Outline. Gothic Architecture: design and history. HA2 Autumn 2005

Transcription

1 Outline Main design issues and innovations Structural outline Chronological development Classical styles (France) Outside the canon Gothic in the UK Case study: Burgos Cathedral 2 Dimitris Theodossopoulos 1

2 Main design issues Definition a sharp change from Romanesque? (St Denis 1130) Major elements pre-existing (ribs and shafts, pointed arches, cross vaults) Composition and scale Light and height Role of patrons (royal vs. secular foundations) and cathedral buildings Strong technological input European regional characteristics Decline: decorative character and historical reasons 3 Main design issues 4 Dimitris Theodossopoulos 2

3 Technological innovations Dynamic composition Dynamic equilibrium Linearity origin in Norman timber technology? Role of the ribs (and shafts) Spatial flexibility of cross vaults use of pointed arch Flying buttresses Openings and spans Bar tracery and linear elements Large scale construction and transmission of knowledge 5 The role of geometry 6 Dimitris Theodossopoulos 3

4 Light Contrast Durham Cathedral ( ) and Sainte Chapelle in Paris (1240) 7 Layout and behaviour Nave (high) vaults: symmetrically supported by lateral walls and buttresses Aisle (lateral) vaults: span between nave arcade and external wall Ribs reinforce the intersection between the vaults (groins) 8 Dimitris Theodossopoulos 4

5 Structural behaviour Nave enclosed between the façade and the apse Divided into regular bays, abutting each other longitudinally Transverse thrusts counteracted by a system of flying buttresses Rampant arches: lower tier (gravity), higher (wind) 9 Failure pattern Clerestory - natural light Triforium and lateral wall passage Cross-section fits haunches - not resting on vaults (porte-á-faux) Nave s weight carried with offset? Possible hinge Balanced upper thrusts - weight carried vertically Low stresses on base of piers 10 Dimitris Theodossopoulos 5

6 Failure pattern Intrados: hinge line close to longitudinal vertex Extrados: cracks parallel to edges Serviceability limit: abutments displacement at 1/50 of transverse span Failure observed at 1/20 of the span 11 Development Vezelay First experiments in 1130 s Domain Royal (France) St Denis, Paris (Abbot Suger) Sens (Arras, Noyon) Durham (rib vaults) Notre-Dame, Paris (in. 1163) High Gothic Chartres ( ) Bourges ( Reims Amiens ( ) 12 Dimitris Theodossopoulos 6

7 Consolidation Rayonnant Gothic ( ): Sainte-Chapelle, Beauvais English Decorated ( ): Lincoln, Exeter, Wells 13 Consolidation German High Gothic Hallenkirche (Frauenkirche, Nuremberg) Cologne cathedral (in. 1248, fin. 19 th c.) 14 Dimitris Theodossopoulos 7

8 Outside France East Europe: Germanic influences, decorative potential of structural elements (St. Vitus, Prague) Norway: timber Norman architecture (Nidaros Cathedral, Trondheim) 15 Italy Santa Croce, Florence (Arnolfo di Cambio, ) Basilica di San Francesco, Assisi 13 th c. 16 Dimitris Theodossopoulos 8

9 Spain & Portugal Direct influences from (south) France in Castille Earlier cistersian influences (romanesque appearance, ribbed vaults, chapels on transepts) Hallenkirche type in Catalonia Fusion with islamic tradition Main cases: Toledo cathedral (in. 1224) Burgos (major influence) Barcelona (in. 1298) Manuelin style in Portugal (XV c.): ornamental richness with Flamboyant elements (Jeronimos, Lisbon) 17 Spain & Portugal 18 Dimitris Theodossopoulos 9

10 Decline and revival French Flamboyant ( ) English Perpendicular ( ) German Sondergotik Collapse of Beauvais 1284 Vasari: term Gothic Gothic Revival and national styles (Viollet-le-Duc, Pugin) 19 High Gothic 20 Dimitris Theodossopoulos 10

11 Durham and the ribs Earliest high-level ribbed vaults in Europe, 25m height Ribs Smooth finish of groins Interpretation of Norman timber architecture Timber-frame vocabulary Together with shafts, convey unitary approach to construction design Careful balance of massive construction with voids Flying buttresses! 21 St Denis (1140) Abbot Suger ( ) Major renovations at apse First conscious composition of load-bearing elements into a new style Ribbed cross vaults enabled geometry of ambulatory and plan flexibility Stonework as light skeleton: large stained glazing, integrating role of light 22 Dimitris Theodossopoulos 11

12 Notre Dame, Paris Started 1163 Large scale applications: total height 32 m Round piers balanced with emphasis on vertical elements Major application of flying buttresses Lack of confidence of masons unsuccessful illumination 23 Chartres and its School The first classic gothic church ( ) Engaged shaft piers Classic gothic sculpture at portal Quadripartite vaults (subs. sexpartite): uniform character Balanced cross-section 24 Dimitris Theodossopoulos 12

