Patrick J. Wilson, P.E.

Patrick J. Wilson PE

Patrick J. Wilson, PE, is a native of Memphis, Tennessee. He received his B.S. in Civil Engineering from the University of Notre Dame in 1970. After a stint in the U.S. Army Corps of Engineers where he served as a Combat Engineer Platoon Leader and Heavy Equipment Platoon Leader, Mr. Wilson worked for a consulting engineer in Louisville, Kentucky for 7 years. Following this employment, he went back to graduate school at the University of Illinois at Urbana-Champaign where he earned an M.S. in Engineering in 1982.

Following an assignment as an engineer with a steel fabricating company, Mr. Wilson joined Volkert and Associates, Inc. in 1985 as a bridge design engineer. Since then he has been involved in many facets of bridge design and construction including bridge rehabilitation, bridge inspection, retrofit of steel I-girders and box girders to repair fatigue cracks, bridge load ratings, and bridge scour analyses. With Volkert Mr. Wilson has been involved with the design and construction of bridges across the Mobile River, the Black Warrior River, and Perdido Pass in Alabama. He has also been involved in the design of numerous bridge widenings for structures constructed of prestressed concrete girders, reinforced concrete deck girders, and rolled steel beams.

Mr. Wilson is currently a Vice President with Volkert and Associates, Inc. and is manager of Volkert’s New Orleans office. He is currently serving as project manager for the Rehabilitation of Runway 10-28 at Louis Armstrong New Orleans International Airport. Volkert is the prime consultant for this project which, at $64 million, is the largest single construction contract ever undertaken at Louis Armstrong New Orleans International Airport.

Mitigation of Embankment Settlement at Bridges Using Pile-Supported Approach Slabs

Approach Slabs are used at most bridges in the United States to minimize the “bumps” which are prone to develop at the ends of bridges. This is because most bridges are founded on either driven piles or on rock, whereas approach embankments are supported by the underlying soils. Since soils underlying approach embankments are subject to consolidation, the potential exists for differential settlement between pile-supported bridges and earth-supported embankments. Approach slabs are provided to ease the transition from roadways supported on embankments to the roadway carried on more rigid bridges.

In south Louisiana, the problems associated with differential settlement at bridge ends are magnified since the depths of compressible layers are greater there than just about anywhere else in the country. Over the years the Louisiana Department of Transportation and Development (DOTD) has attempted to solve this problem by utilizing pile-supported approach slabs. The lengths of these approach slabs have been up to 120 feet. However, the lengths of piles used was not based on any rational method and the performance of the approach slabs has been mixed. Consequently a study was funded by the Louisiana DOTD and the Louisiana Transportation Research Center. The resulting study, performed by the Tulane University Department of Civil and Environmental Engineering, determined that better performance of pile-supported approach slabs might be achieved by utilizing a rational method to determine pile lengths in pile-supported approach slabs. A spreadsheet program, TU-DRAG, was developed as part of this study.

The TU-DRAG software was used to determine the pile lengths in two pile-supported approach slabs currently under construction at Louis Armstrong New Orleans International Airport. These approach slabs are needed to provide transitions between earth-supported runway pavements and a runway bridge being constructed to carry the airport’s main east-west runway (Runway 10-28) over a roadway tunnel (the DOTD-Kenner Tunnel) at the west end of the runway. In the past, since the tunnel is supported on piles and the runway is not, severe “bumps” have developed over the years on each side of the tunnel.
It is believed that the use of the TU-DRAG software to determine pile lengths for the pile-supported approach slabs at the Louis Armstrong New Orleans International Airport is the first use of this program in the ste of Louisiana.