• Structural Engineering and Mechanics
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• 제91권2호
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• pp.123-133
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• 2024

The assessment of seismic behavior and seismic performance of ageing Sarıyar concrete gravity dam constructed on Sakarya River in Türkiye is the main focus of this paper. For this purpose, the impact of sediment domain, ageing of concrete material under the impact of chemical and mechanical actions, and dam-water-sediment interaction are included in the two-dimensional (2D) finite element (FE) model developed in FORTRAN 90 environment. In the FE model, the dam and age dependent sediment domains are modeled by solid elements, while reservoir domain is modeled by Lagrangian fluid elements. The radiation of reflected waves to the unbounded water domain is modeled by infinite Lagrangian fluid elements, while unbounded sediment domain is modeled by infinite solid elements. The coupled system was assumed to be under the simultaneous impact of Vertical (V) and Horizontal (H) ingredients of 1976 Koyna earthquake and the coupled system was analyzed in Laplace domain by direct method. Due to the deterioration of the concrete, the H and V displacement responses together with the fundamental period of the body, elongate throughout the lifetime and this reduce the seismic safety of the dam. It was deduced that the ageing dam body will not experience major damages under the Koyna earthquake both at the earlier and later ages. Furthermore, at the heel of the dam, the hydrodynamic pressure responses are decreased by rising the sediment domain depth.

• Earthquakes and Structures
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• 제26권1호
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• pp.59-75
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• 2024

This paper presents a dam-reservoir interaction model that includes, water compressibility, sloshing of surface water, and radiation damping at the far-end reservoir, to investigate the influence of concrete deterioration on seismic behavior along with seismic performance of gravity dams. Investigations on seismic performance of the dam body have been conducted using the linear time-history responses obtained under six real and 0.3 g normalized earthquake records with time durations from 10 sec to 80 sec. The deterioration of concrete is assumed to develop due to mechanical and chemical actions over the dam lifespan. Several computer programs have been developed in FORTRAN 90 and MATLAB programming languages to analyze the coupled problem considering two-dimensional (2D) plane-strain condition. According to the results obtained from this study, the dam structure shows critical responses at the later ages (75 years) that could cause disastrous consequences; the critical effects of some earthquake loads such as Chi-Chi with 36.5% damage and Loma with 56.2% damage at the later ages of the selected dam body cannot be negligible; and therefore, the deterioration of concrete along with its effects on the dam response should be considered in analysis and design.

• 한국산학기술학회논문지
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• 제21권3호
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• pp.1-9
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• 2020

가뭄은 한번 발생하면 사회·경제·산업 활동 등 인간의 생활 전반에 걸쳐 영향을 미치게 된다. 이러한 가뭄 등의 자연 재해로부터 국민의 생명과 재산을 보호하는 것은 국가의 중요한 책무이다. 현재 우리나라 저수지의 약 75.7%는 준공 후 50년 이상 경과된 노후 저수지이며, 이로 인한 토사 퇴적 등의 영향으로 제원정보 대비 저수능력이 부족할 수 있다. 따라서 본 연구에서는 자율항법 무인측량선을 활용하여 노후 저수지 10개소에 대해 저수용량을 분석하고, 과거 경험적 공식에 의해 추정된 퇴사량과 비교·분석하였다. 분석 결과 6개 저수지는 제원정보 대비 약 16.2% ~ 55.3%의 저수용량이 감소하였으며, 4개 저수지는 제원정보 대비 약 1.5% ~ 380.2%의 저수용량이 증가하였다. 실제 측량 결과와 경험적 공식에 의한 퇴사량 비교·분석 결과 어린지와 용포 저수지는 유역면적만을 활용한 윤용남 공식(1982), 대곡과 우곡2, 오치 저수지는 유역면적과 유역경계의 총 연장, 유료연장을 매개변수로 활용한 서승덕(1988) 공식이 가장 유사하게 추정되었다. 연구 결과는 저수지 노후화에 따른 퇴적 증감폭과 같이 저수지의 효율적인 운영·관리를 위해서는 지속적인 측량이 필요함을 제안하였다.