Miami-Dade Water and Sewer Authority
In 2010, Miami-Dade Water and Sewer Authority (MDWSA) instituted a continuous inspection and repair program for their 48 in. to 96 in. dia. prestressed concrete cylinder pipes (PCCP). With brief periods to perform repairs and field conditions (e.g., high groundwater levels) making pipe replacement difficult, MDWSA preferred to implement internal repairs on selected distressed pipe pieces. Over the years, SGH has analyzed failure risk, designed repairs for more than 100 MDWSA pipes, and provided field engineering services during repairs.
SGH designed internally bonded carbon fiber-reinforced polymer (CFRP) repairs that act as standalone system capable of resisting all design loads without relying on strength from the host pipe. We prepared repair drawings and specifications and provided engineering support during construction, as needed.
Highlights of our construction engineering services include the following:
- Inspecting repair work through various stages, including pipe surface preparation, material preparation, installation of the liner, and curing
- Documenting repair procedures, typical installation conditions, and deviations from the project specifications or repair drawings
- Witnessing pull-off tests performed by the contractor on mockup areas
- Performing tension tests on CFRP witness panels in our laboratory
- Addressing construction and engineering issues arising during construction