Page 4

Robert Harn Receives 2015 T.Y. Lin Award Harn’s technical paper on seismic design alternatives for prestressed concrete piers is considered an important reference in the design and construction of marine structures. Robert Harn, a senior project manager with BergerABAM, has been awarded the 2015 Robert Harn T.Y. Lin Award by the Structural Senior Project Manager Engineering Institute for his technical paper, “Seismic Stability of Marine Piers Built with Prestressed Concrete Piles.” The award will be formally presented on 8 November at the 2015 American Concrete Institute (ACI) Concrete Convention and Exposition in Denver, Colorado. T.Y. Lin, an eminent prestressed concrete pioneer, endowed the award to the American Society of Civil Engineers (ASCE) to recognize outstanding engineers and their contributions to the field of prestressed concrete. The award is presented each year for the best professional paper authored or coauthored by members of ASCE in various professional publications during a 12-month period. Harn, along with his coauthor Stuart Stringer (formerly of BergerABAM), joins the list of previous BergerABAM recipients of the T. Y. Lin Award. They are Dr. Lee Marsh (2014), Catrina Walter (2013), Bob Mast (1969,1973), Charles Dolan (1973), and Arthur Anderson (1970).

Harn has provided seismic structural design and analysis for numerous waterfront projects, including the Broadway Pier seismic retrofit in San Diego, CA (pictured)

The paper, published in the Precast/Prestressed Concrete Institute Journal and by the ACI in 2013, investigates the stability of pile-supported marine piers during earthquakes and identifies the conditions that can

4

cause piers to collapse. Additionally, the paper analyzes different alternatives for the prevention of a pier’s collapse and proposes designs to help reduce potential for collapse. During review of the paper, the awards committee made particular note of the paper’s importance to the construction of marine structures that have different design requirements and challenges from buildings because of the way these structures are used and the particular ground conditions on which they are built. As the 2010 earthquakes in Haiti and Chile and the 2011 earthquake and tsunami in Japan have shown, loss of port facilities can have a devastating effect on the post-earthquake recovery effort and lives of millions of people. Therefore, increasing the safety and stability of port structures, such as piers and wharves, is important to ensure business and economic continuity during and after an earthquake. Piers are pile-supported platforms constructed perpendicular or nearly perpendicular to the shore. Under seismic attack, large sway forces and displacements can be expected in piers due to the long slender piles supporting the deck. Additional swaying forces are generated as the weight of the deck moves relative to the ground, further amplifying the motions that can lead to collapse of the pier if the deck is sufficiently heavy, the displacements are large, or the piles are so heavily damaged that they do not have the strength to recenter the deck during or after the earthquake. The paper identifies conditions, such as ground motion characteristics, gravity loading, pier geometry, and inelastic demands, that increase the risk of global side-sway collapse, and proposes design considerations to help mitigate the threat of collapse. The origin of his research for the paper can be attributed to Harn’s work on the ASCE committee that developed the recently published ASCE 61-14, Seismic Design of Piers and Wharves.

Profile for BergerABAM

Inside/Out Newsletter | Autumn 2015 | Issue 59  

BergerABAM is a consulting firm offering services in the areas of planning, civil and structural engineering, architecture, environmental se...

Inside/Out Newsletter | Autumn 2015 | Issue 59  

BergerABAM is a consulting firm offering services in the areas of planning, civil and structural engineering, architecture, environmental se...