Paul B. Pizzimenti presented Golden Apples to Mr. Lacy and Mr. Ellman on February 18th (Photo by Walter J. Papp, Jr.).

The 34th Martin S. Kapp Lecture and the 5th Annual "Meet & Greet" Dinner was held at Il Campanello Ristorante in Manhattan on Thursday, January 15, 2009. The featured speaker, Clyde N. Baker, Jr., of AECOM Technology Corporation was unable to travel from Chicago due to a severe snow storm. Hugh S. Lacy and Roderic A. Ellman, Jr., both Partners with Mueser Rutledge Consulting Engineers, stepped in on very short notice and delivered a lecture titled "Foundations of the Woodrow Wilson Bridge."

The Woodrow Wilson Bridge project was named the winner of ASCE's 2008 Outstanding Civil Engineering Achievement Award (OCEA award) at the Outstanding Projects and Leaders (OPAL) gala. The bridge carries I-95 and I-495 across the Potomac River and connects Maryland and Virginia in the Washington D.C. area. The new bridge was constructed while the old span of the bridge continued to service traffic right alongside. The bridge is a bascule bridge, with the drawbridge span located right near the west approach.

The average depth of water in the river near the bridge was approximately 30 feet and another 30 to 80 feet of soft silty clay was immediately below the riverbed, underlain by competent foundation material. Some of the geotechnical challenges in design and construction were faced in an attempt to provide high capacity piles in stiff marine clay and to minimize scours.

An extensive pile load test program was undertaken as part of the initial design phase, to optimize design. Both static and statnamic pile tests were conducted, in addition to studies to determine driveability, vibration, and noise.

The preliminary design model was based on 54-inch diameter, open-ended steel pipe pile, with ultimate axial load capacity of 3,000 kips (unit skin friction of 3 ksf and unit toe bearing resistance of 63 ksf). Based on results of the pile tests, the final design in the bascule span consisted of a total of 36 open ended steel pipe piles (72-inch diameter), with ultimate axial load capacity of 5,000 kips (unit skin friction of 1.7 ksf and unit toe bearing resistance of 63 ksf). The working load capacity of each pile was 1,200 tons. Though battered piles were considered during the preliminary design, only plumb piles were selected in the final design. The bascule pile caps were 130 ft by 90 ft by 16 ft.

The installation process was simplified by specifying the tip criteria, not allowing field splicing. The use of hydraulic hammers operating under water eliminated the need for underwater pile cut-off and helped avoid schedule delays. The cost of piles was estimated to be approximately $14.5 million per foundation.

The land piers on Virginia side were typically supported on 24-inch square pre-stressed precast concrete piles with load capacities between 170 and 350 tons. On the Maryland side, the piers were supported on 48 to 66-inch diameter steel pipe pile, with load capacities between 750 and 1,065 tons.

Extensive hydraulic flume testing and analyses were undertaken to estimate the effects of both contraction and pier scour. The use of Potomac Cofferdams reduced contraction scour within the channel. The use of pile-supported vessel collision protection, in lieu of conventional cellular dolphins, reduced scour at the bridge piers.

Summary by Anirban De