Concrete Pipe Fault Line Solution

This was a highly complex project in many ways, as it required Oldcastle Infrastructure and the contractor to overcome a series of unique and difficult circumstances. These included:

• The waterline went through a fault line.
• Extensive tunneling was required underneath the busy Beltway 8 Freeway.
• The project location was in close proximity to high voltage transmission lines.
• The size and weight of the required concrete pipe made installation challenging.
• Hydraulics were required to jack the pipes in place.
• The pipe jacking machine required constant monitoring and maintenance.

Oldcastle Infrastructure, working in tandem with Harper Brothers Construction, designed, manufactured, and installed 17 pieces of 108” concrete pipe as a Tunnel Liner or Jacket around the 84” water line. Normally, a trench would be dug to install the concrete pipe underground and the trench would be backfilled after the pipe was installed. Conditions in this case, however, called for a trenchless installation. The contractor had to tunnel under the Beltline 8 Freeway and hydraulically jack the 108’ diameter concrete pipes into place. This had to be done one after the other – and all from one location at the side of the freeway. The hydraulic jacking required 12 hours to push each pipe into place.

This was a highly specialized application at a fault line crossing – and only the second time Harper Brothers Construction has used concrete pipe as a tunnel liner. After two months, the project was completed on time. The waterline was well-supported and protected across the fault line and the entire installation went smoothly without disrupting freeway traffic.