Thornton Tomasetti (formerly the Thornton-Tomasetti Group, Thornton Tomasetti Engineers, Lev Zetlin & Associates and LZA Technology) is a 1,500-plus person engineering consulting firm headquartered in New York City. The company operates more than 50 offices, serving clients worldwide.
The company has expertise in structural engineering, façade engineering, forensics, renewal, construction engineering, property loss consulting, sustainability, applied science, protective design and transportation. The engineering firm provided the structural design for several of the world's tallest building structures, including the Petronas Towers in Kuala Lumpur, Malaysia; and Taipei 101 in Taiwan. Other structures designed by the firm include Soldier Field in Chicago, Petco Park in San Diego, and the Minneapolis Public Library in Minneapolis. Among other architects of note, Thornton Tomasetti has collaborated with Cesar Pelli, Santiago Calatrava, Renzo Piano, and Rafael Vinoly.
Thornton Tomasetti works to advance sustainable design and construction practices. About one-fifth of its staff are LEED accredited professionals (LEED AP). Thornton Tomasetti was the first structural engineering company to sign the AIA 2030 Commitment.
The company began using the name Thornton Tomasetti in 1975 when Charlie Thornton and Richard Tomasetti purchased Lev Zetlin & Associates (LZA) from Gable Industries, to which Lev Zetlin had sold LZA in 1971. Thornton Tomasetti immediately began to branch out and enter the highrise market with several innovative designs.
The New York City office essentially began in 1956 as Lev Zetlin & Associates (LZA), founded by Lev Zetlin upon the completion of his PhD at Cornell University. Zetlin pioneered the use of the double layer bicycle wheel roof system used in the Utica Civic Auditorium (also known as the Utica Memorial Auditorium), as well as the hyperbolic (hypar) roofs used in American Airlines 747 super-hangars at airports in Los Angeles and San Francisco. Lev Zetlin also embraced the creative use of materials, most notably demonstrated in a bridge design made entirely of paper products for an International Paper ad.
In 1993, Thornton Tomasetti acquired Cohen-Barreto-Marchertas (CBM) and created a Chicago office. Founded in 1965 by Eli Cohen, CBM pioneered the use of the now-common composite steel structural system, which combines a reinforced concrete core wall (to resist lateral loads) with a light steel floor framing. The development of 50- to 60-story buildings became more feasible and efficient because the lighter framing reduced construction time and expense, and allowed for large, column-free spans, giving architects greater freedom in exterior expression. In the early 1960s, Cohen's adaptation of the concrete cooling tower design to high-rise offices required a change in the way the unions worked. Until that time, ironworker contracts forbid members of other trades to work at higher elevations at job sites. But the proposed system was reviewed with them and they agreed to let concrete workers work above them.
On September 8, 2015, Thornton Tomasetti announced that it had merged with structural engineering firm Weidlinger Associates. "The combined firm will have 1,200 employees operating in 34 cities internationally", and will operate under the Thornton Tomasetti name.
In addition to founding Thornton Tomasetti, Charlie Thornton founded The ACE Mentor Program, which is a not-for-profit organization, formed to enlighten and motivate students toward architecture, construction, engineering, and related careers by providing mentoring opportunities for future designers and constructors.In 2008 Thornton was awarded the Henry C. Turner Prize for Innovation in Construction Technology from the National Building Museum for his work with this program.
875 North Michigan Avenue, formerly the John Hancock Center, is a 100-story, 1,128-foot supertall skyscraper located in Chicago, Illinois. Located in the Magnificent Mile district, its name was changed to 875 North Michigan Avenue on February 12, 2018. However, despite this, the building is still colloquially called the John Hancock Center.
Skidmore, Owings & Merrill LLP (SOM) is a global architectural, urban planning and engineering firm. It was founded in Chicago in 1936 by Louis Skidmore and Nathaniel Owings. In 1939, they were joined by engineer John O. Merrill. The firm opened its second office, in New York City, in 1937 and has since expanded all over the world, with offices in San Francisco (1946), Los Angeles, Washington, D.C., London, Hong Kong, Shanghai, Mumbai and Dubai.
Helmut Jahn is a Chicago-based German-American architect, known for designs such as the Sony Center on the Potsdamer Platz in Berlin, Germany; the Messeturm in Frankfurt, Germany; the One Liberty Place in Philadelphia, Pennsylvania ; and the Suvarnabhumi Airport, an international airport in Bangkok, Thailand. Recent projects include a residential tower in New York City, 50 West St in 2016 and the ThyssenKrupp Test Tower in Rottweil, Germany in 2017.
Kohn Pedersen Fox Associates (KPF) is an American architecture firm which provides architecture, interior, programming and master planning services for clients in both the public and private sectors. KPF is one of the largest architecture firms in New York City, where it is headquartered.
The architectural firm now known as Holabird & Root was founded in Chicago in 1880. Over the years, the firm has changed its name several times and adapted to the architectural style then current — from Chicago School to Art Deco to Modern Architecture to Sustainable Architecture.
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Shreve, Lamb, and Harmon, founded as Shreve & Lamb, was an architectural firm, best known for designing the Empire State Building, the tallest building in the world at the time of its completion in 1931.
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.
3 Park Avenue is a mixed-use office building and high school located on Park Avenue in Manhattan, New York City that was built in 1973. The building, surrounded on three sides by a plaza, is categorized as a Midtown South address in the Kips Bay, Manhattan, Murray Hill, and Rose Hill neighborhoods. It is located between East 33rd and 34th Streets, close to the 33rd Street subway station, an entrance to which is built into the building.
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 600 employees at seven offices in Boston, Chicago, Houston, New York City, San Francisco, 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, Tower A is the 18th tallest residential building in the world, and has been officially announced as the second tallest building in Korea, according to the Ministry of Land, Transport and Maritime Affairs. The Haeundae Doosan We’ve the Zenith consists of three residential buildings, with 70, 75 and 80 stories respectively, comprising 1,788 households in total, and one office building on its 42,500 square metres (457,000 sq ft) site. The total construction work took 48 months from November 2007 to November 2011.
The Indiana State Fair stage collapse was an incident during an August 13, 2011, outdoor concert by Sugarland 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.
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.
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.
One Bennett Park is a skyscraper at 451 East Grand Avenue, in the Streeterville neighborhood of Chicago. The project was first announced as the building at 451 E. Grand Ave. in July 2014, approved in December 2014, and named One Bennett Park in October 2015. The building is named for Edward H. Bennett, the Chicago architect and urban planner who coauthored the 1909 Plan of Chicago. The building topped-out in late 2018, and later opened in the spring of 2019. It is among Chicago's tallest skyscrapers.