现浇混凝土弧形梁结构设计分析

Analysis on the structural design of cast-in-place concrete curved beams

由于弧形梁在竖向荷载作用下受力复杂,不仅存在弯矩、剪力,还有扭矩,其计算在结构设计中是一大难点。常规设计软件如PKPM,YJKS1.8在弧形梁计算中扭矩折减系数取值偏大,截面设计偏于保守。针对此设计现状,对单跨无直线段圆弧梁及两端带直线段圆弧梁进行了理论分析,并结合实际工程,采用常规设计软件PKPM,YJKS1.8和本文的公式分别对单跨无直线段圆弧梁及两端带直线段圆弧梁的内力进行计算,基于梁内力的理论分析结果与常用设计软件分析结果的比较,提出软件设计中扭矩折减系数的参考取值,建议将其默认取值1.0改为0.85,符合结构设计的＂安全、适用、经济＂目标。

Due to the complex forces of curved beam under vertical loads,there are not only bending moments,shear forces,but also torque,and the calculation of curved beam is a big difficulty in the structural design. Conventional design software such as PKPM and YJKS1. 8 has a large torque reduction coefficient and the design calculation of curved beam section is conservative. In view of the current design situation,the theoretical analysis of curved beam with single span without straight line segment and curved beam with straight line segment at both ends were carried out. Combined with practical engineering,the conventional design software PKPM,YJKS1. 8 and the theoretical analysis were used to calculate the internal forces of curved beam with single span without straight line segment and curved beam with straight line segment at both ends. The theoretical analysis results based on the internal force of the beam were compared with the analysis results of the common design software,and the reference value of torque reduction coefficient in the software design was proposed.It is recommended to change the default value of 1. 0 to 0. 85,conforming to the structure design of the ＂safe,applicable and economic＂goals.