复杂条件下隧道开挖循环进尺优化方法研究

Study of footage optimization method of tunneling cycle under complicated conditions

复杂条件下如何选择合理的开挖进尺一直是隧道施工的难题之一。在已有的研究成果基础上,提出了圆形或近圆形隧道开挖过程的时空关系表达式,并给出基于现场位移监测数据的参数计算方法。结合关角隧道9#工区二郎洞断层破碎带现场施工情况及监测资料,建立了该断层破碎带开挖过程的时空效应关系式,结果表明,该关系式能够反映开挖过程中洞周位移的时空的变化。在此基础上提出了断层破碎带软岩开挖过程的时空效应分析及进尺优化的方法,对关角隧道9#工区几条较大断层破碎带隧道开挖的进尺进行了优化,优化后的开挖进尺是可行的,也解释了断层破碎带围岩隧道开挖"短进尺"的合理性。同时文中也分析了该方法的优点及适用范围。

How to choose a reasonable footage of tunneling cycle in complicated conditions has been a problem in tunnel construction.Based on the existing research results,a spatial relational expression about tunnel excavation is proposed,and a calculation method which based on the on-site displacement monitoring data is also work out.Combined with on-site construction conditions and monitoring data about Erlang fault-rupture zone at #9 work area of Guanjiao tunnel,the spatial effect expression of displacement during tunneling is established,results indicate that the spatial relational expression can reflect the displacement change with the changes of time and space.On the basis,the methods of spatial effect analysis and footage optimization of tunneling cycle about tunnel excavation in the soft rock with fault-rupture zone are achieved,and the footage of tunneling cycle in several large fault-rupture zones is optimized.Practice has proved that the method is feasible.Advantage and application scope of the method are analyzed too.