# Structural Analysis of the Historical Sungurlu Clock Tower
## 2 Materials and Methods
### Calculation Parameters  
The tower is located on Alparslan Turkes Street in Sungurlu District of Corum Province, on the square without a parcel in front of the Sungurlu Municipality Building located on 150 block 8 parcel and Ulu Mosque located on 150 block 6 parcel. Sungurlu Clock Tower, allocated to the Ministry of Culture and Tourism, was registered as a Group I building by the Ankara Cultural and Natural Heritage Conservation Board with the decision dated 10.08.2000 and numbered 6493. The historical clock tower has a square plan measuring approximately 2.60 \(\times\) 2.60 m at ground level (\(-\)1.30). The building, which rises with a constant width until the first-floor level (+1.15 level), has a slightly narrowing structure from the first-floor level to the second-floor level (+3.02 level). At the second-floor level, the plan dimensions of the masonry structure are approximately 2.25 \(\times\) 2.25 m, and the plan dimensions are constant until the balcony level at the +9.94 level. At the balcony level, the tower, which has dimensions of 2.15 \(\times\) 2.15 m with 5 cm more retracted on each facade, has plan dimensions of 1.95 \(\times\) 1.95 m from the +11.94 level where the clock dial is located to the +13.30 level where the masonry system ends. The masonry structure of the tower has a height of 14.60 m from the \(-\)1.30 ground level to the +13.30 level, and the total tower height is 19.00 m with the wooden mansion and the world above it (Figure 12). Figure 12: Plans, sections, and views (units cm). The masonry wall thickness of the tower structure is 33 cm from the ground to the first-floor level (+1.15 elevation), and it tapers down to 27 cm from the first-floor level to the second-floor level (+3.02 elevation). The masonry wall thickness between the second-floor and balcony levels (+9.94 elevation) is 22 cm from the balcony level. Existing restitution, restoration, and conservation reports were utilized to determine the material properties. No earthquake with a magnitude of M > 5 between 1900 and 2022 was found in the area where the building is located in the search made in the Bogazici University Kandilli Observatory Earthquake Inquiry System [20]. For dynamic analysis, earthquake parameters (Table 1, Figure 13) were determined with the help of the \"Turkey Earthquake Hazard Maps Interactive Web Application\" published by the Disaster and Emergency Management Presidency according to the coordinates of 40.162500\({}^{\circ}\) latitude and 34.374200\({}^{\circ}\) longitude [21]. Assuming that the stone masonry building elements show a single material property together with the mortar, the modulus of elasticity E = 450.000 kN/m\({}^{2}\) and the unit weight of the material, 24 kN/m\({}^{3}\), were accepted. On the prepared calculation model, constant loads and earthquake loads were applied separately in two principal directions: EQx and EQy loading. For easy evaluation of the results, two separate load components were defined as G+EQx (constant loads + earthquake loading in the x-axis direction) and G+EQy (constant loads + earthquake loading in the y-axis direction). The first 12 modes were considered in the spectral calculation, where earthquake effects were determined. The finite element model of the clock tower was prepared using 1272 points, 4770 vertices, 168 frames, and 1212 shell elements. In the Turkish Building Earthquake Code [22], compressive safety stress fem = 0.3 MPa is recommended for stone masonry walls. No reduction was made in the forces obtained due to the calculation (R = 1). The safety stresses were increased by a coefficient of 3. In this case, the bearing stresses for stone walls are (Table 2) as follows:  
Compression: fm = 0.3 \(\times\) 3 = 0.9 MPa;  
Tensile: fm(check) = 0.9 \(\times\) 0.15 = 0.135 MPa;  
Shear \(\tau\)m = 0.30 + 0.5 (0.9/2) = 0.53 MPa.