Awards

 Fewell Geotechnical Engineering, Ltd. (FGE, Ltd.) developed geotechnical recommendations for the design and construction of hollow, drilled pier foundations for the steel pole structures of Hawaii Electric Company, Inc's Waiau-Makalapa 138kV Overhead Line, No. 2. The hollow drilled pier foundations "float" in the soft soils and minimize the foundation settlements in areas where excessive pole settlements,and the resulting drawdown of the surrounding ground surface, could result in serious problems within the heavily congested utility corridor. This was the first known us of this method in Hawaii. 

The floating foundations are hollow, drilled pier foundations, consisting of a corrugated metal casing and concrete shell surrounding an octagonal steel tube. The corrugated metal casing was installed in the drilled shafts and grouted into place. The octagonal steel tubes were then filled with water, to counter the buoyant effect of the shallow groundwater table, and lowered within the secured casing. The octagonal steel tube provided the hollow interior required to minimize the foundations weight, as well as serving as the foundation's flexural steel reinforcement. The annulus between the octagonal tube and the outer casing was filled with concrete which was poured in multiple phases to prevent the buildup of excessive buoyant forces which could result in thetube "popping" out of the shaft. After the concrete was completely placed, the water within the octagonal tubes was immediately pumped out, resulting in a "hollow" foundation with the total foundation weight essentially matching the weight of the soils displaced by the foundations.

The floating drilled pier foundations cost approximately $92,000.00 per foundation, compared to estimated cost of about $171,000.00 per driven pile foundation, resulting in an overall saving of approximately $1.2 million for the project. The floating foundations allowed the construction to proceed with minimal traffic and utility disturbance within the heavily congested utility corridor adjacent to Kamehameha Highway with no delays in the construction schedule and no significant change orders resulting from the use of hollow foundations. 

 The AES Barbers Point is a $383 million dollar coal-fired cogeneration facility capable of supplying over 189 megawatts of electricity to Hawaii Electric Company, approximately 18% of Oahu's electricity needs. The plant is one of the cleanest coal fueled plants in the world and is designed to minimize emissions using a clean coal technology which reduces particulate emissions to less than half of the new source performance standards of the Federal Clean Air Act. Coral is crushed and added to the boiler with the coal to react chemically with the sulfur dioxide in the coal, reducing sulfur emissions dramatically. The exhaust gas is directed to the fabric-filter baghouses where the line particulate (fly ash) is removed and stored in hoppers for disposal. Between 100and 200 tons of ash byproduct us produced each day.

FGE, Ltd., working with AES Barbers Point, Inc. and using geotechnical testing and engineering techniques, developed a process to convert the ash into a lightweight construction aggregate, thereby eliminating the need to dispose over 100 tons of ash per day in landfills. The aggregate has the strength properties of similar natural aggregates, but less that 70% of their weight. The Ash Rock is uniquely suited as structural fill behind retaining walls due to its lightweight which reduces lateral pressures. It can be used for all applications, where Select Borrow is required and about half the cost. FGE, Ltd., developed the placement, compactions curing and crushing methods to obtain the maximum aggregate strength. This is one of the first uses in the United State of this type of ash byproduct for the production of synthetic construction aggregate.