Download pdf - Understanding historical structures: Gaudí and the Palau Güell

STRUCTURAL ANALYSI$ OF HISTORICAL CONSTRUCTIONS li P. Roca, J.L. González, E. Oi'la te y P.B. Lourenço (Eds.)

© ClMNE, Barcelona 1998

UNDERSTANDING IDSTORlCAL STRUCTURES: GAUDÍ AND THE PALAU GÜELL

J. L. Gonzâlez Moreno·Navarro, Escula T. S ú'Arq/lileclura úe Barcelona Ulliversital Politecnica de Calalullya Barcelona, Spail1

The Palau Güell

Eusebi GüelJ i Bacigalupi commissioned Antoni Gaudí to build the Palau Güell in 1885 when the Catalan architect was only 34 years of age [1]. It was his first major work, since the buildings that he had already built, several ofthem also for the Güell family, certainly reflected his strong personality but they had neither the volume nor lhe social imponance Df the projected Palau Güell residence.

Eusebi Güell fonned part of the powerful, cultivated and enterprising bourgeoisie of the industrial Catalonia Df the second half of the 19

th centuI)'. Through the Güell Palace he

sought to rea.ffinn his personality and position within lhe Barcelona bourgeoisie. Gaudí was six years younger. He hailed from a family of rural craftsmen and was at the outset of his career. According to Ràfols[2], Gaudí presented 25 different proposals for the Palau Güell façade and it was Eusebi Güell himself who, in his eagemess to achieve notoriety, chose the one most likely to cause the maximum vi sual impact at that time, which was, with cenain minor variations, the one that was finally built

The building pennit was granted by the Barcelona City Council in November 1886 and the building was completed towards the end of 1890.

Regarding the Palace's value in the architectural context ofthe time, "it is important to point out the pioneering role played by that early renovative Catalan architecture, not only in relation to the earlier local Ar' Nouveau but in the corrtext of European architecture in general. Let it suffice to mention the dates of some of the key works Df European Art Nouveau: 1893, the building ofthe house ofPau\ Hankar in Brussels; 1894, the construction ofthe Vienna Metro by Otto Wagner; 1896, the Elvira House in Munich by August Endell; 1898, the Glasgow School of Art, by Mackintosh, and the Sezession Palace of Vienna, by Olbrich; 1900, the Paris Metro designed by Guimard. As can be seen, aJl these were built after the early work of Gaudí. [ ... ] at that time, Gaudí was, without any doubt, a pioneer within European architecture. "[3]

The building was to be the Güell residence until the 1940s, when it became the

206 STRUCfURAL ANALYSIS OF HISTORICAL CONSTRUCfIONS 11

property af lhe Barcelona Provincial Council (Diputació Provincial de Barcelona), which since then has been canying oul an ongoing programme Df maintenance and restoration work. The hause, sei in lhe building Df lhe "Institut dei Teatre". did nOI require any major transfonnations, 50 Ihat we can safely say lhat it is coe of lhe few Df Gaudí' s works to have come down to us almost as he created i1. The restoration work Ihat was carried out, in lhe first phase in 1945, and lhen 1aleT between 1971 and 1977. served to correct lhe wear and tear of lhe passing of time and restore lhe building to its originaJ splendour. A series af Preliminary Studies began to bc carned OUI in 1981 under lhe auspices af the new management Df lhe Loca1 Architectural Heritage Service. These Studies have since been in progress interspersed with partial restoration projects, such as the restoration ofthe roof[4].

With regard to the building's structural behaviour, these Studies included an assessment of the building's structural solidity. an analysis of its seismic resistance and its wooden flooring. a detailed study of downward load transmission and a comparative study of the structural rramework in the original design and the present-day structure of the actual building [5). This present paper is based directly on Ihese last two studies, but it would not have been possible without the eartier studies which provided the indispensable preJiminary infonnation.

The Relationship between the Building.'s Function~ Space and Load-Bearing.Struc.ture

As can be seen in lhe diagrams 1 to 10, the building consists ofa total ofseven floors from the basement up to lhe 10ft. The tille assigned' lO each floor indicates the original uses for which il was destined. <'The rooms of tbis peculiar urban palace - built in an area which was a1ready beginning to be socially run down - are organised-around a centrat space,.. almost tuming its back, as it were, on the streels outside (the large bay window or tribune. more than a viewing point, is a continuation of lhe interior space). And in lhe block' s inner courtyard, which was more run-down looking than lhe streets outside, lhe lattices of lhe back façade seem to be there to proteet lhe occupants ITom undesirable views more than trom the hostile sun. The large central space, markedly vertical in nature (its total surface space is 80 m2 as opposed to a heighl of a1most 20 m), takes on a singularly important role in lhe composition, assuming the functions oflhe traditional Mediterranean central patio. In addition, lhe spatial sequences and impressions it creates seem to multiply lhe relatively small-sca1e dimensions of the building. which occupies a site of scarcely 500 square metres" [6].

In its essential elements, the load-bearing structure consists of lhe perimeter walls and a complex interior combination of pillars, arches, vaults, bt::ams and walls. 111t:: three exterior façades are ofnatural stone, whereas the party wall is made ofbrick. The interior is more complex: the three lower floors, (the basement, the ground floor and the mezzanine) are supported main1y by means of brick or stone pillars. and arches and vaults made of bricks or metal beams and girders. The upper floors are supported by load-bearing walls running parallel to the line of the streel but in combination with the structure which supports the central space and originates trom the piano fJobile and eloses with the elliptical parabolic dome on which the spite is supported.

