• 한국물환경학회지
• /
• 제30권5호
• /
• pp.477-485
• /
• 2014

Imha Reservoir is connected to Andong Reservoir via a diversion tunnel allowing water to pass between. The diversion tunnel is equipped with screens to exclude exotic largemouth bass due to their predatory impacts on prey assemblages resulting in a degradation of species richness of local fish fauna and extinction of local fish populations in Korea. Flow pattern changes resulting from the fish screens and trash racks were investigated using a computational fluid dynamics (CFD) model. Numerical simulations showed that the decrease in the discharge capacity of the tunnel is approximately 8.6% and the headloss coefficient for fish screen at Andong intake tower was determined to be 1.5. In order not to allow the small fishes enough to pass through the wire openings enter into Imha Reservoir through tunnel, the velocity in the tunnel should be greater than 1.48 m/s which is a critical ascending velocity of the bass. This study suggests that it can keep the velocity higher enough to exclude largemouth bass when a gate opens with the condition of 1.0m difference in water stage between two reservoirs.

• 태양에너지
• /
• 제20권2호
• /
• pp.67-73
• /
• 2000

This study represents the methodology of performance prediction for small hydro power(SHP) sites. Nine tunnel type SHP sites with diversion dam were selected and the performance characteristics were analyzed by using a developed model. Also, primary design specifications such as design flowrate, plant capacity, and operational rate were suggested and feasibility for tunnel-type SHP sites were estimated. It was found that the design flowrate was most important parameter to exploit SHP plant and the methodology developed in this study was useful tool to analyze the performance of SHP sites.

• 터널과지하공간
• /
• 제9권1호
• /
• pp.20-26
• /
• 1999

바쿤 수력발전 프로젝트에서 발전댐의 건설은 가배수로 터널의 완공에 따라 시작되믈 공사기간 측면에서 가배수로 터널의 완공시기는 전체 프로젝트에서 매우 중요한 요소이다. 바쿤 가배수로 터널의 내부단면은 물의 저항을 최대한 줄이기 위하여 원형으로 설계되었으며, 내부직경 12m 인 3개의 터널로 구성되어 있다. 일반적으로 터널 시공과정의 마무리 단계에서 수행되는 터널 라이닝 작업은 굴착 및 지반보강 공정과 더불어 시공비와 공사기간에 많은 영향을 끼치므로 적정한 수준의 라이닝 설계가 요구된다. 바쿤 가배수로 터널에 있어, 라이니으이 두께는현장여건에 따라 다소 차이가 있으나 500~700mm로 타설되었다. 가배수로 터널의 원설계안에 따르면 터널내 전체 라이닝에 필요한 보강콘크리트의 철근량은 5,985 ton 이었으나, 암반의 상태와 여러종류의 하중조건을 고려하여 5종류의 철근 보강 콘크리트 유형으로 구분한 후에 각각의 유형에 따른 상세설계를 통하여 최종적으로 소요 철근량을 2,178 ton으로 감소시킬 수 있었다. 감소된 양은 원설계에서 제시된 양의 절반에 해당되며, 이에 따라 공사기간 및 건설비용을 절감시킬 수 있었다.

• 한국환경과학회지
• /
• 제26권9호
• /
• pp.1031-1043
• /
• 2017

Recently severe drought caused the water shortage around the western parts of Chungcheongnamdo province, South Korea. A Diversion tunnel from the Geum river to the Boryong dam, which is the water supply dam for these areas has been proposed to solve this problem. This study examined hydraulic impacts on the Geum river associated with the diversion plan assuming the severe drought condition of 2015 would persist for the simulation period of 2016. The hydraulic simulation model was verified using hydrologic and hydraulic data including hourly discharges of the Geum river and its 8 tributaries, fluctuation of tidal level at the mouth of the river, withdrawals and return flows and operation records of the Geum river barrage since Feb. 1, 2015 through May 31, 2015. For the upstream boundary condition of the Geum river predicted inflow series using the nonlinear regression equation for 2015 discharge data was used. In order to estimate the effects of uncertainty in inflow prediction to the results total four inflow series consisting of upper limit flow, expected flow, lower limit flow and instream flow were used to examine hydraulic impacts of the diversion plan. The simulation showed that in cases of upper limit and expected flows there would be no problem in taking water from the Geum river mouth with a minimum water surface level of EL(+) 1.44 m. Meanwhile, the simulation also showed that in cases of lower limit flow and instream flow there would be some problems not only in taking water for water supply from the mouth of the Geum river but also operating the diversion facility itself with minimum water surface levels of EL(+) 0.94, 0.72, 0.43, and 0.14 m for the lower limit flow without/with diversion and the instream flow without/with diversion, respectively.

