Shrinkage and Creep Predictions Evaluated using 10-Year Monitoring of the North Halawa Valley Viaduct

The North Halawa Valley Viaduct (NHVV) is a 1.5 km box girder viaduct with span lengths up to 110 m. It is part of a new freeway on the island of Oahu in Hawaii. The paper discusses a 10-year instrumentation program that was designed to provide long term monitoring of the structural performance of the viaduct. The measurements obtained include concrete strains, span shortening, tendon forces, span deflections, and support rotations. In order to perform the measurements, over 200 instruments were installed. The paper presents results from the vibration wire stain gauges, span longitudinal and vertical deflection measurements, and tendon prestress forces. The results of the study have been incorporated into the development of an instrumentation system for a planned bridge on the Island of Hawaii.