1.1 Extended Introduction

1.1 Extended Introduction

This study will initially focus on the context of Tirana's cultural heritage buildings, designed during Italian influence at the period 1920-40s, literature and data collection, “also analysis, which will be further compared with the European context, Italian architecture and with similar cases in content. Tirana represents a very special occasion, unique in terms of intertwining the Italian architectural design, combined with Albanian motives and details. This feature of this category of buildings has resulted from many political, economic and social factors of the time that radically changed the way of vision and architectural conception in the Albanian capital. It has been a long time since that period, now the urban-architectural and construction vision of modern Tirana is changing, but it still preserves the most valuable part of the assets and the beauty of the old architecture.”

During the period 1920 to 1940, a group of Italian architects, or rather designers reviewed existing urban plans and proposed new and more efficient plans for Albanian cities. The Italianstyle architectural heritage and its monumental structures designed during the 1920s in Albania possess precious architectural and cultural elements that must be preserved and promoted, and to achieve this, we can begin by first identifying and presenting them to the community, also a wider range of professional stakeholders and experts. Through the treatment of this study, some of these buildings have been identified and selected, the research focuses on buildings with institutional functions, highlighting their architectural qualities through analysis, investigations and modeling in addition to engineering performance. Through the cases of study on the typology of buildings the aim is to explain and know the design morphology, materials, architectural survey, data collection and BIM modeling. The data of this study will serve for future restoration interventions, in order to help re-evaluate the architectural and urban landscape.

Looking over Albania territories, many professionals are surprised by the big quantity and the quality of this architectural heritage for which have left traces among the best Italian architects and engineers of that period, each with their own skills and militancy in the movements of that time. These designers can be placed within a well-defined cultural "map" that reflects the great ideological aspirations of their country, “the spirit of the beginning of the twentieth century, Eclectism, Rationalism etc.”. The “historical period considered is marked by a rich production of projects, sometimes realized, in some cases not, which have however produced a trace in the imagination of the citizens, often marking a drastic change in the way of "living in the city", closely linked to politics and to the ideology of power.”

The current situation of these buildings today can be considered problematic in terms of urban performance. During this period in Tirana, an urban-plan is being implemented where it considers the vertical and horizontal expansion of the city, extending in three new rings. Approximately within 2030 the city it will extend to 4 rings. Also, the current city of about 1 million citizens anticipates a progressive increase in the coming years, this has given priority to the government for "expansion, urban planning and infrastructure". “Referring to the buildings in the study we can say that they are also neglected in terms of structural performance aspect. These buildings, being positioned in the central axis, are also considered the assets of the city, so, have been constantly maintained to their façades in aesthetic terms, mainly” in painting and plastering. There has never been an in-depth scientific study regarding their structural performance as well as seismic consolidation projects. “Apart from this, no structural engineering

studies have been carried out over the years, on the capacity and current state of their construction. Currently, there are no in-depth, accessible computer models with complete data on these buildings (with a time file) including their architectural or engineering point of view.”

The main difficulty as well as dilemmas related to 3d models dealing with “seismic rehabilitation of historical monuments is the dominance of ambiguous data but compelling values of the structure model that comes across with the transparency and ease of structural (or seismic) engineering techniques and technology in reducing seismic hazard risk on old buildings. The gap between these two different classes of problems is similar to the known gap between art and science and their reconciliation can be achieved only based on morals and theories.”

The “inherent value of architectural heritage buildings is indebted to their originality and authenticity, matured appearance and the charm of their designer impression. None of these values have a real substitute, or any solution in our contemporary life and any damage to these architectural assets cannot be authentically restored. This is, perhaps, the main reason for our nostalgic sentiments toward any change, modernization or restoration in these category of buildings. Accordingly, architects, engineers, archeologists, historians and those institution responsible for cultural-historical aspects of the society have developed a kind of sensitive attitude against any restoration strategy for these treasures. In many similar cases, this attitude has reached to a 0-tolerance level if restoration program for the building suggests strengthening the whole system beyond its authentic capacity” . In many literatures, “it's always argued that the great designers of the past” have accomplished creation of a "perfect building" and there is no need for strengthening of such structure for a long time. “But it must be admitted that this argument does not serve the reality and our precious buildings need to be studied, investigated and simulated many unfavorable scenarios, seismic risks or beyond” .