The structure of lhe building is ditectly linked to the uses to which the difterent floors were intended to be pUl: the ground floor provided access to lhe building for carriages in lhe fonn of two spaces which are perpendicular to lhe façade and which are structured around

J. L. GONZÁLEZ I Gaudí and lhe Palau Güell

, - ...... .

Fig. I General rear view of the Pa1au GüelJ

Fig. 2. Main façade

[r CÜJ

000000

207

208 STRUCTURAL ANALYSIS OF HISTORICAL CONSTR UCTIONS 11

Fig. 3. Thc OOsement: lhe stables

Fig.. ·t 1be ground floor: cntrnncc for ClITÍagcs.

Fig. 6. PUlnO noblle: on lhe stroet sidc salons for sociaJ life. in lhe interior the grand saIon and privalc rooms, l...ocation for lhe 1000 plans in figures 14-17,

anel officcs Fig. 7. lntcrfloor area: extcosion cf lhe grand sa1on, servicc quancrs.

Fig. 5. Thc mC7..zarUne: GüclJ's librnry andofficcs. Fig. 8. Main bcdrooms.

J. L. GONZÁLEZ I Gaudí and the Palau Güell

Fig. 9. Transversal section.

ft J l ~l

Fig. 10. Longitudinal section.

.. , . , .... " "" .. , .... "",,-1,,1 I I I J

,-

......

209

210 STRUCTURAL ANALYSIS OF HISTORICAL CONSTRUCTIONS 11

pillars, and wàl!ed off aI lhe levei cf lhe mezzanine. The other uses reserved for these tWQ

floors (lhe ground Iloor and mezzanine), coach house and oftices. respectively. also fil in with a structure built around pillars, as lhe pillars cnsure flexibility as regards use af space. The brick pillars and arches and vaults employed in lhe basement are therefore a direct consequence cf lhe conception of lhe other two floors, lha! is, lhe ground tloor and lhe mezzanine, and their uses, and, ofcourse, they did no! c1ash with lhe use aflhe basement as a stable,

In contrast, lhe three upper floors, deslined lor domestic uses, have lhe more usual load-supporting mechanism cf load-bearing walls, which also have to SUpPOll lhe powerful central space. The entire syslem which provides structural support for lhe dome, the difficulty of which is heightened by the fact that its dimensions are smaller Ihan those af the grand salon, is based on the walls parallel to the main façade (a standard solution for supporting the façade bay in Barcelona) and lhe shear walls, by means of large-scale melai beams. This arrangement also altows for the inclusion of a conidor around lhe central space providing access to the rooms, which was one of Gaudi 's preferred solulions, and it can also be seen in his La Casa de lus Bu/ines in León and in La Pedrera.

In ils general conception. we can dearly see lhe building's structure as the positive outcome ofa dialogue between ali three ofthese diflerent spatial compositions. which are in tum lhe resu!! of lhe different uses planned for the various floors and Gaudi's precise architectural intenlions.

Nevertheless, there is a general opinion, based on lhe analysis of bOlh general and specific issues, which holds lhat the struclure ofthis building is somewhat "confused".

Enigmatic and Puzzlillg Elements

Ali lhe studies carried out on lhe Palau Güell, both structural and more general in nature, have coincided in pointing out the complexily of lhe building's structure and the existence of a number 01' elements which are rather enig.matic viewed ITom lhe perspective of slandard construction practice.

Thus for example, Bassegoda claims that one of lhe most oUlslanding features of the Palau Güell is its structural originality: ' \vhal were Ihougbl to be simply decorative or crafted ceilings tum oul lo be supporting structures" [7]. While this area is not lhe concem of lhe pícsenl papcí, il is ncvenheless an opponunity to poim out lhal lhe ceiling panels ofthe piano lIobile are a masteípiece ofwooden structure-building [8].

Bassegoda goes on lo claim: «In lhe mezzanine, where Güell had his library and oflice, there is a famous pillar which has ofien becn lhe source of comments, for it does nOI correspond to any oflhose on lhe ground floor and is supported directly on lhe fioor"

This is perhaps lhe mOSI suíprising featuíe ofthe stmcture. However it is nol only the pillar mentioned by Bassegoda lhat is sUíprising; there are also a number of others: a pillar supported directly on the flooring is found over and again.

The study which deals in most deplh with Ihese enigmatic features, indeed these features which seem to dei)' logic, is that carried out by the Professors of Stmcture of lhe

J. L. GONZÁLEZ I Gaudí and lhe Palau Güell 211

School of Architecture of Barcelona, Joan Margarit and Carles Buxader that is mentioned above. This study also fonned the basis for an articJe which was published in a number of joumals ofwide circulalion [9]

Given lhe recognised authority ofthese professors and lhe fact that to date no studies unearthing new data have appeared, the concJusions presented in those articJes can be taken as representing lhe CUrTent state of general opinion on the maUer

Let us now examine live controversial structural solutions in more detail, and Ihen we will move 00 10 consider the various assessments of them that have been made by the two authors mentiooed above. Almosl ali of lhe features in question are situated in four of the different load transmission plans [10] which, we can call A. B, C, and D, as seI out in lhe altache<! diagrarn (figs. ii, i2, i3 , i4, and 6).

Firstly, analysis of ali these features enabtes us to see that~ despite the facl that lhe load being bome by lhe ceiling of the basement does nOI increase significantly, oevertheless lhe diameter of lhe basement pillars is much greater than Ihat of lhe ground Ooor pillars. Furthennore, load plan A enables us to see lhe tirsl surprising feature lha! lhe basement pillars receive considerable loads rrom lhe upper floors , but the lwo central basement pitlars, lhe section measuremenlS ofwhich are very simi lar, do nol receive any load whalsoever. In short. in lhe basement Ihere exisls a cJear disproponion between lhe dimensions of the supporting sections of lhe pillars and lhe loads bome by Ihem This phenomenon is mOSI sl rikingly reflected in lhe case oflhe two pillars which support no load

Secondly, on the same load plan A, in the area marked on the diagram, there is another area which is problematic: the intersection of the system of upper floor walls and the system oflateral and perpendicular walls oflhe mezzanine. In this interseclion ofwalls there is a concentration ofloads which has contributed 10 causing certain disorders in the component materiais ofthe lower wall .

