摘要
为研究梁拱组合连续刚构桥在活载作用下拱与梁的分担比例,将吊杆力等效为膜张力作用于梁拱闭合体上,使用力法推导了三跨梁拱组合连续刚构桥在均布荷载作用下的拱肋活载分担比例的解析解,通过与有限元结算结果的对比,提出既定假设条件下解析公式的修正方法,并通过灰色关联分析法研究了拱梁组合连续刚构桥拱肋活载分担比例的敏感影响因素;结果表明:经与有限元结果比较,本文解析公式的计算误差在±10%以内,推导出的既定拱肋荷载分担比例下拱肋截面抗弯刚度的计算公式可以用于梁拱组合连续刚构桥概念设计中;结论:吊杆与拱肋等代刚度比和梁拱弯曲刚度比kba为影响拱肋荷载分担比例的主要因素,增大拱肋截面刚度可以使拱肋分担更多的荷载;在刚梁柔拱的假定下,拱肋至少能承担30%以上的活载,但当拱肋分担的荷载比例超过60%后,继续拱肋截面抗弯刚度已不能大幅提高其分担的荷载比例。
Objective: To explore the load sharing ratio of beam and arch combination continuous rigid frame bridge under live load. Methods: Axial force of hanger is regarded as a film tension acting on the arch ribs and girder simultaneously, and an analytical solution about the load sharing ratio responsible for the arch under live load is derived. In addition, a correction method is proposed by comparing the analytical results with the finite element results. Finally, gray correlation analysis is conducted to investigate the critical and sensitive factors affecting the load sharing ratio responsible for the arch. The results show that the calculation error between the analytical solutions and numerical results is basically within 10%, and a theoretical formula is proposed to determine the arch ribs’ sectional stiffness under a given load sharing ratio responsible for the arch under live load, which may be used to conduct conceptual design of a beam and arch combination continuous rigid frame bridge. Conclusions: The equivalent stiffness ratio of the suspender arch rib and the beam-arch bending stiffness ratio are the main factors affecting the load sharing ratio of arch ribs. The arch ribs may undertake at least 30% of the live load in case of rigid beam and flexible arch. When the load-bearing ratio of the arch ribs exceeds 60%, it is hardly possible to increase the sectional stiffness of arch ribs to raise the load-bearing ratio of arch ribs.
作者
徐岩
XU Yan(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)
出处
《铁道标准设计》
北大核心
2022年第5期83-88,共6页
Railway Standard Design
基金
中铁第四勘察设计院集团有限公司科研开发课题(2020K121)。
关键词
公路桥
梁拱组合连续刚构桥
荷载分担比例
解析公式
梁拱刚度比
拱肋截面刚度
highway bridge
beam-arch combination continuous rigid frame bridge
load sharing ratio
analytical calculation formula
beam-arch bending stiffness ratio
section stiffness of arch rib
