银西高铁彬县隧道施工关键技术

Key Technology for the Construction of Binxian Tunnel of Yinchuan-Xi’an High-speed Railway

银西高铁彬县隧道是全线最长隧道,具有工程地质复杂,围岩对各工序影响较大,尤其仰拱受Ⅳ级围岩影响较大,同时,存在砂质富水弱成岩出渣难工效低、掌子面月进度受仰拱进度制约影响大、富水地层易沉淀抽水困难等难题,致使整个隧道工期进展较为缓慢。为此,通过砂质富水弱成岩三台阶快速开挖技术、仰拱双栈桥快速施工技术、砂质富水弱成岩旋流脱砂排水技术的应用,优化了作业工法,提升了成洞质量,保障了施工安全,将各洞口最高进尺提升至130 m/月,解决了长大隧道反坡排水出渣难题,实现了该隧道的按期顺利贯通。

The Binxian Tunnel of Yinchuan-Xi’an High-speed Railway is the longest tunnel in the whole line,with complex engineering geology,the surrounding rock has a greater impact on the processes,especially the inverted arch is affected by theⅣlevel surrounding rock.At the same time,the progress of the tunnel schedule is slow due to the problems such as high difficulty of slagging and low working efficiency in weak diagenesis with rich water,great effect on monthly progress of the tunnel face restricted by the progress of inverted arch,and pumping difficulty caused by easy of precipitation in water-rich strata.In this regard,through the application of a series of technologies,including three-bench rapid excavation technology of sandy water-rich weak diagenesis,back-arch double-stacked bridge rapid construction technology,centrifugal desanding drainage technology of sandy water-rich weak diagenesis,the operation method is optimized,the quality of hole-forming is improved,and the safety of construction is ensured.The highest progress of each hole is increased to 130 m/month,which solves the problem of drainage and desanding from the back slope of the long tunnel,and achieves the smooth completion of the tunnel on schedule.