Number of locations
|Mike Squarzini (Co-CEO)
Peter DiMaggio (Co-CEO)
Wayne Stocks President
Gary Panariello Director
Tom Scarangello Executive Chairman
Number of employees
Thornton Tomasetti (formerly the Thornton-Tomasetti Group, Thornton Tomasetti Engineers, Lev Zetlin & Associates,LZA Technologyand Weidlinger Associates ) is a global, 1,500-plus person scientific and engineering consulting firm.
Thornton Tomasetti has expertise in structural engineering, facade engineering, forensic engineering, structural renovations, construction engineering, Resilience (engineering and construction), sustainable design, applied science, protective design and security, civil engineering and bridge design and rehabilitation. The firm's services are supported by its internal research and development CORE teams, which provides technology-focused expertise, computational simulation and software development as well as artificial intelligence and machine learning.
The firm provides consulting expertise to clients in a variety of industries, including architecture/engineering/construction, insurance and law firms, real estate developers, building owners/operators, defense, life sciences, manufacturing, natural resources and space systems.
1949—Paul Weidlinger opens consultancy: Weidlinger Associates dates back to 1949 with the launch of Paul Weidlinger Consulting Engineers in Washington, D.C. A native of Budapest, Hungary, Paul earned a master's degree from the ETH Zurich in Zurich. He apprenticed with Le Corbusier in Paris and László Moholy-Nagy in London before coming to the United States in the late 1940s.
1950s—Applied Science division launched: Paul Weidlinger, Dr. Mario Salvadori and Dr. Melvin Baron shared an interest in the dynamic response of structures, which led the firm to create an Applied Science division. The group developed analysis and design procedures to protect structures from the effects of blast loadings. Their methods led to early and continuing use of computers in advanced analysis and design.
1956—Lev Zetlin starts Lev Zetlin Associates: After earning a doctoral degree from New York’s Cornell University, Lev Zetlin decided to start his own company, Lev Zetlin Associates (LZA).
1960—Charlie Thornton joins LZA: Charlie Thornton, who earned master’s and doctoral degrees from New York University and authored a thesis on cable nets, joined Lev Zetlin Associates in 1960. Serving as co-chairman of the firm until 2004, he was involved in the analysis, design and construction of projects worldwide.
1964 -- 1964 New York World’s Fair (Flushing Meadows, New York): Early in his career, Lev Zetlin devised a “double-layer bicycle wheel” roof system. The system combines upper and lower cables with varying tensions that are jacked apart and connected by rigid vertical struts. Connecting cables that have differing natural frequencies minimizes wind-induced fluttering. First developed for the Utica Memorial Auditorium, which was completed in 1960, Lev Zetlin's bicycle wheel system has helped to shape the design of other tensile structures, among them the New York State Pavilion, Madison Square Garden, the Seoul Olympic Gymnastics Arena, Tropicana Field, and the Georgia Dome.
1968—Richard Tomasetti joins LZA: Richard Tomasetti joined Lev Zetlin Associates after working in the aerospace and submarine industries. Tomasetti created Environspace Research and Development, the firm’s first research and development group.
1977—Charlie Thornton and Richard Tomasetti buy LZA from Gable Industries: Charlie Thornton and Richard Tomasetti purchased Lev Zetlin Associates while it was a subsidiary of Gable Industries. It was at this time that the firm began performing some work as Thornton Tomasetti. The firm's name changed officially from the TTG Group to Thornton Tomasetti in 1999.
1980s-1990s—FLEX code introduced: The FLEX code was first developed by Weidlinger in the early 1980s to support Nuclear Test Ban Treaty monitoring. Its name is derived from its primary focus, performing ”fast large explicit’ time-domain dynamic simulations, and from its versatility and speed in modeling unusually large structures. In the early 1990s, the FLEX code was diversified into a family: NLFlex (blast), EMFlex (electromagnetic waves), and PZFlex (sonar and ultrasound). In 1999, SpectralFlex was developed to serve the growing field of medical therapeutics, and in 2002, Weidlinger created the FLEX Template System, for modeling and simulation of structural components of civilian structures subjected to bomb blasts.
2001—World Trade Center collapse (New York, New York): In the 10 months after the September 11 attacks, crews removed more than 1.6 million tons of debris. Thornton Tomasetti staff were the first engineers on the site on September 11,[ citation needed ] and started work that afternoon. The firm supervised 20 member firms of the Structural Engineers Association of New York and arranged for 24/7 coverage of the site for nine months. The firm assisted in rescue, demolition and clean-up, advising on structural issues that required resolution as part of the recovery effort.
