梅树岭隧道洞口段浅埋偏压施工技术.doc

梅树岭隧道洞口段浅埋偏压施工技术
李小勇
(京福闽赣铁路客运专线有限公司福州 350013)
摘要:以京福铁路客专(闽赣段)梅树岭隧道为工程背景,针对隧道洞口浅埋偏压段的施工,从方案确定及施工过程中所采取的措施出发,对可能发生的状况提出具体的处理方法;重点介绍了此技术的工艺流程,以便推广应用。实践证明,所采取的措施及处理方法保证了隧道洞口的施工安全及施工进度。
关键词:浅埋;偏压;施工技术;加固措施
中图分类号:U455 4 文献标识码:B
Construction Technology for Shallowly-buried Bias Part of Mei Shu Ling Tunnel Adit
LI Xiaoyong
(Beijing-fuzhou Min-Gan railway line for passenger transport Co.,LTD Fuzhou 350013 China)
【Abstract】According to engineering background of mei shu ling tunnel of Jing-Fu railway line(Fujian and Jiangxi Section) for passenger transport, Article aiming at the construction of shallowly—buried bias part of tunnel adit,specific treating approaches are presented for possible situations based on theory and measure applied during introduced the process especially, for the purpose of popularizing. The practice shows that the measure and treating approaches ensure the safety and progress of construction of tunnel adit.
【Key words】shallowly;buried;bias;construction technology;reinforcement measure
1 基本概况
合福铁路(闽赣段)梅树岭隧道全长737 m,起讫里程为DK502+953~DK503+690,出口明暗分界里程DK503+671。设计行车速度250 km/h(为预留350 km/h进一步提速提供条件);设计为单洞双线隧道。
原设计隧道出口DK503+671~DK503+690段为19 m明洞段;DK503+628~DK503+671段43 m设计采用Ⅴc支护, m2。此区段暗洞严重偏压,洞顶覆盖层较薄,存在漏顶缺肉情况,洞身需穿过较厚地段全风化覆盖层。设计考虑回填反压,并设置锚固桩和挡墙进行挡护。DK502+628~DK503+665段高山侧设计考虑了注浆加固全风化层,暗洞采用6步CD工法和洞口管棚预支护。
原设计隧道出口段线路右侧山体陡峭及左侧漏顶情况见图