Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2024Damage assessment of Siverek Castle during the Kahramanmaraş Earthquakes (Mw 7.7 and Mw 7.6) on 06 February 2023: Remediation and strengthening proposals
Nasery, Mohammad Manzoor; Çelik, Muhammet; Şadoğlu, Erol
On February 6, 2023, two significant earthquakes with magnitudes (Mw) of 7.7 and 7.6 struck Turkey, occurring nine hours apart. In addition to the tragic loss of over 50,000 lives in the earthquakes centered in Kahramanmaraş, hundreds of thousands of engineering structures, such as residences, schools, hospitals, historical landmarks, highways, and more, were severely damaged. This study assesses the damages and risk scenario following the Kahramanmaraş earthquakes concerning Siverek Castle. In addition, remediation and strengthening proposals, required to eliminate the damage and the possible risk, have been developed. The initial stage involved observational damage assessments on the castle and surrounding slopes as part of field studies, identifying five different types of damage and potential risks. Subsequently, a precise 3D digital model of the damaged castle and its slopes was generated using the digital photogrammetry method. Additionally, geological and geophysical studies were conducted in the field to determine the characteristics of the mound structure, historical castle walls, soil and rock on the slope. Non-destructive, geophysical methods consisting Vertical Electrical Sounding (VES), Seismic Refraction Method (SRM) and Multichannel Analysis of Surface Waves (MASW) measurements were specifically employed in the area with historical remnants. To verify the obtained data, five boreholes were drilled in the lower parts of the slope, and experimental studies were conducted to determine the soil and rock material properties of the slope. In the numerical studies, a total of 54 2D stability analyses were performed under static, long-term static, and dynamic conditions. Additionally, 1000 different probabilistic rockfall analyses were conducted, both in 2D and 3D, to calculate the run-out distance, bounce height, velocity, and kinetic energies of the blocks that fell or were about to fall during the earthquake. In the final stage of the study, remediation and strengthening recommendations were prepared for the strengthening of the fortification walls and slopes where failures occurred, and stability analyses were conducted. Consequently, a design proposal recommending five distinct approaches to remediate and strengthen the castle and slopes impacted by the Kahramanmaraş earthquakes was endorsed by the relevant authorities, and construction has commenced. When the remediation and strengthening works are completed, the security of the cultural heritage will be ensured, and it is planned to be opened to visitors.
- MakaleYalnız künye2023Multi-Scenario Analysis of Rockfall Hazard for a Historical Vaulted Masonry Building in Sumela Monastery
Nasery, Mohammad Manzoor; Cosgun, Suleyman Istemihan; Temel, Bayram Ali
Sumela Monastery located in the northeast city of Trabzon is one of the most-visited touristic places in Turkey. As it is located in a mountainous area, rockfall hazards have become a crucial problem that the Monastery complex faces, especially in the last decade. Due to several rockfall cases, the monastery was closed for visitors in 2015 to take preventative measures. The current study examines the whole stages assessing and eliminating rockfall hazards that a historical Vaulted masonry building in the Sumela Monastery is exposed to. First of all, field studies were conducted to determine the kind and type of rockfall hazard. For this purpose, the regional geology of the area was evaluated and due to the inaccessibility of the region, industrial climbers were recruited to climb the slope above the Historical Vaulted building to determine the locations, dimensions, and risk level of the risky blocks that threatened the building. After that, the terrain of the risky area was modeled with Unmanned Aerial Vehicle (UAV) using the digital photogrammetry method. In the last step of the field studies, samples were taken to determine the mechanical and physical properties of the rocks and several laboratory tests were conducted. In the second part of the study, probabilistic analyses of 2400 rockfall simulations with eight different trajectories were conducted to calculate the maximum run-out distance, velocity, kinetic energy, and bounce heights of falling blocks. In the third part, to evaluate the damage status on the vaulted building, six different possible rockfall scenarios determined by the rockfall analysis were simulated using the Finite Element Method. After determining the rock block size that would not cause significant damage to the building, the cleaning and controlled removal method of the risky blocks was determined. In the last stage, controlled crushing and removing practices for risky rock blocks were carried out and the building was restored. Consequently, the rockfall hazard for the historical Vaulted building was eliminated and the monastery complex opened for visitors in 2021.
- MakaleAçık Erişim2021Evaluation of Load-Transfer Efficiency of Steel Mesh Reinforced Contraction Joints in Concrete Pavement: Accelerated Pavement Test and FE Analysis
Celik, Muhammet; Seferoglu, Mehmet Tevfik; Akpinar, Muhammet Vefa; Nasery, Mohammad Manzoor; Seferoglu, Aysegul Gunes
Transverse contraction joints are by far the most common type of joint in jointed plain concrete pavements. Early loading of contraction joints can create a weakened vertical plane and later grow as a full-depth crack. In this study, load transfer efficiency (LTE) of steel mesh reinforced transverse contraction joints were studied at accelerated pavement tests (APT). 3D finite element (FE) model of jointed plain concrete pavement (JPCP) was developed to study deflections and crack propagation in just under the joint of the concrete pavement. The APT tests were focused on the LTE values before and after the crack initiation under the contraction joint region. Experiments were performed on three slabs in which two of these slabs were prepared without reinforcement and one of them was reinforced with steel mesh. Data generated by APT was used for verification of crack propagation modeling in the finite element analysis. Steel mesh reinforced slab gave the lowest vertical deflections (51μm) and highest LTE (91.56%). The LTE value in the reinforced slab after 25,000 passes was 13.63% higher than the average of unreinforced slabs. The findings suggest that the load transfer efficiency was found to be a complex parameter and should be interpreted together with average displacement values when contraction joints are evaluated at early traffic loadings.