Rooted-in-Innovation-Pittsburgh-International-Airport - Terminal steel tree columns and performance-based fire engineering

Oct 28, 2026

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Pittsburgh International Airport’s new terminal delivers a transformation in passenger experience through a distinctive steel “tree column” system and an organically formed rolling roofline. The $1.7 billion project replaces the former landside terminal and removes the need for an automated people mover by improving connectivity to existing concourses. The design tackles major challenges from APM and utility tunnels above, using long-span grade beams, grade-level transfer girders, and composite embedded plate girders to manage heavy column loads. Performance-based fire engineering and concrete-filled columns support structural stability during fire events while also enabling a smooth paint finish.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages7

Reading Time18 min

AccessFree to download

Pittsburgh terminal design overview

Roofline and AESS tree columns

Project scope and connectivity

Structural solutions over active tunnels

Composite plate girders and splices

Tree column geometry and fire protection

00'8ssn 火*CAR-RT LDT**C-009 MIX CDNAIL3123639 1_028_SCN001 P1592640283565583ROBERT STACHEL HRY CONFORMANCE VERIFICATION ASSoCIATES,420 ROUSER RD STE 400MOON TOWNSHIP PA 15108-3090 |l中中|lp中川山 |hl 7G030NOUo!ohisuo leəiS ★ 4L IS Jos20215n⁶nyujapoN Tree columns and an organically formed roof are the steel backboneof Pittsburgh's new airport terminal that will transform passenger experience. project is generating about $2.5 billion in economic activity forthe region,including more than 14,00 jobs. PITTSBURGH IS SOON TO WELCOME a striking addi- tion:a new terminal at Pittsburgh International Airport.With itsexposed steel tree columns,unique architectural roof form,andchallenging site conditions over active tunnels,the 800,000-sq.-ft,three-story steel structure showcases how collaborative design andinnovative thinking can deliver elegance and efficiency on even themost challenging of projects. The terminal's distinctive rolling roofline is inspired by theregion's topography.The roof is supported by 38 architecturallyexposed structural steel (AESS)Category 1 tree columns spacedup to 120 ft apart,creating a vast entry point for travelers (learnmore about AESS at aisc.org/AESS).The roofcantilevers roughly60 ft beyond the building facade,sheltering the curbside drop-offarea and visually linking the structure to the adjacent landscape.The new terminal includes four outdoor terraces—two landsideand two airside,a rarity for U.S.airports—offering further viewsof the surrounding topography. The new terminal is an architectural statement and a crucialefficiency boost for the airport that meets the market's currentneeds.The $1.7 billion project consists of a new pre-securitybuilding and a multi-modal complex focused on the Pittsburghpassenger rather than a single airline.It replaces the old landsideterminal,which is located a half-mile from the passenger gates andconnected to them by an automated people mover(APM).Thenew building is immediately adjacent to the existing concourses,providing better connectivity for passengers and eliminating theAPM.The Allegheny County Airport Authority estimates the The new terminal presented a major design challenge with itslocation directly above the APM and utility tunnels.These tunnelsare critical to the current function of the airport and were required left:A tree column with a finished coating. below:The tree columns are spaced as far as 120 ft apart. opposite page:A rendering showing the terminal roof and the AESSCategory 1 tree columns that support it. below:HSS tree columns support custom plate girder spine elements.Both create moment frames in the east-west direction.The spineelements support conventional roof framing. 理 to remain fully operational during construction.The design solu-tion to accommodate the tunnels is a structural slab at grade sup-ported by a series of long-span grade beams—extending as long as70 ft—that in turn support the loadsfrom the grade level and serveas transfer girders for the building columns above. Due to the heavy column loads and limited depth between thetop-of-tunnel and top-of-slab elevation,up to 5-ft-deep embed-ded 50 ksi wide-flange steel plate girders were introduced at manylocations.These plate girders were designed compositely with thesurrounding concrete to maximize their efficiency. The size and length of the plate material required for theplate girders,up to 4 in.thick and 52 in.wide,neceitated theintroduction of splices.Several of the girders were multi-spanmembers to take advantage of continuity and enhance structuralperformance.The Thornton Tomasetti design team and steelfabricator,Sippel Steel Fab in Ambridge,Pa.,collaborated todetermine splice locations that would minimize demand to allowthe splices as bolted connections rather than field-welded con-nections.The resulting connections used 1/s in.A490-SC-Bbolts in double shear # Consistey Among Variation The sculptural and structural tree columns ar

FAQs

How is fire protection achieved for the steel tree columns?

Fire protection relies on performance-based fire engineering: simulated fire conditions evaluate real structural behavior, and columns are filled with concrete up to the roof to help carry temporary loading if steel strength is reduced.

Oct 28, 2026

Upload by Ezra