July 21, 2022 1:00 pm
Konjit (Konnie) Eskender, P.E., Bridge Engineer, District of Columbia Department of Transportation (DDOT); John Seifert, P.E., Associate Vice President, JMT; and Ben Cartwright, P.E., Senior Associate, JMT
DC Department of Transportation (DDOT) I-295 over South Capitol Street Bridge Rehabilitation (Bridge 1016 NB & 1017 SB) - pdf of presentation
Video: Construction Project Overview (courtesy of JMT)
Q&A Session - pdf
News - July 21, 2022 - pdf of presentation
Description: The District Department of Transportation (DDOT) needed an innovative solution to upgrade the deteriorated Anacostia Freeway (I-295) bridges over South Capitol Street in Washington, DC. With high traffic counts on this key commuter route, minimizing the construction schedule was a primary objective. DDOT tasked Johnson, Mirmiran & Thompson, Inc. (JMT) with developing the solution. Because the bridge substructures remained usable, JMT proposed replacing the superstructure with precast modular deck units comprised of steel plate girders, tied together with a UHPC closure pour. The new bridge superstructures were designed to fit within the geometric constraints of the heavily skewed existing substructures. The steel girders topped with concrete deck were fabricated in a controlled environment before each modular unit was shipped to the construction site. Installation and construction were completed in 2018 in several phases on each bridge using temporary weekend detours. By applying ABC principles and meticulously planning the proposed weekend construction sequences, the project was completed within six months, minimally impacting regular motorists on their daily commutes. This presentation includes design and construction details and lessons learned.
Konjit (Konnie) Eskender, P.E.
DC Department of Transportation (DDOT)
Konjit (Konnie) has been the District Department of Transportation’s (DDOT) Bridge Engineer since February 2012. She worked as a structural engineer in the private sector before joining DDOT in October 2001. Konnie received her Master’s degree in civil structural engineering from the University of Wisconsin-Milwaukee in 1990. Before becoming a bridge engineer, she worked as a project design structural engineer and project manager. She has significant experience in bridge engineering. In her role as a bridge engineer, Konnie ensures that structurally deficient bridges are programmed; design and construction projects follow current code and manuals, and she also assists in the integration of new technologies in bridge rehabilitation or reconstruction projects.
John Seifert, P.E.
Associate Vice President
Johnson, Mirmiran & Thompson, Inc.
John is an Associate Vice President in JMT’s Hunt Valley, Maryland office. He has 20 years of experience in structural engineering and serves as one of JMT’s Senior Structural Engineers. John received dual bachelor’s degrees in Engineering and Architecture from The Catholic University of America in Washington, DC, in 2002. He holds Professional Engineering Licenses in Maryland, Delaware, and Texas. John’s experience is diverse and covers new and repair/rehabilitation design of highway bridges, pedestrian bridges, culverts, retaining walls, and noise walls. He has worked on multi-million-dollar transportation projects from Maryland to Texas.
Ben Cartwright, P.E.
Johnson, Mirmiran & Thompson, Inc.
Ben is a Senior Associate in JMT’s Hunt Valley, Maryland office. He received his undergraduate degree in Civil Engineering from Penn State University in 2007 and a Master of Civil Engineering degree from Johns Hopkins University in 2013. He is a Licensed Professional Engineer in Maryland and a certified Inspection Team Leader. His experience covers a variety of assignments including the design, inspection, repair, rehabilitation, and evaluation of highway bridges, culverts, retaining walls, and noise walls. He has been assigned to multiple on-site consultant contracts for the MDOT State Highway Administration and has also worked on several high-profile jobs in various other states including New York, Virginia, Washington D.C., and Texas.
1) Setting of a typical precast modular unit
4) Completed bridge rehabilitation