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METHODOLOGY CONCERNING THE RESTORATION OF HISTORICAL BUILDINGS

Case Studies : THE TURKISH MANSION AND THE HAGI MEHMET AGA MOSQUE IN RHODES

E. Tsakanika Civil Engineer 1 - Lecturer NTUA Athens

Neapoleos 50 – 15123 Nea Filothei – Marousi, Athens tel: 00301-6890146 e-mail :eletsaka@central.ntua.gr

1. Introduction Cultural, historical and scientific reasons, dictate the necessity to protect and save our architectural heritage, including their load bearing system, which is a very important factor of their architectural value. Ingenious systems can be found, that can surprise the modern engineer, who in many cases realises, that he discovers through modern analysis what has been discovered hundreds, even thousands of years ago with certainly much lesser means of technology. There is a lot of "hidden knowledge" even in the most poor or humble ones, about the effort of the traditional builder, to save his building and withstand the forces induced in his structure with excellent results, giving us ideas and solutions for compatible and successful interventions. The procedure of analysing and intervening has to be conducted with the close collaboration from the beginning, of all the professions that must be involved in a restoration project. The methodology of studying and assessing the structural systems of the historical buildings, has to be based on systematic survey, conducted and presented mainly in 3d axonometric sketches and drawings, of the whole building and its structural details. Non structural elements, their connection and interaction with the main load bearing system has to be recorded too, and in some cases taken into account in the numerical models, because their contribution to the overall behaviour of the building (good or bad) may be important, especially in seismic areas. The above described procedure for the evaluation and intervention has been followed in the 2 case studies that are presented in this paper (constructional analysis and the recognition of the structural system with detailed axonometric drawings and sketches, recording of the pathology, and analytical models using finite elements). In these cases, as in many historical buildings, very interesting constructional details were discovered, that pointed out the effort of the builders to tie the building, in order to withstand earthquakes, using, as usually, the timber parts of the structure. The mentality of the interventions that were proposed was chosen compatible with each structure avoiding strong interventions, reinforcing them, with light, reversible timber diaphragms at the roof and the floor, using the existing timber constructional details for the tying of the building, and the non load bearing parts (windows- partition members) as a second line of defence against a strong seismic event.

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2. THE TURKISH MANSION IN RHODES 2.1. Building’s Description - Pathology – Analysis – Assessment It is a rectangular two-storied building, of general dimensions nearly 21.0×10.0, with timber floors and a horizontal timber roof (photo. 1)2. The present situation of the building has significant problems due :

to the moisture that has penetrated it’s inside causing decay to many timber elements,

to the degradation of the porous stones, and mainly, due to the earthquake, which is the most important problem, in a very

seismic area and for a very vulnerable structural system, with which the Turkish houses of Rhodes are built. In these cases, almost all the masonries of the first-floor are just ~22cm wide, built by one single porous stone, and completely perforated due to many openings. (fig. 1)

Almost all these thin walls, have already profound from side-to-side cracks and

detaches, which appear on all the external and transverse walls. The back wall of the 1st floor is of rubble masonry, about 65 cm width, and fortunately a part of the façade is made of timber (fig. 1) .

The ground floor, which is made of rubble masonry walls, 60-70 cm wide and a

frontal arcade, of 25 cm wide, has no significant earthquake damages. (fig. 1) The biggest “headacke” for the civil engineers was the justifiable intention of the architects and the Supervision’s Committee, to reinstate the authentic morphology of the mansion and as a result, to open up all the openings of the masonries of the 1st floor, that had been built up during the last phase of the building and remained closed till now. (Fig. 2). Usually, walls with so many openings and so closely placed are made of timber. The building’s pathology was recorded in the corresponding drawings and the mathematical analysis of masonry’s present situation, with finite elements, verified the damages, the significant sensitivity of the monument in seismic events and the favourable influence of forming timber diaphragms at the levels of the 1st floor and the roof (Fig 2). A parallel systematic constructional analysis was decided to be performed concerning mainly the timber elements and their structural details, using axonometric 3d drawings and sketches. The most important result of the above analysis was, the localization of a very interesting and ingenious tying system of the building, with timber lacings in three levels of the vulnerable 1st floor.(Fig 1,2)

