2013年4月下 施工技术 第42卷第8期 CONSTRUCTION TECHNOLOGY 65 D0I:10.7672/sgj2013080065 程儿山隧道富水第三系粉细砂岩段施工技术 杨扶银 (兰州铁道设计院有限公司，甘肃兰州730000) [摘要]程儿山隧道进出口段围岩均为第三系粉细砂岩，地下水较丰富，对照此段施工中出现的问题，分析了其中 的原因.并针对第三系粉细砂岩成岩性差，泥质弱胶结，遇水或长时间暴露极易产生结构破坏，很快变成松散的砂 状，隧道围岩稳定性迅速变差的特点，采取多级轻型井点真空降水、深孔真空降水和管井降水相结合的系统降水方 案，超前旋喷桩预加固及注水泥浆超前预支护等一整套措施，取得了较好的施工效果.对于在此种地层中较易发 生的涌水、涌砂等突发事件，采取椎幕注浆超前大管棚的施工方案也可有效应对. [关键词]隧道工程；第三系粉细砂岩；降水；涌水；涌砂 [中图分类号]U459.1 [文献标识码]A [文章编号]1002-8498(2013)08-0065-02 Construction of Cheng-er-shan Tunnel in Water-rich Tertiary Fine-silty Sandstone Yang Fuyin Lanzhou Railway Survey and Design Institute Co.Lid.Lanzhou Gansu 730000 China) Abstract:The surrounding rock of the entry and exit segments of Cheng-er-shan Tunnel is Tertiary fine- silt sandstone with rich groundwater.Analysis was performed to uncover the reasons for the problems occurred during its construction.The tertiary fine-silt sandstone has the characteristics of poor diagenetic performance and muddy weak cement.It is susceptible to structural damage when reacting with water or subjected to prolonged exposure because it can bee loose sand quickly and cause the surrounding rock stability to lose its stability.With respect to these characteristics a prehensive treatment scheme was adopted including a bined dewatering scheme of multi-level light well vacuum precipitation deep- hole vacuum dewatering and well dewatering as well as advanced pre-strengthening with jet grouting pile and advanced pre-support with injecting cement slurry....
程儿山隧道富水第三系粉细砂岩段施工技术.pdf
