Munich 2008 minoan timber structures - constructional analysis -tsakanika


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Munich 2008 minoan timber structures - constructional analysis -tsakanika

  1. 1. “The constructional analysis of timber load bearing systems as a tool for interpreting Aegean Bronze Age architecture” Dr. Eleftheria Tsakanika-Theohari Civil Engineer, NTUA Introduction Though, timber masonry reinforcements constituted a common feature of wall construction, attested in most of the civilizations that developed in the Eastern Mediterranean during Bronze Age, most studies on the architecture of this era do not emphasize on the use of wood as a structural element. Wood “is the invisible hero. Invisible since hardly any wood has been preserved to prove its presence and hero since it carries a large part of structural loads” as Palyvou comments characteristically for Akrotiri.1 Invisible indeed, also because the systematic and generalized use of timber as autonomous structural elements (columns, pillars and piers), frames (pier-and-door partitions, doors, windows), or horizontal and vertical timber reinforcing systems of rubble, mud brick and ashlar walls, is rarely and not systematically studied. This paper is based on a research conducted for Minoan timber load bearing systems and reinforcements of masonry in the framework of a Ph.D dissertation.2 The difficulties that such a research faces are many. In prehistoric archaeology one has to work with architectural remains, and not whole buildings, trying to understand the role of structural elements that do not exist anymore3. As Graham points out4 “Since well preserved remains are rare we must depend largely upon inference, conjecture, and analogy for the study of the use of wood in Minoan architecture”.5 The only indications of its presence are voids in the walls, mortises and horizontal beddings curved on dressed stones to provide a resting place for the connection of horizontal timber elements. Even these few but valuable data, can be lost due to the unavoidable “destruction” during the excavation procedure, due to restoration works, in several cases necessary, and unfortunately due to the luck of protection of vulnerable structural materials (Fig. 1). Concerning the method of recording the architectural remains, another problem arises since in several cases, especially in older excavation projects, there is inadequate documentation of the architectural and structural elements, either of the whole building, or of significant constructional details.6 Documentation consisted of a few drawings, mainly plans, lacking usually sections and elevations7. The constructional details were briefly recorded, usually in texts, but 1 2 3 4 5 6 7 Palyvou 1999, 425. Ε. Τsakanika-Theohari, «O δομικός ρόλος του ξύλου στην τοιχοποιία των ανακτορικού τύπου κτηρίων της Μινωικής Κρήτης», Ph.D. diss. N.T.U.A, Athens 2006. There are many difficulties in understanding the structural role of timber load bearing systems even in existing buildings with existing timbers. Graham 1962, 145. But even in cases as Akrotiri, where the “amount of information is overwhelming”, we must be very careful in our interpretations because “one may easily fall into the trap of thinking he has understood it all” (Palyvou 2005, 13). Naturally it depends greatly on the presence of architects during excavation works. See also Nelson 2001, 4–5,17. A usual problem for the documentation of archaeological sites is the recording, in one general plan, of architectural remains which belong to different levels. If the conventions of architectural design are followed, each level should be depicted in a different drawing. In order to have an idea of the whole excavation area, the architectural remains of a lower floor could be included in the plan of the last preserved floor, but they should differentiated. The sections in these cases are very important too. 127
  2. 2. (Mylonas PAE 1971) (Tsakanika 2004) Fig. 1. Mycenae. Building E, Room 1. The very rare imprints of the timber reinforcing system on the mud-brick wall have been gradually lost for ever. rarely in drawings or sketches. Therefore, it is quite difficult for a modern scholar to understand an architectural element or a constructional detail that was found years ago. Their original state as found during excavation can not be reproduced through written descriptions, not mention the considerable problems regarding terminology.8 Taking into account that the language of communication in architecture is drawings, the best way to record architectural remains in order to present them in a comprehensive way for the next researchers,9 is the use of general plans, sections, elevations and mainly axonometric sketches either of the whole building10, or of the structural details11 accompanied but not replaced by photographs. Data recording should be followed by an analytical procedure, that includes constructional