Project
Bridgeport Village

Location
Portland, Oregon

Owner
URS Corporation
Villiamsburg, VA

Engineer
Terra Associates, Inc.
Kirkland, Washington

Installer
Ken Leahy Const.
Cornelius, Oregon

Problem
Abandoned quarry yields unsuitable foundation soils

Solution
Construct reinforced foundation comprised of structural soils and high tensile strength Geogrid.

Located in Portland, Oregon Bridgeport Village, a proposed high-end retail center, was planned for construction on an abandoned gravel quarry. The site, reclaimed with unsuitable bearing materials including concrete, asphalt and other construction debris, presented engineers with several foundation design challenges. Traditional construction options such as drilled shafts would be difficult and costly.

An effective and affordable option to improve foundation soils was to utilize geogrid soil reinforcement. After over-excavation of native soils, 2-5 layers of geogrid were placed within structural fill materials at 12” spacing.

The contractor preferred the strength, versatility, custom roll dimensions and affordability of Synteen SF90 geogrid. With an ultimate tensile strength of 8,500 pounds per foot and minimal effects of creep degradation, SF90 possessed the long-term loading capacity to support a variety of building pads. Successful completion of the Bridgeport Village project is scheduled for 2005.