A rhird point ; observation ofload plans B and C. shows us Ihat there exist four pillars whose purpose is 10 Iransrnit ai least three-quaners of the load of the entire central space, along with thal of the corresponding dome and spire. which are not supported 00 any other venical element but ralher on bearns which are perpendicular to the plan in the case of load pia0 C, and on elemenls which are impossible to locate in load plan B. The poinl marked in load plan C, which can be seen in lhe photograph 15, is without any doubt one of the most puzzling features of the entire building. According to lhe above-mentioned study, this cantilever slipped and lhe consequent downward movemenl of lhe pillar which it supported opened up a void between it and lhe main beam, which il also served to support This gap had to be filie<! in with piaten (Fig i6).

Now luming 10 a founh example; load pia0 D illustrates lhe case of lhe pillar mentioned by Bassegoda, which can be clearly seen in the diagram 14. In fact , it does have a lower structural element supporting it and it is not lhe only pillar of this type, since ils symmetrical partner and lhe two walls which are perpendicular to the plan and which enclose the central corridor are identical in lhis respect: they are ali supported on the ends ofthe metal brackets which transmit their load 10 the three definitive pillars which, connected to those of the basernent, stabilise lhe entire structure.

Finally, lhe study c1aims thal several of lhe load-bearing brick walls. including. lhat


Fig. 11 . u,ad plan A See floor location in figure 6

I

b;d( J[][] Fig. 12. Load plan B

J. L. GONZÁLEZ I Gaudí and the Palau Güell 21 3

~

~ ~v In U

ri b

JUL -,~, "., h • l ~ ~'. -I-'UI'

~

li I

11

I t...l...i.J..l.'

Fig. 13 . Load plan C

~ illI p Tn

In no rn lr []]] -n- o

hJl~,.~ 1K1 OO OOLJI

Fig. 14. Load plan o

2 14 STRUCTURAL ANALYSIS OF Ii ISTORICAL CONSTRUCTIONS 11

Fig. 16


iIIustrated in plan C above the pillars we have just been discussing, support excessive stresses ofthe order of20·30 kglcm2.

The first of the points that we have just discussed, the seemingly excessive section dimensions of the non·load bearing pillars in plan A, leads me to the opinion that Gaudí "is motivated by considerations of fonn but he disguises his intentions in a cloak of technology" [li).

The second point is considered to be due to "the excess of distortion Of [ • . ] not waiting for the beams to come under load before fitting the cladding" [12].

The third point, illustrated in lbad plans B and C. prompts the foltowing question "why should an architect such as Gaudí, gifted with such a clear stll.lctural instinct and possessor of such fonnidabte technical skills [ ... 1 be so careless as to fali into lhe trap of having to make these improvised arrangements? [ ... ]. Perhaps the answer lies in the overwhelming and multi·coloured nature of lhe Gaudí style, since it is not hard to imagine thal lhe degree of improvisation employed when he gave rein lo his decorative talents might have also extended to other areas ofhis work" [t3].

The fourth point is explained as a "measure tha! seems to be more ao attempt to limit the span" of the girders and "is certainly not a construction solution that is justified without powerful arguments" [14].

Wilh regard to lhe stresses bome by the walls and lhe excessive load mentioned when discussing plan A, its can infer that "Gaudí' s sound structural judgement led him to pay less attention to lhe walls and beams than to the arches and piltars [ ... ]. The resul! ofthis approach could have been that lhe confidence he deposited in lhe walls led to their being, paradoxically, the least stable of the structural elements in the Palau Güel1." [15]

In conclusion, these five features, taken together, along with a number of other elements of lesser importance, have led to the Palau GüeU being judged as a somewhat "confused" building, and has aroused doubts as to how "this structural rramework which we have just discussed could possibly be the skeleton for a masterpiece of architecture." These doubts "could well serve as the starting point for a revision of our present·day assessment of catalan Ar! NOllveou in general and Gaudí in particutar''[ 161

There are of course opposing opinions, though some of them coincide in part, such as that of Antoni González, who holds that "it is true that the overall framework of supporting structures in Palau Güell is somewhat confused, but it is quite another trung to sustain that the skeleton of an architectural masterpiece of the 19

1h century must necessarily fit the idea of

structure we now accept in the light ofthe contributions ofthe Modem Movement in general [ ... ]. lt seems c1ear that for Gaudí, working out the elements which were to contribute to holding the building up in the Palau Güell was a secondary matter at lhe service of the truly fundamental issue in hand: the construction of a spatial idea" [17]

Reinforcing lhat ralher instrumentai vision of structure, Giorgio Croei. another expert in Palau Güell, declare·

"Gaudí a1so knew how to use structure solely as an indispensable sup.port whose on1y purpose is to free every possible type of fonn, space, void and light, as in his Güell Palace."[18]


The Original Structure

Ooe ofmy maio objectives in lhe present paper is 10 draw attention lO new data which will pennit us to make some progress in Dur evaJuation Df lhe Palau Güell and af Gaudí 's ideas on lhe integration cf lhe structural framework ioto his architecture. I hope to do this while bearing in mind the concluding recommendations af lhe two Professors, who urged us to "combine lhe dispassionatc approach cf the scicntist in the intcrpretation Df data and the enthusiasm af lhe devotee in lhe search for these data, so lha! none of Dur c1aims will suffer trom a lack af foundation cr justificatian." [19]

Fonunately, we nQw nave access to a docurnent which may well contribute infonnation thal will enable us to reach new, solidly-based conclusions: this document is lhe sei af plans lha! Gaudí signed and presented to lhe City Council in 1886 in order to obtain the building pennit for the Palau Güell . However. before beginning to consider these plans, I would Iike to add some further comments conceming the "confused" features we have just discussed. Some of the following comments are based on careful observation and study of the building, while others are based on new assessmenls canied oul on olher works by Gaudí in the aftel111ath of lhe publication of lhe comments I quoted in the previous section of this paper.

