“Stacked, Circular Tower To Join Tbilisi Skyline”, Civil Engineering

Robin Monotti Architects’ design for a new tower in Tbilisi, Georgia, pays homage to the nation’s past and the city’s present.

April 23, 2013—The history of the capital city of Georgia, Tbilisi (T’bilisi), located on the banks of the Kura River, extends back a mere 1,500 years, although settlement of this area of the nation extends back millennia. Now a design for a new development called the Tbilisi Business Centre, conceived by London-based Robin Monotti Architects, draws on the nation’s ancient history while providing a distinct contrast to the center’s relatively modern neighbor, a stern Soviet-era bank. The design of the new tower is a delicately balanced stack of glass-enclosed disks that seem to spiral upward, and the structure will be located next to an angular, boxy structure designed by the architects Giorgi Chakhava and Zurab Jalaghania and built in 1975. This angular structure now serves as the headquarters of the Bank of Georgia.

The 16-story circular tower will offer 16,000 m2 of space as a new business center and will include offices, conference halls, trading floors, restaurants, outdoor garden terraces on each level, and parking, according to Robin Monotti Graziadei, FRSA, RIBA, an architect and managing partner of Robin Monotti Architects. Monotti Graziadei wrote in response to questions posed by Civil Engineering online.

The tower’s spiraling disks were inspired by the Georgian gold collection at the Georgian National Museum. “This is maybe Georgia’s most important national treasure in terms of history and culture,” Monotti Graziadei explained. “The first and most ancient items in the display, dating from at least the 7th century BC, are Colkhetian gold rings that were used as hair bands at around the height of a woman’s temple.

“Most of these gold temple rings are spiral in shape,” Monotti Graziadei said. “[I] thought there was a lot of power in their beauty and simplicity and thought it significant to recall an ancient geometrical shape into modern times.”

The building will contain a continuous concrete central core that will house all vertical circulation, ancillary services, and facilities, Monotti Graziadei said. Circular floor slabs floor slabs, each rotated a few degrees with respect to the one below it, create the tower’s spiral; the floor slabs will extend out from the circular core. Each of these eccentric circular stories will take the form of a steel and concrete composite cylinder with perimeter glazing—and exterior terraces—to maximize views of the city. “A steel structure will run all along the perimeter of the cylinders, a bit like a Vierendeel perimeter beam,” Monotti Graziadei explained. “In parts this perimeter beam will cantilever over the edge of the cylinder below.”

Seasonal temperature shifts in the city, which range from an average of approximately 35°F in winter to 90°F in summer, inspired the architects to select solar control glass for the facades; the glass will reflect more than 30 percent of the sunlight during the summer months.

“The new Tbilisi Business Centre was designed for its context and was only developed after a visit to the site and a careful consideration of how to create a new building next to the Bank of Georgia, formerly [the] Ministry of Highways [building], a listed national monument of Georgia,” Monotti Graziadei said. (National monuments are protected under a law on cultural heritage passed in 2007.) To offer a balance to the stark, 90-degree angles of its neighbor, which plays with space and volume via cantilevering floors perched atop one another, Monotti Graziadei and his team decided to offer a counterpoint in the form of a rounded, spatially compact building, in a matching height.

“If the Bank of Georgia’s shape is very ‘male’ because of the sharp angles, Tbilisi Business Centre is ‘female’ because of its rounded shape,” Graziadei said. “The initial concept models, perhaps appropriately for a business center, were made with coins on a table. This allowed many different combinations to be tested very quickly.”

The foundations and below ground construction methods have not yet been determined, and the same is true of the construction schedule. But the design concept has been approved by all of the local government departments in Tbilisi, according to Monotti Graziadei. The project must still go through a planning permission stage. Tbilisi-based Unix Construction and Development Group is developing the project.

Catherine A. Cardno, 23/04/13

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