CRD工法在南华一号隧道进口段适应性研究

Research on the Adaptability of CRD Method in the Entrance Section of Nanhua Yihao Tunnel

南华一号隧道是在建的广大（广通～大理）铁路控制性工程之一,其进口段围岩极其软弱破碎,结构面发育,最小覆土厚度仅6m,施工风险极高。围岩稳定性的影响因素众多,施工工艺直接影响围岩卸荷变形,如有处理不当,超过围岩的承载能力,极易造成掌子面失稳以及地表塌陷。为此,为了安全、顺利施工,施工方拟采用CRD工法。结合数值模拟和现场实测手段对CRD工法的在该地质条件下的适应性展开研究,取得了一些列成果,可以为同类型的隧道设计和施工提供借鉴。

Nanhua Yihao Tunnel is one of controlling projects of Guangtong-Dali Railway,of which the surrounding rock is extremely rock and the structural surface is developed,the minimum overburden is only 6 meters.Many factors influence the stability of tunnel surrounding rock,while the construction method directly affect the unloading deformation,which can very easily lead to the instability of tunnel face and surface subsidence.For this reason,in order to ensure safe and smooth construction,CRD method is planned to be adopted.In this paper,the adaptability of CRD method is researched by means of numerical simulation and filed measurement.A series of results can provide a reference for the tunnel design and construction of the same type.