analysis. This kind of analysis is based on the identification of the main characteristics and the typological classification of the structural systems. The study of the typology of load bearing systems includes several parameters12: – The structural type and quality of the masonry (type of stone and mortar, width, way of construction of the wall both in the horizontal and vertical level), – the type and dimensions of the timber elements, their number and location within the thickness of the masonry (in one face of the wall, both faces, hidden in between), their number and location along the length and the height of the wall, – the connection of the timber members to each other13, the most critical part for the evaluation of their structural behavior, 8 9 10 11 12 13 Palyvou 1999, 39–40. See also Tsakanika 2006, 52–54 concerning the term “xylodesia” in Greek and English. Tsakanika 2001, 232–233. See axonometric drawings of buildings or parts of buildings in Palyvou 1999, 2005, Rethemiotakis 1999, pl.CL3 – Galatas, Sakellarakis 1997, fig. 31 – Archanes, Platon 1974, fig. 40, 103, 105 – Zakros, Evans PMI–IV). See axonometric drawings of details in Palyvou 1999, 2005, Shaw 1973, Nelson 2001. For the evaluation of the timber structural systems used during Bronze Age in Aegean, every gap timbers left, the existence and the exact position of every mortise or bedding on ashlar members has to be recorded. The method of recording and presenting the collected data, must be suitably organized in order to be easy to recall, observations that refer many times to small, tiny constructional details hidden in a corner of palace. See also Tsakanika – Palyvou – Touliatos 2006, 2 (in press). Unfortunately, in Bronze Age architecture, information regarding the connections of the timber elements is almost non existent. The fact that nails or other metal connectors were not used, as in most timber 128
  3. 3. – the connection to the other load bearing and non load bearing elements of the building, an equally critical issue. The next step, the interpretation of all the collected data (synthesis procedure), may lead us to conclusions, comments and queries concerning : – the role of each structural element, as a basic step towards the recognition of the overall load bearing system of the building.14 – the building techniques applied and their relation to the type, the chronology and the phases of the buildings and, – the reasons that made one structural solution to be preferred over another, since the choices of initial design, and the final quality of the architectural result, high or low, depend crucially and directly on the construction techniques applied and vice versa. The interpretation of architecture is a complex procedure and must be derived from the assessment of all the parameters that affect the architectural design: historical, architectural, constructional and structural. Case Studies Some of the main typological characteristics of Minoan timber structural systems will be discussed briefly, focusing mainly on examples that highlight their possible use as a tool for interpreting Aegean Bronze Age architecture. Horizontal timber reinforcing system of rubble masonry The horizontal timber reinforcing system embedded in masonry walls, was continuously used for about 1300 years, throughout Minoan era. During the Prepalatial period, at Vasiliki Ierapetras (Red House) and during the Protopalatial period (first palace of Phaistos), this system was used as a reinforcement for the rubble walls of these important buildings. It is interesting to note that especially for the Red House at Vasiliki, several scholars, including Evans15, expressed the opinion that a vertical timber reinforcing system was used in walls made of sundried mud bricks16. In reality, the masonry both at Vasiliki and at the first palace of Phaistos, 14 15 16 load bearing systems built during historical periods for which we have a lot of information, is one more difficulty. The structural role of a load bearing system can be evaluated by engineers also through mathematical models (quantitative way). But in order to use this tool, a necessary presupposition “is the recognition of the structural system, its behaviour and pathology through constructional analysis (qualitative way). The results of this evaluation will give the necessary information for the formation of the proper mathematical model that must be compatible with the existing building. Otherwise a significant danger is to calculate with the best computer program and the best knowledge of the relevant Standards the wrong model even of the simplest structural system”. (Tsakanika 2001, 231). Evans PM I, 72, “Large sun-dried bricks were used in the upper part of the walls, which were also framed vertically and horizontally with wooden beams, their inner and outer framework being linked by cross bars … Α massive timber framework was from the first associated with the good masonry of the MM age, an inheritage from the Early Minoan buildings of which the remains at Vasiliki supply the best example”. See also: Pendelbury 1963, 62, Vermeule 1964, 35, Branigan 1970, 46, Hood 1971, 61. Shaw is the first who pointed out that the materials and the structural system of this very important building for the evolution of constructional methods in Minoan Crete could not be the above, at least with the evidence that exists on site today. (Shaw 1973, 140, note 2). See also Tsakanika 2006, vol. 2 (Vasiliki, first palace of Phaistos), Tsakanika – Palyvou – Touliatos 2006, 3 (in press). 129
