• Geomechanics and Engineering
• /
• 제31권3호
• /
• pp.319-328
• /
• 2022

Ensuring the integrity of a country's infrastructure is necessary to protect surrounding communities in case of disaster. Embankment dam systems across the US are an essential component of infrastructure, referred to as lifeline structures. Embankment dams are crucial to the survival of life and if these structures were to fail, it is imperative that states be prepared. Southern California is particularly concerned with the stability of embankment dams due to the frequent seismic activity that occurs in the state. The purpose of this study was to create a numerical model of an existing embankment dam simulated under seismic loads using previously recorded data. The embankment dam that was studied in Los Angeles, California was outfitted with accelerometers provided by the California Strong Motion Instrumentation Program that have recorded strong motion data for decades and was processed by the Center for Engineering Strong Motion Data to be used in future engineering applications. The accelerometer data was then used to verify the numerical model that was created using finite element modeling software RS2. The results from this study showed Puddingstone Dam's simulated response was consistent with that experienced during previous earthquakes and therefore validated the predicted behavior from the numerical model. The study also identified areas of weakness and instability on the dam that posed the greatest risk for its failure. Following this study, the numerical model can now be used to predict the dam's response to future earthquakes, develop plans for its remediation, and for emergency response in case of disaster.

• 한국안전학회지
• /
• 제21권1호
• /
• pp.120-132
• /
• 2006

Seismic safety evaluation of concrete gravity dams is very important because failure of concrete gravity dam may incur huge loss of life and properties around the dam as well as damage to dam structure itself. Recently, there has been growing much concerns about earthquake resistance or seismic safety of existing concrete gravity darns designed before current seismic design provisions were implemented. This research develops the dynamic fluid pressure calculation using 'added mass simulation'. The actual analysis using structural analysis package was performed. According to the analysis results, the vibration which is transverse to water flow seems to be very critical depending on the shape of the dam.

• Geomechanics and Engineering
• /
• 제9권1호
• /
• pp.83-100
• /
• 2015

Water and energy supplies are the key factors affecting the economic development and environmental improvement of Turkey. Given their important role and the fact that a large part of Turkey is in seismically active zones dams should be accurately analyzed since failure could have a serious impact on the local population environment and on a wider level could affect the economy. In this paper, a procedure is proposed for the static, slope stability, seepage and dynamic analysis of an earth dam and the Pamukcay embankment dam. The acceleration time history and maximum horizontal peak ground accelerations of the $Bing\ddot{o}l$ (2003) earthquake data was used based on Maximum Design Earthquake (MDE) data. Numerical analysis showed that, the Pamukcay dam is likely to experience moderate deformations during the design earthquake but will remain stable after the earthquake is applied. The result also indicated that, non-linear analysis capable of capturing dominant non-linear mechanism can be used to assess the stability of embankment dams.

• Spatial Information Research
• /
• 제9권1호
• /
• pp.125-135
• /
• 2001

집중호우로 인한 산사태, 낙석, 지반침하 등으로 인한 지반붕괴로 인명 및 재산 피해가 계속되고 있으며, 이러한 특히 댐, 교량, 도로, 터널, 공단 등 국가 주요 시설물에 대한 피해가 우려되고 있다. 따라서 이러한 지역에 대한 지반 안정성 평가가 우선적으로 이루어져야 하고 이러한 평가에 근거에 대책마련을 해야한다. 본 연구에서는 기존의 산사태 취약성 분석 및 검증 결과를 이용하여 주요 시설물인 전국 40개 댐 주변지역에 대해 지형, 지질, 토양, 임상, 토지 이용, 확률강우량도, 인공위성 영상 등 공간자료를 수집, 공간 DB로 구축하였다. 그리고 구축된 공간 DB를 검색 및 안정성 분석을 할 수 있는 공간 정보시스템을 개발하였다. 이 시스템은 ArcView 3.2의 스크립트 언어인 Avenue를 이용하여 개발되었고 풀다운 메뉴 및 아이콘 메뉴방식을 사용하여 사용하기 쉽게 개발되었다. 개발된 시스템의 활용성을 검증하기 위해 안동댐 주변 지역의 광역적 지반 안정성 평가를 실시하였다. 구축된 DB 및 개발된 시스템은 광역적 지반 안정성 평가 및 관리에 활용될 수 있으며, 지반 안정성 평가 결과는 댐 등 주요 시설물의 지반 안정성을 평가함으로서 재해예방 및 지반관리에 기초자료로 활용될 수 있다.

• Structural Engineering and Mechanics
• /
• 제51권4호
• /
• pp.663-683
• /
• 2014

In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismic-resistant capacity of the gravity dam.

• Structural Monitoring and Maintenance
• /
• 제6권2호
• /
• pp.103-124
• /
• 2019

Present study concerns the safety evaluation of SefidRud dam's block No. 18 regarding probable crack propagation in the foundation gallery under a MCE record. Accordingly, a 3D finite element model of the block in companion with the reservoir and the foundation is modeled. All the associated thermal and structural parameters are derived via calibration with the records of thermometers and pendulums installed inside the dam body. The origination of the cracks and their whereabouts are determined by primary thermal and static analyses and through a linear dynamic analysis the potential failure zone and their extent and level are studied. The foundation gallery is the most probable zone among the other intensive tensile stress area to compromise the dam stability. Therefore, the nonlinear analysis of this risky region is inevitable. The results depict the permissible expansion of the cracks inside the gallery even under another future earthquake in MCE level. As a consequence, the general dam performance is assessed safe in spite of the seepage flow rate growth from the gallery fractures.

