Council on Tall Buildings and Urban Habitat
Council on Tall Buildings and Urban Habitat

About Hi Sun Choi

Hi Sun Choi is a Senior Principal at Thornton Tomasetti and has over 20 years of experience in structural analysis, investigation, design and review of a variety of building types, including commercial and residential buildings. Her expertise includes the design of super tall buildings for seismic risk assessment, building motion due to wind, performance-based design, and waterfront developments on reclaimed land. She has worked on projects in the United States, South Korea, the U.A.E., Azerbaijan, China, and Vietnam.

Hi Sun’s key projects include the Hudson Yard Development and Barclay Headquarters, New York; New Songdo City Development, We’ve the Zenith, and Incheon Airport Phase III, South Korea; Shanghai Center, China; Socar Tower and Baku National Stadium, Azerbaijan; and Lotte Hanoi Center. Her work on Baku National Stadium, Azerbaijan received the ENR Global Best Project Award in 2015…


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About Hi Sun Choi

Hi Sun Choi is a Senior Principal at Thornton Tomasetti and has over 20 years of experience in structural analysis, investigation, design and review of a variety of building types, including commercial and residential buildings. Her expertise includes the design of super tall buildings for seismic risk assessment, building motion due to wind, performance-based design, and waterfront developments on reclaimed land. She has worked on projects in the United States, South Korea, the U.A.E., Azerbaijan, China, and Vietnam.

Hi Sun’s key projects include the Hudson Yard Development and Barclay Headquarters, New York; New Songdo City Development, We’ve the Zenith, and Incheon Airport Phase III, South Korea; Shanghai Center, China; Socar Tower and Baku National Stadium, Azerbaijan; and Lotte Hanoi Center. Her work on Baku National Stadium, Azerbaijan received the ENR Global Best Project Award in 2015 and ACEC-NY Diamond Award in 2016. The Plaza at PPL in Allentown, Pennsylvania received the Urban Land Institute’s “Best of the Best” award in 2004. The # (Sharp) Star City in Seoul, South Korea, received the Presidential Prize in 2007, and Metapolis received the “Best Award” in 2010. She has lectured on super tall building design at several universities including MIT, Lehigh University, Seoul National University and Korea University. She also presented “Structural Design of the Tallest Concrete Tower in Korea, The # (Sharp) Star City” and “Reaching New Heights, 151 Tower” at the Council on Tall Buildings and Urban Habitat conferences in 2004 and 2010 and “BIM, IPD, and Beyond” at the 2010 CTBID international workshop. She is a co-author of “Outrigger Design for High-Rise Buildings –CTBUH, 2012” and “Design of Steel Structures, 2016.”

She is a licensed professional engineer in New York and a registered structural engineer in South Korea. Hi Sun has served as an adjunct professor at the Pratt Institute and the New Jersey Institute of Technology for several years. Hi Sun has a bachelor’s degree in civil engineering from The Cooper Union and a master’s degree in civil engineering from the Massachusetts Institute of Technology.

CTBUH Involvement

  • Past Roles:
  • Working Group: Outrigger Design, Co-Chair (2011 – 2012, 2016 – 2017)
  • Annual Conference, Presenter (China 2016; Chicago 2019)

Events/Initiatives Involving Hi Sun Choi

Second CTBUH Damping Research Meeting

Second CTBUH Damping Research Meeting

26 Oct 2015, Event Report – Nearly 30 industry professionals and academic experts were in attendance at the…

Outrigger Workshop, Shanghai

Outrigger Workshop, Shanghai

18 Sep 2012, Event Report – The workshop attracted 18 professionals from various backgrounds, including…

2011 CTBUH Leaders Meeting

2011 CTBUH Leaders Meeting

9 Oct 2011, Event Report – Tall building industry leaders from around the globe met at the seminal Dongbu…

Events/Initiatives Involving Hi Sun Choi

Second CTBUH Damping Research Meeting
26 Oct 2015, New York City – Event Report
Nearly 30 industry professionals and academic experts were in attendance at the second meeting for the CTBUH research project on damping.
Outrigger Workshop, Shanghai
18 Sep 2012, Shanghai – Event Report
The workshop attracted 18 professionals from various backgrounds, including structural engineers, architects, construction managers, professors and researchers.
2011 CTBUH Leaders Meeting
9 Oct 2011, Seoul – Event Report
Tall building industry leaders from around the globe met at the seminal Dongbu Financial Center tower for the 2011 CTBUH Leaders Meeting.
Korea Chapter 2010 Conference
27 Aug 2010, Seoul – Event Report
The Korean CTBUH Conference 2010 was held at Seoul Olympic Parktel Olympia Hall and hosted by the CTBUH Korea.

