• 지구물리와물리탐사
• /
• 제23권3호
• /
• pp.149-156
• /
• 2020

복잡하고 다양한 광상 생성 과정과 부존 위치의 심부화로 인하여 광물자원 탐사의 효율을 높일 수 있는 예측탐사의 필요성이 점차 높아지고 있다. 최근의 머신러닝 기법의 활용성 증가와 광역 지질 데이터베이스의 구축 상황을 고려하면, 예측탐사의 기반인 광상 배태 가능성 평가 기술의 신뢰도는 점차 높아질 것으로 예상된다. 이번 연구에서는 심층신경망을 이용하여 화성암과 단층 및 자력탐사 정보의 광화 인자로의 활용 가능성을 확인하였다. 지질 정보의 수치화 기법으로 단층, 화성암, 자력 정보를 입력 자료로 구성하여 0.9 이상의 정확도를 가지며 예측 값이 안정적으로 수렴하는 금속 광상 예측 모델을 구축할 수 있었다. 이 기술은 추후 정밀한 지질 조사 결과와 물리탐사 정보가 확보된다면, 광화대 규모에서의 예측 탐사에도 활용할 수 있을 것으로 기대된다. 또한, 이 연구를 통해 지하의 화성암 정보를 제공하는 자력자료를 활용할 경우 지표의 화성암 정보를 보완하여 보다 높은 성능의 모델을 구축할 수 있는 것으로 확인되었다. 즉, 단순히 많은 자료를 융합하는 것 보다는 광체 성인과의 지질학적 상관관계를 고려하여 입력 자료를 구성하는 것이 보다 중요하다.

• 지질공학
• /
• 제17권2호
• /
• pp.263-270
• /
• 2007

터널 시공 중 일상적으로 수행되는 계측에 의해 정량화되는 터널의 거동은 안정성 평가를 위한 주요한 항목이며, 이는 지역적인 지질학적 특성에 크게 의존한다. 본 연구에서는 지질학적 특성 차에 의한 RMR 항목별 터널 거동에 미치는 영향도를 분석하기 위하여, 터널의 face mapping 자료와 계측자료를 각각 설명변수와 종속변수로 한 수량화 분석을 실시하였다. 분석 결과, RMR 인자가 터널의 변위에 미치는 중요도의 평균은 R1, R2, R3, R4, R5 각각 17.0%, 20.4%, 20.4, 11.6%, 30.6%로서, 이는 분석지역의 지하수특성이 변위에 크게 영향을 미친 것으로 판단된다.

• Geomechanics and Engineering
• /
• 제9권1호
• /
• pp.57-81
• /
• 2015

Water inrush and mud outburst always restricts the tunnel constructions in mountain area, which becomes a major geological barrier against the development of underground engineering. In view of the complex disaster-causing mechanism and difficult quantitative predictions of water inrush and mud outburst, several theoretical methods are adopted to realize dynamic assessment of water inrush in the progressive process of tunnel construction. Concerning both the geological condition and construction situation, eleven risk factors are quantitatively described and an assessment system is developed to evaluate the water inrush risk. In the static assessment, the weights of eight risk factors about the geological condition are determined using Analytic Hierarchy Process (AHP). Each factor is scored by experts and the synthesis scores are weighted. The risk level is ultimately determined based on the scoring outcome which is derived from the sum of products of weights and comprehensive scores. In the secondary assessment, the eight risk factors in static assessment and three factors about construction situation are quantitatively analyzed using fuzzy evaluation method. Subordinate levels and weight of factors are prepared and then used to calculate the comprehensive subordinate degree and risk level. In the dynamic assessment, the classical field of the eleven risk factors is normalized by using the extension evaluation method. From the input of the matter-element, weights of risk factors are determined and correlation analysis is carried out to determine the risk level. This system has been applied to the dynamic assessment of water inrush during construction of the Yuanliangshan tunnel of Yuhuai Railway. The assessment results are consistent with the actual excavation, which verifies the rationality and feasibility of the software. The developed system is believed capable to be back-up and applied for risk assessment of water inrush in the underground engineering construction.

• 자원환경지질
• /
• 제33권2호
• /
• pp.117-128
• /
• 2000

Regional evaluations of slope stability by the failure criterion and by environmental geological factors were conducted. The failure criterion is the general conditions for plane failure which consider the geometrical conditions between geological discontinuities and topographical slope planes. The factor focused in this condiction is dip and dip direction. Geostatics, named semivariogram was used for establishing structural domains in slope stability evaluation by the failure criterion. The influential range was calculated to 6 km in the case of dip direction of dominant joint set and 7 km in the case of dip of the same dominant joint set. Then applying this failure criterion to the study area produced a slope stability map using the established domains and slopes generated by TIN module of ARC/INFO GIS. This study considered another regional slope stability analysis. 5 failure-driven factors 9the unstable slope map, geology, engineering soil, groundwater, and lineament density) were selected and used as data coverages for regional slope stability evaluation by geoenvironmental factors. These factors were weighted and overlayed in GIS. From the graph of cumulatave area (%) and instability index, finding critical points classified the instability indices. The most unstable slopes are located in the southern area of Mt. Eorae, Dabul-ri, and the eastern area of Junkok-ri in the first area is plane failure. Also, the expected orientations of failure are 59/338 and 86/090 (dip/dip direction).

