Architecture, Spain · New retractable roofs on existing buildings. Case study: The Montjuic...

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New retractable roofs on existing buildings. Case study: The Montjuic swimming pool in Barcelona J. Llorens, A. Soldevila Departments ofConstruction and Projects,Barcelona School of Architecture, Spain Abstract The use of rapidly assembled structures in movable roofs on existing buildings is presented. Ancient examples are mentioned as historical background and special requirements to be taken into account are listed. Contemporary solutions as different means of answering to the aforementioned requirements introdu- ce the exposition of the movable roof for the Mont- juic swimming pool in Barcelona. 1.- Introduction Convertible roofs are applications of mobile and rapidly assembled structures in existing buildings whose original design did not take this possibility into account. There is an increasing demand for this type of structure in cultural or sport facilities. Retractable roofs allow the period of use to be extended, increase profitability and prevent bad weather from causing interruptions. Other common applications are extensions of roofed surfaces on tourist or commercial facilities during peak periods of activity. 2.- Antecedents (fig.l) Evidence of convertible roofing has been found in roman structures (Graefe, 1979), squares and streets in southern countries (IL 30, 1984). Recompositions had been drawn up from old illustrations, engravings and reliefs (Viollet le-Duc, 1875). In Catalunya, Spain, a suspended roof was erected on the main Transactions on the Built Environment vol 21, © 1996 WIT Press, www.witpress.com, ISSN 1743-3509

Transcript of Architecture, Spain · New retractable roofs on existing buildings. Case study: The Montjuic...

New retractable roofs on existing buildings. Case

study: The Montjuic swimming pool in Barcelona

J. Llorens, A. SoldevilaDepartments of Construction and Projects, Barcelona School of

Architecture, Spain

Abstract

The use of rapidly assembled structures in movableroofs on existing buildings is presented. Ancientexamples are mentioned as historical background andspecial requirements to be taken into account arelisted. Contemporary solutions as different means ofanswering to the aforementioned requirements introdu-ce the exposition of the movable roof for the Mont-juic swimming pool in Barcelona.

1.- Introduction

Convertible roofs are applications of mobile andrapidly assembled structures in existing buildingswhose original design did not take this possibilityinto account. There is an increasing demand for thistype of structure in cultural or sport facilities.Retractable roofs allow the period of use to beextended, increase profitability and prevent badweather from causing interruptions. Other commonapplications are extensions of roofed surfaces ontourist or commercial facilities during peak periodsof activity.

2.- Antecedents (fig.l)

Evidence of convertible roofing has been found inroman structures (Graefe, 1979), squares and streetsin southern countries (IL 30, 1984). Recompositionshad been drawn up from old illustrations, engravingsand reliefs (Viollet le-Duc, 1875). In Catalunya,Spain, a suspended roof was erected on the main

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136 Mobile and Rapidly Assembled Structures

Fig.l.- Antecedents. Top left: Karnak temple accor-ding to Viollet-le Due (1875). Top right: streetroofed in Sevilla. Bottom: the "envelat", a big dan-cing tent in Catalunya (Llorens & Soldevila, 1986).

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square of towns and villages during local holidays(Llorens & Soldevila, 1986).

3.- Special requirements

Designing convertible roofs on existing buildings issubjected to particular requirements. General solu-tions are not appropriate because special featuresare needed:- Formal compatibility between the added roof and theexisting building.- Requirements of use. The roof may change the pre-vious situation.- Anchors, joints and load transmission from the newstructure to the existing elements.- Movements during the erection and dismantling pro-cesses, auxiliary means, operation time available,noise level, existence of neighbours, presence ofusers or spectators.- Storage of roofing material and ancillary devices.Permanence or withdrawal of structural elements.- Connections: appearance, strength, deformability,transparency, impermeability.

Provision has also to be made for the size and weightof the movable elements. They condition the afforda-ble solutions because the erection process is notunique and extraordinary means should be avoided.Changing the scale is much more than changing thesize. Increasing the size could spoil a feature or atlist reduce efectiveness. The membranes suspendedfrom one mast provide a good example of efectivenessrelated to the size (fig.2).

4.- Contemporary solutions

Extension, reuse, rehabilitation and restoration ofexisting buildings mean frequently the conditionningof semiopen areas like courtyards and squares. Theopen air theater of the former Krizanke monastery(Ljubjana) and the umbrellas for the Prophet's HolyMosque in Medina are outstanding examples (fig.3).

5.- Movable roof for the Montjuic swimming pool inBarcelona (figs. 4, 5, 6)

The Montjuic swimming pool in Barcelona is an exis-ting sport facility used only during the summer. Aconvertible roof is under consideration to extend theperiod of use all over the year.

