REVITALIZATION OF THE “KULA-GRDONJ”
Patriotske Lige 30
Patriotske Lige 30
Fatih Sultan Mehmet Vakif Üniversitesi, Istanbul
A good restoration project should primarily be initiated with a successful consideration of the
original idea the original designer had. It is necessary to preserve the original idea, as the
building was in the condition to bear tremendous loads during its existence. Therefore, to
renovate means to understand the way in which the structure succeeds to prove its durability.
Problems arise when there are no confidential pieces of evidence about original construction.
To add any change to the original load-bearing system should be considered as a failure in
activities of restoration, and it could be only adopted in the case of necessary demand, at the
same time respecting autochthonous architecture.
Decisions on intervention have to result from accurate estimation of the present safety level of
a construction. In order to accomplish a new satisfactory safety level, it is obligatory to take
into consideration the extent and type of planned interventions. Causes of collapses of
dilapidated and old facilities are various and they range from insufficient tensing capacity of
walls to insufficient continuity of walls, as well as the “economical aspect” of original
construction, the level of technical culture at the time, the “extended” duration of the facility,
the mistakes made while creating the original design, and finally, to the inevitable tear-and-
wear process, especially in wooden and some types of stone elements, etc. The tear-and-wear
process results from physical-chemical changes of materials’ properties.
The “Kula–Grdonj” building represents a stone masonry structure (made of hreša
walls were erected from quarry stone carved in mortar.
During the 1992-1995 war, there were large destructions of buildings caused by direct hits of
bombs, grenades and mines. Further damages were caused by atmospheric factors (rain, wind,
A type of stone found on hills surrounding Sarajevo; most similar to marble.
great oscillations in temperature) against the unprotected building, which resulted in a
complete deterioration of the whole building. What is more, the roof was also devastated.
After destruction, there were no visible signs of the roof construction.
1. PRESENT CONDITION OF THE BUILDING
The outline of the building is rectangular (9.75x9.15 m) with extensions of elliptical towers
added to the eastern and western sides of the building. The building's height is 6.95 m. The
building has the ground floor and the first floor. The floor's height is 2.94 m. The roof is flat-
moulded with the fascia height of approximately 1.10 m. The towers are covered by tin. There
is one central staircase in the building for vertical communication.
The building is made of layered hreša stone bricks. Most of the walls were erected using
quarry stone carved in mortar. The walls’ thickness is 110-120 cm. The roof structures are
made of tensioned steel metalwork and concrete leaning onto the bearing walls. All the
interior walls once had mortar layers (both rough and fine coating) and were distempered.
During the 1992-1995 war, the building was utterly damaged and directly hit by shells,
grenades and mines. The unprotected building was further damaged by atmospheric factors
(such as rain, wind, or great oscillations in temperature).
Figure 1. The condition of the building after the 1992-1995 war
The roof structures are in a rather bad condition as the steelwork has been significantly
damaged by corrosion, which is the reason there are visible open spaces in the metalwork,
parts of which have been preserved but are no longer possible to serve their purpose. The
bearing stone walls are also in a bad condition since wide gaps have remained after the
building was shelled. For that reason, the walls have lost their firmness. Apart from the war-
caused factors, the long-term effects of atmospheric factors have also contributed to the
present bad condition of the building. Also, the original design sketches are non-existent.
After a detailed inspection of the building, it has been estimated that there have not been done
any significant further interventions on the building (e.g. upgrading, reconstruction, removal
of bearing elements, replacement of materials, etc.) and that the building, as a whole, is quite
stable. Unfortunately, the investor was not able to provide additional workers who would
unearth the foundations and estimate their present bearing capacity. The project on
interventions regarding the building estimates that the load will increase. With the exception
of inspecting the present condition of the foundation structure, the preliminary detection and
diagnostics level has met the requirements, which is the reason the project documents on
eliminating damages, as well as allowing for rehabilitation, adaptation and revitalization, may
The binding materials have to be removed from the damaged walls' surfaces that need to be
removed by carving deeper into the wall surface; also, the joints need to be cleaned. After
these steps, it is necessary to carefully replace the crumbling material by new, i.e. add new
structures to the walls while at the same time preserving the original design when adding new,
rehabilitated wall pieces to the existing ones. In case the same material cannot be found, it is
possible to insert concrete in such places. As the walls are in some parts completely damaged,
it is necessary to solve the problem on how to bind the newly-constructed wall with the
existing wall mass. If done properly, a greater resistance to seismic activities will be allowed.
