合肥地铁隧道地层组合分类及暗挖适用性研究

Study on Classification of Stratum Combination and Application of Shallow Tunneling Method in Hefei Metro Tunnel

地铁隧道的施工与所穿越的地层条件联系紧密。通过对现有的合肥轨道交通1～5号线地质勘探资料和工程资料的整理总结,结合合肥地区地形地貌特征,采用统计分析、数值模拟和现场实测的方法,对合肥地区的暗挖工程地质条件进行较深入地研究。研究结果表明:对合肥地区工程地质层组进行总体概化可以遵循"以地层的沉积年代为主,以岩土的工程适用特征为辅"的划分原则;按照地层断面特征将合肥地铁隧道可能穿越的地层组合归纳为A～D 4种类型,其中A类地层组合对隧道施工最为有利,B类地层组合对围岩变形的控制能力优于C,D类地层组合。以上结果可为合肥地铁沿线地质条件分析及暗挖隧道施工提供指导性的建议。

The construction of metro tunnel is closely related to the geological conditions. Through summarizing the geological exploration data and the engineering data of the planned Hefei metro line 1~5, the distribution of geomorphic feature in Hefei area was also taken into consideration to study the geological conditions of shallow tunneling engineering of Hefei metro in depth. Three different methods including statistical analysis, numerical model and field measurement had been adopted to make the research more comprehensive and rigorous. The results indicate that the overall generalization of the engineering geological layer, namely, unifying and simplifying the serial number of strata by engineering geology, can be followed by the principle that "the sedimentary age of stratum is given to the priority with the application of geotechnical engineering as the complement" in Hefei area. According to the characteristics of stratigraphic section, the stratum combinations which Hefei metro tunnel might cross can be classified as A^D, among them A stratum combination is the most favorable for the tunnel construction, B stratum combination’s ability to control the deformation of surrounding rock is superior to C and D stratum combination. The above results can provide guidance for the analysis of geological condition and the construction of Hefei metro tunnel.