13 The School of Bourges Started naves: follows Paris model Arcade occupies most elevation Smaller clerestory - lighting Less hierarchy between parts Normal transfer of thrusts Less popular than Chartres (Normandy) Influenced Beauvais? 25 Amiens Perception of space through movement: Horizontal, towards Altar Vertical, proportions of elevation Uninterrupted vertical shafts Height: m ; span: m Triforium lets light in Gradual dissolution of elevation turning point 26 Dimitris Theodossopoulos 13

14 Beauvais Collapse 1284 Nave height 68m Maximum expression of Gothic verticality and experimentation Reconstruction halted after subsequent tower collapse 27 Beauvais 28 Dimitris Theodossopoulos 14

15 Gothic in Britain Length: delicate balance between verticality and horizontality Moderate scale: measured excitement, less spatial explorations Clear structural logic Monastic foundations: transepts and choirs Flat east end Periods Norman ( ) Early English ( ) Decorated ( ) Perpendicular ( ) Reformation 29 Canterbury Reconstruction after fire 5/9/1174 till 1184 Pioneering construction following Durham Master-mason: William of Sens Shrine of St. Thomas a Becket (+1170) Choir: abrupt junction of piers to upper structure Sexpartite vaults Linearity emphasised by leaner ribs and Purbeck shafts 30 Dimitris Theodossopoulos 15

16 Wells Construction The first English Gothic church Modest scale (height 20.5 m) Design based on pointed arches Elegant use of shafts in piers (stone colour, proportions, light) Stiff-leaf capitals Horizontal emphasis weak vertical articulation Unique 3D treatment of screen-type façade 31 Lincoln Cathedral Reconstruction ( ) by St. Hugh after earthquake 15/4/1185 Uniformly carried out scheme Transepts and projections: effect of diffusion and lack of concentrated spatial effects Linear pattern Carved and linear elaboration (Purbeck shafts) Improved verticality Extensive tierceron ribs, unified by ridge-rib 32 Dimitris Theodossopoulos 16

17 Lincoln 33 Lincoln English vocabulary Inspirations from Canterbury Height 25 m., tot. span 24 m Proportions: vault too low, piers are slender and sparse Unsatisfactory façade Later innovations in vaulting and scale improvements at Angels Choir Clerestory and triforium Sharp intonations Crazy vaults 34 Dimitris Theodossopoulos 17

18 Westminster abbey Norman church restructured by Henry III Return to French influences (chevet, scale and proportions, triforium) and vaults (Lincoln more popular) Bar window-tracery skeleton becomes an infill Transition to (Geometrical) Decorated Ridge ribs Segmental window as equilateral triangles 35 Salisbury Construction (spire 1380) Great length (144 m), 6 times the width (24 m) Projections and double transepts Improved proportions enable lightness and elegance Nave: horizontal lines too sharp Mouldings highlight depth of elevation Interior too perfect? Linear emphasis on façade Spire and external layout 36 Dimitris Theodossopoulos 18

19 Perpendicular ( ) Reaction to contemporary Flamboyant ( ) Classical precision in craftmanship Preference for Hall Church layout and single volumes Perpendicular mullions used to support glazing of free openings required more horizontal transoms Deeper springing of vaults and gradual integration of triforium to clerestory Fan vaults: combination of (Anglo- Norman) corbelling and tierceron ribs 37 Perpendicular - King s College Tudor foundation (John Wastell) Fan vaults Heavy transverse arch separating bays Twelve rectangular bays (plan: 7.37 by 12.6 m) Fan vaults Pendentive function of cone and stone laying Stiff spandrels and low bending stresses 38 Dimitris Theodossopoulos 19

20 The Cathedral of Burgos Supported on slope of citadel hill and underground chapels Latin cross in plan: Longitudinally enclosed and fixed by a façade incorporates deep buttresses and spires East end: ambulatory and chapel of the Constables of Castile is added ring of radial chapels at apse Two-level cloister braces SE quarter Similarly stiffened facades at transepts 39 Plan 40 Dimitris Theodossopoulos 20

21 Load-bearing elements Crossing tower: focal point of scheme supported on heavy pilasters (reconstruction after collapse in 1539) Nave elevation: typical division Nave arcade: pointed arch; tas-de-charge has a large offset Top windows occupy most of clerestory but do not compromise the lateral stability of wall Double tier of flying buttresses Stone units: accurately dressed limestone (caliza de Hontoria) Load-bearing capacity of the stone masonry in good condition 41 External views 42 Dimitris Theodossopoulos 21

