Tailor Made Concrete Structures – Walraven & Stoelhorst (eds)© 2008 Taylor & Francis Group, London, ISBN 978-0-415-47535-8

The new Lisbon indoor sports complex

J.N. BastosFaculdade de Arquitectura- Universidade Técnica de Lisboa, Lisbon, Portugal

ABSTRACT: The recently inaugurated Lisbon Indoor Sports Facility represents one of the major achievementsof the City of Lisbon regarding public sports equipments. The 15,000 sq. mtr. Sports Complex facilities consistof several building units, particularly, a 50.0 m × 50.0 m indoor sports pavilion with 1,000 seats. A 300 car spacesunderground parking area was required. The materials being used were reinforced concrete (RC) for the generalstructural system and structural steel lattice space trusses for the roof systems.

The purpose of this study is to present the difficulties created by the need of designing large span roof structuresthat are simultaneously aesthetically pleasant and economically sound, and integrate them with the extensive RCstructural system. Several design solutions were used and an useful design comparison can be made relating themain advantages/shortcomings of each solution.

1 INTRODUCTION

In the Summer of 1991, a limited design competitionwas organized by the City of Lisbon – Department ofSport, in order to develop the required studies to builda multi-sports indoor pavilion complex. The winningteam was led by the late Prof. Emer.Arch. Frederico H.George, a well known Portuguese designer, author ofthe Lisbon Navy Museum and the Gulbenkian Plane-tarium located near the Hyeronimus Monastery, closeto the noble riverside area. The arch. F. H. Georgeand his team developed the preliminary studies forthe construction site located in Areeiro, Lisbon. TheCity’s sport department closely followed the architec-tural and engineering studies with helpful criticismsand suggestions.

From the early 1991 competition proposal to thefirst 1993 design solution many change-the-ordermodifications were made until the final constructiondocuments (memories, building specifications, tech-nical drawings) were submitted to the City of Lisbontechnical staff and approved at a total cost estimate of5.0 m Euros, see Fig. 1.

The first construction phase started one year laterafter the approval and the reinforced concrete (RC)structural work (foundations, retaining walls, waffleslabs, columns, beams, girders) for the large sportshall complex was completed before a new halt on theconstruction site occurred.

The geotechnical tests carried on this location indi-cated that the stiff Miocenic clay layers were on a 50◦slope along the transverse direction, diving into theTagus River. Due to the large transverse extension part

of the building units were founded om footings andthe other units on cast in-situ RC piles.

In the Summer of 1997, a new major change-the-order modification was implemented by SportDepartment technical staff.The available undergroundparking area had to be increased from the designed100 car places up to 300 car places. This new esti-mate was the required parking dimension so thatthe economic management of this space would befeasible. The initial City of Lisbon proposal was tocreate the extra parking spaces under the existingones, i.e., underneath the large sports pavilion floor,by creating two or three extra underground floor lev-els. The alternative solution suggested by the designteam – to create the required parking space on theexisting plot area, by inserting the parking placesunder all the building units adjacent to the mainsports pavilion was eagerly accepted by the SportDepartment officials as they considered the mostefficient one.

In the Spring of 1998, the whole project wasredesigned except the Large Sports Hall (Bldg. No.1)with some new functions e.g. a swimming pool, beingintroduced into the final design project – phase 2, seeFig. 2. The final concrete works were completed andthe new cost estimate reached nearly 6.0 m Euros forthe structural RC work done on the construction site.

The completed first phase was inaugurated by theMayor of Lisbon – Dr. João Soares, in April 2000, andthe second phase (construction finishing’s) started afew months later. In 2007, the Sports Complex wasinaugurated after the total construction costs soaredup to 11.0 m Euros.

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Figure 1. Initial general plan (1991–95).

2 THE SPORTS COMPLEX

2.1 The initial design solution (1991–95)

The initial design solution consists of a nine units setoccupying a very large space with a total length of120,00 m by a width of 70,40 m. The total constructionarea reached 10.020 m2 with a 100 car parking area of2546 m2, see Fig. 1 and Table 1.

