Fachthemen
DOI: 10.1002/stab.201410167
400 © Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin · Stahlbau 83 (2014), Heft 6
1 Introduction
Spartak Moscow is one of the most high profile clubs in the Russian Federation and they regularly qualify for the UEFA Champions League. However, the club has never owned their
With the 2018 FIFA World Cup in Russia in everyone’s sights, international architects and engineers are beginning to grapple with the challenges and complexities of delivering world class stadium designs in unfamiliar territory. In this paper, the authors explain how they have overcome both the technical and regulatory challenges in delivering the engi-neering design of the Otkritie Arena, the new home of FC Spartak Moscow.
Otkritie-Arena: Die Gestaltung des neuen Stadions von Spartak Moskau. Langsam, aber sicher gewinnt der FIFA World Cup 2018 in Russland mehr Raum im öffentlichen Be-wusstsein. Für Architekten und Ingenieure ist es an der Zeit, sich den Aufgaben und Her-ausforderungen zu stellen, die der Bau eines Stadions auf Weltniveau in ungewohntem Gebiet mit sich bringt. Im vorliegenden Beitrag wird berichtet, wie sowohl technische als auch behördliche Hürden bei der Gestaltung und der Konstruktion der Otkritie-Arena – dem neuen Heimatstadion von Spartak Moskau – zu meistern waren.
own stadium and currently uses the facilities at the Luzhniki Olympic Stadium.
AECOM was appointed in early 2010 to design a brand new 45000 seat stadium for the club (Fig. 1). Teams of AECOM architects and engineers
from the company’s London and Moscow offices worked together on both the conceptual and detailed design for the new stadium to ensure that both international best practice and local regulatory compliance were met.
Prior to AECOM’s appointment, the club had been trying for many years to get the project off the ground, but had been frustrated by both the approvals process, and spiralling costs. They had a number of design options under consideration which really did not reflect the realities of what the club needed. AECOM’s initial task was to get right back to first principles to produce an efficient, economically sustainable stadium design.
2 Site Conditions
The new stadium is located on the site of the disused Tushinskiy Aerodrome in the North West of the city and sits alongside the Moscow River. The Moscow metro confines the site to the North West with the Moscow River to the south and east of the site. The site is within the flood zone of the Moscow River and has had extensive flood protection measures put in place over the past 30 years.
The site conditions themselves had a major influence on the design. The site geology was very challenging; the top 15 m of soil comprise highly compressible alluvial deposits, and groundwater is less than a metre below the existing site formation level. As a result, the entire stadium sits on piles up to 45 m long and an interconnected grillage of 1.5 m deep ground beams, to raise it out of the ground (Fig. 2).
The poor ground conditions and high water table meant there was little
Otkritie Arena: Design of the new Spartak Moscow Stadium
Peter AyresThomas Webster
Fig. 1. The Otkritie Arena: A new home for Spartak MoscowBild 1. Die Otkritie-Arena: Das neue Heimatstadion von Spartak Moskau
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cope with the thermal movements expected for an 80 °C temperature range, the bowl is split into 12 segments with vertical movement joints at approximately 50 m intervals through the grandstands. Each of the 12 segments has its own stability system allowing them to act independently making a multi phased construction sequence available to the contractor (Fig. 4).
One of the most noticeable features of the new stadium is that the VIP boxes, banqueting suites and Presidential lounges are all banked together over three floors on the west side of the stadia. This was a direct response to the Russian tradition of hospitality and networking. The team initially considered a conventional bowl with VIP boxes at one or two levels around the stadium, but in discussion with the owner, it soon became clear that an intimate, interconnected VIP zone was much more suited to the Russian way. Moscow is home to more billionaires than any other city in the world, so inspiration was taken from how horse race courses, which are well known for their more affluent clientele, worked, and that became the model (Fig. 5).
Another key benefit of locating the VIP suites and main club facilities into one stand is that the remainder of the stadium can be extremely cost effective, since the other stands can be treated as semi open spaces and require very few building services and only basic finishes.
phere and contribute to the team’s home field advantage.
Reinforced concrete is the material of choice for stadium structures in Russia; the approach suits the everyday construction worker and the additional robustness provided by continuously tied reinforced concrete beams helps in achieving Russian code requirements and provides resilience against the harsh climatic conditions that are experienced in Moscow.
The structural frames are on a consistent 7.6 m grid which allows for maximum repetition of the concrete frame and precast seating unit. To
opportunity to recess the lower tier of the bowl into the ground to provide a top fed lower bowl. The design team considered landscaping the site to bring the external levels around the stadium up to ease internal spectator access, but the ground was so soft that the overburden weight of the fill material on the compressible soils would have left the client with long term sett lement problems for decades.
As a result, all spectators will enter the stadium at pitch level, accessing the lower tier at mid height via staircases; upper levels are accessed via a series of lifts, staircases and escalators. In addition, the stadium is surrounded by a 50 m standoff zone. This was designed in response to recent Russia counter terrorism guidelines, but also provides excellent space for event overlay for the FIFA World Cup (Fig. 3).
