• Journal of Korea Water Resources Association
• /
• v.49 no.11
• /
• pp.931-939
• /
• 2016

Bangudae Petroglopys of the national treasure No. 285 located in elevation of 53 m to 57 m have been damaged by repetition of submergence and exposure due to the Sayeon-dam of EL.60 m constructed in down stream. In this study, as a preservation plan of the petroglyphs from the contact with water, the construction of eco-levee was suggested and its effect was investigated in the views of hydraulic engineering. It was designed to be located aside of 80 m from Bangudae Petroglyphs with the length of 440 m in streamwise direction, and it was need to construct a new channel maintaining the original hydraulic capacity and conveyance. Hydraulic characteristics such as water surface elevations and velocities near Bangudae Petroglyphs were measured after the eco-levee was installed in the hydraulic model with the scale of 1:50. It showed that there were not much changes of water surface elevations and velocities between sayeon-dam spillway EL. 60 m (Suggestion 1) and EL. 54 m (Suggestion 2). It was concluded the eco-levee could be made of natural materials like soil, pebble, gravel in terms of allowable velocity and shear stresses. The slope of water surface at Suggestion 2 was steeper, and velocities near Bangudae Petroglyphs were also faster than Suggestion 1. As the vorties occured at the left side in Suggestion 2, more detailed study is required.

• Tunnel and Underground Space
• /
• v.20 no.3
• /
• pp.194-206
• /
• 2010

It has been presumed that Bangudae-petrogram and Chunjonri-petrogram have been sculptured along the river Taewha in the prehistoric age. These petrograms have been sculptured on shale, the sedimentary rock of cretaceous in Mesozoic era and have been weathered by wind and rain for around 6000 years, resulting in weathering grade 5. Specially, Bangudae-petrogram has been in submerged zone in Sayeon dam for 168 days a year and the submersion has been repeated for 45 years up to date. This paper adopts an engineering approach to these petrograms' properties and discuss how to enhance strengths of petrograms themselves and stop weathering.

• 보존과학연구
• /
• s.33
• /
• pp.69-83
• /
• 2012

Field experiments for Conservation damage on selected spots were carried out prior to direct conservation treatments for Bangudae Petroglyphs in Ulsan. It was found that there is a big difference in treatment effects according to the treatment technique and application rather than on the treatment material use. Based on the results of this study, a plan for the conservation treatment of Bangudae Petroglyphs will be suggested by providing new materials and application techniques for cracks, adhesive application and consolidation by conducting artificial weathering tests and continued monitoring.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.1103-1107
• /
• 2009

최근 기상이변에 따른 국지성 호우 등으로 인하여 지역별로 홍수량 차이가 많이 나고 있는 상황으로 유역내 중요시설물 및 인명의 보호를 위해서는 유역의 특성을 정확하게 반영한 홍수분석이 필수적인 실정이다. 유역 주요지점의 정확한 홍수량을 산정하기 위해서는 지역특성이 반영된 호우를 선정하고, 유출모의를 위한 유역특성이 잘 구현되어야 한다. 이를 위해서는 홍수량산정에 영향을 주는 매개변수의 정확한 산정이 필요하며 본 연구에서는 미공병단(US Army Corps)에서 개발하여 배포한 차세대 프로그램인 HEC-HMS(v3.3)를 이용하여 집중시간, 저류상수, Curved Number, 감수상수, 초기손실, 초기기저유량, Threshold 등 7가지 매개변수에 대한 최적화를 수행하였다. 종래에는 첨두홍수량을 중시하여 집중시간과 저류상수는 최적화하고 나머지 변수들은 실측치 및 계산값을 적용하였으나, 금번 연구에서는 첨두홍수량 및 총유출량 모두 관측값에 최대한 일치하도록 7가지 매개변수를 최적화하는 방안 및 최적화시 초기값 선정이 매개변수 최적화에 미치는 영향을 연구하였다. 매개변수 최적화 순서는 먼저 전체적인 평균유출량 또는 평균유출고가 실측치와 모의치 간에 일치하도록 CN, RC를 보정하고 다음 단계로 첨두발생시간이 일치하도록 Tc, K를 보정하고, 마지막으로 홍수 수문곡선의 형태를 결정하는 나머지 매개변수를 조정하여 전체적인 수문곡선의 형태와 첨두홍수량이 일치하도록 수행하였으며, Tc, K, CN 등의 중요 매개변수는 신뢰구간(계산치의 0.8${\sim}$1.2)을 설정하여 목적함수의 수렴을 유도하였다. 위를 이용하여 수렴된 매개변수들로 강우-유출 모의를 분석한 결과를 기존 홍수사상과 비교한 결과 상당히 근접한 결과를 도출할 수 있어, 매개변수는 7가지 모두에 대한 최적화를 가능한 것으로 연구되었으나 목적함수들의 수렴되는 과정에 대해서는 좀 더 심도있는 고찰이 필요할 것으로 판단된다.

