Kaneohe Interchange, Oahu, Hawaii

A 21 m high embankment for an emergency ramp at the Kaneohe Interchange on Oahu, Hawaii was constructed with geofoam as lightweight fill (Mimura and Kimura 1995). The embankment was initially designed to consist entirely of earthfill with geotextile reinforcement. Site conditions encountered during construction were worse than assumed in design. Up to 6 m of very soft organic soils were found to overlie soft alluvial soils and artesian pressures. Conditions encountered at the time of construction further implied proposed wick drains of up to 24 m lengths would penetrate into artesian formations. The re-design and construction employed shorter depths of wick drain penetration and 17,000 m³ of EPS geofoam as lightweight fill. The use of geofoam in this project was effective in reducing settlements and improving safety factors against instability.

References

Mimura, C.S., and Kimura, S.A., (1995) "A Light-Weight Solution." Geosynthetics '95, Conference Proceedings, Vol. 1, Nashville, TN, pp.39-51.