复杂地质条件下铁路隧道勘探钻孔问题及其处理

Questions and Solutions for the Exploration Drilling of Railway Tunnels under Complex Geological Conditions

在对兰新客运专线隧道地层钻探过程中发现,由于地质情况复杂及工艺选择不当,往往导致成孔困难和取芯达不到地质要求。文章分析了达坂山隧道的复杂地层情况及钻进中遇到的困难,提出了在注重地质因素分析的基础上采取新型泥浆、双级单动钻具及规范的钻进操作等多种工艺措施,以保证孔壁稳定和岩芯采取率达到地质要求,对复杂地层隧道勘探具有一定的参考价值和指导意义。

In the exploration drilling processes for the complex ground formations of tunnels on Lanzhou-Xinjiang passenger-dedicated line,complexity of ground formation and improper selection of drilling techniques often led to difficulties in bore completion and coring failures.The paper analysed the difficulties in drilling for Dabanshan tunnel with complex ground formation,put forward a comprehensive method including applying new type drilling slurry,dual-stage and single action drilling tools and bottom-jetting bit,etc.These measures could maintain borehole stability and meet the requirements of core recovery,providing guidance on drilling in complex ground formations of tunnels.