The great diameter of the basement pillars may nOl seem so excessive when we consider lhat if lhe stone pillars of the ground floor had to bear teosioos of 15 to 30 kglcm2 lhe basement pillars served to reduce these tensions 10 5 to 15 kglcm2, which are nol so low if we bear in mind Ihat lhe material is brickwork [20}. Ir, in spite of this, we still think lhe pillar sections could have been narrower. we should nOI criticise Gaudí 's structural design skills, since il seems clear lhat these pillars will never cause structuraJ problems, rather we should criticise his lack of a sense of economy. In any case these pillars seem to be in response to some kind offol111al requirement but lhey do nol pose any kind of confIict or threat 10 lhe building's stability.

Evaluatioo of the load borne ai lhe intersection of the walls in lhe. mez.zanine.. [2 1] confinns lhat lhe craclcing on lhe outer surfaces is due to excessive load, bUl is not due to flexion ofthe girder since it is supported at that paiOl .

Of lhe cases considered, the fourth one, set oul in load plan D, is undoubtedly the easiest to understand and the comparison of lhe meuanine and lhe ground fIoor does not lead 10 any confusion: the facI Ihat lhe axes followed by the pillars do not correspond trom one levei lo lhe next is obviously in response to a desire to facilitate lhe tuming of carriages ai lhe back oflhe groulld Ooor, which made it neu:ssary to separate lhe two pillars and have instead ooly ooe central pillar. lt is an unusual solution, bul nevertheless one that was nol overly expensive and lhat has not 1ed to any defect in lhe overall load plan. Furthel111ore, as will be seen short1y, it is ooe of a repertoire of architecturaJ techniques which were genuine Gaudí tradernarks.

Retuming to lhe matter of Gaudi's excessive confidence in lhe load-bearing capacity of the walls. I would like to offer lhe following consideration. The negative evaluation of lhe load-bear1ng walls was made on the basis of comparison of walls conceived in 1885 and those buílt in response to the demands of a modem standard established in 1972. BUl the 1972 standard (MV-201) carne about as the result of the building boom of the sixties and was designed to avoid the disasters that were beginning to occur as a result of the decline of the

J. L. GONZÁLEZ I Gaudí and lhe Palau Gücll 217

greal building tradition, ofwhich Antoni Gaudí was apart . Using lhe present-day NBE-FL-90 slandard, (the new term for the MV-201) for evaluation purposes leads in general to a near catastrophic evaluation of practically ali 19

110 century Catalan architecture and a good

deal of the architecture of the early part of the present century. ali of which is still standing, Further consideration of this can be found in some of my other papers [22] and a1so in the study of another ofGaudí's buildings which is almost contemporary with lhe Palau Güell, the Casa de los 801ines in León 123].

Other recenl studies incJude informarion which provides insights into Gaudí 's structural intuition and a1so into lhe link between his architecture and his sense of slructure [24].

However, returning to lhe central concem of the earlier pan of lhis paper> lhe first three cases (those illustrated in load plans A, B, and C). do not have such a convenient or immediate explanation. Nevertheless, an explanation can be found if we study the original structure as seI OUI in lhe adminislrative plans I menlioned earlier.

lt was nol until 1974 that these administrative plans~ which Eusebi GüeU presented in application for the municipal building pennit, were discovered in lhe city's municipal archives through lhe research efforts of lhe Gaudí Chair of Architecture of Universitat Ploitêcnica de Catalunya. These plans were completely unknown before lhen [25]. The figures 17 to 21 incJude a simplified reproduction of lhe plans.

Seing strictly administrative plans, they do nOI incJude any detail other Ihan the definition of lhe form, volume and space of lhe building in those areas which were lhe concem of lhe City Counci!. Nevenheless, the plans do cast Iight on lhe exact ideas Gaudí sei out with as regards the organisalion ofthe structural framework ofthe building.

If we compare the data contained in Ihese administrative plans with the plans we looked at earlier, we can see di.fferences in some details, but the spatial intention is essentially the same, both in the lower and higher floors and a1so in the central space. The details reveal some differences in lhe finaJ solution - load bearing in lhe mezz.anine was achieved exclusively by the use of piUars, the piano lJobile has two colonnades to the sides - the rest however, in general, is the same,

It is important to analyse the original plan in as much depth as the drawings will permit [26]. We will Slart at lhe lower levei, and move as far upwards as it is possible to do. Like the actual building itself, we can see evidence of an interrelationship between different spaces, structures and uses, and it is lhe interface between ali three which provides the key to understanding lhe structure of the building.

The relationship between the basement and lhe ground f]oor is lhe same~ both are isotropic in formo The relationship between the ground floor and the mezzanine a1lows us to see lhat the lack of coincidence between the axes of the pillars which appeared in load plan D (Fig. 14) was also present in the original design, and was c1early due to the need to alIow for the movement of carriages. This lack of coincidence between axes occurs in other locations and we will refer to it as an "arborifonn" or Y -shape figure.

