Redevelopment of the International Market Place, located one block off Waikiki Beach, not only presented logistical construction issues, but was also a treasured historical and cultural landmark that had to be protected and respected. At the center of the marketplace was a giant banyan tree gifted to the island in the mid-19th century by Henry McFarland, a New Zealand entrepreneur credited with bringing gas lights to the island. Preserving and protecting the health of the banyan tree, as well as several monkeypod and palm trees, was critical to the success of the project.

The construction schedule of the International Market Place allowed nearly no time for delays from unexpected challenges. The team worked hard every day to stay on track and accelerate the work where possible, while maintaining high standards of quality and honoring the historic significance of the site.

The local geology in Waikiki is complex. Volcanic soils that formed the Hawaiian Islands combined with coral formations from adjacent reefs resulted in highly layered and vastly variable soil/rock conditions. Erosion from the tropical climate and the rise and fall of ocean level over time further complicates the subsurface conditions.

Local geotechnical engineers believed the project site had some of the most challenging soil conditions encountered in Waikiki, including a deep alluvial valley which cut through the site and presented an added concern. SME and the entire team chose high capacity micropiles drilled at depths of up to 300 feet to address subsurface conditions. Relatively small in diameter, they could be easily shifted or relocated as necessary to work near the banyan tree and around sensitive areas.

A total of 698 micropiles were installed over six months at depths ranging from 165 feet to 300 feet. A total of 115,040 linear feet of micropiles were installed on the project, including approximately 85,700 cubic feet of portland cement grout (mixed at the on-site batch plant).

Toward the end of the micropile construction, the grout level in the piles rose significantly overnight. Some drop in grout levels is normal; however, a rise in grout levels is very unusual. Several piles were found to have bond zones with anomalous grout that was partially or completely washed out. To remedy this, grout was injected under pressure to fill any voids in and around the piles. The reinforcing bars were reinstalled where needed, and the micropiles were tremie-grouted.

The new IMP was designed to ensure a strong “Hawaiian sense of place” and exists meaningfully for the local community and tourists alike. While visitors may not realize the impact their shopping and dining adventures have on the local community, the revenue generated by the redeveloped IMP will help sustain the Queen Emma Medical Center for decades to come.