土岩组合地层浅埋隧道埋深确定方法研究

为能更好地确定土岩组合地层浅埋暗挖埋深,以青岛地铁某浅埋暗挖车站为依托,采用数值模拟为研究方法,研究岩跨比、覆跨比等指标对隧道埋深的影响,并在此基础上从多指标角度出发研究其对隧道埋深的敏感性影响。研究表明:1)在强风化-微风化花岗岩地层隧道施工过程中上覆岩体和土体对围岩的稳定贡献程度不同,上覆岩体更有利于隧道的稳定;2)在青岛典型土岩组合地层中确定地铁车站埋深时,隧道的安全性对上覆岩层的厚度最为敏感,其次为覆跨比,覆盖层自重荷载影响隧道施工后的变形及受力。

Study on Determination of Cover Depth of Shallow-covered Tunnel in Soil-rock Strata

The influence of rock span ratio and cover span ratio on the cover depth of a shallow covered mined station of Qingdao Metro is studied by using numerical simulation method and in terms of several indices. The study results show that: 1) In intensely weathered to slightly weathered granite strata, compared to the soil cover, the rock cover plays more important role on the stability of the surrounding rock and is more helpful for the stability of the tunnel; 2) In the typical soil rock strata in Qingdao, the stability of the tunnel is most sensitive to the depth of the rock cover, with the cover span ratio at the second place. And the dead weight of the cover may impact the deformation and force conditions of the tunnel after construction. 