At mezzanine levei, there is one notable difference between lhe original pia0 and lhe actuaJ building, and it lies in the dcuble-height wall cf lhe back cf lhe haII, cne 'pan funher

218 STRUcrURAL ANALYSIS OF HISTORICAL CONSTRUcrlONS 11

~~=-~ • • - I

'~.' .......c..~ . J~ O ••.

T T

Fig. 17. The basement Fig. 20. PiaJJo l10bile

, o

, ,

Fig. 18. The ground floor

Fig. 19. The mezzanine Fig. 21 . Bedrooms


back, in load plan D. It is resolved by means of four large rectangular buttress piers, between which there are eight pillars of smaller diameter. It must be pointed out that in the lines perpendicular to the façade there is no continuous wall but rather there are piUars of rectangular section which fonn a grid among which there are circular pillars of smaller diameter.

Continuing to move upwards. examination of lhe piano "ohile shows us two important differences in addition to some minor differences affecting the right-hand side ofthe building: firstly: the mam access stairway, situated to the left, and secondly. lhe two colonnades at the sides of the main salon

The most difficult intetface to resolve was that which interrelated the system of loadbearing pillars of the meuanine with the system of walls and lhe central space of the grand salon or piano l1obile. Superimposing one floor on the other allows us to see that the columns anel their adjacent walls are synunetricaUy situated one on each side of lhe tine of load transmission of lhe pillars of the mezzanine; observing il from above enables us to see lhat we are dealing with another case of an "arboriform» configuration, which leads to a doubling up of the pillar by means of two cantilevered elements on lhe wall and column, both - it must be presumed - supporting similar loads se as not to upset lhe overall balance (Fig. 22).

lt is now time to consider a littJe further this «arborifonn" or Y -shape figure which, as we have seen, is recurrent. It seems c1ear that it is not a usual techn.ique, since lhe most common solution would be lo make the axes of lhe pillars coincide rrom one levei 10 another. But the fact lhat it is unusual does not mean it is flawed or mistaken or was excessively expensive to execute. In fact, it was the same technique Gaudí used in building lhe school "Las Teresianas", which was one of lhe most economical buildings he built, and yet it was very rich in leons of space and conceptual rigour. That building' s design and construction was almost contemporary with lhat ofthe Palau Güell (Fig. 23).

The arborifonn figure constitules one of Gaudí 's pennanent resources of composition and structure, and il reaches its high point in the Sagrada Fanlilia, practically ali of which is arboriform~ it is a1so found in the partial building and the model for lhe church in lhe Colonia Güell. The origin of lhis element lies, of course, in lhe early work of lhe architect.

lf we continue moving upwards through the building, the wall which closes off the bedrooms is supported not on the axis of lhe arboriform structure of column-wall but on lhe lateral walls, thus achieving - and perhaps this was its purpose - greater widlh for lhe perimeter conidor which provides access to the bedrooms (Fig. 22) .

However. examination of the floor of bedrooms, which is the last one drawn in lhe plans, leads to a question about the supporting mechanism for the central dome which, as is clear from these plans. was basicaUy similar in the original conception and the finished building: above the salon of the piano nobile the central space is reduced to a smaller square, which frees up space for the access conidor to the bedrooms and which, it seems reasonable to suppose, also served to support lhe spire. The solution to this problem is found on the walls of the piano Ilobile running parallel to the façade.

It seems reasonable to suppose that the pilasters marked with lhe letters m, n, p, and q (Fig.24) would have supported two beams which would have been perpendicular to the façades, and tangential to the central space in a similar way to the actual Qnes bUI in a perpendicular direction (I and J in Fig. 22).

220 STRUCTURAL ANALYSIS OF HISTORICAL CONSTRUCTIONS "

-

~

A ~~ v 1;\

J -

lJUt , ,

-I - !

bdL JI I(JLJ{] ~----------------

Fig. 22. Longitudinal section af lhe building

Fig. 23


~ ~ p O

O O

O O

~ O

O M

O O

Fig. 24

§l I ~ Pl P2 ql q2

~

== = lliI f= f= == -

r- }j ~ ~" Ml Me n l ne -

í ')( ') Fig. 25

222 STRUCTURAL ANALYS IS OF HISTORICAL CONSTRUCTlONS 11

Pilasters p and q were to be supported on four pillars at lhe mezzanine levei (p I, p2, ql . q2, in Fig. 25), where ance again an arborifonn configuratian was employed but upsidedown, There was no aplion but for pilasters m and n to be supported on beams resting on lhe another mezzanine pillars (m I, m2, n 1, n2, in Fig. 25), which led to another inverted aroorifonn figure af greater span which would have required a beam af larger dimensions. This solution is nol at ali frequent but it is in keeping with the freedom with which Gaudi worked - setting out fram the basis af solid resolution af rui the structural problems af the intersections, he related floors which were planned for different uses and which were structurally different by means af lhe arborifolm fih'Ure, which was unquestionably effective, as demonstrated by his major works canied out later.

Superimposing the floors trom an axonometric perspective (tig. 26) enables us lo conclude lhat in lhe original design lhere was total coherence belween use, space and structure. and lhal lhe structure could not by any means be lemled "confused" a r "confusing". The next question is obvious: why did he change fIom a c1ear·cut slructural framework to one which could be secn to be, at least in part, confusing?

We will now tum to this queslion.

