,the joint of arch pier and beam of a tied arch bridge is taken as the research object,the finite element model is established,the stress state and change rule of the structure under dead load,dead load combined with live load and operation stage are analyzed,and the structural optimization suggestions are put forward accordingly.The results show that the total level of the third principal stress in the joint of arch pier and beam is not high,which is between 0.7~10.4 MPa;the first principal stress of the structure is basically between-4.5~7.0 MPa;the shear stress is basically between-3.0~4.6 MPa;the place with high stress appears in the local area where the arch rib is connected with column and beam.It is suggested that arc chamfering should be set in the connection part with large tensile stress for transition,and anti crack reinforcement should be added at the same time.In the local area where the side of the arch rib is connected with the cross beam,stirrups and diagonal bars shall be arranged according to the structural requirements,and the shear strength shall be checked.