News & Features

Alumnus Hossein Yousefpour - PCI Robert J. Lyman Award


Researchers Todd Helwig, Hossein Yousefpour and Oguzhan Bayrak at Ferguson Structural Engineering Laboratory.

Nov. 2, 2016

Research Engineer Hossein Yousefpour (PhD 2015) received the Precast/Prestressed Concrete Institute’s 2016 Robert J. Lyman Award for a paper that provides unique insight into the behavior of concrete arches built by an accelerated construction method.

The award, named in honor of PCI’s third president, recognizes a paper that offers the greatest contribution to the advancement of plant production, site erection, or general construction of precast concrete structures. The paper, “Construction Stresses in the World’s First Precast Network Arch Bridge”, was co-authored by Professor Todd Helwig and Professor Oguzhan Bayrak, who also received the award. 

The researchers reported major findings from a monitoring study on the West Seventh Street Bridge in Fort Worth, Texas. Designed by the Texas Department of Transportation, the bridge is believed to be the first precast concrete network arch bridge in the world.


The West Seventh Street Bridge has precast concrete arches that run the length of the structure, measuring 24 feet tall by approximately 160 feet long, and weighing 640,000 pounds.

The innovative bridge, completed in 2013 as a replacement for a century-old bridge, consists of 12 prestressed, precast concrete network arches. Due to the state-of-the-art construction of this bridge, some of the most critical stresses in the life of the arches occurred during construction. The research team conducted an instrumentation program to make sure that the arches were not damaged during the fabrication, transport, and erection procedures.

They instrumented the bridge with 224 vibrating-wire gages that were embedded in the arches prior to concrete placement. The gages were monitored during post-tensioning, handling, and transport as well as deck construction.

The instrumentation provided data on the stresses induced in the arches, which were used to ensure a safe environment throughout construction. The measurements also provided a means for evaluating the accuracy of stress calculations that were made during design. 

This research was also featured in the PCI Journal September-October 2015 issue.