Variations Inlrodllced in the Design Once Work had Started

The almost absolute coincidence between lhe finished building and the original plan in 50 far as the basement is concemed a1lows us to reasonably suppose lhat ali changes were made at a reJatively advanced stage of the construction work. Let us imagine the situation in which the Palau Güell was built, and let us relate it to aur personal experience. lt was a situation in which lhe architect was young, lhe client older, and of course much more powerful, and given lhe complexity and lack of definition af lhe project in hand, the c1ient probably did nOl understand lhe proposals pUl forward by the architect until the work was actually in progress.

Perhaps for this reason, and also having forescen the inevitable difficulries which lay ahead, Gaudi built a ceiling for the basement which would be capable of accepting cenain significant variations in lhe location of stress and lhrust forces lransmined fIom lhe higher f]oors, almost as if it were a cement slab. Although lhis is only supposition, what cannot be denied is lhat lhe service stairway is supponed on the vaults, as are a number of pillars.

lf we compare lhe present-day plans with the original designs, we can see immediately lhe three fundamental changes: on lhe ground tloor two of lhe pillars enclosing lhe central platfonn for lhe ascent and descent of carriages in connection with lhe main stairway disappeared. On lhe mezzanine levei, we can see lhat lhe back enclosing wall was brought forward one span, as has been menlioned already. The third fundamental change is that in the piano l1obile, there is a major change in the positioning of lhe main stairway. Unfortunately, there is no documentation which might heJp to explain lhe origin of these changes, although it seems reasonable to make the foUowing hypotheses:

The disappearance of the pillars would seem to have been due to the fact thal they gOl in lhe way of the caniages entering and leaving the building. Bearing in mind that lhe

J . L. GONZÁLEZ I Gaudf and the Palau Güell 223

Fig. 26


carriages were horse-drawn, lhe position of lhe carriage door could nOl be adjusted very precisely and on occasion a carriage must have come to a halt with its door rather inconveniently blocked by afie ofthe pil1ars. lt seems reasonable to suggest that i1 could have been Gaudi himselfwho took the decision to remove lhe pillars before bcing told to do so by Eusebi Güell .

Bringing Lhe mezzanine wall fon'lard was justified by the fact lhat it led to bcttcr utilisation ofthe space, since it expanded the space available for Güell 's officc. In addit ion, if we consider how difficult it would have been 10 combine lhe original wall and lhe arborifonn tib'Ure we have just identified in load plan D (Fig. 14), we ean see that moving lhe wall forward was a logical step.

Ali lhe changes lhat took place in lhe piano flobile were basically lhe consequence of changing the localion of the staiIVIay. The reason underlying this particular change was simply that it provided for improved utilisation of available space since it gave rise to another room on the bedroom floor and a new surface for the piano nobile at medium height on the interfloor space. Another reason, by no means trivial, could have been that changing the stairway's position perrnitted the establishment of a direcl connection between the rooms on lhe inner courtyard 's façade, lhe slairway and the fooms on the street façade.

Whatever lhe reasons may have been, the new position of lhe stairway led to lhe disappearance of lhe left laleraJ colonnade, and of course, for the sake of symmelty, the one on the right had to go too.

To these reasons, based 011 the house's use, we must also add a number of olher reasons which are more concemed with structural details: in effect, in the case ofthe stairway there was no option but to use arboriforrn fib1Ures to transmit its loads to lhe line of lower pillars in the same way as lhe arboriform figure of lhe colonnade it replaced. However, the staiIVIay was wider and this 100 to further structural ando more important1y, spatial problems. The banister of lhe staiIVIay was c10ser to the axis of symmetry of the salon than lhe earlier columns, and on the other symmetrical side, the disappearance of the colonnade led to the logical solution of maintaining the load distribution of lhe lower floor in lhe upper floors, which changed lhe spatial disttibution radically, and lhe axis Df the salon was moved to its present situation 40 cms mor or less to the tight ofthe original position.

Without any doubt, this was a radical change which broke one of the key fonnal features of the building: the absolute continuity Df a plane of symmetry ITom lhe basement to lhe spire which involved the coincidence of lhe axis of the helicoidal ramp with lhe axis of lhe central space and even with lhe nxis ofthe wcather vane. However, the lack of coincidence is difficult to notice because of the complexity of the interior, and lack of sufficient viewing perspective prevents it from being noticed from the outside, a1though it can be noticed from the inner platfonn ofthepiallo lIobile.

lt would seem reasonable to imagine that Gaudi must have been deeply upset by these changes, though there is no record to the effect. In the plans presented in the 1910 Paris exhibition ali the axes coincided. However, none of his disciples ever gave a written account ofthe matter.

The structuraJ consequences of ali these changes, which carne about as the result of changing conceptions of the uses to which the house was to be put, were significant and

J. L. GONZÁLEZ / Gaudí and lhe Palau Gücll 225

coincided in more than a few points

The removal of the two pillars from load plan A required a supporting arch of voussoirs, which seem to be out of proportion for the task. This arch was combined with a linte1. The overall mechanical behaviour of these features is still difficult to understand. To reduce the span of this new arch-lintel the supporting pillars were brought eloser together, with the result that they were no longer situated directly above lhe original pillars of the basement, se the latter had to be rebuilt with a greater section (Fig. 27)

It is reasonable to assume that Gaudí had his doubts as to whether this replacement for the original piUars was sufficient to assume the load transmitted to it from the central space, the dome and the spire, through the beams which were described earlier and the pilasters m and n of the piano l1obi/e and m2 and n I of the mezzanine leveI. For this reason, or perhaps for others difticult to discern at this distance, Gaudi seems to have decidOO on another major structural change: the original ceiling beams ofthepicUlo Ilobile were discarded for others parallel to the façade, i.e. perpendicular to lhe original ones (which we will refer to as B and C since these are lhe load plans in which they appear (Figs. 12 and 13) and supported on elements which were not at ali contemplated in the original design (Fig. 28). Beams 1 and J are maintainOO in the final solution but without the main load-bearing function because they bear on beams B and C.

