广州北二环高速立体扩建桥梁方案简析

Brief Analysis of the Three-dimensional Expansion Bridge Scheme of Guangzhou North Second Ring Expressway

广州北二环高速公路是国高网G4京港澳高速公路和G15沈阳~海口高速公路的共线段,总体采用双向6车道标准,设计速度为80 km/h,项目于2002年通车。由于车流量超过原设计远景流量,车道服务水平难以满足日益增长的交通需求,故总体上采用双向10车道标准对其进行扩建。分析了复杂城市建设条件下广州北二环高速公路桥梁的设计特点及需考虑的各方面因素,阐述了其代表性工程萝岗高架桥方案的设计思路。综合考虑扩建路线整体走向、交叉道路、沿线高压管线、互通方案等因素,对萝岗高架桥设计方案进行优化调整,并结合路线方案提出推荐桥梁结构方案。实践表明,在城市多因素条件约束下,创新性地大面积采用大跨径钢盖梁可以较好地满足多因素多主体的技术诉求。

The Guangzhou North Second Ring(GNSR)Expressway is the common section of the National Expressway Network G4 Beijing-Hong Kong-Macao Expressway and G15 Shenyang-Haikou Expressway,which generally adopts the dual 3-lanes standard and the design speed of 80 km/h.The project was opened to traffic in 2002.Because the traffic flow exceeds the original designed long-term flow,the carriageway service level is difficult to meet the growing traffic demand,as such the dual 5-lanes scheme is generally used to make widening.In the paper,the design characteristics and various factors that need to be considered in the bridge design of the GNSR under the condition of complex urban construction are analyzed,and the design idea of Luogang Viaduct scheme is expounded.The design scheme of Luogang Viaduct is optimized and adjusted by combining the factors such as the overall direction of the expansion route,the cross road,the high-pressure pipeline along the line,and the interchange scheme,and the recommended bridge structure scheme is proposed based on the route scheme.The practice shows that under the constraints of urban multi-factor conditions,the innovative large-scale use of large-span steel capping beams can better adapt to the technical requirements of multi-factor and multi-shareholders.