passerella olimpica torino, 2006 press-kit

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- 1 - Passerella 2006 Winter Olympics Turin Italy - HDA Introduction HDA Hugh Dutton Associés is a design consulting company formed in 1995. HDA is a team of architects and structural engineers who specialise in technical design services, in particular, for structural glass, steel structures, facades and architectural structures. HDA work as Architects Engineers Independent design consultants In collaboration with other architects as part of a design team HDA’s offices are based in Paris, France and have experience working in Asia, the United States, and Europe. Hugh Dutton is a former director of Rice Francis Ritchie, and worked closely with Peter Rice from 1981 until his death in 1992, and co-authored ‘Structural Glass’, on RFR’s work on cable structures and bolted glass. He taught at Columbia University and co-authored with Bernard Tschumi ‘Glass Walls/Glass Ramps’ publication on the University student centre entrance hall. At RFR he developed the ‘Rotule’ bolted glass system, now widely used worldwide, and worked closely with Peter Rice on RFR’s principle projects between 1982 and 1995, such as: -La Villette Science Museum and Park footbridges and galleries -La Defense Grande Arche fabric ‘clouds’ -Louvre Museum Inverted Pyramid -Japan Bridge La Defense -Citroen Cevennes Greenhouses -Charles de Gaulle airport Terminals 2F and TGV station Recent Projects: Projects Under Construction: Westlands Road Development, Hong Kong. Specialist Consultants for Office Tower Facades, lobby and canopies. (Arch. Wong & Ouyang) 2004 - New Acropolis Museum, Athens. Gallery for Parthenon Marbles, Archaic gallery and typical facades, Specialist Glass and facade consultants including facade energy studies for Greek Ministry of Culture. (Arch. Tschumi/Photiadis) 2002 - Lasalle School of Art, Singapore. Design and tender drawings for glass façades and fabric roof system. (Arch. RSP) 2004 – Changi Airport, Terminal 3 Singapore. 4500 m² cable net façade and 45000m² conventional facades with bowstring truss mullions (Arch. CPG). 2000 – 2008 Changi Airport, Terminal 2 Singapore. 15000 m² Canopies, Departure hall ceiling and façades. (Arch. RSP) 2002 - 2006 2006 Winter Olympic Games, Passerella,Turin Designers and structural engineers for competition winning entry for 400m cable footbridge. ( Arch. HDA ) 2002 - 2006

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Official Press-kit for the Turin Olympic Footbridge 2006

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Page 1: Passerella Olimpica Torino, 2006 Press-kit

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Passerella 2006 Winter Olympics Turin Italy - HDA

Introduction HDA

Hugh Dutton Associés is a design consulting company formed in 1995. HDA is

a team of architects and structural engineers who specialise in technical design services, in particular, for structural glass, steel structures, facades and architectural structures. HDA work as

• Architects • Engineers • Independent design consultants • In collaboration with other architects as part of a design team

HDA’s offices are based in Paris, France and have experience working in Asia, the United States, and Europe. Hugh Dutton is a former director of Rice Francis Ritchie, and worked closely with Peter Rice from 1981 until his death in 1992, and co-authored ‘Structural Glass’, on RFR’s work on cable structures and bolted glass. He taught at Columbia University and co-authored with Bernard Tschumi ‘Glass Walls/Glass Ramps’ publication on the University student centre entrance hall. At RFR he developed the ‘Rotule’ bolted glass system, now widely used worldwide, and worked closely with Peter Rice on RFR’s principle projects between 1982 and 1995, such as: -La Villette Science Museum and Park footbridges and galleries -La Defense Grande Arche fabric ‘clouds’ -Louvre Museum Inverted Pyramid -Japan Bridge La Defense -Citroen Cevennes Greenhouses -Charles de Gaulle airport Terminals 2F and TGV station

