小断面通道进入大断面主洞垂直交叉口CRD法与上挑洞法施工比较

为解决地铁车站的施工通道与主隧道的施工转换，从转化工序、临时支护费用、安全、质量、综合效益等方面对CRD法和上挑洞法2种不同的方案进行分析比较，总结出在地层较好时小断面转入大断面隧道交叉口可优先考虑上挑洞法，对于地质条件较差时可考虑CRD法。对与本工程类似的洞口转换有一定的借鉴作用。

Comparison and Contrast between CRD Method and Roof Ripping Method:Case Study on Construction of Junction Section between Access Tunnel and Main Tunnel

CRD method and roof ripping method are proposed for the construction of the junction section between the access tunnel and the main tunnel. The two methods proposed are compared in terms of technical measures and construction process. Finally, roof ripping method is adopted, with the geological prospecting data, the actual geological conditions and the safety, quality and schedule requirements considered. In the end, the construction of the junction section has been completed with high quality and high speed. The paper can provide reference for similar projects in the future.