  4. 4. Possible arrangement of the horizontal timber grid embedded in a wall of the first Palace of Phaistos. Fig. 2. Red House at Vasiliki Ieraperas. The position of horizontal timber elements in the rubble masonry behind the thick layer of the plaster, are marked (Tsakanika 2006) by yellow color at the photos and by green color at the published plan by Zois (1976). was built with small and medium size rubble stones, with large amount of mud mortar, reinforced with a horizontal timber grid of unworked timber trunks or tree branches laid longitudinally as runners and transversally as cross-ties in different levels of the walls (Fig. 2). Vertical timber reinforcing system of rubble masonry During the neopalatial period the load bearing system of palatial buildings changed17 and the use of wood increased considerably18. One of the most important changes concerns the reinforcement of rubble walls. The above mentioned timber horizontal system though it was aban17 18 Compared to the first palace of Phaistos. It must be pointed out however, that the high level of technological knowledge used in the construction of new palaces and villas, characteristic of the Neopalatial period, could not be achieved in a short period of time. It must have been the result of experience that was enriched over time. The amount of the wood used for the construction of the palatial buildings is enormous. See also Tsakanika – Palyvou – Touliatos, 2006, 11–12, fig. 8 (in press). 130
  5. 5. doned in the palaces and palatial buildings (type 1 according to McEnroe)19, continued to be used at least in Thera, in houses of type 2 according to McEnroe. The well-built walls of the palatial buildings of the Neopalatial period, with medium and large stones, were reinforced by an elaborate vertically placed timber system. The vertical timbers set in pairs, were based directly or with the interval of a transverse timber member, on a stone base placed as stretcher through the wall, 20–90 cm above the floor. Traces for longitudinally placed horizontal timbers appear at the level of the lintel of the doors and windows within the few walls that exist at that height (Fig. 3). Another pair (?) of longitudinal timbers may have existed at the level of the upper horizontal timber of the pier-and-door partitions20 (Fig. 3). Unfortunately, there are no traces on the walls to indicate the use of transversal timbers, except for some comments by Mackenzie in his daybooks for Knossos21 and Palyvou’s evidence from the South wall of Xeste 322. From a structural point of view, their existence is necessary at least at the same levels that the longitudinal timbers exist, in order to make the timbers on either side of the walls collaborate. The most important information concerning not just the masonry reinforcements but the overall Minoan palatial structural system is derived from the “Hall of Double Αxes”, the best preserved part of the palace of Knossos and probably of all palatial buildings in Crete. This is a suitable occasion to mention again how important is the method of recording architectural data referring to the excellent axonometric drawing of Theodore Fyfe (Fig. 3).23 Even if he had done numerous plans, sections and elevations he could not transfer to us, 100 years later, so vividly and mainly with such clarity, what has been found. Of course between his drawing and the real archaeological data there is always his own interpretation. But this is inevitable. On the other hand, in many excavation reports and published drawings there is lack of adequate recording of the embedded in the walls vertical timbers. As a result, some scholars supposed that their use was limited in certain areas. Working on the documentation for the use of vertical timbers in masonry, it was discovered exactly the opposite. Their use was quite generalised and systematic24, especially at the palace of Knossos and almost all palatial buildings around it, with the only but important exception of the new palace of Phaistos. This exception arises questions that need to be investigated through future research, concerning the reasons that dictated the absence of these reinforcements, while all other typical characteristics of Minoan palatial architecture (ashlar masonry, pier-and-door partitions, timber pillars and tim19 20 21 22 23 24 It could be