Recent Projects: Projects Under Construction: Westlands Road Development, Hong Kong. Specialist Consultants for Office Tower Facades, lobby and canopies. (Arch. Wong & Ouyang) 2004 - New Acropolis Museum, Athens. Gallery for Parthenon Marbles, Archaic gallery and typical facades, Specialist Glass and facade consultants including facade energy studies for Greek Ministry of Culture. (Arch. Tschumi/Photiadis) 2002 - Lasalle School of Art, Singapore. Design and tender drawings for glass façades and fabric roof system. (Arch. RSP) 2004 – Changi Airport, Terminal 3 Singapore. 4500 m² cable net façade and 45000m² conventional facades with bowstring truss mullions (Arch. CPG). 2000 – 2008 Changi Airport, Terminal 2 Singapore. 15000 m² Canopies, Departure hall ceiling and façades. (Arch. RSP) 2002 - 2006 2006 Winter Olympic Games, Passerella, Turin Designers and structural engineers for competition winning entry for 400m cable footbridge. ( Arch. HDA ) 2002 - 2006

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AEM Urban Heating Facility, Turin, Italy. Anodized stainless steel toroidal facade screens(Arch. Buffi) 2002- Built Work : Construction 3 Pacific Place, Hong Kong. Entrance Hall Podium Specialist Facade advisor to Swire Properties ( Arch. Wong & Ouyang) 2001 – 2004 Drugstore Publicis, Champs Elysées, Paris. Facade glass screens, shopfronts & glass terraces (Arch. M.Saee.) 2001 – 2003 Pola Impressionist Museum, Hakone Prefecture, Japan. Glass structures, glass light wall and Bus shelter canopies. Specialist consultants. (Arch. Nikken Sekkei) 1995-2002 Aquarium, Kamogawa, Japan. Glass roof and tensile fabric.(Arch. Nikken Sekkei) 1995-2001 Public Transport station, Lausanne, Switzerland. Footbridge and ‘glass boxes’ for lift and escalator covers. ( Arch. B. Tschumi/ Merlini) 1994 – 2001 Concert hall exhibition park, Rouen. Steel roof structures and toroidal façades, (Arch. Bernard Tschumi) 1998 - 2001 Inchon International Airport, Seoul, Korea. Long Span Roof Structures, Façades and canopy (Arch. KACI of KBHJW Consortium and Fentress) 1996 - 2001. Osaka Maritime Museum, Japan. 73m glazed dome structure. (Arch. P. Andreu) 1994 - 2000. Lerner Student Centre, Columbia University N.Y. Suspended glass wall and glass paved ramps. (Arch. Bernard Tschumi) 1996 - 1999 St. Gobain Research Facility renovation at Aubervilliers, France. Suspended glass and experimental panel north facade. Joint competition winners, design and specialist consultants. (6 M FF, Arch. Odile Decq/Benoit Cornette). 1997 - 1999

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Passerella 2006 Winter Olympics Turin Italy - HDA

‘Passerella’ 2006 Winter Olympics, Turin, Italy

Hugh Dutton

Competition The city of Turin hosts the 2006 winter Olympic games and has embarked on an extensive programme of construction of various venues and infrastructure for the games. The city took advantage of the infrastructure programme to incite urban renewal in the southern part of the city that has been affected by the economic downturn in the car industry. The Olympic village, situated in the disused Mercati Generali in the Lingotto district adjacent to the main railway lines entering the city from the south, is part of this new infrastructure and will contain housing and a logistics centre. An open competition, hosted by the client body, Agenzia 2006, was held to select a design for the village in 2002 that included in it’s brief a footbridge link to the recently completed Lingotto commercial centre situated in Fiat’s disused factory.

The winning design for the village, by a consortium of specialist architects and engineers co-ordinated by Benedetto Camerana, proposed the refurbishment of the Mercati halls as the main communications and logistic centre. The footbridge link, by Hugh Dutton Associes (HDA), was exploited to provide a symbolic focal point for the entire village as well as provide a more ambitious role of a sculptural symbol, both for the Olympic Games and to represent the dynamism of the changing city’s regeneration of the Lingotto area beyond and after the event of the games. After the games, the Olympic Village housing will be available for the city’s residents and the logistics centre will provide shops and general facilities to encourage commercial and cultural activities in the area. The footbridge will provide a much needed direct access to and from the facilities of the Lingotto centre across the railway tracks that cut the city in two.