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In Detail The 1st level of timber lacing, is on the top of all the walls of the ground floor (70 cm wide) where two longitudinal timbers are placed and on which the beams of the floor are based. The 2nd level of timber-lacing is on the level of the lintels of the masonry of the first floor. The timber lacing-lintel, has a cross-section of about 20/7 cm, that covers nearly their whole width of the wall. Revealing and checking the connection of these timber lacings atthe corners of all walls, it was found out the conscious attempt of the builders to form a continuous system along the whole perimeter of the building, that joints efficiently the corners internal and external, feature that is the main principal of any tying system (Fig 2). The 3rd and most important level of timber-lacing at the level of the roof , (Fig 1,2), was revealed after the removal of the earth over the planks.

In the central area of the building, timber elements of great dimensions were found, with particularly impressive connections. Their existence is justified only as an attempt to connect and restrain the timber wall of the façade, which has no transverse walls and therefore, is very vulnerable in forces out of plan.

In Fig 2, the constructional details of the timber elements, revealed again the effort of the traditional builder to tie his building. It is worth saying, that in an American Manual for seismic areas, is proposed the same structural detail for tying the diaphragm timber constructions of the floor and the roof with the walls that are parallel to the timber beams.

The above mentioned analysis, both structural and mathematical, was the base of designing the following described interventions. As already mentioned, these local structural systems, are worth recognised and preserved, not only for theoretical and historical reasons, but mainly for practical ones, since their study, dictates the appropriate intervention for each one, avoiding repairs and reinforcements incompatible to the original and existing structural system of the monument. 2.2. Description of the most important Interventions Proposals for the masonry structures :

Replacement of all perished porous stones with new ones wherever this is possible. Grouting and deep rejointing with mortars, whose compositions will be compatible

with the local used materials, without cement. Good behaviour of the horizontal load-bearing elements and therefore of the whole construction, mainly depend on the capacity of carrying the vertical loads and the capacity of carrying and transporting the horizontal loads (earthquake and wind loads) to the vertical load- bearing elements. Thus, the establishment of the diaphragm action of the roof and the floo, and their connection to the masonry beneath, can improve the aseismic behaviour of the building..

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Proposals for the timber parts of the building :

The existing covering of the roof is replaced. The old parts of beams that can be preserved and have proper dimensions will be reused.

The diaphragm action of the floor and roof is achieved by the use of plywood,

nailed on the main beams (Fig 3). This building, is one of the cases that timber can be used on the top of the walls instead of the usual reinforced concrete belts, by repairing the existing timber lacings. Timber connectors instead of steel ones was proposed to be used, for the connection of the timber lacings to the masonry beneath, it, because the steel ones in many cases have caused significant problems to the porous stones of Rhodes (local climate conditions).

All decorative timber frames of the 1st floor, which are non-load bearing elements,

through proper design, are used as additional reinforcing systems of the whole anti-seismic behaviour of the building (Fig 2,4)

Finally, on the internal sides of the openings of the 1st floor, the timber perimeter

frames of the windows, will be screwed to the timber lintels –lacings of the walls. Their section will be increased and the rigidity of their corner will be reinforced with metal angles. (Fig 5).

Detailed description of the above mentioned interventions can be seen on the corresponding Figures and Tables. 3. HAGI MEHMET AGA MOSQUE IN THE MEDIEVAL TOWN OF RHODES 3.1 Building’s Description - Pathology – Analysis – Assessment Hagi Mehmet Aga mosque is on the first floor of a two storied building (Photoo2 –Fig 6)3. The vaulted constructions of the ground floor belong mainly to Knight’s Period in Rhodes and are consisted of masonries 50-80 cm wide, with limited openings and vaults 35 cm wide. First floor is based on the construction beneath eccentrically. In the mosque, two main structural phases can be recognized (1820 and 1875). During the last one, all initial numerous openings were closed, either for architectural reasons or for improving building’s earthquake behaviour. This intervention was made after repeated catastrophic earthquakes whose epicentre was in Rhodes (1862, 1863, 1869, 1874). The mosque, has been built with the typical structural system of the Turkish buildings in Rhodes ( Fig 6). This is a very audacious construction, of important height, consisted of walls in large distance (from one each other), with just one transverse internal wall. All first floor’s walls are one-stone masonry, by a single layer of local porous stone, 26 cm wide, reinforced in 5 levels by timber lacings. A particular feature of the structural system of the mosque’s masonries, is the numerous levels (5) that these lacings exist, their connection with all structural and non structural (morphologic elements) of the building, and their unusually reinforced connections. The constructional survey and analysis of their structural details is presented in Fig 6.

