Morphology of the Vernacular Masonry Structure in Adana City and Its Qualitative Analysis According to the Rule of Art

Abstract

Adana city has a significant risk for seismicity in the past, today, and in the future. Therefore, traditional unreinforced masonry houses in Adana city and their structural qualifications are essential to provide information on these buildings, which will be of value to researchers and practitioners, policymakers, and disaster managers. Therefore, one of the traditional houses was examined by identifying the construction details, damage, and collapse analysis in the Tepebağ settlement. At the end of the study, the construction details and their description could be added to the literature. In addition, the rule of art was used for interpreting the crack, damage, and predicted structure collapse scenario. Working on the rule of art was not enough separately to identify the collapsed analysis of the building. Besides, engineering applications and calculations are the other critical scientific aspects for determining the collapsed scenario. However, the rule of art is efficient for architects to predict the damage and collapsed analyses of the old structures.

1. Introduction

This paper’s subject is the determination of the morphology of the Adana Tepebağ traditional house structures with their crack, degradation, and predicted collapsed analysis using the rule of art. The traditional houses in Tepebağ are a part of the significant architectural heritage in Turkey. Understanding the primary structural system and its qualifications is essential for sufficient restoration work to conserve those structures. There is always a gap in data for traditional houses’ structure and construction details in restoration work. Moreover, the architects need a practical method for predicting damage and collapse analyses of those structures.

Many researchers work on Tepebağ houses, but a few work on the details of the structures and construction. In addition, the prediction of the collapse scenario of those structures is a gap for research. Therefore, this paper is an improved study of the construction, degradation, damage, and prediction of collapse analysis of the traditional load-bearing structures in the Tepebağ settlement.

The rule of art is used to answer the questions and gaps in research areas. After the analysis, the data show that the construction type and condition of the Traditional houses in Adana-Tepebağ are critical against the seismicity. In addition, their construction details are not very effective for seismic loads. There are some precautions for providing extra strength for horizontal loads. But they are not very sufficient. This paper provides valuable data and analyses for future restoration works and research.

2. Seismicity in the Adana region

Adana is located in the southeastern part of Anatolia, close to the border of the Mediterranean Sea, which was one of the historical cities of Turkey. So many civilizations were placed in this city. In a chronologic order, Adana was a settlement of the Hittite Kingdom (B.C. 1900–1200), Assyria Kingdom (B.C. 713–663), Persian Satrapy (B.C. 612–333), Seleukos Empire (B.C. 312–133), and Roman Empire (B.C. 112–A.C. 395), before being a part of Ramazonoğlu seigniority (sixteenth century) and following Turkish civilizations.

Tepebağ was the oldest historical settlement in Adana. According to the bibliographic sources, this area is the first placement of the Hittite Kingdom. The new neighborhoods such as Kayalıbağ, Ulucami, Sarıyakup, and similar regions were developed when the city was expanded from the Tepebağ through the south. The traditional houses in Adana were built in the seventeenth century in those settlements. With the city’s trade progression, people’s wealth increased; therefore, the typology of the traditional houses changed and got bigger. Those big houses were designed as two or three-story, called “konak” [1]. Mostly those houses belonging to the tradespeople were more prominent than the city’s other houses.

The traditional houses of Adana are authentic and essential heritage in this region. However, from the past to the present, they were at risk of damage from environmental aspects. One of those aspects was seismicity. Therefore, identifying the seismic risk of this region, the tectonic faults, and their location with the historical seismicity of the area was examined. As seen in the below figure, the land had a complex tectonic regime. The location of the Adana was between the Göksu and Ecemiş faults. Besides those faults, the Eastern Anatolian fault and its extension faults are passing on this land. The African, Anatolian, and Arabian plates intersect in this area. The Eastern Anatolian fault is the most effective and causes many seismic events (Figure 1).

Figure 1.

Faults on the Klikya area; AB: Adana Basin, AN: Andırın, DAF: Eastern Anatolian fault, E.F.: Ecemiş fault, GFZ: Göksu fault, G.S.: Girne ridge fault, H.F.: Hatay fault, İB: İskenderun basin, K.B.: Klikya basin, K.F.: Karasu fault, L.B.: Latakia basin, MS: Misis ridge, ÖDF: Ölü Deniz fault, Y.F.: Yumurtalık fault [2].

Historical seismic activities in Adana city and its surroundings are shown below in Figures 2 and 3. In Figure 2, the marked locations on the map were signed according to the estimated and calculated historical seismic location and time. It brought an idea about the historical seismicity of this area. In Figure 3, all the marked areas were the locations of seismic activity after 1951.

Figure 2.

The historical seismic activity of the Klikya region with marked location and time [2].

Figure 3.

“Beach balls” represent the focal mechanism in the region, mainly strike-slip and normal faulting [2].

One of the most significant historical seismic activities in this area happened in 1114 near Ceyhan Adana, with a magnitude of 7. In the recent past, the most important seismic activities happened in Adana city in 1945, 1952, and 1998 with a magnitude of 6.1, 5.2, and 6.3, respectively [3].