Aerial view showing proposed footbridge link between Mercati and Lingotto

Lingotto

Mercati

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Programme The footbridge provides a 365m link, 4m wide, between the main Mercati central ‘gull-wing’ hall and the existing parking access footbridge on the Lingotto development with a free span of 150m over the railway tracks. It is destined for pedestrian and bicycle traffic. The safety considerations with regards to the railway have a major impact on the design and realisation of the bridge. Strict time limitations were given to ensure that construction procedures did not interfere with or provide any danger to railway traffic. A 2.5m high protective barrier, of which the lower 1m must be solid and the remaining 1.5m above in safety netting, is to be provided above the railway tracks for pedestrian safety and to prevent objects from falling on the tracks. The railway tracks are electrified and therefore the acceleration of corrosion of the steel components, notably in the foundations, due to residual electricity in the damp earth is an important consideration. All activities over the tracks during construction and future maintenance are subject to specific safety constraints. The engineering design is required to be in compliance with the railway design codes of practise as well as both European and specific Italian design codes.

Design

Concepts

HDA’s design philosophy is that the architectural composition should find it’s logic in structural expression. We believe aesthetic pleasure is found in feeling the dynamism of structure and in the intuitive satisfaction of understanding the passage of forces. Like the beauty we find in an athelete’s body in a position of extreme effort with muscles taut. We consider this a fitting and appropriate approach for a monument to the Olympic Games. There is nothing superfluous in the design, only the minimum necessary to make it work. Lean and economical, the architecture is a composition of functioning structural parts. The beauty is in the energy of the structural athleticism and how it resolves the forces through elegant curves and the complex geometry of the suspension cables.

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Market Hall before transformation & the first sketch of the footbridge by Hugh Dutton The parabolic arch, inspired by arch framing of the existing Mercati halls by the architect Cuzzi in 1932 is an optimal structural form - the supported loads travel to the ground in pure compression. Traditionally, arches are stabilized by the masonry they carry as these serve to provide geometric stability, keeping the compression rim in it’s plane. In the case of the Passerella arch the suspension cables carry out the same stabilizing role, preventing it from buckleing. The concept is made clearer for the passerella arch and it’s cables if we consider their performance as analagous to a bicycle wheel. The rim supports the weight of the bicycle and it’s rider through the thin wire spokes that connect it to the axle. The spokes, by both their radial geometry and sectional triangular configuration, can resist considerable loads and remain stable. The rim is in pure compression and the spokes are in pure tension. The curved parabolic shape is adapted to optimise the path of the compression forces so as to reduce bending loads in the section.

At 70m high, the arch gently leans over the tracks so as to optimise the geometrical configuration of suspension cables, it’s height governed by the critical angle of the longest ones. The arch also leans laterally slightly to optimise the plan angle of the suspension cables with respect to the steel deck as it’s curved path swings from the central axis of the Mercati gull wing hall toward it’s destination of the existing Lingotto elevated walkway. Beyond the symbolic role of the bridge for the city as host for the Olympic games, the bridge also is an expression of the current ambition, dynamism and capacity of Italy’s steel industry.

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Autocad 3D model

The Arch The arch is founded on a thin strip of land between the railway lines and the via Zino Zini that borders the Mercati site to the east. This strip is one of the only available bearing points from which to support the bridge in the congested urban context. The planar arch structure exploits the potential of a laterally wide base whilst remaining in a singular sectional plane. The arch consists of 370T of welded FeS355K steel plate, in a hollow 3m equilateral triangular section determined both by the necessary structural performance against buckling between the points at which the cables are attached, and the requirement for maintenance access for inspection. The triangular profile is constructed from pre-cut sections curved to conical surfaces and includes stiffeners and diaphragms at the cable attachment points. The cable anchors are located inside the arch to maintain the purity of the arch form. They are also therefore easily accessible for inspection and maintenance. They consist of cylindrical tubes that receive standard adjustable socket end cable filtings. The tubes are welded to diaphragms that distribute the cable loads load to the walls of the arch section. The orangy red colour (RAL 2032 check) reinforces the formal dynamism of the arch and recalls the traditional orange ‘minium’ rust protection paint. The bold colour is highly visible in the day and in the low light of overcast days. At night, 5 1000W projectors at the base of each leg, highlight the colour to provide a nocturnal image. Corrosion protection is achieved by metallisation using hot projected zinc, followed by epoxy and polyurethane protective and decorative coatings.

