Analysis of the Structural Behavior of Traditional Houses with an Emphasis on the Relative Wall Element; A Case Study of Kermanshah Berenji House

Abstract
This research is an interdisciplinary approach to the coexistence of structure and architecture and has investigated the architectural spaces for seismic improvement of traditional buildings which were built during the first Pahlavi Period. Despite the importance of structure and its stability in traditional architecture and in houses that have cultural heritage value, due to the complex and unknown behavior of masonry buildings and the lack of sufficient information, the regulation 2800 has not provided a specific formulation for traditional buildings. But for their seismic improvement, the magazine 360 has been used. This research seeks to answer two questions: a) What are the most important factors affecting the stability of the Berenji building in Kermanshah based on the images and data analysis? b) In the field of architecture, what is the basis for the coexistence of structures and architecture during the first Pahlavi Period? To collect information, field observation and collection methods have been used. The detailed analysis and calculations of relative wall data have been carried out by quantitative method (causal-experimental research) and library technique, and the conclusion has been expressed by qualitative method. With this method, the stability of the structure of traditional buildings could be evaluated by means of relative walls that behave like windbreaks or shear walls. If the structure did not have enough resistance against lateral force or load, it was possible to increase the relative wall or provide other methods to strengthen the structure in relation to its stability; Therefore, it is necessary to research about the cohabitation between the structure and architecture due to the increase or placement of the relative walls. Thus, static principles have been complied in Iranian architecture during the first Pahlavi Period. Now, if similar buildings are evaluated in the mentioned period and this result is obtained, it could be said that the architectural principles were followed at that time with the approach of sufficient resistance of the building against earthquakes, which was obtained experimentally. In other words, the architects of that time were structural engineers by themselves.
Keywords: Architecture of the First Pahlavi Period, Coexistence of Structure and Architectural Space, Relative Wall, Berenji House.
 
Introduction
There are many sources about the relationship between structure engineering and architecture, written by experts and researchers from both disciplines. The importance of collaboration between structural engineers and architects has long been recognized (Charleson & Pirie, 2009: 97). They have investigated the collaboration of architects and structural engineers and the fusion of the two fields in one educational center. The awareness of the fact that to use the knowledge of structure, the necessary perception must first be created, doubles the importance of understanding the fact that the structure is directly related to the architectural spaces. Thus, on the basis of such capabilities, in-depth discussions between similar scientific fields such as structure and architecture could be created and achieved logically. Dealing with this issue in traditional buildings requires a logical and scientific focus. Any retrofitting action must first respect the inherent historical cultural characteristics and values of traditional buildings (Serghides & Katafygiotou, 2013, 728). Therefore, on the basis of such capabilities, deep discussions between different scientific fields such as structure and architecture could be created and achieved in a logical way. Dealing with this issue in traditional buildings requires a logical and scientific focus.
Research questions: a) What are the most important factors in influencing the stability of the Berenji building in Kermanshah based on the data analysis images? b) In the field of architecture, what is the basis of the coexistence of structures and architecture during the first Pahlavi Period?
Research method: the research method is descriptive-historical-analytical, and the collection of information has been done in the form of field and library method using a combined quantitative and qualitative method. The analysis and detailed calculations of the relative wall data was done using Excel and the results have been expressed qualitatively.
 
Case Study, Berenji House 
This building is in Kermanshah city, Shariati Street. Shariati Street starts from the Ghadir Square (formerly called Shahnaz) and extends towards Se Rah Yaghma and Se Rah Shariati and ends in Lashkar Square. Shariati Street is one of the main streets in the old part of Kermanshah. The houses in this area are built outwardly. This building has a courtyard, the access to the floors is through two access stairs from the sides and is in the center of the transverse direction of the building. Its main design and spatial structure and analysis are shown in the form of addition and deletion, symmetry and balance, communication circulation, spatial hierarchy, repeated and single elements, geometry, and part and whole. Based on the calculations of the relative wall, in each of the longitudinal and transverse sections of the building, the value of the relative wall was calculated according to Table No. 3 of Regulation 2800. As a result, on the ground floor, an acceptable percentage was obtained in both x and y axes. But this value is lower on the first floor along the y axis according to the table mentioned on the first floor. Due to the failure of the calculated percentage of the relative wall of the first floor in the y axis, the construction load calculations were done separately for each floor.
 
Conclusion
The results show that in the presence of a relative wall, the amount of force acting on the inside of the wall has increased by leaps and bounds, and by reducing the thickness of the roof soil of each floor and the vulnerability of the building in the surrounding and internal walls with concrete sprinkled along the length and width, the building will bear more load and will not be damaged. With this method, by specifying two axes perpendicular to each other in the limited and specific walls inside the building, its performance to improve the role of the structure as a wind barrier or shear wall in a traditional brick building with minimal structural intervention could be shown. Also, this method could be a good way to preserve the heritage value of the building, enrich the architectural effect, and improve the existing physical and spatial organization (traditional house), for the proper use of the structure in the architectural space. It could be said that the adherence to the principles of architecture at that time was based on the approach of sufficient resistance of the building against earthquakes, which was achieved experimentally. In other words, the architects of that time were, in a way, structural engineers themselves. As a model for such a spatial structure, these buildings can be modeled in terms of shape for similar contemporary buildings. In other words, due to its similarity to contemporary architecture, the goal and achievement of this research can be a model for old houses and could be extended to modern houses.