非开挖HDD在垃圾填埋场渗滤液导流治理中的应用研究

Field Study on Horizontal Directional Drilling Technology in Diversion Governance of Landfill Leachate

非开挖HDD技术具有对环境干扰小、施工效率高等优点,被广泛应用于给排水、电力、通信、油气等领域的新管道敷设和既有管线修复中。本文结合英国某垃圾填埋场的渗滤液导流治理工程,分别从技术原理、工程背景、工艺过程、应用效果和改进措施等方面展开了论述。工程实践表明,HDD技术可应用于垃圾填埋场渗滤液水平排放孔的施工中,并应根据现场地层条件和工艺参数对施工过程加以优化。由于填埋堆体含有大量金属废弃物,采用有线导向系统替换了无线电磁导向,可极大提高导向钻孔轨迹的定位精度。采用正向扩孔和管道敷设技术有助于降低阻力,提高敷设效果。对比运行结果显示,相对于传统的渗滤液竖井抽排模式,水平钻孔排放效率更高,成本投入也相对较低,但在设计施工中应充分考虑堆体非均质对施工过程的影响,降低施工风险。

As one method of Trenchless, HDD technology is widely used in new pipeline laying and existing pipeline repair in the fields of water supply and drainage, electric power, communication, oil and gas associated with its advantages of low environmental interference and high construction efficiency. This paper presents the leachate diversion governance project of a landfill in the UK by HDD. Based on the technical principle, engineering background, process, application effect and improvement measures, some practices were achieved by the authors. Field practice indicates that HDD technology can be applied to the construction of horizontal discharge holes of landfill leachate, and the construction process should be optimized according to the site conditions and process parameters. Since the landfill contains a large amount of metal waste, the wireless electromagnetic guidance is replaced by a wired guiding system, which can greatly improve the positioning accuracy of the guiding drilling trajectory. The use of forward and over-reaming and pipe laying techniques helps to reduce drag and improve laying. The comparison operation results indicate that compared with the traditional leachate shaft drainage mode, the horizontal drilling efficiency is higher and the cost input is relatively lower. However, the impact of the heterogeneity of the pile on the construction process should be fully considered in the design and construction to reduce construction risks.