Selected FCI Bridge Metrology Commercial Projects

Bridge Load TestBridge Load TestBridge Impact Damage

URS Corporation (AECOM)

MD Rt. 6 over Nanjemoy Creek
Nanjemoy, Maryland

The FCI Laser System was used to perform a load test on a three-span bridge. This test was a good application for the laser system as very small magnitude deflection measurements were made over water. With very short spans, deflections of only 0.009 to 0.017 inches were measured.
	The FCI Laser System was used to measure deflections of the bridge during a load test. Three spans of the bridge were simultaneously measured, with three laser deflection measurements per span. The movement of the two abutments was measured during the load test. Additional measurements were also made that provide a frame of reference for load test data (pier, abutment, deck edge, parapet locations). The bottom edge of the deck was measured. Long-term bridge movement measurements were illustrated.

URS Corporation (AECOM)

MD90 over Assawoman Bay
Ocean City, Maryland

Fuchs Consulting, Inc. (FCI) performed laser measurements on two spans of MD90 over Assawoman Bay near Ocean City, Maryland. The purpose of the measurements is to access the performance of the bridge before and after repair of a broken transverse tie rod at the mid span of Span 22. A nominally undamaged span, Span 21, and a span with a known broken and removed tie rod, Span 22, were measured under various controlled loading conditions.
	Unexpected hysteresis behavior was observed with the BRIDGE RLS measurements. Possible explanations of this behavior are 1) temperature induced movement and 2) the bridge not returning to the initial position after removal of load. The BRIDGE RLS measured both deflection and rotation of each beam during loading and under no load conditions. Measurements were made directly on the concrete beam surfaces over water. Very small deflections and rotations were measured. Maximum measured deflection was about 0.1 inches. Many measurements were less than 1/16 inch. The high density transverse measurement at mid span provided the most useful data to describe the behavior of the bridge.
Measurement of the very small level of movement of the bridge would not have been possible without the use of a very precise and accurate measurement system. The ability to measure this structure without targets, or any other direct contact with the beam surfaces, allows very spatially dense measurements that reveal important behavior of the structure. The unexpected behavior of this bridge observed in the measurements may reveal behavior that is not currently considered in design and analysis. This information may potentially improve future design and rehabilitation of similar structures.

Virginia Department of Transportation (VDOT)

I-66 over VA Rt-29
Centreville, VA

Fuchs Consulting, Inc. (FCI) performed laser measurements of Virginia Department of Transportation (VDOT) Bridge 2020, I-66 over VA RT-29 Bridge in Centreville, VA.

The structure has been struck by multiple over-height vehicles and several girders have been permanently deformed. The FCI Laser System was used to measure the out-of-plane deformations of four of the girders in the area around the impact location. The laser system was also used to take rapid scans of the impact location on two girders during a static load test to determine if any web deformations resulted from the load.