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It was proved, that there was an initial design of the building, since a lot of its architectural parts (external decorative projections, perimeter zones of ceilings e.g.) depend on the position of structural member (timber lacings) and in many cases protect this system that is mainly responsible for the safety of the building. The floor is constructed of timber beams (6×14 cm) every 20-24 cm. The building has a timber roof based on the last timber lacing on the top of the walls (Fig 7) . It has been built, so that the loads from the rafters are transported through the studs and the struts to the horizontal elements ( tie-beams), which finally bear all the roof’s load working not only in tension but mainly in bending, spanning 9.5 m. The above is confirmed from the dimensions of the tie-beams (the cross-section is much bigger (19/25 cm) than the section of the rafters (9/16 cm) and from the way the members are connected to each other. The studs and the struts are timbers of small cross-section (7×10 cm), their connection to the rafters and the tie-beams are quite poor, working only in compression and not in tension. Some of them are missing (Fig 7). Mosque’s structural behaviour was generally satisfying, with mainly local damages. The most important are presented consicely : cracks (top of vertical walls, lintels, opening’s base,) due to earthquake forces in and out of plane. The biggest percentage of timber lacings seems to be in good condition, although there are locations that appear local decay. Floor’s condition is generally good. Mosque’s assessment was completed with the mathematical analysis of the existing structural system of the whole building (ground and first floor). The damages were verified. The masonry was modelized by plane finite elements and the major roof’s members, and timber-lacings by linear elements. At the same time another more detailed 3d mathematical model was used for the roof, using linear finite elements (Table 1). The most critical parameter for the mathematical analysis of timber structures, is the appropriate modelization, of the connections. For this roof, the modelization of the inability to bear tension by the studs and the struts was taken into account using non-linear analysis, the results of which were compatible to the behaviour and pathology of the roof. Linear analysis gave false results, since most of the studs and struts were working in tension suspending the tie-beamw from the rafters. Through the above analysis it was verified that the structural behaviour of the roof was generally satisfactory and that the main problems were the deformation of the tie-beams and the inefficiency of the connections of the studs and struts . 3.2 Description of most important interventions For the masonry, the decided interventions are almost the same with the ones proposed for the Turkish mansion. The basic principle forf the proposed interventions, was the preservation of the existing load-bearing system, local repairs and minimization of replacements of timbers. For timber lacings, it was proposed, preservation of their healthy parts, local replacements of

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the rotten areas and reestablishment of the continuity of the old and new parts. The timber floor didn’t need any structural intervention. The most important problem of the roof, as was mentioned before, was the deformation of the tie-beam. The proposed interventions were :

Improvement of the original load-bearing system (since both studs and struts did not function due to poor initial design of their connections) by placing suspension steel systems to the tie beams, at middle of the roof, so that no bending moments are introduced to the rafters (photo. 4)

Replacement of the missing struts and studs and reinforcement of their connection

by timber wedges and bolts. (photo. 3)

The connection of the rafter with the tie-beam was reinforced with a screw in order to carry the additional axial forces that were introduced to the rafters from the new steel suspension systems.

