缙云山隧道部分地段由于所处地层地质情况差以及二次衬砌滞后等原因，在施工过程中发生了五次较大的坍方。承建单位按坍方的不同情况，分别采用了YLF方法、YF方法和K方法进行处理，取得成功。 Due to the geological conditions of the strata in the Jinyun Mountain Tunnel and the lagging of the secondary lining, some large collapses occurred in the construction process. According to the different conditions of the slump, the contractors adopted the YLF method, the YF method and the K method, respectively, for their success.