重庆地区层状岩地层超大断面暗挖地铁车站施工工法比选

Comparison of Chongqing Metro Station Construction Method in Super-large Section Tunnel of the Stratigraphic Strata

针对重庆地区层状岩地层暗挖地铁车站的特殊地质条件、超大断面及受施工工法影响显著等特征,建立了层状岩地层双层叠合初支拱盖法、双侧壁导坑法、中隔墙加台阶法数值计算模型,进行了施工工法适应性分析,并结合实际工程经济指标进行了对比分析。结果表明:双层叠合初支拱盖法的各项考查指标均能很好地满足控制标准,且3种工法对洞周收敛形态控制都较好,衬砌结构的安全性亦较高;同时该工法能较好地适应重庆地区的地质条件及经济性要求,具有工作面大、效率高、工序少、施工安全等显著优点,亦具有较强的经济适用性。建议在重庆地区层状岩地层超大断面暗挖车站施工中采用双层叠合初支拱盖法施工。

Considering the special geological conditions of stratigraphic strata in Chongqing City,the super-large section and remarkable influence of the construction,where the metro station is constructed with subsurface excavation method,a numerical calculation model is established which adopts the double-layer superimposed initial support arch-cap method,double-sided heading method and CRD method,in order to analyze the adaptability of construction methods,and compare the actual engineering economic indicators.The results show that all the indexes of the double-layer superimposed initial arch-cover method can meet the control standards,and the convergence shape around the tunnel is better controlled by using each of the 3 construction methods,and the safety of the lining structure is also higher.The double-layer superimposed construction method adapts to the geological conditions and economic requirements of Chongqing area due to its obvious advantages such as large working face,high efficiency,less working procedures and safe construction,therefore has better economic applicability.In the construction of super-large cross-section underground excavation station in stratigraphic strata of Chongqing City,the double-layer superimposed method is recommended.