大跨无仰拱隧道二次衬砌墙脚结构受力分析

对于普通大跨度隧道,一般采用仰拱设计,更好地进行受力支撑。若超大跨断面处采用无仰拱衬砌类型,结构受力很不利,但当满足某些特定条件时可采纳无仰拱设计。通过对某隧道大断面无仰拱情况拟定不同高程的墙脚进行数值模拟,分析二衬结构受力,并总结拱顶下沉随着墙脚厚度变化的规律,找到最优墙脚高度,确定设计施工方案。

Stress analysis on large-span non-inverted tunnel with secondary lining construction

In order to make a better support of the stress, the design of inverted arch is usually employed when it comes to the case of ordinary large-span tunnel. Providing that the non-inverted arches lining tech- niques adopted to tackle the problems of super-long span section, it will exert a negative effect on its struc- tural force. Nevertheless, the above-mentioned techniques can be adopted when certain specific conditions are met. Then, analysis is made on the structural force-support of secondary lining. For the purpose of finding out the optimal altitude of linear level, it also summarizes the changing rule of the vault crown set- tlement when the angel of the foot corner changes. Last, it presents the design scheme of construction.