The magnitude of the Adana earthquake in 1998 was 6.3, which caused various damages to more than 4000 buildings [4]. Although the historical structures essentially in the Tepebağ region and its surroundings were affected by this earthquake, most of them collapsed. Today, few numbers of registered buildings remained in this region. Most of those structures were in bad condition [5].

In site analysis, it was observed that the structural systems of the historical houses in Adana-Tepebağ region were damaged. Those damages could be occurred from the seismic activities or other environmental effects.

The morphology of Vernacular masonry wall structures in the Adana-Tepebağ traditional houses clarifies the key concepts of masonry construction techniques against seismicity.

3. Morphology of Vernacular masonry structures in Adana-Tepebağ traditional houses

In general, the traditional houses in Adana-Tepebağ were built in the nineteenth century up to two to three floors. The load bearing and timber frame system were used on the structures of those houses. Oriels and eaves were the architectural units of those houses.

In this chapter, the construction materials and construction techniques that were used in Adana-Tepebağ traditional house structures were examined.

3.1 Building materials

In the Adana-Tepebağ region, dry soil, stone, and timber were the primary construction materials in traditional buildings. The building materials were an essential step for getting the historical texture. Mainly timber was used in a vast area.

Stone, brick, and adobe were widely used as masonry wall materials and infill materials in historical structures in Adana.

The construction materials and their application areas were varied in historical buildings. The dry soil is used in flat roof structures to provide extra heat to the interior spaces. Stone material was used in basement wall structures identically used in Turkish house construction. And the timber was used on the upper floors as a frame system with infill of brick, stone, and adobe blocks for keeping the temperature in the interior space and providing a light structure for the upper floors against the seismic action. Besides this specification, the timber frame wall with infill materials provides airflow and prevents humidity inside the wall [4, 6].

3.2 Building techniques

Three primary structural systems were used in traditional houses in the Adana region. The load-bearing system with stone or brick was widely used in these buildings (Figure 4). The second technique was timber frame with stone, brick, and adobe infill. Generally, brick was used for the infill material around the Tepebeğ region. The corners of the building were strengthened with timber bracing for the seismic actions. Besides, timber beams were passed inside the stone masonry walls to provide horizontal strength for the masonry structure. In last, “Bağdadi” was a construction system with a timber frame covered with timber lath and finished with plaster.

Figure 4.

The elevation of the traditional Adana-Tepebağ house [7].

The traditional houses in Tepebağ were raised from the underground water with stone masonry, and after, brick masonry was knitted on a stone base. The brick masonry structures were supported with 80–90 cm timber beams on the outer walls. The timber lintels were placed on upper and lower parts of the window and the door openings. The masonry wall thickness of the ground floor was 60–65 cm (Figure 5).

Figure 5.

The cross section of the traditional Adana-Tepebağ house [6].

The space between timber studs was 120, 200–250 cm, which was used to build timber frame walls with infill materials to support timber beams on the first and above floors of traditional Tepebağ house structures. The timber bracings were used on the corners of the timber walls to prevent collapse under seismic effects.

The timber beams inside the brick masonry walls were placed with a checker pattern. The general use of the timber beams was 8–10 cm. The dimension of the timber studs was 20–25 cm. The corner studs of the walls are thicker than others.

The roofs were designed as flat or hipped roofs with the use of dry soil or timber [4, 6]. The oriels were supported with 15–15 cm timber bracings, which were repeated with 80–100 cm space horizontal. The balconies were designed in half cantilevers with 100–150 cm lengths.

4. The rule of art

The rule of the art was to define brick masonry walls and timber frame structural deficiencies with their mechanical behavior. The following steps were identified according to the rule of art.

• Interpretation of quality through the walls of the crack.

• The behavior of the masonry wall according to the horizontal and vertical actions.

4.1 Interpretation of quality through the crack walls

The picture of the lesions is highly indicative of detecting the quality of the walls. Irregular cracks or degradation on the wall layer, which are spread everywhere, indicate that the wall is not properly connected with its unit element brick or could be a sign of separation of masonry layers. Therefore, masonry walls could be at risk of getting damaged or collapsed.

The masonry wall has a monolithic behavior, and the wall is composed of two or more layers. The layers of the masonry walls were attached to retain their shape and form under horizontal and vertical forces. But lesions on the layers could decrease the connection and overall functioning of the masonry wall.

The purpose of the survey of the masonry is to define the degradation and failures of the materials and structure. By these definitions, the damage mechanism of the masonry structure is identified. In the analysis of typical vulnerabilities of the structure, defining degradation and disruption of the structure is to be determined.

The figures in Tables 1–3 are the proposal symbolism for the representation of the crack and degradation of the masonry wall structures (Tables 1–3), [8, 9, 10, 11].

Table 1.

Crack and degradation of the masonry; A [8, 9, 10, 11].