interesting to note the comment of Loyd (1963, 169), for the evolution of the timber reinforcing systems at Beycesultan “the habit of strengthening stone or mud-brick walls by inserting at regular intervals rows of runners cross-ties goes back at Beycesultan to considerable earlier period. The elaboration of this system by means of vertical timber posts, extending from the foundation to the roof and thus creating a timber framework in the structure of the building, seems to have been an innovation in the Middle Bronze Age”. Tsakanika – Palyvou – Touliatos, 2006, 4–6 (in press). See Page 1L, Wednesday, 1 March–Saturday, 11 March 1905. The access to Mackenzie’s daybooks and Evans’s notebooks was possible through an electronic version that made the work much easier. I. Paterson had the kindness to give me permission to use them since their transformation to electronic files was a part of his dissertation thesis “Structures and Stratigraphy of the So-called Reoccupation Period at the Palace of Knossos, Crete and the Contexts of the Linear B Archives”, University of Edinburgh, 2002. Palyvou, 2005, 123, fig. 173. The axonometric drawing was made in ca. 1929 and was published in the third volume of the Palace of Minos (as plan G) without any reference to the architect who made it. I would like to thank the recently established Society Aegeus and in particular Nektarios Karadimas for helping me to identify the real creator, i.e. T. Fyfe. Of the same opinion is also Shaw (1973, 145). It is worth mentioning that a first version of this axonometric drawing was published in 1901 (BSA 7, 1900–1, 116, fig. 36). At least for one building phase. See also Tsakanika – Palyvou – Touliatos, 2006, note 9 (in press). 131
  6. 6. (PM I, fig. 251). Remnants of timbers as found during excavation. Possible connection of the vertical and horizontal timber members. The presence of the 2nd horizontal longitudinal timber is documented at the level of the lintel of the “skylights” of the pier-and-door partitions. The presence of the 1st longitudinal timber is documented at the level oof the lintel of the doors, windows and pier-and-door partitions. Possible constructional representation of the vertical timber reinforcing sysstem embedded in masonry walls. Fig. 3. Palace of Knossos, “Hall of Double Axes”. Axonometric drawing by T. Fyfe (PM III, plate G). 132
  7. 7. Fig. 4. Villa of Ayia Triada. The visible vertical timbers embedded in the retaining rubble walls of room 4, a unique example for Minoan Crete, show that the Minoan builders knew how to use timber. They wouldn’t make the mistake to hide them behind gypsum slabs, trapping the humidity of the ground and causing their decay.26 ber piers embedded in the walls) are present.25 Another question that emerges is why the use of vertical timber reinforcements is so extensive in Ayia Triada (Fig. 4), being similar to Knossos palace and not to Phaistos which is closer, just 1500m away?26 Once the constructional features of a structural element (e.g. the above described vertical timber reinforcements) is well understood, we have to go back and re-examine the buildings because now we may see things we couldn’t see before. For example the vertical timber at the West face of the wall seen in Fig. 5 (white frame in the picture), can not be recognized easily. Its existence starts to become evident when we expect it to be there since at the other face of the wall there is clear evidence of a vertical timber, its pair. Using the following two examples we could highlight how the recognition of the features of a structural system could help clarify the constructional phases of the buildings. 25 26 According to some theories, a distinctive structural feature of the palace of Phaistos in relation to the other palaces, is the unquestionable use of stone for the upper floors. But there are reasonable doubts whether this difference really exists. The extensive use of mud brick walls at the upper floors of the Minoan palaces and villas as several scholars have stated, is not so self-evident. In Minoan palatial buildings, the reduction of the loads at the upper floors, a common argument for the use of mud brick walls, could be achieved by the extensive use of wood inside the walls and the extensive use of timber frames (pier-and-door partitions, doors, windows) which substitute large masses of compact walls. For more arguments see Tsakanika, 2006, 237–240. It must be noted that in Domestic Quarters of the Knossos palace, the vertical timber reinforcing system of the rubble walls was covered by gypsum slabs till the level of the lintels, and by plaster till the roof (Fig. 3, axonometric drawing). Visible vertical timbers may existed in four archaeological sites, but in these cases they were reinforcing ashlar walls (at the Palace of Knossos – N Bastion, at Archanes-Room 32, 33, at the Royal Villa – Hypostyle Crypt and in area 9, of Ayia Triada). 133
