黄土隧道地表塌陷原因分析与施工对策研究

基于兰渝铁路工程某大断面黄土隧道的工程背景，分析在黄土地层不良地质段发生地表塌陷、初期支护严重变形、拱顶沉降及洞内收敛过大等现象的原因；同时根据地表塌陷段的地质情况，结合数值模拟分析，提出地表旋喷桩注浆加固地层、洞内超前注浆预支护以及提高初期支护强度的综合处置方案，很好地实现了隧道安全施工的目的。针对黄土地层大变形及地表塌陷区采取的施工控制技术可供今后类似隧道借鉴和参考。

Analysis on Causes for Ground Surface Collapse Induced by Excavation of Tunnel in Loess and Study on Construction Countermeasures

Analysis is made on the causes for the ground surface collapse,large deformation of primary reinforcement structure,excessive crown settlement and horizontal convergence of tunnel in poor geological sections in loess,with a large cross-section tunnel in loess on Lanzhou-Chongqing railway as an example.Countermeasures,including ground consolidation by installing jet grouting piles from the ground surface,advance grouting executed in tunnel and improving the strength of the primary reinforcement structure,are recommended on basis of the geological conditions in the ground surface collapse section and numerical simulation results.The paper can be served as reference for similar projects in the future.