Table 2.

Crack and degradation of the masonry; B [8, 9, 10, 11].

Table 3.

Crack and degradation of the masonry; C [8, 9, 10, 11].

4.2 Behavior of the masonry wall according to the actions

The behavior of the masonry wall structures is under the effect of three actions.

• Vertical actions

• Horizontal loads in-plane action

• Horizontal loads out-of-plane action

4.2.1 Vertical actions

The masonry wall structures are under risk of vertical action, which means vertical loads are subjected to the state of compression. The wall under the state of compression determines different situations depending on the stress, such as gravity loads besides and various magnitudes of seismic actions escalated the amount of vertical loads on the structure.

The masonry walls are composed of a varied number of vertical leaves and quality of materials, which determined its behavior under compression. In the following table, the effect of vertical loads on masonry as a result of cracks, possible sector of rotation, and single wall failure mechanism is symbolized (Table 4), [8, 9, 10, 11].

Table 4.

Vertical actions [8, 9, 10, 11].

4.2.2 Horizontal loads in-plane actions

In-plane action, the mechanism of the masonry wall can be triggered by various seismic intensities. The wall’s quality and ductility level allow for avoiding collapse even for earthquakes of high intensity.

The quality of the connections between masonry walls, the type of masonry, and the characteristics of the laying materials determine the behavior of the masonry under the effect of in-plane action.

In the following table, the effect of in-plane action on masonry occurs cracks, possible sector of rotation, sliding, and single wall failure mechanisms, which are symbolized (Table 5), [8, 9, 10, 11].

Table 5.

Horizontal loads in-plane actions [8, 9, 10, 11].

4.2.3 Horizontal loads in out-of-plane actions

In out-of-plane action, the masonry wall is under the effects of perpendicular loads, categorized as seismic and wind loads. The presence of connections between two leaves of a masonry wall is crucial for its behavior for out-of-plane actions. The type and tied connections between masonry leaves are determined by the failure mechanism of the wall structure.

In the following table, the effect of out-of-plane action on masonry occurs in cracks, possible sectors of rotation, and single wall failure mechanisms are symbolized (Table 6), [8, 9, 10, 11].

Table 6.

Horizontal loads in out-of-plane actions [8, 9, 10, 11].

5. Case study

The rule of art applies to the case study to identify the building’s damage analyses and possible collapse scenarios. The case study is selected from the Adana-Tepebağ region, which is under risk of seismicity.

5.1 Traditional Tepebağ house with inventory number 63

The house is located in Adana-Tepebağ, with inventory number 63. It is assumed that it was constructed in the nineteenth century. The house is built on two floors with load-bearing structural system. Brick material was primarily used in masonry walls. Timber material was used in different parts of the structure; in floor-roof slabs and beams inside the brick masonry walls. Besides, the oriel was constructed with timber materials. And dry soil with timber beams was used for building the flat roof (Table 7), [12].

Table 7.

Traditional Tepebağ houses with inventory number 63 [12].

According to the rule of art, crack and degradation analysis and possible collapse scenario were determined for the traditional Tepebağ house with inventory number 63. In the following pictures (Figures 6–9), cracks and damaged areas of the house are identified with arrows, lines, and instructions.

Figure 6.

Traditional Tepebağ house with inventory number 63, north-east view.

Figure 7.

Traditional Tepebağ house with inventory number 63, east view.

Figure 8.

Traditional Tepebağ house with inventory number 63, south-west view.

Figure 9.

Traditional Tepebağ house with inventory number 63, west view.

On the north side of the building facade, there was a significant loss of brick materials because of the low bonding strength of the bricks and the detachment of the masonry leaves. The second clue of the detachment of the masonry leaves was one crack on the upper corner of the roof, which was under the stress of vertical loads (Table 8).

Table 8.

The rule of art, crack, and degradation analysis and possible collapse scenario for the traditional Tepebağ house with inventory number 63, A.

The timber beams and lintel were at risk of deterioration and were not continuing through the entire wall length. The load-bearing walls are insufficient to support the dead load of the flat dry soil roof. Therefore, there was a detachment and outpour within the joint parts of the masonry and the roof beams. The stone arch was supported with thick masonry brick walls. However, one side of the arch wall was standing on the opening of the brick masonry, which caused cracks and deflection (Table 9).

Table 9.

The rule of art, crack, and degradation analysis and possible collapse scenario for the traditional Tepebağ house with inventory number 63, B.

6. Conclusion

With the use of methodological progress and analysis, with bibliographic research, it will be understood that traditional houses in the Adana Tepebağ settlement are at risk of deflection and collapse against seismic activities because of their uncared and damaged structures. Moreover, it was understood that the rule of art was an efficient tool for predicting the collapse scenario of those structures. For improving the bibliographic research, the construction materials and the exact historical construction techniques were identified for future conservation works and research studies. For future research, the possible conservation ideas and applications of those buildings could be studied to provide a bibliographic source for restoration works.