  8. 8. Fig. 5. Palace of Knossos. North part of the West Wing. The vertical traces and the stone base that can be detected on the face of the wall, indicate the existence of a vertical timber. At the South and central part of the West Magazines in the palace of Knossos, the stone bases we expect to see under the vertical voids that timbers had left in the masonry, are not there (Fig. 6,7). Taking into account that at the North part of the West Magazines, the stone bases exist and are visible (Fig. 8), as in most other places of the Knossos palace, a probable hypothesis is that the existing floor at the South and central part has raised and may belong to a more recent construction phase than the walls. Such an observation may prove to be valuable for an archaeologist working on the history and the phases of the palace. The second example comes again from the Knossos palace. Having always in mind, that a typical building technique is that the vertical timbers are always in pairs, we expect that behind the transversal walls with direction N–S in the West part of the palace (areas 31,34) are hidden vertical timbers that belong to the longitudinal wall with direction W–E (Fig. 9, black frame). Their existence would mean two things. Either the longitudinal walls with direction W–E belong to an older building phase from the transversal ones since they were built first, or they belong to the same phase, but the construction procedure of the particular structural system dictates the longitudinal walls (W–E) to be built first and the transversal ones (N–S) after them. 134
  9. 9. Fig. 6. Fig. 7. Fig. 6, 7. South and central part of the Magazines at the West Wing of the Knossos palace. There are no traces of the stone bases on which the vertical timbers usually rest. Storeroom 13 Fig. 8. At the North part of the Magazines, the stone bases are visible. 135
  10. 10. Fig. 9. Fig. 10. Fig. 9. Plan of the area West of the Central Sanctuary (Hood and Taylor 1981). The vertical timbers are marked by red color (Tsakanika 2006). Fig. 10. (PM I, fig. 241). The vertical timber (white frame) was embedded in the wall before the construction of the pier-and-door partition. Of course, another hypothesis could be that the rule of using vertical timbers in pairs is not so strict and in the areas that two walls meet transversally (in a “T”), is not followed. But if we examine the data we have for the longitudinal North wall of the “Hall of the Double Axes”, from the excellent survey of the palace made by Hood and Taylor (1981) along with photos during excavation (Fig. 10), we can see that a pair of vertical timbers existed behind the pierand-door partition. The above item constitutes another indication for the second assumption, according to which the longitudinal walls were built before the transversal ones, if of course the pier-and-door partition belongs to the same building phase with the North wall of the “Hall of the Double Axes”. It is interesting to note that a building method of this kind is not typical at all. Usually the load bearing walls of a masonry structure are built all together as the building is rising up. Horizontal timbers in coursed ashlar masonry The coursed ashlar walls of Minoan Neopalatial buildings, both in palaces and houses, are of exquisite craftsmanship – the best in the eastern Mediterranean world.27 It is a mixed structural component since the outer face is made of ashlar blocks, wedge shaped or trapezoidal in plan, an intelligent technique, since the rest of the wall is made of rubble backing and needs to be connected and collaborate with the ashlar part. A very important characteristic of Minoan coursed ashlar walls, that seems to be common during the Bronze Age around the Aegean28, is the use of horizontal timber elements placed between the ashlar courses. Their use is not common for the facades of the buildings29, but they exist in ashlar walls inside the buildings30, in light wells (Domestic Quarters of the Knos27 28 29 30 Palyvou, 1999, 154. Their existence has been testified also in ashlar walls of Mycenaean palatial buildings, in Mycenae, Pylos and Thebes. But in these cases, contrary to the Minoan examples, the 1st level that a horizontal timber member has been documented interrupting two successive courses, is above the 1st course. See also Wright’s representation (1984, fig. 10) for the SE façade of the Palace at Pylos, ashlar walls around the Central Court at the palace of Mycenae. Palyvou, 2005, 119. Some of them are retaining walls, as the West wall of the light well in Queen’s Megaron and the West wall of the four-pillared Hall in the Unexplored Mansion. 136
