Browsing by Author "Ay, Bekir Ozer"

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Citation - WoS: 5
Citation - Scopus: 5
The Effect of Vertical Motions on Damage Accumulation on Concrete Gravity Dams
(Wiley, 2023) Soysal, Berat Feyza; Arici, Yalin; Ay, Bekir Ozer
The effect of vertical ground motions on the seismic response of dams has long been a concern in the seismic design and evaluation of concrete gravity dams. The guidelines regarding the use of vertical motions in time history analysis (THA) are not clear due to the complexity of the effect as well as the large uncertainty in the motion selection process. The goal of this study is to assess the significance of vertical motions' effects on concrete gravity dams considering the relevant variability due to ground motion, system frequency response as well as the shaking level. To this end, a carefully selected ground motion set providing realistic vertical(V)/horizontal(H) loading was used in nonlinear THAs of three different systems with different modal properties. In order to evaluate the intensity of shaking on the vertical motions' effect, the responses were calculated at different seismic levels corresponding to operation, design, and maximum shaking levels. Along with traditional demand parameters commonly employed in assessing seismic response, cracking on the base and at the upstream face of the monolith was adopted as demand measures using a model capable of yielding discrete cracking on the system. The effect of vertical motions was quantified by comparing the response of H + V to H only shaking. The results show the vertical shaking can significantly affect upstream cracking for the operation or design level earthquakes, the effect increasing for larger dams.
Citation - WoS: 1
The Significance of Vertical Shaking on Seismic Assessment of Gravity Dams: A Case Study
(Springer International Publishing AG, 2024) Arici, Yalin; Soysal, Berat Feyza; Ay, Bekir Ozer
Vertical motions' effects have recently been recognized in building codes. The corresponding effects on infrastructure components is less certain. Current industry practice ignores vertical shaking based on earlier recommendations obtained using linear analyses. The goal of this study is to assess this suggestion for a case study and investigate the significance of the use of vertical motion, along with the horizontal component, during the seismic assessment of dam structures. A 50 m concrete dam monolith was used to this end and the effects of the vertical motion was assessed for two groups of engineering demand parameters (EDP). Such displacement and crack based EDPs are commonly used in the assessment of gravity dams. The response of the chosen system with and without the contribution of vertical ground motion was obtained and compared. The results show an increase in the horizontal displacement and vertical acceleration on the system when vertical ground motion was used along with the horizontal, in lieu of the horizontal only shaking case. The cracking around the neck of the system can be significantly different with the use of vertical motion, both with regard to extension and distribution.