3 Superstructure
The superstructure design is dominated by the stadium bowl and VIP zone. The aim was to produce a tight, efficient bowl which would create an intimate club atmosphere, and be highly cost effective to build. To create this sense of intimacy, a twotier rectilinear design, which places fans as close as possible to the pitch, was chosen. Views of the pitch will be excellent; almost every seat in the stadium has Cvalues in excess of 90 mm. This will generate an intense atmos
Fig. 2. Ground conditionsBild 2. Beschaffenheit des Untergrunds
Fig. 3. Arial view of the new stadium and precinctBild 3. Luftbild des neuen Stadions in seiner Umgebung
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3.1 Dynamic performance
A key aspect of the design development was how the structure would perform under crowd excitation. The response of structures to vibration is an increasingly important area of work for structural engineers; stadia must provide unobstructed views for spectators and clear access and circulation within the concourses, a brief that lends itself to long cantilevers and slender members with column free spaces. Consequently, these structures can be sensitive to dynamic loading. Whether an exciting game of football or a high tempo rock concert, the crowd itself applies a dynamic load to the stadium structure that can excite natural modes of vibration.
Conventionally, the dynamic analysis of stadium structures has been based on simple harmonic motion, with many designers choosing to limit the first dynamic response of the primary structure to 6 Hz. This is a conservative method that attempts to model crowd behaviour as a harmonic input force to a singledegree of freedom (SDOF) vibrating system. A theoretical force is applied to a model of the structure and the behaviour of the structure is then estimated (Fig. 6).
The traditional method does not model how actual crowd behaviour affects loads applied to the structure, an effect known as “human structure interaction” (HSI). The modelling of HSI leads to a higher level of analytical complexity, a multidegree of freedom (MDOF) vibrating system, where there is a basic feedback loop – the vibration of the structure affects the force which is driving the vibration. By taking this effect into account in the design of Stadium Spartak, AECOM’s engineers were able to avoid unnecessary and potentially costly additional stiffening of the structure.
3.2 Roof design
For structural engineers, the dominant feature of any stadium is the roof. Stadium roof structures are very different from the structures encountered in conventional buildings. The sheer scale of these structures means that many of the simplifying assumptions that engineers can usually justify
Fig. 4. Revit model showing reinforced concrete bowl structureBild 4. Revit-Modelldarstellung der Stahlbeton-Konstruktion der Tribüne
Fig. 5. Interior view showing VIP boxes in West standBild 5. Innenansicht mit Blick auf die VIP-Bereiche der westlichen Tribüne
Fig. 6. Schematic of dynamic model Bild 6. Schema des Modells für dynamische Belastungen
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midspan depth of approximately 21 m and the shorter perpendicular trusses span approximately 180 m, with a midspan depth of 17 m. Secondary beams then spans from the concrete columns at the back of the grandstands to the primary trusses spanning across the stadium. The secondary beams and roof cladding are designed to intersect with the primary trusses at mid height. The effect of this is that approximately half the truss sits above the roof plane and half below, which helps to soften the visual impact of such massive structures (Fig. 7).
The interlocking megatruss design specifically addresses Russian disproportional collapse regulations, since even under a theoretical failure of one truss, the orthogonal trusses can redistribute the loads safely. This may seem like a conservative approach to international designers, but the requirement for such onerous conditions is born of concerns about the quality of steelwork fabrication in the emerging Russian market.
The interaction of the megatrusses is more complex than it appears. It is necessary to balance the relative stiffnesses of the trusses so that they each carry a reasonable proportion of the load under normal conditions. The overall geometry of the megatrusses has a greater direct influence on the stiffness of the trusses than the individual sizes of the steel components. The intersecting nature of the top and bottom chords meant that a change in geometry in one set of trusses needed to be followed through to the other trusses. This
There are plenty of highly sophisticated computer programmes at our disposal today, but it is essential that specialist stadium engineers retain an intuitive three dimension understanding of the structure, how forces will be transferred to the supports, and how the roof will deform under loading and thermal stresses.
The roof for the Otkritie Arena is supported by four interlocking steel megatrusses which span back to eight principal support points around the stadium. The design responds to a range of criteria including buildability, structural efficiency and robustness together with being able to cope with the extremes of the Moscow climate.
The longer trusses span 217 m along the length of the pitch with a
for general structural engineering cannot be applied.
One very basic and underlying assumption of most structural engineering is that the deformations under load remain small relative to the cross sectional size of the structural members elements used in the structure. This one assumption cannot be applied for long span structures, as deformations can be much greater than the cross sectional size of the structural members within roof structure. The effects of the change in geometry must be fully considered and this includes the use of large displacement non linear analysis.
This is one of the reasons why stadium designers consider themselves part of a very exclusive club.