2004—Taipei 101 (Taipei, Taiwan) Completed: The first 21st-century building to become the world’s tallest upon completion, Taipei 101 is, as its name implies, a 101-story tower. Working with engineer of record Evergreen Consulting, Thornton Tomasetti established an efficient steel-based dual structural system and solved wind behavior problems with distinctive double stair-step corners. By 2020, Thornton Tomasetti had designed five of the 20 tallest complete buildings in the world.
2011 – CORE studio founded: CORE studio is the firm's internal research and development group that specializes in application development, computational modeling and artificial intelligence to create efficiencies in the structural design and construction process.
2012—Response to Hurricane Sandy: On October 29, 2012, Hurricane Sandy made landfall near Atlantic City, New Jersey. In response, the firm conducted damage assessment in three states related to structural and architectural integrity, HVAC, electrical, plumbing and fire protection equipment and systems. Included in the investigations were high-rise office and residential facilities, and other retail, rail, aviation and government facilities.
2015—Thornton Tomasetti and Weidlinger merge: Thornton Tomasetti and Weidlinger Associates announced a merger. Weidlinger Associates was a U.S.-based structural engineering firm that designed and rehabilitated buildings, bridges, and infrastructure and provided special services in applied science, forensics, and physical security. The merger created two new entities: CORE Lab - a sister internal group to CORE studio - that focuses on the long-term development of internal methods, capabilities and products to evaluate new business opportunities; and TTWiiN, a technology accelerator and product commercialization platform.
Skidmore, Owings & Merrill LLP (SOM) is an American architectural, urban planning and engineering firm. It was founded in 1936 by Louis Skidmore and Nathaniel Owings in Chicago. In 1939, they were joined by engineer John Merrill. The firm opened its second office, in New York City, in 1937 and has since expanded, with additional offices in San Francisco, Los Angeles, Washington, D.C., London, Melbourne, Hong Kong, Shanghai, Seattle, and Dubai.
The Citigroup Center is an office skyscraper in the Midtown Manhattan neighborhood of New York City. Built in 1977 for Citibank, it is 915 feet (279 m) tall and has 59 floors with a combined 1.3 million square feet (120,000 m2) of office space. The building was designed by architect Hugh Stubbins, associate architect Emery Roth & Sons, and structural engineer William LeMessurier.
HOK, formerly Hellmuth, Obata + Kassabaum and legally HOK Group, Inc., is an American design, architecture, engineering, and urban planning firm, founded in 1955.
330 North Wabash is a skyscraper in downtown Chicago, Illinois, United States, at 330 N. Wabash Avenue, designed by architect Ludwig Mies van der Rohe. A small bust of the architect by sculptor Marino Marini is displayed in the lobby. The 52-story building is situated on a plaza overlooking the Chicago River. At 695 feet, 330 North Wabash is the second-tallest building by Mies van der Rohe, the tallest being the Toronto-Dominion Bank Tower at Toronto-Dominion Centre. It was his last American building.
The architecture of the Kansas City Metropolitan Area, especially Kansas City, Missouri, includes major works by some of the world's most distinguished architects and firms, including McKim, Mead and White; Jarvis Hunt; Wight and Wight; Graham, Anderson, Probst and White; Hoit, Price & Barnes; Frank Lloyd Wright; the Office of Mies van der Rohe; Barry Byrne; Edward Larrabee Barnes; Harry Weese; and Skidmore, Owings & Merrill.
LeMessurier Consultants is a Boston, Massachusetts firm, founded by William LeMessurier in 1961. It provides engineering support services to architects and construction firms. They focus on advanced structural techniques and impacts to construction materials. They are known for their modular construction techniques including the Mah-LeMessurier System for precast concrete in high-rise housing, the Staggered Truss System for high-rise steel structures, and the tuned mass damper used to reduce tall building motion. One of the best known uses of the damper is the John Hancock Tower in Boston. In addition to new construction, they also work with retrofitting buildings and historic preservation.
Peter DiMaggio is an internationally recognized expert on the design of blast-resistant buildings. He was the lead engineer for construction of the U.S. embassies in Moscow, Berlin and Baghdad. He is currently the co-CEO of engineering firm Thornton Tomasetti.
Simpson Gumpertz & Heger Inc. (SGH) is a privately held ENR 500 engineering firm that designs, investigates, and rehabilitates structures and building enclosures. Their work encompasses commercial, institutional and residential buildings, transportation, water/wastewater, nuclear, science, and defense structure projects throughout the U.S. and over twenty foreign countries. SGH has 625 employees at eight offices in Atlanta, Boston, Chicago, Houston, New York City, Oakland, Southern California and Washington, D.C.
Wiss, Janney, Elstner Associates, Inc. (WJE) is an American corporation of architects, engineers, and materials scientists specializing in the investigation, analysis, testing, and design of repairs for historic and contemporary buildings and structures. Founded in 1956, WJE is headquartered in Northbrook, Illinois, and has over 600 professionals in twenty offices across the United States. WJE personnel are specialized in architectural, structural, and civil engineering; materials conservation, chemistry and petrography, and testing and instrumentation.
