隧道围岩挤压变形预测方法研究

研究目的:围岩挤压变形预测是高地应力地区软弱围岩隧道勘察和设计阶段的一项重要工作。目前常用的临界埋深法和临界应力比值法均有局限性,迫切需要提出更加符合实际的隧道围岩挤压变形预测方法。研究结论:围岩挤压变形预测可采用强度应力比进行,建议采用Hoek-Brown经验强度公式和GSI法对岩体强度进行估算,F中地应力应取垂直于隧道走向的最大地应力。挤压变形破坏大都发生在F≤1的情况下,而剧烈挤压变形一般发生在F≤0.5时,可将0.5和1分别作为不同级别挤压变形的临界预测值。实践表明,采用F值法对围岩挤压变形进行预测是可靠的。

Research on Prediction Method for Squeezing Deformation of Surrounding Rock of Tunnel

Research purposes: To predicate the squeezing deformation of the surrounding rock of tunnel is an important work for the survey and design of the weak surrounding rock tunnel in high stress area.There are limitations when using commonly-used prediction ways such as critical burying method and critical stress ratio method.So it is urgent to need a new and available method for prediction of the squeezing deformation of the surrounding rock of tunnel. Research conclusions:The squeezing deformation of surrounding rock can be predicted by strength stress ratio value F,and it is proposed to use the Hock-Brown strength criterion and GSI method to estimate the rock mass strength and use the maximum crustal stress trending to the tunnel as the crustal stress in the strength stress ratio value F.Usually,the destroy of the squeezing deformation happens when the F is less than or equal to 1 and the severe squeezing deformation happens when the F is less than or equal to 0.5.Therefore,the 0.5 and 1 can be separately used as the critical values for the squeezing deformation with different degrees.The practice shows the value F method is reliable for prediction of the squeezing deformation of the surrounding rock.