The right-hand end of Beam B, which is the one nearest to the street, is supported on the wall which rests on lhe pillars of the ground floor and basement without any serious problem, However, the left support is rendered vulnerable by the new position ofthe stairway and now requires additional support from a camouflaged arborifonn figure under lhe first landing which is supported by means of an metal distribution beam on the mezzanine wall (Fig 12)

Beam C presented even more difficulties. The second change in use, the bringing forward of the back wall of the mezzanine floor, made the support of beam C more problematic. Due to the disappearance of a supporting wall as a consequence of the second change discussed earlier, the right-hand support of beam C requires the additional help of a beam situatOO in the Ooor of the piano Ilobile perpendicular to load plan C, which has aiready been mentionOO in the discussion offigure 13.

This brings us to its left.-hand support, where ali the consequences of the three changes in use are concentrated: the changing af the position of the stairway, moving the mezzanine wall forward, and the new location of the beams resulting trom the removal af lhe pillars which obstructed the carriages. This was too much for a single peint to suppert but the solution to the problem (photograph 15) was in no way erroneous or confused, though it was strange. Let us see why.

lf a Y -shaped structure six metres high bearing some 25 metric tons is supported by a single beam, it is difficult to prevent it being unstable in iselation. Gaudí took the decision to tie it to the neighbouring wall by means of braces situatOO half-way up the wall, one perpendicular and one rotatOO fonning a double triangulation, se the assembly was totally immobilised. The equal loads bearing on the two ends of lhe Y and lhe more than sufticient width of the double projecting element prevented the left support from yielding at all. The supplements (platen) inserted in the support of the upper beam could be attributed to problems in the adjustment of the measurements of the stone elements, but were certainJy nOl due to the distortion of one ofthe branches ofthe Y.

226 STR UCTURAL ANALYSIS OF HISTORICAL CONSTR UCTIONS 11

r---------------I I I

Fig. 27. Magnification of the section in fib'Ure 9

n---------- ------'T-----------------~------------------11 11 11 11 11 11 11 11 11 " 11 11 ,I I 1 11 " 11 11 1\ 11 11 P " 11 11 11 11

~,'l -.::-----i.f,1. ~,.~r=~~~~~~~~;r~~==lTr===" ~ >" _ " I1 ,---' I

I ~~~i( :1: I: :: : L """'..,!It'~..:~.:...._ . .J!!!'..: !P.!L :.'!IfIt.,.. __ ..:~-... -

: : C : :

, , , 1J-·.c:=rr==1 ' , , , ,-, , , , , , , , , , , , , " : 1----, , , , , B '

~~l::lij:_,.*,,..,-- .,..--...... ,- ,..---~-~-I!f====o!!-=='9 : d :' t

br-----r~:]l1~: ~: Bi.q! :: __ J =========== , , , , , i I I I I

l ________ ~ _____________________________ ~ __ _______ _ Fig. 28. Position of the new beams in lhe plawCt lIoble.

J. L. GONZÁLEZ I Gaudí and lhe Palau Gücll 227

Conclusions

Without any doubt. we are dealing with a building in which, in itself, lhe task of understanding the observed structure is difficult. To try and understand il we must become familiar \YÍth the vicissitudes, changes. doubts and indecision Ihat marked lhe design and construction of this structure

Through this case once more il becomes clear lhat when we are facecl with lhe task of restoling a historical building il is crucial to bear two basic principIes in mind. Firstly, understanding structures ITom the past poses a wide range of problems for our 2011> century mentaJity, and it is therefore necessary to search out 811 the means which may facilitare the task ofunderstanding. Secondly, a knowledge ofhistory is one ofthe most powerful 10015 in our effort to understand these buildings. Let this second principie serve as a posthumous homage to a great master who was a radical defender of the role of history in helping us to understand: Antonino Giutfré (27).

In our case, unless new documents come to light, 811 lhe suggestions I have made today must be taken as hypotheses, some ofthem very reasonable and almost certain, others less so, especially those conceming the intentions of the participants - which we will never be able to confinn. BUI one thing I hope is lhat these considerations may help us to achieve a fuUer understanding of the building and its creator. At least in my case this has tumed out to be 50

Wilhout doubt, lhe two basement pillars in load plan A bear no load simply because the pillars on the ground floor were removed. The range of strange and unusual solutions in load plans B and C were decided by Gaudí in response to developrnents as construcrion work took place. The fact that lhey are hidden in no way detracts ITom the general perception of their appropriateness. The absence of distortion or cracking shows that they were correctly dimensioned. What more can one ask for?

AJI those who have ever been involved in building projects Io-"1l0W the far-reaching effects and sometimes disastrous consequences that can come alx>ut as a result of changes during building work.

Lndeed, it seems c1ear that there is no reason to doubt his extraordinary abiüty and unbending desire of Gaudí for Iigour in the creative di810gue between his architecture as a container of changing uses. his architecture as a spati81 adventure and his architecture as a defiance of the force of gravity.