  11. 11. Fig. 11. Knossos Palace. Coursed ashlar masonry at the light well of the “Hall of Double Axes”. The sketch on the right (section and axonometric view), is a representation of a possible constructional detail of the horizontal timber system embedded in ashlar walls. sos palace), possibly at the open corridor 41 of Phaistos palace, even in roofed spaces as in the case of the four-pillared Hall of the Unexplored Mansion.31 The necessary data to identify the typical structural features of the horizontal timber reinforcing system embedded in ashlar masonry are scant and the representation that is shown in Fig. 11, corresponds to evidence that derives just from one case, the light well of the “Hall of Double Axes”. The external longitudinal timbers were probably orthogonal in section and they were connected to the stones under them with timber dowels.32 Longitudinal timbers were placed at the other face of the wall, made of rubble, as Evans and Mackenzie have noted in their excavation daybooks. From a structural point of view33, we would expect the longitudinal timbers to be connected with transversal ones. The question is whether the original imprint on the mortar that Evans left intact at the West wall of the light well in “Double Axe Hall” is an indication of their existence (Fig. 11, white frame). It must be pointed out that the existence of mortises on the first course of an ashlar wall of Minoan buildings, indicates the position of a horizontal timber that corresponds to the sill of the timber frame of a window34 and not to a horizontal timber that runs along the wall interrupting the first and the second ashlar course (Fig. 12). 31 32 33 34 Further research needs to be done in order to answer why the horizontal timbers are absent in ashlar facades. There must be a clear architectural and structural reason for this. At Phaistos palace there is evidence for the existence of horizontal timbers above the last preserved course of the North ashlar wall of the Central Court. But this case is not the same since the ashlar wall most likely stopped at that height. See also Shaw, 1973, fig. 210, Graham, 1962, fig. 50. The use of vertical timbers embedded in coursed ashlar masonry is another significant feature of Minoan architecture. See Tsakanika, 2006, 127–129. The existence of mortises on the dressed stones under the horizontal timbers, has been testified in the published quite detailed drawings and photos of the Pillared Hall of the Unexplored Mansion (Phopam, 1984). The use of transversal timber members along with the longitudinal ones, is a common feature of the timber horizontal reinforcing systems of rubble and mud brick masonry, used either during prehistory or during more recent historical periods. For their structural role see Tsakanika, 2006, vol. 1, 51–54. For windows see also Shaw, 1973, 174–182, fig. 205a, b, Tsakanika, 2006, vol. 1, 195–202. 137
  12. 12. Fig. 12. Light well at Villa Nirou Hani. The mortises on the ashlar stones (white frames) indicate the presence of a window. The horizontal timber at the level of the sill does not continue on either side of the window while the timber at the level of the lintels usually does (see Shaw, 1973, fig. 205a, b for windows at Ayia Triada). Fig. 13. The horizontal timber is serving various structural roles along the walls of the Hall of Colonnades at the Knossos Palace. In Minoan architecture, the first level that a horizontal timber is embedded in ashlar masonry between two successive courses, is the level of the timber lintel of the openings (pier-and-door partitions, windows and doors) which coincides also with the level of the first horizontal member of the vertical reinforcing system of the rubble walls (Fig. 3). The existence of these timbers at the same level in various structural elements is not accidental. 35 A timber “zone” must have been created intentionally because otherwise how could one explain that at the light well of the Grand Staircase, the horizontal timbers coincide this time with the sill of a window that had to be built higher because behind it there is another staircase. And how could one explain that the horizontal timber that continues at the same level further, turns right and becomes a timber “belt”, that “embraces” the balustrade of the Grand staircase (Fig. 13), while on the 35 PM I, 349–350, fig. 252. See also Tsakanika, 2006, vol. 2. Tables for Domestic Quarters – ashlar masonry, E–W Corridor. From a structural point of view, the above constructional feature is very important. It seems that a horizontal timber zone was created at the level of the lintels in order to provide connection points for the different and autonomous structural elements that constitute Minoan palatial architecture, and moreover make the building work as one entity resisting vertical and horizontal forces. Tsakanika, 2006, 245–249, Tsakanika – Palyvou – Touliatos, 2006, 6–12 (in press). 138
