水工隧洞TBM施工适宜性围岩分类研究

隧洞掘进机TBM已逐渐成为水工深埋长隧洞的常规施工方法,而现行规范的围岩分类主要以隧洞围岩稳定性和支护措施为判别因素,仅适用于钻爆法隧洞。为此,梳理国内外不同工程的围岩分类指标体系和TBM施工特点,在隧洞围岩基本分类的基础上,重点分析了TBM掘进效率和不良地质条件,构建了TBM施工适宜性围岩分类方法。总结大量工程案例,综合权衡超硬岩、岩爆、断层破碎带、大变形、突涌水(涌泥)和高外水压力六个关键因素对TBM施工的定量影响,提出了可量化围岩分类指标。工程应用表明,TBM施工适宜性围岩分类方法可依据工程地质资料快捷完成围岩分类,能有效指导TBM隧洞施工,且具有较好的通用性和易用性。

Study on classification of surrounding rock suitable for TBM construction of hydraulic tunnel

TBM has gradually become a conventional construction method for hydraulic deep buried long tunnels.However,the existing specifications for surrounding rock classification mainly take the stability of surrounding rock and support measures as the main discriminant factors,which is only suitable for drilling and blasting tunnels.Therefore,the classification index system of surrounding rock and the characteristics of TBM construction for different projects at home and abroad are combed.Then,the TBM tunneling efficiency and adverse geological conditions are emphatically analyzed,and the classification method of surrounding rock suitable for TBM construction is constructed based on the basic classification of tunnel surrounding rock.Finally,a large number of engineering cases are summarized,and the quantitative impact of six key factors on TBM construction,namely,superhard rock,rock burst,fault fracture zone,large deformation,water inrush (mud inrush) and high external water pressure,is comprehensively weighed,and the quantifiable surrounding rock classification index is proposed.The engineering application shows that the surrounding rock classification method for TBM construction suitability can quickly complete the surrounding rock classification according to the engineering geological data,and can effectively guide the TBM tunnel construction,that has good universality and ease of use.