The above described reinforced structural system of the roof was calculated again, using new mathematical models. It was found, that the existing cross-sections are now sufficient and no extra reinforcement or replacements of the timber members is necessary. For the establishment of roof’s diaphragm action and its connection to the masonry beneath it was proposed :

The use of plywood instead of timber planks connection of the roof to the timber- lacings at the top of the walls, by metal plates,

and galvanized screws, connection of the timber lacing to the masonry beneath, by timber dowels of

diameter not greater than Φ14. The use of more in number timber dowels and of smaller diameter, was preferred, so that the seismic forces are spread in a better way, and probably, greater energy absorption (photo 5). The use of timber dowels instead of metal ones, was dictated mainly by the poor behaviour of steel connectors in the porous stone of the constructions in Rhodes, and by the need of using new methods of reinforcement, more compatible with the existing local traditional structural systems and with the problems which they present. Notes 1 Working group for the restoration of the Turkish Mansion in Rhodes : E.Tsakanika, K.Athanasiadou, Civil

Engineers Working group for the restoration of Hagi Mehmet Aga Mosque in Rhodes : E.Tsakanika, K.Athanasiadou

Civil Engineers Collaborators: T.Rozos, P.Manolatos, Civil Engineers 2 Architectural survey of the Turkish Mansion in Rhodes : Mr Pitsinos. Architectural study for the restoration of the Turkish Mansion in Rhodes : G. Dellas, M Zerledis 3 Architectural survey and of the Hagi Mehmet Aga Mosque in Rhodes : S. Vogiatzis, R. Oikonomidou Architectural study for the restoration of the Hagi Mehmet Aga Mosque in Rhodes : R. Oikonomidou

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Bibliography

1) Ε. Tsakanika, S. Lazouras, “A traditionally built house of the 16th century in Athens” proceedings of the INTERNATIONAL TIMBER ENGINEERING CONFERENCE, London, 1991, vol. 3

2) P. Touliatos “Seismic Disaster Prevention in the History of Structures in Greece”, Proceedings COST ACTION E5 , “Τimber frame building systems – Seismic behaviour of timber buildings – Timber construction in the new millennium” Venice 2000.

3) Ε. Tsakanika “THE APPLICATION OF EUROCODE 5 AND 8 IN MODERN AND HISTORICAL TIMBER STRUCTURES General principles of design» Proceedings COST ACTION E5 , “Τimber frame building systems – Seismic behaviour of timber buildings – Timber construction in the new millennium” Venice 2000.

4) P. Touliatos “ The construction as a 3d space unit during the dynamic loading. The role of wood in the relevant techniques” Proceedings CULTURE 2000, “ WOODEN HANDWORK / WOODEN CARPENTRY : EUROPEAN RESTORATION SITES ” Porto 2000.

5) P. Touliatos, Ε. Tsakanika, «Examples of the timber construction in Islamic Historical structures in Greece. Αn Islamic mosque in Kos – A Turkish mansion in Rhodes. Proceedings CULTURE 2000, “ WOODEN HANDWORK / WOODEN CARPENTRY : EUROPEAN RESTORATION SITES ” Porto 2000.

Existing beams of the flat roof based on the internal timber lacing.

Fig.1 The constructional analysis revealed the effort of the traditional builder to tie the walls of the building in order to withstand the severe eartquakes of the area.

(3) The use of the diagonal timber element is reinforcing the corner of the building.

(4) At the place of the fire-place where the timber tie-beams had to be cut, metal straps were securing the continuation of the timber lacing.

(2) Small length timber elements nailed to the side of the beams and to both timber tie-beams of the East wall (width 60cm) connecting the construction of the roof to the walls.

Fig.2 Axonometric view of the existing structural system of the building The width of the stone

walls of the first floor (external and internal) is 25cm and full of openings

Timber wall of the façade Timber decorative frames

Lack of transvere walls

On the only wall of the first floor 65cm wide, two timber lacings have been placed of a cross-section nearly 10/10 cm.

Phot.1

(1) Small timber elements nailed to the last beam and the to the timber lacing at the top of the wall. The last beam parallel to the thin wall has grooves on which timber elements of the same cross-section are connected in its plane. These transversally placed elements connect the parallel beams of the roof to the timber lacing of the one-stone wall. This structural solution is found rarely and is an attempt to connect the load-bearing system of the roof to the transverse walls.

Structural model.

Timber tie beams

Timber tie beams

The width of the stone walls of the ground floor 60-70cm

Λ1 Proposed constructional detail for the connection of the timber roof diaphragm to the East wall (thickness 60cm).

Λ2 Proposed detail for the connection of the timber roof diaphragm to the thin internal and external walls (thickness 25cm).

