砂卵石地层中公路隧道围岩变形及破坏特征研究

Study on Deformation and Failure Characteristics of Surrounding Rock of Highway Tunnel in Sand Pebble Stratum

公路隧道围岩的变形及破坏是影响公路工程安全的重要因素。针对砂卵石地层中公路隧道围岩的变形特性,理论上分析了其形成的原因和破坏的机理。其次,结合有限元模型分析了不同含水率的砂卵石地层对隧道围岩的变形影响。研究表明:随着隧道的开挖,隧道围岩会逐步的向隧道四周入侵,最终隧道的拱顶会形成塌落拱;砂卵石地层的含水率的增加,隧道围岩塌落拱的高度也在增加,天然含水率、4%含水率、6%含水率和饱和含水率的塌落拱高度分别为2.3、2.8、5.3和8.3 m。说明隧道在开挖的过程中,隧道围岩的侵入程度与含水率呈正相关。

The deformation and damage of surrounding rock of highway tunnels are important factors affecting the safety of highway engineering.In this paper,the deformation characteristics of highway tunnel surrounding rock in sand and gravel stratum are theoretically analyzed.Secondly,the finite element model is used to analyze the influence of sand and gravel stratum with different water content on the deformation of tunnel surrounding rock.The research shows that with the excavation of the tunnel,the surrounding rock of the tunnel will gradually invade around the tunnel.Finally,the arch of the tunnel will form a collapsed arch;the water content of the sand pebble stratum will increase,and the height of the collapsed arch of the tunnel surrounding rock will also be At the increase,the collapsed arch heights of natural moisture content,4%moisture content,6%water content and saturated water content were 2.3 m,2.8 m,5.3 m and 8.3 m,respectively.It shows that during the excavation process,the degree of invasion of the surrounding rock of the tunnel is positively correlated with the water content.