• Journal of Information Processing Systems
• /
• 제15권6호
• /
• pp.1350-1364
• /
• 2019

The ice damage occurs frequently in cold and dry region of western China in winter ice period and spring thaw period. In the drift ice condition, it is easy to form different extrusion force or impact force to damage tunnel lining, causing project failure. The failure project could not arrive the original planning and construction goal, giving rise to the water allocation pressure which influences diversion irrigation and farming production in spring. This study conducts the theoretical study on contact-impact algorithm of drift ices crashing diversion tunnel based on the symmetric penalty function in finite element theory. ANSYS/LS-DYNA is adopted as the platform to establish tunnel model and drift ice model. LS-DYNA SOLVER is used as the solver and LS-PREPOST is used to do post-processing, analyzing the damage degrees of drift ices on tunnel. Constructing physical model in the experiment to verify and reveal the impact damage mechanism of drift ices on diversion tunnel. The software simulation results and the experiment results show that tunnel lining surface will form varying degree deformation and failure when drift ices crash tunnel lining on different velocity, different plan size and different thickness of drift ice. The researches also show that there are damages of drift ice impact force on tunnel lining in the thawing period in cold and dry region. By long time water scouring, the tunnel lining surfaces are broken and falling off which breaks the strength and stability of the structure.

• 한국터널지하공간학회 논문집
• /
• 제7권2호
• /
• pp.153-163
• /
• 2005

본 논문에서는 타이 방콕의 지하철 터널현장과 홍수방지용 터널현장에 대한 사례연구를 수행하였다. 첫 번째 사례연구는 복식터널인 방콕 MRT 지하철 현장으로써 터널연장이 대략 20 km이고 18개의 정거장으로 구성되어져 있다. 터널은 지표면으로부터 15~20m 깊이에 위치하는 첫 번째 단단한 실트성 점토층에 위치한다. 현장계측으로부터 얻어진 굴착에 의한 지반의 변위거동이 제시되었다. 평면변형율 유한요소해석을 통하여 역해석을 수행하였으며, 이로부터 나온 결과는 현장에서 계측된 결과와 일치하였다. 유한요소해석으로부터 산정된 전단변형율은 0.1~1.0%의 범위내에 존재하였으며, 자동보링 프래셔미터 시험으로부터 나온 결과와 비슷하였다. 한편, 두 번째 사례연구는 지하 장애물 밑으로 관통하는 EPB타입의 터널공사 현장과 관련이 있다. Premprachakorn 홍수방지용 터널은 장마시기에 홍수를 Choapraya강으로 전환하기 위한 지름길의 터널이다. 터널은 대략 지하 20~24m에 위치한 매우 단단한 실트성 점토층에 EPB타입 쉴드터널공법에 의하여 건설되었다. 터널이 이미 존재하고 있는 방콕의 주된 용수터널과 다리의 기초 아래에서 시공되는 동안에 현장계측이 수행되었으며, 이 계측결과를 유한요소해석으로부터 산정된 결과와 비교하였다. 또한 손상평가를 예측하기 위한 수단으로 방지 리스크 포텐셜 방법을 제시하고 논의하였다.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.168-172
• /
• 2009

Shihmen reservoir was started in May 1963. The main purposes of Shihmen reservoir are for agriculture, power supply, flood control and tourism. Shihme Asn dam is an earth dam. Its crown height is 133m above mean sea level, with length 360 m, watershed 763.4 km², and maximum volume 309 million cms. Turbidity in Shihmen dam was severely affected by typhoons Aere (2004) and Masa (2005). Increased deposition after Aere was 28 million cms. Turbidity at Shihmen Canal Inlet is 3000 NTU (Nephelometry Turbidity Unit). Sediment sluicing strategies for downstream channel are demanded. Therefore, diversionary sediment preventing channel is planned in the upstream of Shihmen reservoir. Finally, turbid flow in tunnel channel is bypassed and diverted its flow down to downstream.