22 Ambulatory 43 Roof 44 Dimitris Theodossopoulos 22

23 Nave 45 Vaults Quadripartite ribbed cross vaults Nave vaults span 5.3 x 10.4 m Longitudinal vertex emphasised by rib Vaults next to transept and façade have complex net of tierceron ribs Transverse vault is stilted - thrusts are applied with offset from springing Aisle vaults: Span 6.3 x 5.3 m Transverse vertices are longer - a smooth curve was applied to reduce deflections Transverse thrusts: contained by double flying buttresses capped by pinnacles 46 Dimitris Theodossopoulos 23

24 Buttresses 47 Construction history 48 Dimitris Theodossopoulos 24

25 Upper structure Simulation as parabolic barrel vault running along axis of nave, stiffened by transverse vaults Hoop stresses S22 are low High thrusts are balanced by the flying buttresses Central portion spreads outwards The stiffer transverse web transmits horizontal deformation onto the wall - tension develops between vault and clerestory crown Compression along straight vertex of transverse vault 49 Upper structure Compression increasing at haunches indicate part of weight of vault is supported by ribs and springings Thrust twists longitudinal web Rib is crucial: guarantees good execution and continuity between webs Sharp change in curvature stiffens adjoining webs and stops spread of high stresses between webs The symmetrically supported nave cross vault functions as an assembly of four barrel vaults that form a common boundary along the groins If ribs are weak, each web behaves as a cantilever - deflections increase towards keystone 50 Dimitris Theodossopoulos 25

26 Flying buttresses High hoop compressive stresses at top edge and tension at bottom edge (abutment): indicators of good performance Spandrel fill: provides a wider area for the application of the thrust Counteraction exceeds thrust of vaults (upper tier) Role of upper tier: contain thrusts developing due to wind 51 Lateral wall Forces from upper structures are transmitted on triforium area mainly vertically Low compressive forces at pier extension - maximum 1 N/mm 2 Sharp increase in compression at tasde-charge transition- but maximum is 2.4 N/mm 2 52 Dimitris Theodossopoulos 26

27 Possible failure pattern If wall not properly braced transversely during construction, nave s weight is carried with offset Area will rotate and function as a hinge: lateral wall bursts outwards at top and inwards above capital If thrusts carefully balanced, weight of upper structure is carried to the ground Normal stresses on piers are below crushing strength of masonry: stresses at base = 1 N/mm 2 53 Lower structure Vault contained between arcade and pier buttresses Lateral thrusts are asymmetrically contained Domical pattern: probably chosen intuitively to reduce bending Nave arch fully stabilised by upper weight - mainly compression in hoop direction (max N/mm 2 ) Load twists the vault from adjacent vault - transverse rib stiffener is crucial In-plane, shear deformation similar to nave 54 Dimitris Theodossopoulos 27

28 Lower structure Domical layout: reduces deformations and enhances two-way behaviour Diagonal ribs organically bonded into the webs, acting as stiffeners High tensile forces: cracks anticipated on apex of the edge on the wall and at front haunches Cracks along longitudinal vertex should not develop Inspections show there have been repairs at the haunches - the wind has activated the flying buttresses and consequently reduced torsion of the bay 55 Conclusions Successful original design: stresses overall below strengths; deflections low and no signs of instability Continuity of the fabric is a fundamental assumption: update of support conditions of the main load-bearing elements using survey data might be required in order to improve the knowledge of the behaviour and safety of the building The model highlighted the interaction between the upper and lower structure The rib plays a key role in the execution of the difficult intersection between the webs and the efficient distribution of the loads within the entire vault according to a two-way pattern This FE model can gauge more simplified modelling strategies for the building or parts of it, while more complex loading conditions or the origin of some more specific defects can be examined. 56 Dimitris Theodossopoulos 28

29 Summary Main design issues and innovations Structural outline Chronological development Classical styles (France) Outside the canon Gothic in the UK Case study: Burgos Cathedral 57 References Acland, J. H Medieval structure: the gothic vault. Toronto University Press Clifton-Taylor, A. (1986). The Cathedrals of England. Thames & Hudson Fitchen, J The construction of Gothic cathedrals. Clarendon Press Fletcher, B. A history of Architecture. (Background: building techniques and processes) Leedy, W. C. (1980). Fan vaulting. Scolar press, London. Stalley, R Early medieval architecture. Oxford History of Art, Oxford Theodossopoulos, D., Sinha, B. P., Usmani, A. S Case Study of the Failure of a Cross Vault: Church of Holyrood Abbey. J. Architectural Engrg, ASCE, vol. 9(3), pgs Theodossopoulos, D. (2004). Structural scheme of the Cathedral of Burgos, Proc. Int. Conf. Struct. Analysis Hist. Constructions, Padua; Modena, Lourenço & Roca eds., Taylor & Francis, London, pgs , ISBN Dimitris Theodossopoulos 29