Post-Installation Geotechnical Issues Associated With Large-Scale HDD Crossings

摘要: Horizontal Directional Drilling (HDD) is increasingly being used as a technique to install pipeline through challenging conditions. With this increased use, several post-installation geotechnical issues have, quite literally, surfaced, often many months or years following the original installation. These include sinkhole development around entry/exit points for HDD operations and settlement of surface above bore path. Both can be attributed two major factors, those involving unfavourable ground conditions problematic installation procedures. Several examples each these factors are described along with mitigation measures designed prevent both from occurring Case histories large crossings subsequently presented which illustrate potential magnitude steps that required repair; first crossing Fraser River outside Vancouver, Canada, second river in north-central Argentina. In cases, sinkholes formed behind exit points, resulting property damage possibly threatening neighboring utilities. Site investigation design techniques implemented minimise discussed, remediation options cases presented.Copyright © 2004 by ASME