大跨度公路隧道施工力学响应数值试验研究

A Numerical Experimental Investigation of the Construction Mechanical Response for Lange-Span Highway Tunnels

大跨隧道施工力学行为极为复杂,明确其力学行为及应力水平对大跨隧道设计与施工有积极意义.以某四车道公路隧道为工程背景,借助数值模拟手段建立了三维围岩-结构隧道施工力学模型,对不同开挖方案下四车道公路隧道施工力学响应进行了对比分析,获得了大跨隧道围岩和支护结构的位移、应力及塑性破坏区等的分布特征与演变规律,提出了适合Ⅴ级围岩条件下大跨隧道合理开挖方法和控制措施,研究成果可以为同类隧道工程的设计与施工提供理论参考.

The construction mechanics of large-span tunnels is extremely complicated,and understanding the mechanics behaviors and stress level is of great significance to the design and construction of large-span tunnels.On the basis of a case study of a four-lane highway tunnel,the finite difference method（FDM）using software FLAC3 Dwas adopted to establish a three-dimensional stratum-structure construction mechanical model for researching the distribution characteristics and the evolution rules of displacement,stress,and plastic failure zone on the surrounding rock and the structure of the tunnel,The mechanical responses of the four-lane highway tunnel under varying construction methods were compared and analyzed.Some dynamic mechanics rules were obtained,and reasonable construction methods and control measures of large-span highway tunnels were put forward on this condition.It is hoped that the results obtained in this study can be adopted in the design,construction and research of similar large-span highway tunnels.