Fig. 7. Revit model showing roof structureBild 7. Revit-Modelldarstellung der Dachkonstruktion
Fig. 8. Flume tank testing for snow drift (photos: RWDI) Bild 8. Modellierung von Schneeverwehungen im Strömungskanal (Fotos: RWDI)
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for the primary roof trusses and the use of higher drifting loads for the secondary roof structure. The resulting characteristic snow loads on the stadium roof are, nevertheless, far higher than would be the case in much of Western Europe; the general distributed load is 2.6 kN/m2 and localised drift loads are as high as 5.2 kN/m2.
A further critical aspect in the design of the roof is allowing for movement at the roof bearings due to both thermal movement and shortening of the trusses under loading. Moscow is subject to an extreme temperature range, from –40 °C in winter to +40 °C in summer. For stability, the roof must act as a continuous diaphragm and therefore the roof has been designed to “breathe” to accommodate these thermal movements.
To allow the roof to breathe, a single direction restrained bearing is placed in the middle of the edge roof on each side of the stadium. These transfers the horizontal forces to the stability systems within the concrete structures below. Bidirectional bearings are used on all other supports. The total movement range predicted at the megatruss supports can be in excess of 200 mm when both thermal movement and deformation of the trusses under load are considered.
4 Regulatory environment
Designing a stadium for the extremes of the Moscow winter was only part of the story for AECOM’s design team. Obtaining regulatory approval for construction was the next step.
able height of top and bottom chords. This ensured that the two types of megatruss intersected at exactly the same point and would deform evenly.
3.4 Climatic conditions
Snow falls in Moscow are very high. The snow freezes onto roof structures throughout the winter and the weight builds up as rain and meltwater is trapped within it through the daily freezethaw cycle. Russian codes for snow loading do not accurately predict snow loading on major long span structures, especially the effects of snow drift over large areas.
To optimise the structural members sizes and reduce the self weight of the roof, AECOM commissioned RWDI of Toronto Canada to undertake a series of wind tunnel and water flume modelling tests of the snow drift distribution on the roof (Fig. 8). This allowed the design of the roof to be based on lower distributed snow loads
made balancing the stiffness a complex and iterative exercise.
3.3 Parametric design
A series of parametric design studies was undertaken to rapidly investigate and optimise the roof geometry. To break the problem down into manageable parametric loops, the approach was to disassociate the geometry of the top and bottom chords for each of the trusses; the curved top chords were given priority in defining the geo metry whilst the bottom chords were manipulated to control stiffness.
Bespoke inhouse parametric tools were developed using Excel and VB script to calculate the geometry and iteratively optimise the member sizes of the roof trusses via an XML link with the finite element software. For each calculation, parameters were set at acceptable deformation limits between the two sets of trusses along with a minimum and maximum allow
Fig. 9. Construction progress internal March 2014Bild 9. Bauzustand innen, März 2014
Fig. 10. Construction progress external March 2014Bild 10. Bauzustand außen, März 2014
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sented both technical and regulatory challenges, but by employing a combination of international stadium experts with experienced local Russian engineers, the design of the project has been successfully delivered and construction is nearer completion; the stadium is on target to open in 2014, four years ahead of the World Cup (Figs. 9 and 10).
The successful and timely delivery of the stadium has been rewarded with conformation from FIFA and the Local Organising Committee that the stadium will be a host venue for the 2018 World Cup.
Autoren dieses Beitrages:Peter Ayres BEng CEng MICE MIStructE, [email protected],Thomas Webster MEng CEng MICE MIStructE,AECOM, MidCity Place, 71 High Holborn, London, WC1V 6QS
tions from the Russian SNiPs, GOSTs and STC must have been met. This process can be lengthy, and engaging with the local Design Institutes from the conception of the project is essential to ensure that all these criteria are met without delay to the programme.
The Expertize approvals process can be very challenging for a nonRussia practice. Engineers can use state of the art performance based design techniques to develop a highly efficient structure, but it still needs to be approved by Russian State Authorities. The contribution of AECOM’s incountry Russian engineers and architects was crucial in successfully obtaining the necessary approvals.
5 Conclusion
The new Otkritie Arena will be one the first new generation stadia to be completed since Russia was awarded the 2018 FIA World Cup. The design and delivery of the stadium has pre
The Russian “SNiP” Design and Construction Codes Regulations and “GOST” State Standards and regulations are the only primary codes of practice currently recognised in Russia. These codes are normally aimed at the design of typical 6 to 10 storey buildings. Unfortunately much of this documentation is not applicable to stadium design, so as part of the design process documents known as the Special Technical Conditions (STC) must be created by the design team and approved by local Russian Design Institutes.
The STC is specific to the development, and once created, it effectively passes into law, and becomes the technical benchmark against which the design and construction of the project is assessed for regulatory approval by the Russian permitting authorities, collectively known as “State Expertize”. To achieve receive approval to construct from Expertize can be complex. All the design condi