  13. 13. North wall of the E-W corridor becomes the timber that rests between the two constructional phases of the wall (Protopalatial and Neopalatial) ? It is quite clear that through all the Domestic Quarters this horizontal timber “zone” is systematic, constant and continuous,36 highlighting and proving once more that Minoan palatial buildings are the result of a high-level initial design and not an incoherent and arbitrary arrangement of space. Epilogue In all the above cases different structural systems and details have been presented along with observations, conclusions, comments, and queries that could be helpful to the future researchers of the same or similar structures, to suspect the existence of timber elements, search and detect the way they were constructed, since most of them do not exist anymore. The methodology used for the identification of the structural features of the Minoan load bearing systems could also be helpful for comparative studies concerning various timber systems used by neighboring civilizations that flourished during Bronze Age. Finally through this work, the contribution of another scientific field, civil engineering, could be recognized as another tool in the hands of archaeologists for the interpretation and study of ancient civilizations. Selected bibliography PM I–IV: EVans, A. J.: The Palace of Minos at Knossos, vol. I–IV, London 1921–1935. GrahaM, J. W., 1962: The palaces of Crete, Princeton 1962. hood, W. – Taylor, S., 1981: The Bronze Age palace at Knossos: plan and sections, London 1981. McEnroE, J., 1982: The Typology of the Neopalatial Houses, American Journal of Archaeology 86 (1982): 3–19. Mylonas, G., 1971: Ανασκαφή Μυκηνών, PAE 1971. nElson, M. C., 2001: The Architecture of Epano Englianos, Greece, Ph.D. diss, University of Toronto, 2001. PalyVou, C., 1999: Ακρωτήρι Θήρας – Η οικοδομική τέχνη και μορφολογικά στοιχεία στην Υστεροκυκλαδική αρχιτεκτονική, Athens 1999. PalyVou, C., 2005: Akrotiri Thera. An Architecture of Affluence 3,500 Years Old, Athens 2005. PalyVou, C., 2007: The Cosmopolitan Harbour Town of Ugarit and the “Aegean” Aspects of Its Domestic Architecture. In: BETancourT, Ph. – nElson, M. and WIllIaMs, H. (eds.): Krinoi kai Limenes, Studies in Honor of Joseph and Maria Shaw, INSTAP Academic Press, Philadelphia. PoPhaM, M. R., 1984: The Minoan Unexplored Mansion at Knossos. Texts and Plates, London 1984. shaW, J., 1973: Minoan architecture: materials and techniques, ASAtene 33, 5–256, Rome. shaW, J., 1999: A tale of three bases. New Criteria for Dating Minoan Architectural Features. In: BETancourT, P. – KaraGEorGhIs, V. – laffInEur, R. – nIEMEIEr, W. (eds.): Meletemata. Studies in Aegean Archaeology presented to Malcolm H. Wiener as he enters his 65th year, Aegaeum 20, Liège-Austin Texas 1999, vol. 3, 761–767. TsaKanIKa, E., 2001: The application of Eurocode 5 and 8 in modern and historical timber structures. BErTolInI, c. (ed.): Proceedings of European Program Culture 2000: Italian Action: Wooden Handwork/ wooden carpentry: European Restoration Sites, Torino 2001, 223–234. TsaKanIKa-ThEoharI, E., 2006: O δομικός ρόλος του ξύλου στην τοιχοποιία των ανακτορικού τύπου κτηρίων της Μινωικής Κρήτηs, Ph.D. diss. NTUA, Athens, 2006. TsaKanIKa, E. – PalyVou, c. – ToulIaTos, P., 2006 (in press): Ο δομικός ρόλος του ξύλου στη Νεοανακτορική Αρχιτεκτονική της Μινωικής Κρήτης, Proceedings of the 10th Cretological Congress, Chania 2006. ZoIs, A., 1976: Βασιλική Ι, Νέα αρχαιολογική έρευνα εις το Κεφάλι πλησίον του χωριού Βασιλική Ιεράπετρας, Athens 1976. 36 It is interesting to note that this structural feature is commented by Mackenzie in his notebooks. 139
  14. 14. Die Architektur von Lasttragenden Holzsystemen als Mittel zur Interpretation der bronzezeitlichen Architektur der Ägäis Dr. Eleftheria Tsakanika-Theochari Bauingenieurin, Lektorin an der Technischen Hochschule Athen (EMPA) Zusammenfassung Im ganzen östlichen Mittelmeer zur Bronzezeit ist hölzernes Tragwerk ein gemeinsames Merkmal des Werkstein- und Ziegelmauerwerks und notwendiger Bestandteil der Baukunst in den meisten Kulturen dieser Region. Über Jahrzehnte hindurch konzentrierte sich die Forschung der prähistorischen Bauten hauptsächlich auf die architektonischen Merkmale der Gebäude. Ihre Bauweise, ihre einzelnen Elemente, das Tragwerk und der Bauprozess waren selten Gegenstand der Forschung. Das hauptsächlich in den Forschungen der ägäischen Archäologie hervortretende Bauelement war der Quaderstein, viel weniger das Holz. Vom systematischen, allgemeinen Gebrauch von Holz, sei es am selbständigen Tragwerk (Pfeiler bzw. Säulen), an Rahmen (Polythyra, Türen, Fenster) oder als hölzerne Stütze (horizontal oder senkrecht an Bruch- und Quadersteinmauern) wurde selten und auszugsweise gesprochen, obwohl das Holz erwiesenerweise die Architektur der Minoer und anderer benachbarter Kulturen jener Epoche zeichnet. Dieser Vortrag basiert auf der im Rahmen meiner Dissertation1 erfolgten Untersuchung zum hölzernen Tragwerk und der hölzernen Zugverstärkung der Mauern im minoischen Kreta. Die Untersuchung der verschiedenen Typen, ihrer Einordnung und Klassifizierung führte u.a. zu folgenden Ergebnissen: – Erkennung ihrer Hauptmerkmale und Bewertung bzw. Klärung ihrer Rolle. – Semantische Analyse und Erklärung der