Spalling of Hawaii Kai Drive Bridge.

This contract with the City & County of Honolulu included work to perform seismic analysis and the formulation of seismic retrofit alternatives to prevent the catastrophic failure of two bridges located in the city of Honolulu:

  • Bridge #117 – North King Street Bridge No. 2 (spans Kapalama Canal)
  • Bridge #346 – Hawaii Kai Drive Bridge (spans Kamiloiki Stream)

The scope of work included the inspection and structural assessment of bridge components and roadway conditions, the review of as-built drawings and previous bridge inventory data and the completion of foundation analyses. Our scope also included environmental surveys of the bridges for hazardous materials and the performance of structural analyses conforming to new seismic provisions to determine the structural feasibility of the bridges to sustain seismic events.

HEG proposed the latest, cost-effective retrofitting techniques and strategies that met the seismic demand requirements and performance objectives (i.e. bridge strength, functionality, survivability, and public safety).

Under the direction of HEG, Shinsato Engineering performed geotechnical investigations to obtain information on subsurface conditions and to provide soil parameters for the retrofits. The investigations included the drilling of four test borings at varying depths between 13.667 and 100.5 feet below grade for the North King Street Bridge, and two test borings at depths of 12 and 50 feet below grade for the Hawaii Kai Drive Bridge.

Work also included the development of specifications and other bid documents.