Haeundae Doosan We've the Zenith is a complex of three residential towers in the Haeundae District of Busan, South Korea, which was completed in 2011. With 80 floors and a height of 301 m, as of 2022, Tower A is the 22nd-tallest residential building in the world, and is the seventh tallest building in South Korea.
The Ping An Finance Center is a 115-storey, 599.1 m (1,966 ft) supertall skyscraper in Shenzhen, Guangdong, China. The building was commissioned by Ping An Insurance and designed by the American architectural firm Kohn Pedersen Fox Associates. It was completed in 2017, and is the tallest building in Shenzhen, the 2nd tallest building in China and the 5th tallest building in the world. It also broke the record of having the highest observation deck in a building at 562 m (1,844 ft). It is the second largest skyscraper in the world by floor area after Azabudai Hills Main Tower in Tokyo, Japan.
The Indiana State Fair stage collapse was an incident during an August 13, 2011, outdoor concert by Sugarland as part of their Incredible Machine Tour at the Indiana State Fair in which a wind gust from an approaching severe thunderstorm hit the stage's temporary roof structure, causing it to collapse. The structure landed among a crowd of spectators, killing seven people and injuring 58 others.
American Ground: Unbuilding the World Trade Center is a book by William Langewiesche, published in 2002, about the cleanup and recovery effort at the World Trade Center site following the September 11 attacks. Langewiesche embedded with the team managing the search and removal of The Pile, originally writing a series of articles for The Atlantic that were expanded into American Ground.
Weidlinger Associates, Inc., was a U.S.-based structural engineering firm that designs and rehabilitates buildings, bridges, and infrastructure and provides special services in applied science, forensics, and physical security. Weidlinger's clients include corporations, private clients, institutions, and federal, state and local governments. The firm is headquartered in New York City, with branch offices in Massachusetts, Connecticut, New Jersey, California, New Mexico, and Washington, DC. The firm also conducted business as Weidlinger Associates, Ltd., in Scotland, UK.
Magnusson Klemencic Associates is an American structural and civil engineering consulting firm with its headquarters in Seattle, Washington. The company has completed projects worth more than $99 billion in 48 states and 54 countries. Significant MKA projects through its history include the World Trade Center, the Columbia Center, Aqua, the Doha Convention Center Tower, the Olympic Sculpture Park, and Salesforce Tower.
Enclos Corp, referred to as Enclos, is a specialty glazing and exterior facade contractor in the United States. The firm provides design, engineering, fabrication and assembly services for custom curtainwall systems and structural glass facades. Enclos is headquartered in Eagan, Minnesota, and is a subsidiary of CH Holdings USA, Inc.
Since purchasing the Chicago Cubs baseball team and Wrigley Field in 2009, the Ricketts family have been pursuing an extensive renovation of the stadium and the surrounding venue. At its outset, the 1060 Project was projected to cost $575 million and was to be completed in four phases during consecutive off-seasons. Funding was generated from advertising revenue and increased corporate sponsorship in the form of additional signage placed in and around the stadium.
Guy Nordenson is a structural engineer and professor of structural engineering and architecture at Princeton University School of Architecture. Guy has two children, Pierre and Sebastien Nordenson. He attended the Massachusetts Institute of Technology, graduating with a Bachelor of Science in Civil Engineering in 1977, followed by a Masters of Science in Structural Engineering and Structural Mechanics from the University of California at Berkeley in 1978. After graduating from UC Berkeley he worked at Forell/Elsesser Engineers in San Francisco (1978-1982) and Weidlinger Associates in New York City (1982–1987), before establishing the New York office of Ove Arup & Partners in 1987 where he was a director until leaving in 1997 to begin his own structural engineering practice, Guy Nordenson and Associates.
Lev Zetlin was an Israeli-American civil and structural engineer. Founder of the engineering consulting firm Lev Zetlin & Associates, he developed several innovations in structural engineering including the double layer bicycle wheel roof system which he first employed at the Utica Memorial Auditorium and later patented. Zetlin was the structural engineer on 14 pavilions at the 1964–65 New York World's Fair including the New York State Pavilion which utilized his double layer cable suspended roof design.
110 North Wacker, also known as the Bank of America Tower, is a 57-floor skyscraper in Chicago located at 110 North Wacker Drive. It was developed by the Howard Hughes Corporation and Riverside Investment & Development. It was designed by Goettsch Partners with construction by Clark Construction. Structural engineering was by Thornton Tomasetti. A topping-out ceremony was held in September 2019 and the building officially opened in on October 14, 2020.