Obviously, “seismic rehabilitation in cultural heritage structures causes damage to the originality, impression and beauty of the building and should be done, only, if there is a real necessity, such as when structural stability” is compromised. “When these monuments are located in a region prone to earthquake hazards, the task of the researcher or architect is not to preserve the historical values of the building only at this time, but to extend these values to a longer time span. This can be accomplished in the most efficient way, only if very detailed numerical and graphic models are created, to enable many simulations, scenarios and scientific cooperation between disciplines” . Actually the experts should try to rationalize the concept of historical values. In fact, there is a need to add another dimension to the concept of historical values, their life expectancy regarding the earthquake hazard risk in the Balkan region, carefully analyzing risk factors, reliability coefficients, but not only. Without ignoring the problems of the age of the structure, the degradation of materials or atmospheric conditions which directly affect the performance of structures. So, if historical values can survive longer “considering all the above risks” “they should be considered more valuable through multidisciplinary modeling” .

In this way, “addressing the issue of scientific studies related to these buildings beyond the aesthetic or transitory threshold, including seismic or all risks may add to the historical values of the city and can increase efficiency of the issue of restoration” . This requires weighing the current historical values together with that after the interventions strategy “when contemporary architectural values are reduced but their life expectancy improved”. “Such weighing procedure eventually leads us to a consensus on whether the interventions or seismic retrofit plan should be recommended or not according to each specific case. In general terms there must be a well-

organized interaction between structural engineers, architects, archaeologists, and so on to take their views into the consideration” “regarding the damage tolerance” and prepare not to stick to a predefined level of structural & seismic hazard risk for cultural heritage buildings. This is something difficult in theoretical and applied terms, but a methodological basis which can be advanced through computer modeling can minimize the current gap in this issue.

One of the aims of this topic is to assess the current performance of architectural heritage structures, based on the current scientific knowledge mainly of seismic discipline, summarized in literature, guides, codes and standards, through a conservative process of "research, architectural survey, site investigations, BIM-modeling and simulations", without neglecting the theories of restoration, the basic concepts of international restoration charters.

The primary purpose in dealing with this issue, closely related to the study of Cultural heritage Buildings in Albania is to raise the awareness at the academic level initially, starting with practical guidance to improve theoretical and applied methodology for conservation and restoration practice. It aims to assess the performance of these buildings, and also to evaluate and compare their seismic performance in their existing state even according to the requirements of Eurocodes.

Primary vision with announced objectives of the study is to develop a methodology which will help the process of research in the field of restoration in Albania to be improved. This will be made possible through an input-output system serves in the form of a manual in academic rank for addressing the issue of cultural heritage restoration, collaborating and combining with engineering fields, maintaining an immovable pillar of architectural principles and postulates in implementation.

Structural interventions on historical buildings, must be carried out with great care and sensitivity if important special features of the buildings and its essential historic character are to be properly safeguarded. In the first instance, it is therefore always advisable to do plenty of research and obtain the right advice.

Today there are a lot of solutions or intervention techniques on the market, that are well suited to the needs of reversibility and low invasiveness on existing buildings. These tangible contributions are the result of a lot of researches and technological innovation in the academic environment. Regarding this fact, the aim is to further advance this current research product, addressing specific cases such as Albania, conclusions which may contribute to the regional or global context.

Appropriate refurbishment of cultural heritage buildings and their structures is a crucial part of their conservation to ensure they have a safe and sustainable future. Improving the performance of buildings and protection of the historic environment through a careful and critical process, with more research activities and modeling, are therefore strong objectives.

In the elaboration of this thesis, three main cases are treated in detail, including a fourth case theoretically treated in the annexes. Starting with Municipality of Tirana building was dealt with, a historic masonry building from the early 1929s which during the first half of the 1990s underwent an expansion to accommodate other municipal offices; continuing with the analysis of the Complex of buildings of the Polytechnic University, a typical building of 1940, with the