Bausysteme als archäologisches Instrument zur Erkennung der Bautechniken und zur Datierung der Gebäude und ihrer Bauphasen. – Formulierung von Erkenntnissen und Fragestellungen über die Ursachen der Auswahl diverser technischer Lösungen, ist doch das architektonische Endergebnis, ob hoch- oder minderwertig, direkt abhängig auch von den angewandten Baumethoden und umgekehrt. Die architektonische Planung hängt von vielen Faktoren ab, die vielfach in einander greifen. Die Darstellung eines Bauwerks ist demnach ein äußerst komplexer Prozess und muss sich auf die Mitbewertung aller historischen, gesellschaftlichen, architektonischen, bautechnischen, sogar das Tragwerk betreffenden Elemente stützen, umso mehr, als diese Gebäude vor mehreren Jahrtausenden errichtet wurden und nur geringe Elemente erhalten sind. Anhand dieser Methodik kann eine vergleichende Forschung durchgeführt werden und können die Ähnlichkeiten bzw. Unterschiede der hölzernen Tragwerke an der Baukunst benachbarter Kulturen der Bronzezeit in der Ägäis erkannt werden. Dabei ist zu bemerken, dass die heute geläufige Betrachtung der hölzernen Mauerverstärkungen als einheitliches System zu falschen Schlüssen bezüglich Entwicklung und gegenseitiger Beeinflussung der Bautradition der Ägäis in der Bronzezeit führen kann. 1 E. Tsakanika-Theocharis, Die Rolle des Holzes am Bau der palastähnlichen Gebäude im minoischen Kreta, Dissertationsarbeit bei der Technischer Hochschule Athen (EMPA), 2006. 140
  15. 15. Η κατασκευαστική ανάλυση των ξύλινων φερόντων συστημάτων ως εργαλείο για την ερμηνεία της Αιγαιακής αρχιτεκτονικής της Εποχής του Χαλκού Δρ. Ελευθερία Τσακανίκα-Θεοχάρη Πολιτικός μηχανικός Περίληψη Στην Εποχή του Χαλκού σε όλη σχεδόν την Ανατολική Μεσόγειο, οι ξύλινες ενισχύσεις αποτελούν κοινό χαρακτηριστικό των τοιχοποιιών (λιθοδομών και πλινθοδομών) και αναπόσπαστο στοιχείο της δομικής τέχνης των περισσοτέρων πολιτισμών που αναπτύχθηκαν στην περιοχή αυτή. Για πολλά χρόνια, η έρευνα των προϊστορικών κατασκευών εστιαζόταν κυρίως στη μελέτη των αρχιτεκτονικών χαρακτηριστικών των κτηρίων. Ο τρόπος κατασκευής τους, τα οικοδομικά τους στοιχεία, ο φέρων οργανισμός, καθώς και η διαδικασία οικοδόμησής τους σπανίως αποτελούσε αντικείμενο μελέτης. Επίσης, το δομικό στοιχείο που κυρίως έχει προβληθεί στις μελέτες της Αιγαιακής αρχαιολογίας είναι η λαξευτή τοιχοποιία και πολύ λιγότερο το ξύλο. Ή συστηματική και γενικευμένη χρήση του ξύλου είτε στα αυτόνομα φέροντα στοιχεία, υποστυλώματα (πεσσοί, κίονες), είτε στα πλαίσια (πολύθυρα, θύρες, παράθυρα), είτε ως ξύλινες ενισχύσεις (οριζόντιες και κατακόρυφες σε αργολιθοδομές και λαξευτούς τοίχους), αναφέρεται σπάνια και αποσπασματικά, μολονότι το ξύλο αποτελεί όπως αποδεικνύεται, το υλικό που περισσότερο από κάθε άλλο φαίνεται να χαρακτηρίζει αλλά και να σηματοδοτεί την Μινωική Αρχιτεκτονική καθώς και άλλους γειτονικούς πολιτισμούς της εποχής αυτής. Η παρουσίαση αυτή έχει ως βάση την έρευνα που έγινε στο πλαίσιο διδακτορικής διατριβής1 για την χρήση των ξύλινων δομικών συστημάτων και των συστημάτων ενίσχυσης των τοιχοποιιών στην Μινωική Κρήτη. Η συστηματική εξέταση της τυπολογίας τους, της κατάταξης και ταξινόμησής τους είχε ως αποτέλεσμα : – Την αναγνώριση των κύριων χαρακτηριστικών τους και την αποτίμηση και ερμηνεία του δομικού τους ρόλου. – Την ανάδειξη της τυπολογίας και της ερμηνείας των ξύλινων δομικών συστημάτων ως εργαλείο αρχαιολογικό για την αναγνώριση των κατασκευαστικών τεχνικών, την χρονολόγηση των κτιρίων και των οικοδομικών τους φάσεων. – Την διατύπωση συμπερασμάτων και προβληματισμών για τα αίτια που οδήγησαν στην επιλογή της μιας ή της άλλης κατασκευαστικής λύσης, αφού το τελικό αρχιτεκτονικό αποτέλεσμα, υψηλό ή χαμηλό εξαρτάται άμεσα και από τις χρησιμοποιούμενες κατασκευαστικές μεθόδους και το αντίστροφο. Οι παράγοντες που επηρεάζουν τον αρχιτεκτονικό σχεδιασμό είναι πάρα πολλοί και με πολλούς τρόπους αλληλοεπηρεαζόμενοι. Η ερμηνεία, επομένως, ενός κτιρίου είναι πολύ σύνθετη διαδικασία και θα πρέπει να προέρχεται από την συναξιολόγηση όλων των στοιχείων: ιστορικών, κοινωνικών, αρχιτεκτονικών, κατασκευαστικών ακόμα και εκείνων που αφορούν τον φέροντα οργανισμό. Πόσο μάλλον, όταν το κτίριο έχει κατασκευαστεί αρκετές χιλιάδες χρόνια πριν και ελάχιστα στοιχεία του έχουν διασωθεί. 1 Ε. Τσακανίκα-Θεοχάρη, O δομικός ρόλος του ξύλου στην τοιχοποιία των ανακτορικού τύπου κτηρίων της Μινωικής Κρήτης, Διδακτορική Διατριβή Ε.Μ.Π. Αθήνα, 2006. 141
  16. 16. Μέσω της παραπάνω μεθοδολογίας είναι δυνατόν να γίνει συγκριτική μελέτη και να αναγνωριστούν οι ομοιότητες ή οι διαφορές των ξύλινων φερόντων συστημάτων που εμφανίζονται στην αρχιτεκτονική γειτονικών πολιτισμών την Εποχή του Χαλκού στο Αιγαίο. Πρέπει να επισημανθεί ότι η συνήθης θεώρηση των χρησιμοποιούμενων ξύλινων ενισχύσεων των τοιχοποιιών ως εάν να ήταν ένα και μόνον σύστημα, μπορεί να οδηγήσει σε λανθασμένα συμπεράσματα για την εξέλιξη και την αλληλεπίδραση της αρχιτεκτονικής παράδοσης στο Αιγαίο την Εποχή του Χαλκού. 142