Author(s): LIU Yongping
Pages: 64-67
Year: 2014 Issue:  12
Journal: Railway Engineering
Keyword:  Collapsible loess tunnel; Construction; Key technology; Control points; Survey technology;
Abstract: Linxian tunnel is 10 632 m long and its main component is Ⅳ,Ⅴ surrounding rock,which is located in the loess hilly beam area. T here are many shallow-buried bias segments,the clayey soil layer of which have weak expansibility and are easy to cause the collapse and deformation with difficult construction. T his paper introduced the construction difficulty,construction principle and key technology control points for soft surrounding rock section of collapsible loess tunnel and stability discriminant method of surrounding rock and supporting structure according to displacement control benchmark and displacement time curve shape. Combining with the construction experience, this paper concluded deformation control measures for large section collapsible loess tunnel construction and collapsible loess tunnel construction is completed with security,high quality and efficiency based on these measures, w hich could provide a reference for tunnel construction in other special conditions.