基于粗糙度的连拱隧道开挖断面线分析

超欠挖一直是隧道开挖中遇到的一大难题，文章在对金丽温高速木西岙连拱隧道超欠挖现场调查的基础上绘制出开挖断面线及平均开挖断面线，应用在评价岩体结构面几何形态时普遍使用的粗糙度方法对断面线进行评价，以分析开挖断面上不同部位超欠挖的差异性。得出连拱隧道开挖断面的超欠挖特征，同时估算超欠挖方量及由此造成对隧道成本的影响。

Analysis on the Excavating Section Lines by Roughness for Doubled Arch Tunnels

It is a very difficult problem of overbreak in tunnel excavation.On the base of the investigation on phenomenon of overbreak in Jinliwen Highway MuXiAo doubled arch tunnels,the excavating section lines and their average line are drawn in this paper.In order to analyze the difference of overbreak on the excavating section lines at different position,the method of roughness is applied to determine those section lines,which are used to evaluate the geometry shape of the structure of the rock mass.At last,the overbreak characteristic of double arch tunnels' excavating section are gained,at the same time,estimating the effect on the investment of the tunnel owing to overbreak.