• 한국환경과학회지
• /
• 제17권7호
• /
• pp.733-741
• /
• 2008

The object of this study is the safety insurance of the dam to provide for the extraordinary flood. The safety insurance of the reservoir was taken by the preparatory discharge using the temporary division tunnel used during the reservoir construction. In this study, the Sungju reservoir was simulated. The existing discharge facilities of the intake tower of the Sungju reservoir could nat have influence on the flood control. When the Sungju reservoir operated to begin preparatory discharge for 48 hrs by the temporary diversion tunnel that have discharge of an 20-years frequency, the water level was lowered about 20 cm. When the Sungju reservoir operated to begin the continuous discharge after the preparatory discharge, the water level was lowered over 1m but the downstream at risk was caused by the resulted. If it is possible to operate to begin the preparatory discharge of the reservoir for 24 hrs by the temporary diversion tunnel, that will improve the flood control faculty of the reservoir without other hydraulic structure and safety of the Sungju reservoir will be higher.

• 한국암반공학회:학술대회논문집
• /
• 한국암반공학회 2007년도 특별심포지엄 논문집
• /
• pp.63-79
• /
• 2007

Several remedial works were attempted to stabilize the collapsed area of the inlet slopes of diversion tunnel, but prevention of any further movement was being only carried out at beginning stage by filling the area with aggregates and rock debris, after several cracks had been initiated and developed around the area. The extra specialty developed folding zone is consisted with highly weathered Greywacke and Black shale. The suggested solution is to improve the properties of the rock mass of failed area by choosing the optimum level of reinforcement through the increment of slope rock support design so as to control the movement of slopes during the re-excavation. The Bakun hydroelectric project includes the construction of a hydroelectric power plant with an installed capacity of 2,520MW and a power transmission system connecting to the existing transmission networks in Sarawak and Western Malaysia. The power station will consist of a 210m height Concrete Faced Rockfill Dam. During the construction of the dam and the power facilities the Balui River has to be diverted of the tunnels is 12m and the tunnel width is 16m at the portal area. This paper describes the stability analysis and design methods for the open cut rock slopes in the inlet area of the diversion tunnels. The geotechnical parameters employed in stability calculations were given as a function of four defined Rock Mass Type (RMT) which were based on RMR system from Bieniawski. The stability calculations procedure of the rock slopes are divided into two stages. In the first stage, it is calculated for the stability of each "global" slope without any rock support and shotcrete system. In the second stage, it is calculated for each "local" slope stability with berms and supported with rock bolts and shotcrete. The monitoring instrumentation was performed continuously and some of the design modification was carried out in order to increase the safety of failed area based on the unforeseen geological risks during the open cut excavation.

• 한국구조물진단유지관리공학회 논문집
• /
• 제12권2호
• /
• pp.75-82
• /
• 2008

국내에는 약 18,000여개의 댐이 있는 것으로 보고되고 있다. 이 중에서 대댐으로 분류되는 1,200여개의 대댐은 비교적 양호하게 운영 관리되고 있으나, 지자체 등에서 관리하는 소규모의 댐들은 대부분 제체를 관통하는 복통을 갖고 있으며, 제도적 장치의 미비와 전문 인력의 부족으로 체계적인 유지관리가 거의 이루어지지 않고 있는 실정이다. 본 연구에서는 소규모 댐들에서 자주 발생하는 결함의 유형에 대해서 고찰하고, 결함의 보수보강을 통하여 소규모 댐의 안전을 확보할 수 있는 방법을 제시하고자 한다. 또한, 전기비저항 탐사를 통하여 결함의 진행정도를 파악하고, 보수보강 이후의 보수보강 효과를 판정하는 방법론을 제시하고자 하였다.