• 대한토목학회논문집
• /
• 제12권2호
• /
• pp.87-99
• /
• 1992

댐 붕괴의 유형을 순간적 붕괴와 점진적 붕괴로 구분하였고 각 경우에 대하여 첨두유량의 산정식을 Metric 단위로 환산하여 유도하였다. 기존의 SMPDBK 모형에서 사용된 거리 매개변수의 개념을 도입하고 국내 댐 및 저수지의 자료를 기초로 한 새로운 무차원 홍수추적곡선을 유도하였다. 새로운 추적곡선은 기존의 모형에서 다루지 않은 사류(射流)상태의 경우도 포함하고 있으므로, 산지하천이 많은 국내유역에 적용시킬 수 있도록 하였다. 본 연구에서 유도된 무차원 홍수추적곡선은 Froude 수가 증가됨에 따라 유량감쇠비(流量減衰比)도 증가하고 있는 경향을 보여주었으며, 그 증가율은 Froude 수가 증가함에 따라 감소하고 있었다. 특히, 사류의 경우에서는 Froude 수가 커짐에 따라 그 증가율이 비교적 작게 나타나는 특성을 보이고 있었다. 효기(孝基) 댐 붕괴의 경우에 대하여 본 연구에서 유도한 무차원 홍수추적곡선을 적용한 결과를 실측치 및 동역학적 모형에 의한 계산결과치와 비교할 때, 댐 붕괴 지점에서의 첨두유량, 최고수위 및 홍수파의 도달시간 등에 있어 비교적 잘 일치되었다. 본 연구결과는 국내의 중소 댐에 경제적으로 활용될 수 있을 것으로 기대된다.

• 한국지반공학회논문집
• /
• 제35권4호
• /
• pp.5-14
• /
• 2019

국내 농업용 댐 17,5000여개의 안전점검 결과를 바탕으로 필댐에 나타나는 내부침식(internal erosion)과 관련된 대표적인 4가지 상태를 설정하였다. 이들 상태들을 정량화하기 위하여 댐 안전관리 전문가를 대상으로 설문조사를 실시하고 각 상태들에 대한 정량화된 점수를 제시하였다. 또한 4가지 대표 상태 이외의 다양한 댐 상태의 정량화를 도와주면서 댐 관리자들의 댐 상태 정량화 결정에 제한을 최소화 하고자 각 상태별 '부여가능한 점수의 범위(possible score range)'를 제시하였다. 각 상태별 '정량화된 점수'와 '부여가능한 점수의 범위'를 바탕으로 Case Study를 실시하여 본 방법이 댐의 위험 정도를 일관성 있게 반영하고 합리적인 수준의 파괴확률 값을 제공함을 알 수 있었다. 이는 기존의 댐 안전관리 방법이 가지는 가중평균에 의한 댐 상태등급 결정의 한계점을 극복할 수 있게 도와주어 실제로 위험한 댐을 위험한 댐으로 인지할 수 있게 도와줄 것이다.

• Geomechanics and Engineering
• /
• 제31권6호
• /
• pp.637-651
• /
• 2022

The seismic design of embankment dams requires more comprehensive studies to understand the behaviour of dams. Deformations primarily control this behaviour occur during or after earthquake loading. Dam failures and incidents show that the impacts of deformations should be reviewed for existing and new embankment dams. Overtopping erosion failure can occur if crest deformations exceed the freeboard at the time of the deformations. Therefore, crest settlement is one of the most critical deformations. This study developed empirical formulas using Gene Expression Programming (GEP) based on 88 cases. In the analyses, dam height (H_d), alluvium thickness (H_a), the magnitude-acceleration-factor (MAF) values developed based on earthquake magnitude (Mw) and peak ground acceleration (PGA) within this study have been chosen as variables. Results show that GEP models developed in the paper are remarkably robust and accessible tools to predict earthquake-induced crest settlement of embankment dams and perform superior to the existing formulation. Also, dam engineering professionals can use them practically because the variables of prediction equations are easily accessible after the earthquake.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1991년도 추계학술발표회 논문집 지반공학에서의 컴퓨터 활용 COMPUTER UTILIZATION IN GEOTECHNICAL ENGINEERING
• /
• pp.47-61
• /
• 1991

建設完了 直前에 破壞된 英國의 CARSINGTON DAM에 대하여 주어진 設計强度定數 및 實驗結果値를 適用하여 'PC-SLOPE'과 'PCSTABL5M'에 의해서 斜面을 解析하고 그 結果를 本稿에 收錄하였다. 解析過程은 設計斷面의 解析과 破壞後의 調査過程에서 나타난 特性을 考慮한 解析으로 나누었다. 解析結果 設計斷面은 주어진 間隙水壓係數를 適用할 때 安全係數가 1.2以上으로 適切한 設計가 이루어진 것으로 나타났으며, 暴雨에 의한 急　한 地下水位上界과 黃色粘土層의 影響으로 設計時 適用한 間隙水壓以上의 過剩間隙水壓이 作用하게 되어 DAM上流 斜面의 破壞는 不可避하였던 것으로 分析된다.