Λ3 For the tying of the walls parallel to the beams, the existing timber constructional details are going to be used.

Fig. 3 Proposals for the establishment of diaphragmatic action at the roof level, using light reversible diaphragms of plywood, nailed to timber lacings (tie beams) at the top of the walls.

plywood sheets

Λ1

Λ2

Λ3

final surface (mortar reinforced with fibers)

water proof membrane plywood battens 6/6-insulation plywood

roof beams – new ceiling

Different ways of screwing the timber lacings and the above diaphragm to the walls, using timber elements.

timber lacing 25/10cm.

Τimber lacings 10/14 cm.

Μasonry of rubble stone Back wall of 1st floor.

the decorative elements help the collaboration of the main structural members.

Λ3

RC belt.

The frames will be reconstructed using an one piece strong timber element for their corner

They frames is proposed to be connected to the timber lacings of the longitudinal walls helping their out of plane behaviour in a seismic event.

Fig 5. The timber perimeter frames of the windows, will be screwed to the timber lintels –lacings of the walls, their section will be increased and the rigidity of their corner will be reinforced with metal angles.

The “non load bearing parts” of the building (windows and partition members Plate 3.) are used as a second line of defense for a strong seismic event

Fig 4. Reinforcing of the building using the existing decorative frames.

Timber decorative frames of poor construction .

Kalamata earthquake – Greece Photo. P. Touliatos

Fig.6. Axonometric view of the Mosque of Hagi Mehmet Aga – Constructional details of the timber lacing system of the building.

Structural model

Photo 2.

Λ2. Longitudinal connections of the timber lacings.

Λ7. Timber lacings at the level of the floor.

Λ6. The external decorative projection is based on the 3d lacing. The presense of this projection is protecting the 3d and 4th timber lacing

Λ3, Λ4. Metal plates and nails are reinforcing the connection of the timber lacings at the corner of the building.

1st, 2nd level of tying

3d, 4th level of tying

5th level of tying

37.1 33.9 33.9 24.8 24.8 11.3

33.9 37.1 24.8 33.9

11.3 24.8

0 11.3 11.3

0

0.2

37.1 37.1

37.1 37.1 18.4

0 6.2 6.2

11.3

6.2

8.2 8.2

24.8

8.2

2.9 2.9

33.9

2.9 2.8

37.1

2.8 2.8

37.1

2.9

33.9

2.8 2.9

8.2

24.8

2.9

8.2 8.2

0

2.8 0.6 0.6

0.2 0.2 0.7 0.7

2.8 0.6 0.7

The building has a timber roof based on the last timber lacing on the top of the walls (Fig 7) . It has been built, so that the loads from the rafters are transported through the studs and the struts to the horizontal elements ( tie-beams), which finally bear all the roof’s load working not only in tension but mainly in bending, spanning 9.5 m. The above is confirmed from the dimensions of the tie-beams (the cross-section is much bigger (19/25 cm) than the section of the rafters (9/16 cm) and from the way the members are connected to each other. The studs and the struts are timbers of small cross-section (7×10 cm), their connection to the rafters and the tie-beams are quite poor, working only in compression and not in tension. Some of them are missing. For this roof, the modelization of the inability to bear tension by the studs and the struts was taken into account using non-linear analysis, the results of which were compatible to the behaviour and pathology of the roof.

Fig 7. Axonometric drawings of the structural system of the roof and the connections of the timber elements.

Equivalent structural system Φ1 Without studs and struts.

The loads are not transferred from the rafters to the tie-beam.

-9.9 -9.0 -6.9 -9.9 -9.0 -6.9 -3.4 -3.3 0 -1.2

-1.5

-1.3 0.5 0.5

-1.3

-1.3

1.8 1.8 1.8

1.8 -0

Φ1 Φ2 Φ3

Plate 1. Structural model of the roof – Non linear analysis.

Central part of the roof.

