管道定向钻穿越河流的工程地质勘察问题

Geological Survey of Directionally Drilled Rivers.

对管道定向钻穿越河流的工程地质勘察工作中出现的一些问题进行了总结和探讨,认为勘察钻孔工作量的布置应随场地条件而异,科学合理地安排,而不宜教条地执行规范、规程中的某些条款。在勘探手段的应用上,提出采用工程物探与地质钻探相结合的综合勘探方法。即用工程物探成果解释穿越断面的地层结构,用钻探验证、校验物探解释成果。这样,既节省了投资、缩短了外业工期,又可较全面、系统地掌握穿越断面的地层结构,弥补了钻探孔仅“一孔之见”的弱点。勘察工作的重点应是对定向钻穿越有较大影响的地层、拟定的管道设计深度上下7m范围内的地层及管道入土、出土段的地层。

Some problems that develop with the geological survey of directionally drilled river are summarized and analysed. It is pointed out that the amount of work for exploration drilling shall be defined according to specific geologic conditions on the job site.rather than inflexibly following codes and standards. As for the application of exploration means, comprehensive exploration method is recommanded of combining engineering geophysics and geologic drilling,that is to say,the stratigraphy of the section crossed is interpretated with the results of engineering geophysics,and the results,in turn,are checked and reviewed through drilling. By doing this,not only can the cost be held down,field work time shorterned,but the stratigraphy of the crossed sectioin can be interpretated thoroughly and systematically. Attention shall be paid especially to the formations having considerable effects on directional drilling operation,the formations within 7m above and below the proposed design depth,and the formations where the pipeline enters into and exits from ground.