Cables The inclined arch is supported by eight pairs of 75mm diameter locked strand galvanized cables on the Mercati side gathered in double anchor points on either side of the deck corresponding to the four ‘piedritti’ column supports that transfer the tension loads directly to the foundations. The deck spanning the railway tracks is suspended from the arch with another eight pairs of 55mm diameter steel cables, matching the ones that support the arch. Additional cables at the base of the arch in a diamond configuration tie the arch and deck together.

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Typical locked strand cable Structural redundancy is provided by the multiple piedritti anchorage points of the cables. In the case of failure of any one of the columns or foundation points, the adjacent columns are capable of supporting the loads. The dead load of the arch can be supported by only two of the sixteen cables. The complex geometry of the cables tensioned between the arch end the deck creates a virtual sculptural volume that adds further dynamism and interest to the architectural composition.

Distinct structural systems

Deck The deck is divided into two distinct parts that are structurally independent. The larger portion, called ‘strallata’, spans the railway tracks suspended from the arch with extensions at both the Mercati and Lingotto ends, totalling 235m in length. The smaller portion, called ‘Lingotto’, provides the link between the Strallata section and the existing parking access footbridge of the Lingotto shopping centre building. The 150m span strallata deck is suspended from the arch by the cables on 18m spacings. At the Mercati end, it extends 95m to the stair access point in front of the ‘gull wing’ Mercati building. The Lingotto portion extends a further 120m to the existing parking access footbridge. The total length of the two portions is therefore close to 365m in total. The strallata portion spanning the railway is gravity supported by the arch while the Mercati and Lingotto portions by the ‘Piedritti’ columns.

Lingotto

Strallata

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Deck with 3D view showing protection mesh The strallata deck consists of two primary built up edge beams connected by standard transverse and diagonal secondary beams at the level of the lower flange. The spacing of the cable supports is compatible with the maximum span of a 1.2m high steel ‘I’ beam, which corresponds to a 1m solid parapet required as by the RFI railway authority including the thickness of the walkway and secondary transverse beams. In addition to the plan curve, the deck is gently sloped in section to achieve adequate clearance of the electric catenary cables whilst minimizing the height at each end for the access staircase and link to the existing Lingotto footbridge. To optimise standardisation, the deck geometry is defined as a slice of a conical surface. As such, the steel deck structure can be realised in identical trapezoidal segments. The deck edge is clad in aluminium that is shaped to form an aerodynamically stable profile. The underside is also clad to reduce the surface roughness for air flow. Cable anchors are welded to the deck primary beams with the same detail as those inside the arch. ‘Piedritti’ columns Where it is not suspended by the cables, the deck is supported on simple tubular steel ‘piedritti’ columns at both the Mercati and Lingotto ends. The ‘V’ and ‘N’ configuration of the columns provides minimal structural fixity to the ground for lateral support. The connections to both the deck and the foundations are articulated with spherical bearings to permit longitudinal thermal expansion of the deck. The arch support cables deliver very large forces to the Mercati deck whose vertical component is resolved in the typical Piedritti. The horizontal components are accumulated at the ‘Piedritto Centrale’ beneath the arch. This anchorage support is the only point of longitudinal fixity for the deck. The strategy of a single point of longitudinal stability simplifies the thermal behaviour of the deck, leaving it free to expand and contract as the temperature changes.

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Force distribution of Mercati cables in Piedritti columns For lateral stability, the deck is fixed to the foundations twice at each extremity to exploit the bending stiffness of the braced deck. At the Mercati end, the deck is laterally fixed at the Piedritto centrale and at the piedritti columns at the Staircase, where they have an ‘N’ configuration capable of resolving the lateral loads to the foundations. A similar configuration of double lateral supports is used at the ‘Lingotto’ end.