Figure 2. The interior of the building before interventions
The inter-floor structures are removed and the new ones, made of steel concrete, are
introduced by opening ''crevices'' in the existing structure of the bearing walls to allow the
panels to lean onto the walls. The fascia ends with a horizontal reinforced concrete ring beam
and is joined to the topmost ceiling by means of vertical reinforced concrete ring beam. This
is done to further reinforce the structure as a whole and to alleviate load of the new steel roof
structure introduced by rehabilitation, adaptation and revitalization plans of the ''Mala Kula-
Grdonj'' fortification building.
The vertical communication has been realized by means of an elevator, intended to be used by
persons with special needs, as well as by means of a staircase made of steel concrete.
Figure 3. 3D model of the building
2. METHODOLOGICAL FRAMEWORK
There follows a methodological approach (framework) to the implementation of restoration
works on heritage properties or groups of properties, which will be developed to a greater
detail at a later stage:
Table 1. Restoration Methodology Framework
As all monuments are precious, one has to respect them and try to intervene as little as
possible even though it might lead to taking certain calculated risks in order not to disturb the
structure or alter its authentic concept. The general dilemma is whether to accept and
implement the minimum intervention, which will have to be revised after a certain period of
time, or to opt for more extensive works once the structure is undergoing an intervention.
In today's circumstances, the intervention has to foresee a monument as a whole in its larger
context. This is an eclectic task - from structural aspects, conservation, but also an active
utilization and sustainable development. To this, we must add the sense of relation between
memory, territory and quality of a meaningful life, which underlies the associative heritage
work in considering the importance of place. For that reason, we highlight the concepts of
community resilience and risk management, key aspects of a response to change as we define
the word “sustainability” and the responsibility of us, the ones living at present towards the
heritage we received and towards the heritage we will leave to our successors.
We believe this sense of responsibility is under risks of disappearing, together with the ability
to interpret and understand the wisdom and knowledge pertaining to “past” technologies and
techniques. The fear is that, by lingering on the present, the ability of assessing the damage
and future devastation will be difficult to implement.
3. THE ANALYSIS AND RECORD OF STRUCTURAL CONDITION
On site survey included analysis of permanent and temporary loads, interactions between
ground foundations and structure, estimation of earthquake risk or other dynamic loads and
decay of material. The resistance of walls to static loads is usually sound, but not so for
seismic since stone structures have low resistance to tension and shear.
The structure is threatened due to tensions at the bottom of the tower, but also to the effects of
thermal variations, and especially the seismic effects (the object is in VIII seismic zone).
Analysis of the model of behavior of the tower will be the basis for evaluation and decision
making in regard to intervention and subsequent maintenance.
Reinforced concrete from the interior was probed and researched in detail and will be possible
to remove. Not only possible but absolutely necessary in order to restore the structure and
significance of the Towers.
3.1. Proposed interventions
Interventions aim to ensure the veracity of the structure:
•Restore its integrity with use of the local authentic materials and construction system.
•Historical and architectural features (openings)
•Presentation of different historic layers
•Use, maintenance plan (as a part of overall management plan for the historic core)
Specific interventions would include: Damaged wall stones must be cleaned of residual
mortar and vegetation, and replace individual stones with new ones, in exact manner of the
walls of the object. Injection of adequate material in order to strengthen the connective
substance, and prevention of further vegetation growth, as well as prevention of further
widening of the cracks, through rebuilding sections, possibly inserting steel rods and
3.2. Main aim is to explore the extent of necessary level of intervention
As all monuments are precious, one has to respect it and try to intervene as little as possible
even though it might lead to taking certain calculated risks in order not to disturb the
structure or alter its authentic concept. The general dilemma is whether to accept and
implement the minimum intervention, which will have to be revised after a certain amount of
time, or to go to more extensive works once the structure is undergoing an intervention.
In the circumstances today the intervention has to foresee a monument as a whole in its larger
context. This is an eclectic task - from structural aspects, conservation but also active use and
The analysis model of mechanical behavior of the tower is an important basis for evaluating the
reliability and the decision on the scheme intervention and maintenance. The paper will present
results of numerical FEM analysis. Detailed numerical models of two objects are developed and
3.3. Proposed repairs to the walls of the tower
•Damaged wall surfaces should be cleaned of crumbling mortar, by hand and water
•Carefully replace the destroyed wall tissue, taking into account the final appearance of
repaired and rebuilt the surface to be in the same manner as the existing wall surface.
