PRINCIPLE AND PRACTICE OF REHABILITATION OF THE HISTORICAL
BUILDINGS IN SEISMIC REGIONS
Moshe Danieli1, Jacob Bloch2
1
Ariel University Center of Samaria, Ariel, Israel, madanieli@ariel.ac.il, 2 Ariel University Center
of Samaria, Ariel, Israel, blochj@smile.net.il
Many heritage buildings in the Mediterranean region are of certain value in historical,
architectural, engineering and utilization aspects. In the past these structures endured severe
earthquakes, resulting in significant destruction and human fatalities. Preserving architecturalhistorical monuments in their original state is one of the responsibilities of civilized society. As
far as preservation is concerned, it can be done in three different modes or groups of
construction techniques, namely: Conservation, Restoration, and Maintenance. Different as they
are, these groups may include similar techniques. Conservation is aimed at preventing damage
by maintaining and improving loading capacity to fit a required level. Thus, conservation is
based on proper structural design in each individual case. One should distinguish between
Temporary and Permanent conservation. Restoration is primary aimed at architectural aspects,
such as external and internal appearance, and functional roles of internal spaces, courtyards, etc.
Restoration is most important also in historical aspects. Maintenance refers mostly to utilization
of buildings. It implies large variety of checkouts and repair works carried out periodically and
based on a detailed program. The major purpose of maintenance is to prevent malfunctioning of
engineering systems, as well as loss of structural integrity and problems of durability. Repairs
are done only if needed, according to the results of periodical checkouts. All three different
modes mentioned above have their specific purposes. Successful application of these methods
depends on several factors: importance of the historical monument, its engineering state, safety
demands, possible level of technology to fulfill these jobs on the exact site, special
considerations of engineers, owners of monuments, and so on. Use of reinforced concrete
provides wide possibilities in strengthening of stone buildings, as reinforced concrete is a
material well compatible with stone masonry. It is possible to create elements that are almost
invisible in order to maintain the original look of the monument. This paper deals with examples
of actual restoration and strengthening of three religious structures in mountainous regions of
Caucasus, in Georgia, two of which were damaged by an earthquake on April 30, 1991 (a
temple in Nikortzminda and a synagogue in Oni, built in the 11 th and 19th centuries,
respectively) and a mosque in Ahaltsiche, built in the 18th century.
Fig. 1 Temple in
Nikortzminda
Fig. 2 Synagogue in Oni
Fig. 3 Mosque in Ahaltsiche
Temporary conservation of the dome of the temple in Nikortzminda was carried out, without
any delay, in order to prevent its collapse by possible aftershocks. Retrofitting of these
structures was aimed at preservation of initial geometry and appearance by creating composite
(stone–reinforced concrete) structures, which were partially or fully hidden. The stress-strain
states are analyzed using the finite-element method. This paper presents the description of the
design procedure for such cases. The authors believe that design principles applied in these
projects can provide substantial contribution to successful conservation of other stone domes. It
is worth mentioning that both the temple in Nikotzminda and the synagogue in Oni survived the
Richter magnitude 6.2 Earthquake in this region on September 8, 2009, without any substantial
damage caused.