-9.7

-8.9

-6.7

-9.7

-8.9

-6.8

-6.6

-9.8

-8.9

-6.8

-9.8

-9.0

-6.8

-8.7

-8.1

-6.2

-8.7

-8.1

-6.2

-0.2

-0

-0 -0

-3.1

0

0

-3.3

-3.3

0

-3.2

-3.1 0

-3.3

-3.3 0

0

0

-0

-0

-4.1

-9.4

-8.0

-9.4

-8.9

-8.0

0.2 0.1

0

0

0

0

-0

-0

-0

0

0

0

0

-1.2 -0 -1.5

-0 -1.3

-0

0.5

-0

-0

0

0.5

0

-1.3

-1.3

1.7 1.7

1.7

1.7

-0

-1.2 -0

-0 -1.3

-1.5

-0

1.7 1.7

-0

-0

-0 -1.5

-1.2

-1.3 1.8

1.8

-0.3

-0 1.7

1.7

-1.3

0 -1.5

-1.2 0

-1.5

-1.2 0

-1.3

1.8

1.8

0

-1.4

-1.4

-0

-0

1.0

0

0

0

-1.5

1.7

1.7 -0

1.7

1.7

0.5

0.5

0.5

0.5

0

0

-9.9

-9.0

-6.9

-9.9

-9.1

-6.9

-3.6 -6.6

-9.8

-8.9

-6.8

-9.8

-9.0

-6.8

-8.7

-8.1

-6.2

-8.7

-8.1

-6.2

-0.2

-0

-0

-0

0

0.1

0

-3.1

0

0

-3.3

-3.4

0

-3.2

-3.1 0 -3.3

-3.3 0

0

0

0

-0

-0

-0.1

-0 -0 -0.1

-4.1

-0 -0 -4.1

-0.1

-0.1

-4.1

-9.4

-3.6

0

0

-3.3

-4.1

-0

-1.1

-1.1

-0.9

-1.1 -1.1

-0.9

-0

-0 -4.0

-2.5

-3.9

-2.5 -0

-0

0 -1.2 -1.0

-1.1 0

-4.1 -3.3

0

-8.0

-9.4

-8.9

-8.0

-0.4

-1.1

-2.7 -1.5

-1.2 -0.8

0 0

0 0

-0.1

0.4

0.4

-0.1

-0.6

-0.6

0.2 0.1 0

0

0.5 0.3

0.5

0 0

-0 -0

-0

0

0

0

0

-1.2 -0 -1.5

-0 -1.3

-0

0.5

-0

-0

0

0.5

0

-1.3

-1.3

1.7 1.7

1.7

1.7

-0

-1.2 -0

-0 -1.3

-1.5

-0

1.7 1.7

-0

-0

-0 -1.5 -1.2

-1.3 1.8

1.8 -0.3

-0 1.7

1.7

-1.3

0 -1.5

-1.2 0

-1.5

-1.2 0

-1.3

1.8

1.8

0

-1.4

-1.4

-0 -0

1.0

0

0

0

-1.5

1.7

1.7 -0

1.7

1.7

0.5

0.5

0.5

0.5

-1.0 0

-1.0 0

-0

-1.0

-1.0

-0 0

2.0 1.9

-0

-1.1 2.0

0

-0.9

-1.0

-0.8 0

-0.9

0 -0.7

0

-0.9 0

-1.1

2.0

1.9

0

0

-0.5

-0

-0.9 -0.7

-0

0

-0.9

-0.9

-0.7 0

0.5

0.5

-0 -0.1

-0.2

-0.1 -0.2

0 0.5 0.5

-0.2

-0.1

-0.2

-0.1 0

0 0

2.0

-0

-0

x y

z

-0.8

-0.4 -0.1 -0.4

0 0

-2.3 -3.4 -3.2 1.1

1.2 -3.4

-3.4

4.4 4.4 4.4

4.4

-2.2 -3.3 -3.4

4.0 4.0

-4.3 -3.5 -3.9 4.5 4.5

4.3 4.3

-3.0

-3.3

-2.5

-3.7

-3.0

-3.1

4.9 4.9

-4.1 -4.1 2.5

-3.7

4.4 4.7

4.4

4.7

1.0

1.6

1.2

0.9

-2.1

-2.1

-2.1

-2.1

2.9 2.8 -1.7

2.9 -1.8

-1.8

-0.8

-1.8

-0.7

-1.8 -1.6

2.8

2.7 -1.1 -1.9 -0.7

-1.7

-1.7

-0.7

0.8

0.8 -0.3

-0.5

-0.4 -0.6 0.7 0.7

-0.5 -0.3

-0.5 -0.3

2.8