•Injection by lime based mixtures of section of the walls to fill voids and achieve a
solid connection. This will improve the seismic resistance of the structure.
•Stop the growth of vegetation by careful removal
•Tops the crowns and walkways should be paved with mortar and clay mixtures to
prevent rainwater damage
•"Tightening" of the Tower with re-stitching the walls through rebuilding, replacement
of wood beams and iron fittings if necessary - the stabilization of the building and
taking the tension stress.
•It is also necessary to fill less visible holes in the walls with the same or similar stone
characteristics and corresponding mortar.
4. PROJECT DOCUMENTATION
Along with implementation, providing project documentation is the fundamental and most
complex task to do with the restoration of this and similar properties. Compiling project
documentation entails a range of activities that underpin the concept on which it is based.
The research, or preparatory activities listed form the starting point of this range of activities,
is the most important process which includes:
Bibliographical research, an indispensable component of the preparatory activities,
providing the project designer(s) with the initial data that enable them to create as true
a picture as possible of the building or group and, if possible, the historical
background of the property up to the present day.
Observation of the current condition of the building and its surroundings. Several
separate observations must be carried out jointly with all major participants in the
compilation of the project documentation and with each individual team member.
The purpose of preliminary observations is to arrive at an overall view of the current
condition of the building, and to conduct a joint analysis of its defects and the potential for
making adjustments to the project solution. As has been demonstrated in practice, this first
impression may also be the final impression, and hence any omissions or oversights will have
an adverse impact on completion of the task.
Figure 4. Cross-section of the new post-project condition
Figure 5. The floor structure, ground floor
Figure 6. Main structures of the building
Figure 7. Construction plans above the ground floor and the first floor
Figure 8. Construction details, roof structure bearing
Figure 9. Construction plan above the first floor
The best way to preserve a historically valuable building is to raise awareness of the historical
heritage property owner by means of projects, lectures or seminars at which she/he will be
provided with the knowledge necessary in the process of maintaining the building and at the
same time being proud to be the owner of such a valuable heritage structure. It is also
important that the building is used, and that it is used in a way that respects its historical
On the other hand, in order to be evaluated as appropriate, a contemporary intervention should
meet the following criteria: physical protection of a historic building or complex, including
conservation and restoration actions, active preservation of a historic building or complex,
incorporation into the modern urban matrix and permanent utilization.
Designers and investors -guided by building legislation, design standards and the
construction zone -need to decide on the acceptable risk level and then, bearing in mind the
costs involved, select a method of achieving either full hazard avoidance or an acceptable
level of hazard.
Designers will also use their judgment in determining the level of protection against a given
hazard (seismic forces, wind load and land subsidence): the cost of protection as ratio to the
probable losses arising during one such incident. In many cases, it is uneconomical to erect a
building that will be immune to extremes such as earthquakes, high winds, fire, etc. Full
provision should be provided against hazards with a high probability of human casualties or
extensive economic losses. Relevant factors on which the cost of seismic prevention depends
are: the seismic locality, local ground conditions, the type of structure, and normative
The basic aim in designing seismically active structures is to ensure continuity of the vital
functions within the building, to prevent human casualties, and reduce damage to a minimum.
The earthquake load to be taken into account at the design stage is based on the selected
recurrence period, which need not necessarily coincide with the maximum potential intensity
of the earthquake expected to occur in the given area, and one must be certain that at that
intensity of designed load the structure will not collapse and will suffer only limited damage.
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Conference H&mH- Hazards&Modern Heritage -"Vulnerability of 20th Century Cultural
Heritage to Hazards and Prevention Measures" Leros, Greece, April 2009
 Original Project Documentation, Faculty of Architecture, Sarajevo, 2008
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University of Sarajevo, Faculty of Architecture, Sarajevo, 2014
A.Čaušević, N. Rustempašić,-"Methodology of reconstruction of cultural-historical
heritage buildings", 9th International Congress on Heritage and Building Conservation,
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TCCE Joint Conference 2 „Seismic Protection of Cultural Heritage“, Antalya, Turkey October 31–
November 1, 2011