金丽温高速公路红枫连拱隧道超欠挖分析

Analysis of Overbreak for Hongfeng Doubled Arch Tunnels in Jinliwen Expressway

超欠挖一直是隧道开挖中遇到的一大难题。该文在金丽温高速红枫连拱隧道超欠挖现象现场调查的基础上,绘制出开挖断面超欠挖块体投影面的平面展示图,对超欠挖现象的各种几何形态进行统计分析,包括投影面的边分析、面分析和块体的空间分布、超欠挖深度、体积分析。统计连拱隧道超欠挖块体空间几何和体积等分布特征,得出开挖断面上不同弧段的超欠挖差异,最后估算由于超欠挖而造成的对隧道成本的影响以及不同弧段超挖造成增加投入的差异。

Overbreak is a very difficult problem in excavating tunnel. On the base of investigation of overbreak in Jinliwen expressway doubled arch tunnels, the projection map of overbreak blocks in excavating section is drawn in this paper. Here, statistical analysis is carried out to various kinds of forms of overbreak blocks, including edge and region analysis of projection plane of overbreak blocks, space distribution of overbreak blocks and excavated depth and volume analysis of overbreak blocks. Getting the difference of overbreak volume to different excavating arch in doubled arch tunnels by statistical distribute characteristics of space geometry and volume of overbreak blocks, etc. At last, estimating the invest effect of the tunnel due to overbreak and difference of increase invest for different excavating arch.