钻爆法和TBM两种不同施工方法下深埋高外水压力隧洞的破坏特点及其力学机制分析

Failure Characteristics and Mechanical Mechanism of Deeply-Buried Tunnels with High External Water Pressure for Drill &Blast and TBM Methods

钻爆法和TBM法是地下工程掘进的两种主要方法,其对围岩扰动程度、加固措施有显著影响。文章以四条平行分布且分别采用TBM法和钻爆法掘进的大型隧洞为研究对象,进行同一地质条件下不同开挖方法对围岩破坏的影响研究。通过大量地质资料的统计处理、力学分析,总结了围岩的破坏方式,并归纳对比两种不同施工方法对围岩影响的共性特征,包括破坏部位相同、破坏面积相近、破坏坑深相近。另外,对比了两种方法对围岩影响的差异性,包括TBM施工时二次破坏范围比钻爆法的二次破坏范围大,并且易于产生岩爆和应力型破坏,但钻爆法施工时岩体易发生结构面型破坏。在此基础上,分析了各种破坏现象的力学机制,研究成果可为同类工程的施工和加固提供参考。

Drill＆blast and TBMs are two main methods for excavating underground works, and both have a signifi- cant impacts on the disturbance degree and reinforcement measures of surrounding rock. Based on four large paral- lel tunnels adopting the TBM and drill＆blast methods, the influence of the excavation method on surrounding rock damage is studied. Through statistical processing of geological data and mechanical analysis, the failure modes of the tunnel＇s surrounding rock are summarizedand common features of the effects of the two construction methods on the surrounding rock are concluded. In addition, a comparison of the effects of the two construction methods on the surrounding rock are conducted, and it is determined that the secondary failure range by TBM is larger than that of the drill ＆ blast method and a TBM is inclined to produce rock bursts and stress failure, while structural plane fail- ure is more likely to occur when the drill＆ blast method is adopted. Furthermore, mechanical mechanisms of various failures are analyzed based on the above.