The specified construction materials for the RCstructure were A400 NR (fsyd = 348 MPa) deformedrebar and B25 (fcd = 13,3 MPa) concrete. The founda-tions were a combination of direct footings and, dueto the large size in plan and bedrock conditions, castin-situ RC piles. A two-way grid made by RC girderssupported on isolated footings and pile caps was castin two phases. In the second phase the RC girders weremade monolithic with the cast in-situ RC slabs.

The column spacing was carefully studied in orderto allow an efficient parking underground space plan-ning. A 8,20 m × 8,20 m o.c. RC column grid was bestsuited for the large sports hall occupying a 50,20 mside square in plan. Each one of the four square sideshas eleven very tall (15,00 m) rectangular RC columnswith a 0,50 m × 1,00 m cross section. In each corner,

a square 1,00 m × 1,00 m RC column was used bysymmetry reasons, see Figs. 3, 4, 5.

The available underground parking space has anestimated 100-car capacity. The sports arena has a50 m × 35 m available area and the RC floor sys-tem is made of a waffle slab with 8,20 m × 8,20 msquare panels. Along the contour line the panels sizeis reduced to 4,10 m × 8,20 m rectangular panels.

The exterior contour tall columns were braced by atrapezoidal RC hollow girder with a 1,80 m × 1,00 m,cross section and 0,20 m thick walls, see Fig. 5. Theinterior face was chamfered in order to distinctlyseparate the sports hall space from space roof gridsystem.

The exterior walls are made of masonry clay hollowbricks with an exterior and interior clay tile veneer. Duethe column‘s height transverse RC girders are usedto confine the masonry walls, spaced at a maximum3,00 m distance.

The space roof grid system deserved careful atten-tion and detailing. For spans with more than 40,00 mit is recommended this type of lightweight construc-tion system [Makowski (1984), Iffland (1982)]. Theadopted design solution – “diamond-off-diamond”,

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Figure 2. New plan – foundation layout (1995–2007).

Table 1. Lisbon sports complex – initial plan (1991–95).

Underground areas (m2) Surface areas (m2)Total Gross

Unit Function Parking Technical Groundfloor Other floors areas (m2)

1 Large sports hall 2546 – 2520 828 58942 W.C./Techn. – 611 612 – 12233 Kitchen – – 267 – 2674 Foyer/Cafetaria – – 617 – 6175 Small Gymn. – 287 287 – 5746 Offices – – 266 – 2667 Admin. Offices – – 508 – 5088 Medium-size Gymn. – – 634 – 6349 Electric Power – – 36 – 36

Total 10.020

used a square pyramid with a 45◦ in-plan rotationgreatly increases the spatiality of this place, see Fig.4.The roof grid height is about 2,50 m (L/20) and theexternal roofing is made of lacquered metal sandwichpanels.

Due to the large covered area dimensions and sand-wich roofing panels being used, a steeper roof slopeof 6% was adopted in order to avoid water leaks onthe arena floor. The roof centre point is 1,50 m abovethe top edge contour. Therefore, to avoid a secondary

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Table 2. Lisbon sports complex – new plan (1997–2007).

Underground areas (m2) Surface areas (m2)Total Gross

Unit Function Parking Technical Groundfloor Other floors areas (m2)

1 Large sports hall 2546 – 2520 828 58942 W.C./Techn. – 611 612 – 12233 Kitchen 837 – 603 – 14404 Foyer/Cafetaria 477 – 585 – 10625 Swimming Pool 1456 354 1622 – 34326 Patio/Foyer/Office 546 – 344 – 8907 Admin. Offices 602 – 819 – 1421

Total 15.362

Figure 3. The large sports hall (50,2 m × 50,2 m) (Apr.2000).

steel purlin and post structure, the main space grid wasdesigned incorporating this slope, becoming a shallowsquare pyramid with a 50,20 m base side and a vertex1,50 m tall.

The available seating capacity is over than 1.280places. The existing RC benches are made of castin-situ concrete (1.000 places) and, the retractablebenches (280 places) can be easily hidden underneaththe RC slab stands.