• Journal of the Mineralogical Society of Korea
• /
• v.17 no.1
• /
• pp.23-35
• /
• 2004

The weathering characteristics of periodically submerged sedimentary rocks in the Sayeon dam, Ulsan was examined by field work, electron probe micro-analysis, X-ray diffraction, and X-ray fluorescence spectrometry. Analysis of fracture zone and exfoliation showed the submerged sedimentary rocks have undergone severe mechanical weathering. Mechanical weathering in the water-rock interface accelerated chemical weathering, such as dissolution and alteration of the most of minerals except for quartz in the weathering zone. The dissolution of carbonates specially calcite, is remarkable creating the cavities, whereas formation of minerals including clay minerals is not active. The sedimentary rocks have been periodically submerged for a certain period of time, and have repeated freezing and thawing. This mechanical weathering favored infiltration, which accelerated mineral dissolution. The high content of easily soluble carbonate of the sedimentary rocks is likely the major cause of intense chemical weathering. The dissolved elements within the infiltrated water interrupted the occurrence of clay and weathering minerals, and expend fractures by infiltrated water accelerated weathering process.

• Journal of the Korean Geographical Society
• /
• v.45 no.3
• /
• pp.342-359
• /
• 2010

The Bangudae Petroglyphs locate at Bangudong, Daegok-ri, Eonyang-eup, Ulju-gun, Ulsan and was designated as the No. 285 national treasure since 1995. After the construction of Sayeon-dam in 1965, there were many controversies of the rock weathering problems by the periodic immersion for approximately a few months. The isopleths of water content on the rock are drawn and the result shows relationships between the isopleths and distribution of joints or exfoliations. The distributions of water content rates in the Petroglyphs show the downward increasing pattern. This may suggest that the rates of water content are further influenced by the duration of immersion. Also, the upper part of the Petroglyphs with dense joints shows high rates of water content. If the water content rates in rocks increase, the water absorption rates increase too, because of the increasement of coefficient of permeability and porosity. The weathering damages of the Petroglyphs in which the pores are saturated by the periodic immersion are in the critical conditions.

• Journal of Korea Water Resources Association
• /
• v.33 no.4
• /
• pp.393-405
• /
• 2000

Monthly runoff was estimated using TOPMODEL which simulates ground water movement as well as surface runoff in the area of catchment. SAYUN dam which is being operated by Korea Water Resources Corporation was selected for the study, and the topographic factors of the watershed were analyzed using 1/5,000 digital map and GIS software(Arc/Info). The comparison shows good agreement between observed monthly runoff and the computation results simulated by using TOPMODEL. The catchment area of SAYUN dam was modeled by using various grid sizes in order to check the sensitivity of grid size, and the grid size of 180m was found most proper among 6 different sizes. TOPMODEL was also found superior to the existing monthly runoff models such as Kajiyama, KRIHS and Tank. Because the model requires limited number of parameters and considers topographic aspects, it is reckoned to be very useful for practical use.