Quick Guide for Pipeline River Crossing Projects

Proper planning, front-end design, installation, and maintenance are critical components of a successful pipeline river crossing project. Crossing methods such as HDD, microtunneling, direct pipe, guided auger boring, open cut, trenchless, trenched, semi-trenched, aerial, bridged should be evaluated using risk-adjusted techniques. This post is designed to act as a quick guide and to escalate risks to project owners that may not have otherwise been captured.

Planning & Front-End Design

• Has there been a thorough on-site planning investigation with buy-in from all project stakeholders?
• Have all land and regulatory permit processes been initiated?
• Have surface and subsurface obstacles been identified? If not, will another on-site investigation take place during construction?
• Which season is construction planned for? Has a local water source been identified? Are access roads required?
• Can the right-of-way or temporary workspaces change as the project progresses or are they fixed?
• Has an adequate ground elevation profile been provided in CAD format? Has the thalweg (river profile bottom) been identified?
• Is a wildlife assessment and archeological site investigation required?
• Have all major crossing risks been identified and communicated to the client in advance of detailed design?

Detailed Design

• Has an appropriate crossing method been selected? Which method was used to select the crossing type?
• Has all the engineering been completed incorporating civil and mechanical principles? Has adequate subsurface data been retrieved? If not, can it be performed during installation?
• Is a geohazard and slope stability analysis required? Is geophysics required? Is there risk of geological fracture?
• What diameter and length pipe is needed and how often is welding required? Will welding occur on site? 
• What depth of cover will the crossing be designed to?
• Have all CSA, ASME, and ASCE codes and regulations been followed?
• What type of pipe coating will be used? Have pumps been sized for hydrostatic pressure testing?
• Have feasibility studies and construction specifications been written?
• Has the owner/client reviewed and approved the detailed design in advance of installation?

Installation & Maintenance

• Have experienced contractors been retained for the installation of the pipeline river crossing?
• If drilling, has a solids and fluids control program been developed? Has a frac-out mitigation plan been developed?
• Which installation equipment is required and at what rating?
• Has a construction schedule been developed? Will installation occur during daytime or day and nighttime shifts? Is installation occurring around urban areas where noise mitigation is required? Have local homeowners and businesses been contacted?
• Will extensive excavation and/or shoring be required?
• How long is the design certified for? Will integrity digs be required on an ongoing basis or can trenchless non-destructive methods be used?
  
  

Your collaboration on this post is encouraged in order to address all the  risks that occur during a pipeline river crossing project. Please add comments, ideas, and solutions below in the comment section!