This unique size building with 50,20 m × 50,20 min plan and a total height of nearly 20,00 m wasbuilt without any expansion joints and designed for

large wind (uplift) loads and medium-size earth-quakes (0,40 g). Particular care was observed on detail-ing the adequate column confinement with closelyspaced transverse reinforcement (stirrups), in orderto reach the minimum ductility behaviour factorof 2,5.

2.2 The modified sports complex (1997–2007)

During the initial construction phase the City of LisbonSports Department decided to increase the availableparking space up to 300 places, while the large sports

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Figure 4. Roof space grid system – 45◦ skewed.

pavilion was being built. This modification occurredwith the replacement of two building units by aswimming pool which became a major challenge.

The pool tank with 20,0 m × 25,0 m × 1,2 m wasdesigned to teach people how to swim. The water flowcircuit required a superficial contour channel to takethe excess water being injected through the pavementwith ozone. The RC bottom slab was 0,50 m thickconsidering the need to leave longitudinal slits wherethe water flow pipes are located, Fig. 6. The latticeroof metal system was designed to support HVAClive loads, dead load, live load and wind load. Thelacquered layers used to protect the structural tubeswere specified with as increased thickness to resist anaggressive corrosive environment.

The new constructed area increased nearly 50%,reaching 15.362 m2, and a new design layout wasdeemed necessary, see Fig. 2 and Table 2. The newsolution reduced the number of units to 7 and, particu-lar care was taken to design the columns that supportedthe heavy load of a suspended swimming pool. A newlayout of construction joints was adopted in order toseparate the different building volumes from the largesports hall unit.

The RC materials being used were upgraded toA500 NR (fsyd = 435 MPa) deformed rebar and B30(fcd = 16,7 MPa) concrete. For the roof space grid,structural tubing of the class Fe 430C (fsyd = 275 MPa)was maintained.

Figure 5. Large sports hall – tall RC columns.

The contractor proposed to the owner to change the45◦ skewed lattice roof layout to a regular orthogonallayout which was accepted because of practical rea-sons. However, the final solution is dull and does notincrease the spatiality of the swimming pool and themedium-size gymnasium spaces.

3 CONCLUSIONS

In 1991, a lengthy design and construction processwas initiated by the City of Lisbon – Departmentof Sport. From a total constructed area of 10.020 sq.mtr. up to 15.360 sq. mtr. Nearly sixteen years havepassed with major change-the-order modifications.The design team had to respond with new solutionsto relevant functional changes that could affect theongoing construction sequence. The extension of aunderground parking lot from 100-car to 300-carcapacity and the removal of two building units to bereplaced by a large swimming pool building, with anarea of 35,2 m × 48,8 m deserves to be mentioned.

The architectural design called for a series of sep-arated space units all of them with different sizes in

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Figure 6. Swimming pool – under construction.

plan and height.These several design options were par-ticular difficult to structure and separate the adjacentspaces without loosing the unity of this large sportscomplex entity.

The structural design proposal recommended anextensive use of RC materials.Although initiallyA400NR steels and B25 concrete were specified, due to thelarge amount of steel required an upgraded steel class(A500 NR) combined with a higher strength concrete(B30) proved to be economically feasible.

The lightweight lattice tubular space structure wasused in three building units – the large sports hall, themedium size gymn. and the swimming pool with a nicestunning effect.

The extensive use of RC in foundations, retainingwalls, beans, girders, slabs, and columns revealed tobe extremely competitive even for a large built area.

This extensive and very large construction projectbecame the largest sports facility that the City ofLisbon is a proud owner.

ACKNOWLEDGMENTS

The author wants to express his sincere thanks to theMagnifico Rector of Technical University of Lisbonand Calouste S. Gulbenkian Foundation which madethe presentation of this work possible.

REFERENCES

Iffland, J.S.B. 1982. Preliminary Planning of Steel RoofSpace Trusses. Journal of the Structural Division. Pro-ceedings of the American Society of Civil Engineers(ASCE), vol. 108, No. ST11, Nov. 1982. NewYork: ASCE.

Makowski, Z.S. (ed.), 1984. Analysis, Design and Construc-tion of Braced Domes. New York: Nichols Publishing Co.

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