Arecibo to San Juan, Puerto Rico

North Coast Superaqueduct

Scope/Solutions

The 72 in. dia. North Coast Superaqueduct carries water 70 km from Arecibo to San Juan. Just after construction, the aqueduct experienced failure of two pipe segments during a transient pressure event caused by sudden closure of a valve. SGH investigated the cause of failure and assessed the condition of the entire pipeline.

Highlights of our work on this project include the following:

  • Performed a condition assessment that included internal and external pipeline inspection, hydrostatic testing, wire strain test, mechanical testing of wires, tests of hydrogen content in wire, and soil corrosivity testing
  • Performed hydraulic and structural analyses
  • Conducted mechanical, metallurgical, chemical, and petrographic testing of pipe constituent components
  • Conducted chemical analysis of soil and groundwater
  • Discovered pipes with low prestress level in the wire and performed tear-down inspection of low prestress pipe
  • Determined failure to be result of the transient pressure event caused by sudden closure of a valve due to improper setting of the valve closure timing and inadequate prestress in manufactured pipe caused by breakage of wires during winding operations
  • Designed repairs that consisted of post-tensioning the low prestress pipes with strands and applying a shotcrete coating on the post-tensioned pipe

Project Summary

completion-date

2004

Completion Date
Solutions
Failure Investigation
Services
Structures | Advanced Analysis | Applied Science & Research
Markets
Infrastructure & Transportation
Client(s)
Dick Corporation
Specialized Capabilities
Repair & Strengthening | Buried Infrastructure | Failure Analysis | Materials Science

Key team members

Rasko Ojdrovic
Rasko Ojdrovic
Senior Principal
Mehdi Zarghamee
Mehdi Zarghamee
Senior Principal