-3.2 -6.0 -5.7 -6.2 -1.8

-1.8

-1.4

-1.8 -2.9 -3.2 -2.9

-3.2 -2.9 -2.9 -1.4

-1.7 -1.7

-2.8

-3.1

-2.7

0.9 0.9 -0.3

-0.5

-0.4 -0.6 0.9 0.9

-0.5 -0.3

-0.5 -0.3

-1.7

-2.8 -3.3 -3.0

MAX=-6.2 kNm Element:1930

x y

z

2.7

2.5 2.5 1.8 1.8

0.8

2.5

2.7

1.8

2.5

0.8

1.8

0.6 0.6

3.0 1.4

2.7

2.5 2.5 1.8 1.8

0.8

2.5

2.7

1.8

2.5

0.8

1.8

3.6

3.3 3.3 2.4 2.4

1.1

3.3

3.6

2.4

3.3

1.1

2.4

0 0

0

0

0

0

0

1.1

0

0 0

0 0

0.8 0

0.8

0

0

1.4 0

1.1 0

0

00.8

00.8

0

0

0

0 0

0 0.7 0.7 0.8 0.8 0.7 0.7

0

0.9 0.8

0.7 0.8 0.8 0.7 0.9 0.8

0

0.7 0.7 0

0

1.8

4.4 4.2

0

0.6

0

0 0

0

0

0.6 0.6

0.9

0

0 0.4

0

0.6 0.4

0.6 0.6

0.4 0

0.6 0.4

0.6 0.6

0

0.5 0.5 0

0.8 0.5 0.5 0

0.8 0.5 0.5

00 0.5 0.5 0

0

0 0.7 0.5

0.6 0.7

0.4

0

0

0

0.6 0.9 0 0.6

0

0

3.7 3.0

4.4

3.7

4.2 3.7 3.7

1.8

0.6 0.6 0.6

0.4

0.6 0.2 0.2 0

0.5 0.2 0.2 0

0 0 0

0

0 00

0

0

0 0 0 0

0 0

0

0.2 0.3 0.3

0.2

0 0.7 0

0.5

0

0.7 2.7 1.9

3.2 2.7 3.6

3.2

4.2 3.6

2.7 2.7 3.6 3.6

4.4 4.2

2.7 1.9

00

00 0

0

3.5

1.9

0

0

0

0

0 0

0 1.4 1.4 1.7 1.7 1.4 1.4

0

2.1 1.7

1.4 1.7 1.7 1.4 2.1 1.7

0

1.4 1.4

0

0

0 0

0

3.6 2.1 0

0 1.4

0

2.7 1.4

3.6 2.7

1.6

0

2.9

1.6

3.6 2.9

1.7

0.9 0.9

0

1.7 0.9 0.9 0

0

0

2.9

1.6

3.6 2.9

0

0

3.6

2.1

0

0

1.9 0.6 0.6

0 1.6

0.7 0.7 0

0 0 0

0

0 00

0

00

4.3

3.6

3.6

4.3 3.5

4.3

3.6

3.7

3.6

3.7

2.7

3.6

1.4

2.7

0

1.4

4.3 4.3

4.2

4.3

MAX=4.4 cm Element:893

Moments diagram

ΦΟΡΤΙΣΗ 1.35g+1.5s+0.9w

Moments diagram - rafters The section of the rafters sufficient to carry the roof loads

The deformation of these members is double the allowable one.

The deformations of the tie-beams is double the allowable ones.

The internal transversal wall diminishes the deformation of the tie beams in this area

Deformation – Tie beams ΦΟΡΤΙΣΗ g

Plate2. Structural model of the roof – Non linear analysis

Photo 3,4. Τhe proposed interventions for the roof of the Mosque during the restoration works.

Steel suspension system

Reinforcement of the joints with bolts

Photo 5. Τimber dowels for the connection of the timber lacings to the masonry below.

Steel suspension system