Lateral Stability The deck of the Lingotto portion is a pair of continuous beams resting on the same ‘piedritti’ type articulated columns, with lateral restraint at each end only and one point of longitudinal restraint at the point where it meets the Strallata portion.

Diagram of Lingotto portion.

Lateral load

Reactions of lateral forces at Piedritti ‘N’ columns

Forces in suspension cables

Vertical Reactions at Piedritti ‘N’ and ‘V’ columns

Reactions for horizontal deck forces at Piedritti Centrale columns

Horizontal component of suspension cables forces in deck

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Countercable Given the plan curve of the deck, there is a tendency to twist as loading changes because of the varying geometrical configuration of the suspension cables. The intrados cables have a more vertical inclination than the extrados ones. This differential in deflection is corrected by the counter-cable which provides a horizontal component of force to react against the twist. The counter-cable also provides a downwards vertical component of force that helps stiffen the deck.

Autocad and structural models showing Countercable.

Foundations Turin is largely alluvial sedimentary ground with ground water well below the foundation level. Initial foundation design by local consulting engineers proposed 18m deep diaphragm walls for the arch and central piedritto foundations This concept was modified after discovery of cemented strata through which the diaphragm excavation equipment was unable to penetrate. The alternative system is based on jet grouting between -18m and -8m with large gravity mass ‘pozzo’ foundation poured into a pocket formed by retaining wall of micropiles. The other typical foundations are also the ‘pozzo’ type.

Foundations

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Model Studies The complex geometry of the curved deck and leaning arch were first studied on physical models using a copper tube for the arch, string for the cables and cardboard for the deck. These studies helped our intuitive understanding of the torsional tendancy of the deck due to the variation in supporting angle of the suspension cables and how this could be corrected by the countercable.

Model Studies

Autocad development Three dimensional geometry models were prepared on Autocad at HDA, for the wire frame geometry and surface modeling for detail studies, notably of critical assemblies such as the cable anchors, arch steel plate geometry, foundations, staircases, cable end socket connection details, countercable struts and piedritti details. Architectural modelling using 3D renderings developed from the Autocad models were an important communication tool.

Analysis standards, Materials and Loading hypotheses The design analysis was carried out at HDA to Eurocode standards with specific exceptions as required by the railway authoritiy’s own regulations. Notably a static wind pressure of 250kg/m² was applied which was well in excess of that required by the Eurocode. The footbridge is designed to accommodate loads of public crowds, taken as full or partial loading in the most unfavourable conditions. Other applied loads include prestress of the cables, snow, wind and thermal stresses. The most significant loadcases were wind and partial crowding. Even though Turin has no history of seismic activity, analysis was carried out at the request of the railway authority, but was shown to have a negligeable effect on the structure. All steel is FeS355K grade and the cables are galvanized locked strand to Young’s modulus 160 000N/mm². The deck is 90mm thick poured in place reinforced concrete.

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Static Structural Analysis HDA’s design analysis included wire frame three dimensional analysis using non-linear computations and finite element analysis of specific details. Analysis included the simulation of eventual failure of supports or cable maintenance and replacement as well as fail-safe situations with several cables removed.

Analysis model showing axial forces

Dynamic Studies Lightweight structures are sensitive to movement, vibration or wind. Curiously, the recent sophisitication of building materials and structural engineering analysis has led to a new dynamic sensitivity of such structures because of their low mass and flexibility. Several well known footbridge projects have suffered from excessive sensitivity to vibration from wind or pedestrian traffic because of their lightness. For the Olympic Footbridge, the design is carried out in collaboration with specialists to resolve in anticipation such potential problems. Typically, a footbridge with natural frequency ranges below 3-5Hz, dynamic sensitivity becomes a major concern. In this case there were many modal configurations below 1, with the lowest in the order of 0,5. Modal analysis demonstrated the most significant ones to be flexural at a frequence of 0,51Hz and torsion at 0,59Hz. Aerodynamic testing was done in a wind tunnel on a sectional model of the deck at the CSTB in Nantes. The studies included edge shape and porosity optimisation to determine the profile of the deck. The final shape, with a largely symmetric solid triangular leading edge was shown to be stable in wind speeds up to the maximum Eurocode value of 28.8m/sec at angles of incidence of +/-2.5°. This edge profile is clearly visible and becomes a distinctive part of the design of the Strallata portion. Vibration damping devices are incorporated in the design in response to the movements caused by wind and pedestrians. Specialist engineers at Arup in London, who had specific experience resolving the problems encountered on the Millenium bridge were appointed to study the pedestrian comfort problem. Arup’s study specified two viscous oil filled dampers, quite similar to large shock absorbers we are familiar with on cars, placed in the structural joint between the Strallata and Lingotto portions as well as two tuned mass dampers mid span over the tracks consisting of 4ton steel plates connected to damping equipment. The dampers are installed when the construction is complete after measurements of the real frequencies, verifying them with the calculated ones.