See all initiatives involving Hi Sun Choi

Hi Sun Choi Related Resources

Outrigger System Design Guide from CTBUH Outrigger Working Group to be Released

Oct 2011 – CTBUH 2011 Seoul Conference
Hi Sun Choi, Thornton Tomasetti

Frontiers in High-Rise Outrigger Design

8 Aug 2017 – CTBUH Journal, 2017 Issue III
Hi sun Choi & Leonard M. Joseph, Thornton Tomasetti; SawTeen See, Leslie E. Robertson Associates; Rupa Garai, Skidmore, Owings & Merrill LLP

Structural Challenges with the SOCAR Tower in Baku, a New Megacity in the Caspian Region

17 Oct 2016 – Cities to Megacities: Shaping Dense Vertical Urbanism
Hi Sun Choi & Onur Ihtiyar, Thornton Tomasetti, Inc.; Young Kyoon Jeong & Hyungsup Sim, Heerim Architects & Planners

Two-In-One Tower: An Expansion in Typology and Technology in Hanoi

16 Sep 2014 – CTBUH 2014 Shanghai Conference Proceedings
Matthias Olt, Callison; Hi Sun Choi, Thornton Tomasetti

See all papers/research

Hi Sun Choi Related Papers/Research

Frontiers in High-Rise Outrigger Design
8 Aug 2017 – CTBUH Journal, 2017 Issue III; Hi sun Choi & Leonard M. Joseph, Thornton Tomasetti; SawTeen See, Leslie E. Robertson Associates; Rupa Garai, Skidmore, Owings & Merrill LLP
In 2012, CTBUH published the first Outrigger Design for High-Rise Buildings Technical Guide. In 2016, the CTBUH Outrigger Working Group felt it would be beneficial to update the design guide with variations of outrigger systems and tall building…
Structural Challenges with the SOCAR Tower in Baku, a New Megacity in the Caspian Region
17 Oct 2016 – Cities to Megacities: Shaping Dense Vertical Urbanism; Hi Sun Choi & Onur Ihtiyar, Thornton Tomasetti, Inc.; Young Kyoon Jeong & Hyungsup Sim, Heerim Architects & Planners
Baku, the capital of Azerbaijan, has been rapidly transforming into a hub of high-rise buildings and cultural centers in the Caspian region. Baku’s population now accounts for more than 40 percent of the nation. With the 2012 opening of the new…
Two-In-One Tower: An Expansion in Typology and Technology in Hanoi
16 Sep 2014 – CTBUH 2014 Shanghai Conference Proceedings; Matthias Olt, Callison; Hi Sun Choi, Thornton Tomasetti
Standing 267m tall, Lotte Center Hanoi is Vietnam’s second tallest tower and set to open this summer. Innovative high-rise design solutions were incorporated that respond to the cultural, environmental, and technical challenges of tall construction…
Overview of Seismic Loads and Application of Local Code Provisions for Tall Buildings in Baku, Azerbaijan
Mar 2014 – International Journal of High-Rise Buildings Volume 3 Number 1; Hi Sun Choi, Onur Ihtiyar & Leonard Joseph, Thornton Tomasetti; James Sze, Arup
Baku, the capital of Azerbaijan, has seen a boom in construction in recent years. The old Baku city has been rapidly transforming into a new hub of high-rise buildings and lively cultural centers hosting the Euro Vision Song Contest in 2012 and…
Outrigger System Design Considerations
Sep 2012 – International Journal of High-Rise Buildings Volume 1 Number 3; Hi Sun Choi and Leonard Joseph, Thornton Tomasetti
Outrigger systems have been widely used in supertall buildings constructed since the 1980’s, eclipsing previously favored tubular frame systems. However, outriggers are not listed as a seismic lateral load resisting system in any code. Design…
Structural Design of the Tallest Concrete Tower in Korea, the # Star City
Oct 2004 – CTBUH 2004 Seoul Conference; Hi Sun Choi & Dennis Poon, Thornton Tomasetti; Jongho Kim, Chang & Minwoo Structural Consultant; Seongsoo Kim, Seong-Jin Structural Group
Residential high-rise buildings, such as apartments and condominiums, were introduced to provide multiple residential spaces in urban and suburban areas for their economic advantage and convenience for commuting to urban business districts.