低等级公路隧道内轮廓拟定方法探讨

Discussion on Drawing-up Method of Inner Contour of Low-grade Highway Tunnel

隧道内轮廓的确定是隧道设计中最重要的环节。由于低等级公路隧道未能像高等级公路隧道一样形成较为完善的设计体系,而现行规范仅给出了原则性的规定,造成各设计单位在同一区域设计时采用的标准差别较大。以省道S306仙莲线德兴城区段改建工程中猪油岗隧道为例,对低等级公路隧道内轮廓拟定方法进行详细讨论,并且分析了其受力情况。结果表明:隧道内轮廓的拟定在满足建筑限界的条件下,结合隧道受力情况尽量提高断面利用率,同时应进行必要的机构受力分析保证结构安全。

The determination of the inner contour of the tunnel is the most important link in tunnel design. Because the low-grade highway tunnel fails to form a relatively perfect design system like the high-grade highway tunnel, and the current code only provides principles, the standards adopted by each design unit in the design of the same area are quite different. Taking the Zhuyougang Tunnel in the Provincial Highway S306 Xianlian Line Dexing Urban Area Section Reconstruction Project as an example, this paper discusses the drawing-up method of the inner contour of the low-grade highway tunnel in detail, and analyzes its stress situation. The result shows that the drawing up of the inner contour of the tunnel increases the utilization rate of section as far as possible combined with the tunnel stress situation under the condition of meeting the building limit. At the same time, it is necessary to analyze the mechanism stress in order to ensure the structure safety.