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Modal analysis graphic Due to the modifications to the design during the construction phase, notably the suppression of the structural capacity of the aerodynamic edge profile and the welding of the connections between the primary edge profiles, the dynamic analyses were repeated by PdiO. The two most significant modes were both flexural torsion at frequencies of 0,472Hz and 0.508 Hz. The suspension cable natural frequencies were calculated and measured in situ by the supplier Tensoteci. Damping devices are included for each cable to prevent them from excessive vibration

‘Costruttivo’ Design analysis The construction design analysis carried out by PdiO of the Sermeca Falcone consortium, a Turin based engineering design office. A global finite element model was made of the complete Strallata structure, from the Mercati to the Lingotto end, with both the arch and the deck primary edge members including the central pin joint at the Piedritto centrale, entirely modelled as shell or brick elements. The transverse members and the ‘piedritti’ were modeled as beams and the cables as ‘cable’ elements. The primary edge beam web stiffeners were modelled as rigid link elements connected to the shell profiles. The cable elements took into account their non-linear behaviour and catenary effect. The prestress of the cable elements was introduced by shortening with respect to the theoretical geometry. The final configuration was achieved using an iterative method, gradually diminishing the difference between vertical deformation and the final theoretical geometry. The non-linear static analysis was conducted using this model for the stress and deflection checks of the structure. Foundation loading was also determined with this model.

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Global Shell Model Stresses in arch during the lifting phases were checked using different models simulating the various inclined positions.

Cable tensioning model Arch lift analysis model In order to control the tensioning operations for the cables 18 different models were made, one for each phase of the erection programme beginning with the first four cables at the initial phase after the lift to the final configuration with all 38 cables and the counter-cable. Cable tension vary enormously with respect to temperature change, for instance, the counter cable tensions vary from between 40T and 50T at 30°C and 0°C respectively. For certain details of the structure with complex geometry or with thick plate, finite element modelling was used.

Detailed Model of arch base Detailed Model of Deck Hinge Joint

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Construction The design was put to bid in april 2004, and the contractor, the Sermeca Falcone consortium, appointed in June. The consortium carried out the execution in difficult conditions in the extremely limited time schedule required to meet the Olympic event. The foundations began in the autumn of 2004, but were briefly interrupted when the problem of the naturally cemented strata proved to be impenetrable with the diaphragm excavation equipment. With the revised method, they were largely complete in july 2005.

Piedritto Centrale foundation construction. From left: Jet grouting/’Pozzo’ excavation with micropile retaining walls/Steel reinforcing bars The prefabrication of the arch began in January 2005 in Varna, Bulgaria. The piedritti columns and deck were fabricated at the steel contractor’s factory in Cuneo, near Turin.

Arch prefabrication. From left: stiffener welding/arch segment assembly/Bulgarian welding crew

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Aerial view of arch and Olympic Village site under construction

Steel Deck edge beam prefabrication – cable connection detail/piedritto lug support Steel began to arrive on site in July, and notably the arch segments. These were welded and painted on site lying horizontally between the Mercati ‘gull-wing’ hall and the arch base joined with full penetration welds and subjected to ultrasonic testing. The Mercati portion of the deck was assembled as it is necessary for fixing the cables that support the arch. For the lift, in September 2005, 4 cables are attached to the Mercati deck and the arch. Temporary hinges fix the arch legs to their foundations and the arch is ready for the lift.

