后张梁曲线钢束段混凝土局部应力解析  

Theoretical Analysis for Local Stress in Concrete of Curved Tendon in Post-tensioned Girder

作　　者：成晟 CHENG Sheng(Taizhou Highway Development Center,Taizhou 225300,China)

机构地区：[1]泰州市公路事业发展中心,泰州225300

出　　处：《现代交通技术》2022年第4期50-54,共5页Modern Transportation Technology

摘　　要：针对预应力混凝土中曲线钢束引起的局部集中应力难以解析的问题,以弹性力学中楔形体在楔顶受集中力的密切尔解为基础,通过应力分解、应力积分和应力合成运算,推导半平面在体内集中力作用下的解析解。在此基础上对后张梁在曲线钢束张拉时混凝土内的附加应力进行计算,给出应力分布特征、最大应力和典型应力公式,并对大跨径梁合龙段底板、悬浇梁节段腹板以及曲线梁底腹板3种典型结构的裂缝成因进行分析,给出工程优化建议,为桥梁设计提供参考。Aiming at the difficulty in analysis of local concentrated stress in prestressed concrete caused by curved tendons,based on Mitchell’s solution for wedges under concentrated forces at the top in elasticity,with operations of stress decomposition,stress integral and stress synthesis,the analytical solution for stresses of half plane under internal concentrated forces was derived.After that the additional stresses of concrete in post-tensioned girders during the prestressing of curved tendons were calculated and the stress distribution,the formulas for maximum and typical stresses were given.The cracking causes for three typical structures as the bottom flange of closure segment in long-span girder,the web of the segment of cantilever casting girder,and the bottom flange and the web of the curved box girder were analyzed,and optimization suggestions were provided for references in bridge design.

关 键 词：桥梁工程 后张梁 曲线钢束 局部应力 裂缝 楔形体 解析解 

分 类 号：U441.5[建筑科学—桥梁与隧道工程]