Construction Technology of Large-section Collapsible Loess Tunnel

Research purposes:Based on the construction of three large-section collapsible loess tunnels, Tongluochuan Tunnel,Gaoqiao Tunnel and Fenghuangling Tunnel,this paper analyzes and summarizes the CRD construction method of grade V large-section collapsible loess and proper process,distance between the stages,personnel,arrangement of facilities and equipments.Reference index of deformation stability-controlling was expounded by analyzing the relationship between ground settlement,vault settlement,horizontal shrink and excavation process,loess water content,rainfall and deformation rule. Research results:It ensures the practical progress index and time of every process circulation.From the experience and practice of construction,deformation-controlling measures are summarized and some problems about design and construction technology are submitted to be further probed and researched.