NOTES I. The tWQ best sources of infonnation on the Palau Güell are AA Vv., EI Palau Güell, Diputació de Barcelona, Barcelona, 1990, and the monographic edition of the joumal INFORMES DE LA CONSTRUCCION, no. 408, July-AuguSl, 1990, entitled "Gaudi constructor"

2. J. F. Ràfols, Amo,,; Calldi, Barcelona, 1928

3 A. González, J::1 Palau Güell, jita de I'arquiteclllra ellropea, in AAVV.I990 pp. 35-48

4. A. González, P. Carbó, IA azoteafal1lástica (La '7lbierla dei Palau Güell) in lNFORMES DE LA CONSTRUCCION 408, pp. 31-4 1

5. Directed by Carles Buxadé and Joan Margarit Diclamen sobre I'estal de solidesa deI Palau Güell, 1982. Directed by Giorgio Croei: Pala/{ Giiell, &"tudi eslructural. Diagnosi i pres(:ripció, 1994. Directed by Enrique Nuere: [ru" artesollados deI Palau Güel/, I"y r Parte, 1995 and 1997. Directed by J. L. González: Estudi defallal deI de.'iCem" de carreque:i gravito/arie!i, 1998(a) and ComJX1raci6 entre les eslruc/ures dei projecle original i I'ac/ual Palau Gliel/, 1 998(b). Justo Hemanz, an Architectural Technologisl and holder of a master's degree in Architectural Restoration, M~ Jesús Pérez., an Architectural Technologist, and Raquel González, a Civil Engineering student collaborated in lhe drawing up of the last two and in lhe present paper.

6. Antoro GonzãJez, in AA W . (1990) p. 39

7. Joan Bassegoda, EI gran Cal/di, Sabadell, 1989, p. 287

8. The previously mentioned study by E. Nuere amply demonstrates this. We now have new data on the non-structural reasons why Gaudí designed his

Slructural elements, lhanks 10 the work (a1so funded by Barcelona Coumy Council) carried oul by "Audioscan Enginyeria dei 50", Estudi d'ai1lament acústic dei Palau e üell, July 1997. This Sludy shows that lhe reason underlying lhe cemplex.ity of lhe flooring and ceiling arrangements separating the service bedroems frem lhe main bedrooms is their high levei of acoustic insulation, which is good enough to comply with curren! French legislation.

9. Joan Margarit and Carles Buxadé, Olra visila ai Palal/ Cüell in ARQUITECTURAS BIS n. 45, dic 1983, pp. 27-31 , and La confuso complejidad eSlnlClural dei Palau eliel/, in INFORMES DE LA CONSTRUCClON 408, 1990 pp. 23-29

10. Data and maps compiled ITom J. L. GonzãJez (1998a)

11. J. Margarit and C. Buxadé (1990) p. 24

12. J. Margarit and C. Buxadé (1 990) p. 24

13 . J. Margarit and C. Buxadé(1 99O) p. 27

14. J. Margarit and C. Buxadé (1990) p. 24

15. J. Margarit and C. Buxadé (1 990) p. 27

J. L. GONZÁLEZ I Gaudi and lhe Palau GüeJl 229

16. J Margarit and C. Buxadé (1990) P 29

17. A. González, EI Palaü Güell de Barcelona. La constnJCción de una idea eSJX1cial, in INFORMES DE LA CONSTRUCCION 408, pp. 17-22, p. 20

18. Glorgio Croei, lhe Conservatioll and Stnlclura/ Resrorarion of Archirecrural Heritage, CPM, Southampton, 1998, p 28

19. J Margarit and C. Buxadé (1990) p. 29

20. Data drawn from 1. L González (1998a)

21 . Conclusion drawn from J. L. González (1998a)

22. l.L. González, Evolueión normativa y progreso en constnlcción arquiteetónica. (A propósito de la renovación de la MV-201) in INFORMES DE LA CONSTRUCCIO, no. 411 , 1991. J.L. González, EI Legado OClllto de Vitrovio, Alianza Editorial, Madrid, 1993 . 1.L. González, L 'aparieió de les lIormarives, en AA. Vv. Manual de diagnosi i intervenció en sistemes estructurals de JX1rers de càrrega, C.d'ApareUadors i AT. de Barcelona, 1995, 1.L GonzáJez, Verificaeión de /a seguridad e~·lmctllral a las cargas verricales. Ap/icación de las PlET 70 y la NBEFL90. Comparación con el EC 6, in REVISTA DE LA EDIFICACION, n. 22.

23 . l .L. González, A. Casais, P. Roca, C. Motins, Los estudiospreviosde la Cam BOlines de León, Revista LOGGIA, no. I, 1996. 1.L. González, Previous sludies oflhe "Casa de los Botines de León in P. Roca er ai. (eds.) Stmctural analysis of hislOrical cOllslruclions, CIMNE, Barcelona, 1997.

24. A. Casals, 1.L. González, P. Roca, La necesaria comprellsión previa de la realidad consrmcliva deI monumento: el caso singular de la Cripta de la C% nia Güell, lNFORMES DE LA CONSTRUCCION, no. 427, 1993. P. Roca, 1.L. González, R. Brufau, 1. Gómez Serrano, Consideraciones sobre la dimensión estmchlral de la obra de Antonio Caudi, in OP no. 38, 1996. P. Roca, StudiesofGalldi's "Cripta de la Colonia Güell" in P. Roca el aI. (eds.). 1997 R. Brufau, Structural inlervelltiofl for lhe rehabilration of "Les golfes de la Pdedrera", in P Roca e/ ai. (eds.) 1997

25. 1. Bassegoda, Los planos dei Palacia Güell. inéditos dibujos de Gaudí, in TEMPLO, 1974.

26. The data and conclusion on the structure of the original plan and the variations made on site are taken from J L González (1998b).

27. Of course, Giuffre is not the only one who defends tbis idea; the writings of rnany other authors, such as Giorgio Creei, a1so put forward tbis view. What was unusual however about the master, who left us last November, was the radical way in which he defended th~ idea, as retlected, for example, in bis impassioned and unforgettable contribution to the first edition of this Serninar, which was published as, Proposal for lhe resloralion of Marcus Aurelill's colllmn, en P. Roca et aI. (eds.), 1997.