Turning Torso is a beautiful residential skyscraper in Sweden and the tallest building in Scandinavia. It is regarded as the first twisted skyscraper in the world.However, it is a Neo-futurist skyscraper. Which was constructed in 6 years from 1999 to 2005. 1999-2001 designing and from 2001-2005 construction. Also, the project was part of the transformation of Malmö’s Western Harbour near the bridge connecting Sweden and Denmark. The structure is 190m tall with 54 stories and 147 apartments. Steel and concrete are the primary building materials.

Case Study of Turning Torso

• Architect: Santiago Calatrava
• Location: Malmo, Sweden
• Design: 1999-2001
• Construction: 2001-2005
• Type: Residential Tower
• Structure: Core and Slabs (concrete)
• Exoskeleton: Steel
• Levels: 56
• Façade Area: 215,278 sqft.
• Net Floor Area: 227,710 sq. ft.
• Height: 190.0 m
• Average Floor Area: 400.0 m²
• Total Residential Space: 14,600 m² (Cubes 3-9)
• Total Office Space: 4,200 m² (First 2 cubes)

Concept

The basic concept of the building is based on the upright human body in motion, twisting the body as far as possible. However, the form is made up of 9 cubes. Also, each individual cube includes 5 floors of the building. There is a difference of 90 degrees from the ground floor to the top floor.

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Foundation of Turning Torso

The foundation of the Turning Torso is a cylindrical box with a diameter of thirty m and a depth of fifteen m. The foundation slab rests on the limestone bedrock. And also has a depth of 7m. The main load-bearing structure is a circular reinforced concrete core, whose center corresponds precisely to the rotation center of the floors. The core’s inner diameter is 10.6m and is constant. The thickness of the concrete is 2.5m at the bottom and gradually tapers to 0.4m at the top. Inside the core are the elevator and the staircase core, which is a secondary structural elements. The tower rests on piles driven into a foundation of solid limestone bedrock at 49ft. below ground level. Avoids unacceptable bending or swaying.

Structure

Every floor consists of a square section around the core and a triangular part supported by an exterior steel structure. A foundation slab supports the central core. The junction of each floor is a concrete column supported by a pile foundation.

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Construction of Turning Torso

Illustration of the known structure of the Turning Torso.

1. Displays a typical floor plan, where the grey circle denotes the core and blue shapes denote the steel framework.
2. Shows the way the 9 segments fit around the core
3. Is a di-metric projection of the building.

Floor plan

Each floor has a square section around the core and a triangular part supported by a steel spine. The foundation slab supports the central core and the corner of each floor is a concrete column supported by a pile foundation.

Construction Process of Turning Torso

After finishing the foundations started the construction of the concrete core. The core was cast in a sliding form, which means that the form is suspended between vertical beams and can slide upwards, one floor at a time, by way of jacks. The walls around the staircase and lifts were poured into forms suspended underneath the sliding form. The walls were sprayed in connection with the casting of the center.

Once the concrete had hardened to a pre-determined degree, the core form as well as the forms for the staircase and lift shafts could then climb upwards to the next floor. The next step in the pouring process was to form and pour the structural slab around the core before the cycle could be duplicated with the core and lift shafts. Most of the reinforcement was prefabricated at a shop in order to form large “steel cages” and then erected to their final position where can be overlapped.

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Core

The core is the main load-bearing structure. Large concrete pipe, with an inner diameter of thirty-five ft. The walls are 8ft. Thick at the bottom, gradually shifting to one ft. thick at the top. The elevator shafts and staircases are found inside the core.

Slab of Turning Torso

• The structural slab is fitted around the core. The forms for the structural slab are triangular forms, together forming a floor. The forms were rotated 1.6 degrees for each floor in order to create the characteristic twist of the building.
• Standard Slabs: Each cube is composed of 6 RC slabs. The upper five are standard slabs twenty-seven cm thick, fully fixed to the concrete core, and supported by means of steel columns at the perimeter that shares the load with the lower conical slab.
• Deck levels: Diagonals anchorage: The upper slab of each cube or “deck level” is where the diagonals and horizontals are linked. These slabs are thicker in the anchorage area.
• Climbing forms and Beam: Each cube was made with so-called self-compacting concrete. Because of its discharge capacity, this type of concrete does not need vibrating.

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Spine

The steel support is located on the exterior of the building, which is connected together by the spine, acting as the loading spine from the winds. The steel support transfers shear forces to the supporting concrete core. Also, every steel section of the spine has to fit precisely in the one below it. The system consists of a spine column at the corner of each floor. There are 20 horizontal and 18 diagonal elements known as CIGAR that reach each side of the glazed spine. Stabilizers also connect the floor slabs with the framework.

Wind Loads at Turning Torso

The twisted form can be very effective, alleviating the effects of vortex-shedding induced by lateral wind loads and minimizing the wind loads from the prevailing direction. When analyzing the building under wind loads, the architect found that the Turning Torso could move up to three ft. at the top during the most severe storm. Giant pins attached to the bottom then implemented, decreasing the movement to less than a foot during the most severe storm, which is almost unnoticeable.

Building Services

The Turning Torso’s elevators, fire stairs, and utilities situated in the concrete core that runs vertically throughout the height of the building. “There are three high-speed lifts in the core of the building servicing the apartments. The commercial area has two separate lifts, also located in the core.” The Turning Torso’s residential services distributed threw out 4 dwellings on each of the thirty-five identical residential floor plates, which duplicate and turn around the core.

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Lifts of Turning Torso

3 lifts service the residential part of the building and HSB Turning Torso Meetings. Two separate lifts service the offices. Ensures high capacity and minimum waiting even during “rush hour” and in the instances when a lift is closed for maintenance.

Facade

The facade panels, made of glass(orange) and aluminum panel(yellow) of the turning torso were double-curved due to the building’s twist. In total, the facade composed of 2,800 panels and 2,250 windows. The facade is a glass and aluminum construction. 2,800 panels and 2,250 windows. Following the twist of the building, the windows are leaning either inwards or outwards by 0 to 7 degrees.

Safety Measures at Turning Torso

• The steel mesh barrier is durable, strong, adjustable, and lightweight and combines the guardrails, toe board, and steel mesh barrier into one product.
• It protects employees at the edge of horizontal or low-sloping surfaces.
• It is also develope with closed-return for greater debris containment and uses precast sockets, clamps, or anchored components for base attachments and posts for upright supports.
• Also, the steel mesh barrier system has maintained and inspected once every week.
• Sprinklers in all rooms
• Pressure increasing pumps
• Rising pipes
• Emergency elevator
• Fire gas ventilation
• Door shutters
• Fire alarm
• Smoke detectors
• Emergency electricity
• Emergency light
• Every floor and apartment is its own fire cell

The building has won many awards such as

• 50 Most Influential Tall Buildings of the last 50 Years
• Ten-year Award from CTBUH
• fib 2006 Award for Outstanding Concrete Structures
• MIPIM Award for the Turning Torso Tower
• SBI Silver Beam Award for the Turning Torso Tower

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