摘要
容桂大桥主桥为主跨254 m的独塔单索面混合梁斜拉桥,由于在拟定结构尺寸阶段采用第二类稳定方法计算桥塔横向受力费时费力,提出采用几何非线性分析方法计算结构的P-Δ效应、采用结构刚度整体折减50%的方式近似等效材料非线性影响的简化方法来计算横向风作用下桥塔的偏心弯矩,以拟定合理的桥塔横桥向厚度及配筋。为验证该方法拟定的结构是否安全,采用第二类稳定方法分析桥塔的安全性,并分析结构参数对桥塔横向受力安全性的影响。结果表明:该简化方法拟定的桥塔横向厚度及配筋较为合理,桥塔第二类稳定系数为2.51,结构安全性稍高于规范要求;在桥塔结构尺寸受限制时提高混凝土的性能、采用较高强度的钢筋可以增加桥塔的安全储备。
The main bridge of the Ronggui Bridge is a hybrid girder cable-stayed bridge with a single pylon, single cable plane and with a main span 254 m. Considering that at the stage of the structural dimension design, the calculating of the force conditions of the pylon in the transverse direction of the bridge by the category 2 stability method would consume time and energy, the analysis method of geometric nonlinearity was proposed to calculate the P-△ effect of the structure and the simplified method of approaching the influences of material nonlinearity by reducing 50% of the global rigidity of the structure was used to calculate the eccentric bending moment of the pylon under the action of transverse wind so as to eventually design the rational thickness and reinforcement of the pylon in the transverse direction. To verify if the structure designed by the simplified method mentioned above was safe, the category 2 stability method was employed to analyze the safety of the pylon and the influence of structural parameters on the force condition safety of the pylon in the transverse direction. The results of the analysis demonstrate that the thickness and reinforcement of the pylon designed by the method is rational, the coefficient of the category 2 stability of the pylon is 2.51 and the safety of the structure is slightly higher than that in the codes. In case the structural dimension design of a pylon is restricted, the improvement of concrete performance and the utilization of high-strength reinforcement can increase the safety margin of the pylon.
出处
《世界桥梁》
北大核心
2011年第4期16-19,共4页
World Bridges
关键词
斜拉桥
桥塔
单索面
第二类稳定
桥梁设计
cable-stayed bridge
pylon
single cable plane
category 2 stability
bridge design