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Arch Lift : Twin crawler cranes holding the arch while strand-jacks are tensioned/ temporary hinges/ strand-jack The spectacular lift became a major event in the city, with very significant press coverage who declared it as the city’s symbol for the games. Two huge crawler

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cranes, one on each side with approx 600T capacity executed the lift on the 25th of September during a pre-programmed stoppage of railway traffic between 9am and 7pm. Strand jacks were used to stabilize the arch during the lift. These are hydraulic traction devices that can apply a 200T force to the stabilizing wire rope cables. They pull it through the delicate moment when the cranes lose a degree of control at the vertical position when the gravity load goes to zero. The strand jacks were also necessary to counter the horizontal resistance of the cables pre-assembled onto the arch.

Cable assembly and tensioning

Countercable The deck was lifted into place on the temporary supports, using the arch lift cranes on the Mercati side and a 500T telescopic crane on the Lingotto side. Cables are attached and tensioned during November. The cable tensioning involved installing hydraulic jacks on the edge of the deck to prefabricated lugs. The tensioning equipment is carefully monitored, including temperature readings to take into account

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the large variation that occurs. The geometry of the deck is a function of the cable tensions that are specifically predetermined in a sequence that takes into account the variation of load as each cable is tensioned. The sequence began with the shortest cables closest to the arch and progressively, in pairs, proceeded to the longest ones at both the Mercati and Lingotto ends of the bridge. The range of tensions vary from 12T for the shorter deck stability cables at the base of the arch to 150T for Mercati cables that bear most of the dead load of the arch.

Concrete deck pour Aerodynamic profile Lift tower and stair The concrete deck is poured in January and diverse finishing operations such as painting, architectural lighting, aerodynamic edge profile, lift staircase and safety netting are installed. In December and January 2006 to be ready for the Winter games that begin mid February and notably for the passage of the Olympic Flame on 9 February. Final finishes, testing and damper installation are carried out after the games up until May 2006.

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Views of the finished footbridge

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Technical Details

Mass of reinforced concrete foundations: 13 500 tons

Arch Height: 69 metres

Arch Width: 55 metres

Arch mass: 370 tons

Number of cables: 38+3 countercables

Maximum cable length: 130 metres

Cable diameters: 75mm, 60mm, 55mm

Weight of deck: 660 tons

Maximum elevation of deck: 11.8 metres

Free span over railway lines: 156 metres

Total length of deck 368 metres

Lowest natural frequency of deck

0,47Hz

Structural damping

1%

Max cable tension force (bridge empty)

170T

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Intervenants

Client: Agenzia Torino 2006

(RUP : Marco Operto) Project: Hugh Dutton Associates

Design Team: Hugh Dutton,

Frédéric Bindji-Odzili, Alberto Rubin Pedrazzo, Nicolas Sterling, Carla Zaccheddu, Cathy Shortle, Roman Stieltjies, Pietro Demontis

HDA site operations Giorgio Mare MOI architectural consortium

group leader:

Studio Benedetto Camerana (Hermann Kohllofel)

Security Co-ordination Site Phase: Proges (Giuseppe Amaro) Foundation Specialist: A&K Electrical Installation: Prodim Architectural Lighting: Faber Maunsell Structural Consultant: Francesco Ossola Pedestrian comfort and damper design: Ove Arup Wind Tunnel: CSTB Nantes Contractor: ATI Sermeca Falcone Contractor design consultants: PdiO Sub-contractors: Sarens, Tensoteci, Taylor,

Progeco, Sergecos, Sicos, Palingeo, Eurocifra, S.M.E.B., Guaschino, 1Emme Noldem, CPC, Tonin, Italia Costruzioni, Cabrino & Gusmano,Maurer Sohne, Metalmont, Vernazza, CAR.SAL., SMV, Euroimpianti, C.M.I., Kone

Welding quality control Insituto di Saldatura Italiano Design checking engineers Conteco/ Prof. Di Miranda Construction checking engineer Prof. Caramelli, (U.of Pisa) Surveyor Facelli Shop Drawings Filonzi Railway Authority representatives Ing. Lia, Ing. Cantore

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