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138 Mobile and Rapidly Assembled Structures

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Fig.2.- Size and efectiveness. Top: 800 m2 open airtheater, Cannes. Middle left: 1315 m2 open air thea-ter, Bad Hersfeld. Middle right: 1800 m2 swimmingpool, Paris (IL 5, 1972). Bottom: Olympic stadium,Montreal (R.Taillibert et al. 1990)

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Fig.3.- Contemporary solutions. Top: Krizanke thea-ter, Ljubjana (IL 5, 1972). Middle: Bodo Rasch jr.unmbrellas in Medina (Gubitosi, 1993) . Bottom left:expandable structure over a swimming pool, Sevilla(Escrig & Valcarcel, 1991). Bottom right: parallelmovable rigid roof sections (IL 5, 1972).

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140 Mobile and Rapidly Assembled Structures

5.1.- Special requirements of the Montjuic swimmingpool:-The location of the swimming pool is unique. It isa belvedere platform and can be seen from many partsof the city. The roof will obstruct the visibilityand appear outstandingly on the slope of the mountain-The profile of the new volume will follow at leastthe heigth requested by the use. It will lean againstthe existing wall and try to minimize the cubic me-ters of air to be heated.-The roof will be removed and stored every yearduring the summer. The erection and dismantle proces-ses should be easy, quick and cheap.-Loads are conditioned by the existing structure andfoundations in spite of the exposure of the slope ofthe mountain to strong winds.-Additional requirements are heating, waterproofingand durability of materials exposed to seashore cli-mate and chlorided atmosphere.

5.2.- Description:- Two parallel movable rigid sections are made of hotdeep galvanized tubular steel trusses and translucidplastic isolating panels sliding towards one side bymeans of wheels and rails on top of 3,40 m hightransparent glazed facades.- The transparent glazed facades do not obstruct vi-sual lines and the translucid plastic panels improvethe thermal performance. Transmission of lightthrough them lightens the volume. It appears as atranslucent box.- The whole is divided in two rigid sliding sectionsto make movements quick and easy. Storage during thesummer is at the end of the rails preventing fromtime consuming dismantling operations.- Plastic pannels, glass and hot deep galvanizedsections are durable materials. - The longitudinalsection of the roof is not horitzontal. It followsthe heights needed by the use, accomodates to theenvironmental configuration of the existing buildingand saves enclosed volume, structu-re and walls.

6.- Conclusions

Mobile and rapidly assembled structures have beenused to provide convertible roofing on existing buil-dings. Special requirements have to be borne in mindto reach the condition of "movable" and the compati-bility with preexistences. Scale and size are parti-cularly influential on effectiveness. Recent examplesshow different solutions according to the volume tobe enclosed, the conditionning needed and the connec-tions .

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144 Mobile and Rapidly Assembled Structures

7.- References

P.H.Broekhoff, 1994: "El Musiktheater del castillo deTelcklenburg". Galvanizacion, vol.4, n*3, p.37-38

P.S.Bulson (ed.),1991: "Rapidly assembled structures"Proceedings of the International Conference held atSouthampton, England. Computational Mechanics Publi-cations, Southampton UK & Boston USA.

A.Capasso, 1993: "Le tensostrutture a membrana per1'Architettura". Maggioli editore, Rimini.

DETAIL Zeitschrift fur Architektur + Baudetail, 1994."Textiles bauen", n=6, p.806-824.

F.Escrig & J.P.Valcarcel, 1991: "To cover a swimmingpool with an expandable structure", "Expandable spacestructures with self-folding textile cover" in P.S.Bulson (ed.): "Rapidly assembled structures", p.273-295.

R.Graefe, 1979: "Vela erunt". Verlag Philipp vonZabern, Main am Rhein.

A.Gubitosi, 1993: "Architettura retrattile". L'ARCA,n^73, July/August, p.10-17.

Institut for lightweight structures, 1972: "IL 5.-Convertible roofs". University of Stuttgart.

Institut for lightweight structures, 1984: "IL 30.-Sun and shade". University of Stuttgart.

J.Llorens & A.Soldevila, 1986: "The ENVELAT, a bigdancing tent for local holidays in Catalunya(Spain)". Proceedings of the 1st International Confe-rence on Lightweight Structures in Architecture,Sydney.

J.Llorens & A.Soldevila, 1995: "Textile structures:detailing for compatibility". EUROMECH 334 "Textilecomposites and textile structures". University Lyon I& Vrije Universiteit, Brussel.

R.Taillibert et al. 1990: "Grandes voutes, stades,ensembles omnisports. Exemples de Montreal et deLuxembourg-Kirchberg". Annales de 1'ITBTP, n^484.

E.M.Viollet-le-Duc, 1875: "Histoire de 1'habitationhumaine". Bibliotheque d'education et de recreation,Paris.

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