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Bid Date/Time: Aug. 19, 2009, 4 p.m.

The city of Portland Bureau of Transportation is a community partner in shaping a livable city by planning, building, managing and maintaining an effective and safe transportation system that provides people and businesses access and mobility. As such, the bureau wants to test a Falling Weight Deflectometer (FWD) on various city streets, and is seeking proposals from experienced firms to provide services on an as-needed basis to accomplish this work.

An FWD is a testing device used by civil engineers to evaluate the physical properties of pavement. The machine is usually contained within a trailer that can be either towed to a location by another vehicle or, when used on railway tracks, placed on a hand trolley and pushed to the location.

The FWD is designed to impart to the pavement surface a local pulse that simulates the load produced by a rolling vehicle wheel. The load is produced by dropping a large weight, which is transmitted to the pavement through a circular load plate. A load cell mounted on top of the load plate measures the load imparted to the pavement surface. FWD data is most often used to calculate stiffness-related parameters of a pavement structure.

The Portland Bureau of Transportation is seeking proposals from qualified firms, teams or consultants with verifiable experience in deflection testing and analysis of city streets using a Falling Weight Deflectometer, gathering traffic data and coring data on selected streets, and analysis of the test results. The services requested under these on-call services contracts may range from a few hundred dollars up to $250,000, subject to specific needs and budget availability in any given year.