定向钻探技术在复杂城区隧道勘察中的应用及探讨

Application of directional drilling technology in tunnel exploration in complex urban areas

摘要:

定向钻探技术具有穿越能力强、轨迹可控的优势，在传统勘察难以实施的区域，定向钻探可远距离开孔绕避地面障碍物对预定区域进行勘察。某城区隧道在建筑密集区域进行定向钻探，选择在合适场地远距离开孔，通过轨迹调整沿隧道底板下方1 m进行钻进，同时在主孔上部实施2个分支孔，采用提钻取心工艺对全部区段进行间隔取心，并完成微动谱比法和孔内声波电阻率等物探测试。主孔最大埋深69 m，进尺650.75 m，轨迹最大偏移0.81 m。项目的成功实施证明，定向钻进技术与物探测试技术结合，可弥补传统勘探方法存在的不足，更好的揭露隧道围岩地质情况，为复杂城区隧道勘察提供一种有效手段。同时建议制定明确可行的技术原则和规范促进定向钻探技术在勘察领域的应用。

Abstract:

Directional drilling technology has the advantages of strong crossing ability and controllable trajectory. In areas where traditional exploration is difficult to implement， directional drilling can leave the hole at a long distance to avoid ground obstacles and conduct exploration in the predetermined area. A certain urban tunnel is undergoing directional drilling in a densely built area. It is selected to leave the hole at a suitable distance at a suitable site， and drilling is carried out along the 1m below the tunnel floor through trajectory adjustment. At the same time， two branch holes are implemented in the upper part of the main hole. The core extraction process is used to perform interval core extraction for all sections， and geophysical tests such as micro motion spectral ratio method and borehole acoustic resistivity are completed. The maximum burial depth of the main hole is 69m， the footage is 650.75m， and the maximum deviation of the trajectory is 0.81m. The successful implementation of the project has proven that the combination of directional drilling technology and geophysical testing technology can make up for the shortcomings of traditional exploration methods， better expose the geological conditions of tunnel surrounding rocks， and provide an effective means for complex urban tunnel exploration. At the same time， it is recommended to develop clear and feasible technical principles and norms to promote the application of directional drilling technology in the field of exploration.