超长水平定向预注浆钻孔施工技术探讨

Construction Technology Discussion of Ultra-long Horizontal Directional Pre-grouting Boreholes

摘要:

水利工程的长大、深埋隧洞沿隧洞轴线往往存在大范围破碎带及富水区域，采用地面超千米水平定向钻孔进行预注浆超前治理，达到了良好的围岩加固和涌水封堵效果，使该项技术在水利行业得到了成功应用。本文介绍了某项目使用螺杆钻具钻进超长水平定向预注浆钻孔的成功经验，探讨了超长水平钻孔排粉困难、应对“托压”问题、强磁场干扰随钻测量系统、绿色勘探的措施，以及作业中钻机适应性不够、硬岩钻进效率低、注浆影响钻进等问题及解决措施。项目施工4个主孔、6个分支孔，最长钻孔1427m，钻探工作量8737.89m。项目的实施证明，目前定向钻进技术具有长距离精准钻进能力，能为超长隧洞复杂地层预注浆超前处理和相关钻探工程提供保障。

Abstract:

In the periphery of long and deeply buried tunnels of water conservancy projects, along the tunnel axis of a wide range of fracture zones and water-rich areas, the use of the ground more than 1,000 meters of horizontal directional drilling pre-grouting ahead of the management, to achieve a good effect of the surrounding rock reinforcement and gushing water blocking, is a successful attempt in the water conservancy industry. This paper introduces the successful experience of drilling ultra-long horizontal directional pre-grouting holes with screw drilling tools in a project, and discusses the difficulties of powder removal in ultra-long horizontal drilling holes, coping with the problem of “back pressure”, the interference of strong magnetic field with the drilling measurement system, the measures of green exploration, as well as the problems of insufficient adaptability of drilling rigs, low efficiency of hard-rock drilling, and the influence of grouting on drilling in operation, etc. and the measures to solve them. and measures to solve the problems. The project has 4 main holes and 6 branch holes, the longest hole is 1427m, and the drilling workload is 8737.89m. The implementation of the project proves that the current directional drilling technology has the ability to drill accurately over long distances, which can provide a guarantee for the pre-grouting and over-treatment of the complex strata of the ultra-long tunnels and the related drilling projects.