不同施工方法对隧道岩爆的影响研究

Influence of different construction methods on rockburst in railway tunnel

岩爆作为高地应力环境中特有的地质灾害,发生时具有很强的突发性、随机性与破坏性。为深入研究高地应力条件下岩爆发生过程,有效控制隧道施工过程中岩爆发生程度,为深埋硬岩隧道工程的设计、施工提供指导。以桑珠岭隧道为工程依托,运用有限元仿真技术对钻爆法、TBM两种不同的施工方法进行了数值模拟对比研究,主要从开挖扰动区域、应力场以及岩体能量变化等角度分析出TBM法和钻爆法对隧道岩爆的影响。研究表明钻爆法施工相对于TBM法虽然也产生应力集中,但周边最大应力值大大降低,因为钻爆法产生的破碎区,使得隧洞周边的应力集中程度下降较大,应力向围岩深处转移,降低了岩爆发生的风险。因此,针对高地应力岩爆区段的隧道开挖,采用钻爆法施工更有利于控制岩爆的发生。

Rockburst,as a special geological disaster in high geo-stress environment,has strong suddenness,randomness,and destructiveness.To further study the occurrence process of rockburst under high in-situ stress,effectively control the occurrence degree of rockburst during tunnel construction and provide guidance for the design and construction of railway deep buried hard rock tunnel engineering.In this paper,based on sichuan-Tibet Railway Sangzhuling tunnel as the project,the finite element simulation technology is used to compare the numerical simulation of TBM and TBM,two different construction methods.The influence of TBM and TBM on railway tunnel rock burst is analyzed mainly from the Angle of excavation disturbance area,stress field and rock mass energy change.The research shows that compared with TBM method,the drilling and blasting method also produces stress concentration,but the maximum stress value around the tunnel is greatly reduced.Because of the fracture zone generated by drilling and blasting method,the stress concentration around the tunnel decreases greatly,and the stress transfers to the depth of the surrounding rock,thus reducing the risk of rock burst.Therefore,for tunnel excavation in rock burst section with high in-situ stress,the method of drilling and blasting construction is more beneficial to control the occurrence of rockburst.