• 한국항공운항학회지
• /
• 제26권3호
• /
• pp.1-8
• /
• 2018

Aviation industry is growing rapidly, and this growth is expected to continue. However, aircraft accident rate is still high, and 65 percent of accidents occur during landing phase due to unstable approach. Therefore, this research analyzed causes and countermeasures of unstable approach. In order to derive countermeasures, this study selected P International Airport as an example case. In addition, this research analyzed A airline's FOQA data, regional Standard Operating Procedures, and 5 years of environmental factors to identified correlation of those contributing factors. In conclusion, his research concluded following results. First of all, because of P International Airport's geological features, pilots are required to conduct Circling Approach, and this advanced maneuver increases workload at the final stage of flight. Secondarily, meteorological factors such as crosswind, seasonal rain front, local visibility contributes unstable approach. Lastly, these geological and meteorological factors are interrelated, and this uncommon environment can decrease circumstantial judgement ability of pilots and jeopardize aviation safety. As a consequence, it is recommended to reinforce the Crew Resource Management and Threat & Error Management systems so that pilots can perceive identical safety target.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
• /
• pp.710-712
• /
• 2006

The aim of this study was to analyze limestone deposits potential using an artificial neural network and a Geographic Information System (GIS) environment to identify areas that have not been subjected to the same degree of exploration. For this, a variety of spatial geological data were compiled, evaluated and integrated to produce a map of potential deposits in the Gangreung area, Korea. A spatial database considering deposit, topographic, geologic, geophysical and geochemical data was constructed for the study area using a GIS. The factors relating to 44 limestone deposits were the geological data, geochemical data and geophysical data. These factors were used with an artificial neural network to analyze mineral potential. Each factor’s weight was determined by the back-propagation training method. Training area was applied to analyze and verify the effect of training. Then the mineral deposit potential indices were calculated using the trained back-propagation weights, and potential map was constructed from GIS data. The mineral potential map was then verified by comparison with the known mineral deposit areas. The verification result gave accuracy of 87.31% for training area.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
• /
• pp.59-62
• /
• 2004

Hydraulic conductivity tests were conducted on a geosynthetic clay liner (GCL) for more than 2.5 yr using inorganic salt solutions to evaluate how the long-term hydraulic conductivity is affected by cation concentration and valence. Only small changes (i.e., $\leq$ 2X) in hydraulic conductivity (K) occurred during the test duration when the permeant solution was deionized (DI) water or 100 mM KCl and NaCl solutions. For weak CaCl$_2$ solutions ($\leq$ 20 mM), the hydraulic conductivities initially (< 0.2 yr) were comparable to the hydraulic conductivity obtained with DI water, but gradually increased by a factor of 2 to 13 over a period of nearly 2 yr. In contrast, the GCL permeated with strong CaCl$_2$ solutions ($\geq$ 50 mM) reached equilibrium nearly immediately, with a hydraulic conductivity approximately 2 orders of magnitude higher than the hydraulic conductivity to DI water.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.254-257
• /
• 2003

Statistical analysis is performed to estimate the correlations between geological or geographical factor and groundwater inflow rates in the Seoul subway system. Correlation analysis shows that among several geological and geographical factors fractures and streams have most strong effects on inflow rate into tunnels. In particular, subway line 5∼8 are affected more by these factors than subway line 1∼4. Time series analysis is carried out to forecast groundwater inflow rate. Time series analysis is a useful empirical method for simulation and forecasts in case that physical model can not be applied to. The time series of groundwater inflow rates is calculated using the observation data. Transfer function-noise model is applied with the precipitation data as input variables. For time series analysis, statistical methods are performed to identify proper model and autoregressive-moving average models are applied to evaluation of inflow rate. Each model is identified to satisfy the lowest value of information criteria. Results show that the values by result equations are well fitted with the actual inflow rate values. The selected models could give a good explanation of inflow rates variation into subway tunnels.

• 지질공학
• /
• 제17권4호
• /
• pp.535-544
• /
• 2007

퇴적암에서 발달된 불연속면들은 암반의 공학적 특성들을 결정하는 가장 중요한 인자이다. 이들 불연속면을 기재하는 요소들은 일반적으로 불균질성과 불확실성을 내포하고 있다. 본 연구에서는 이러한 불연속면의 기재요소를 정량적이고 객관적으로 결정하기 위해 확률론적 통계기법을 이용하였다. 울산 일대의 33개의 퇴적암 사면을 선정하여 ISRM(1978)에서 제시한 불연속면의 조사항목을 바탕으로 불연속면의 특성 조사를 수행하였으며, 조사된 항목의 확률분포함수를 분석하여 울산지역 백악기 하양층군 퇴적암류의 지질공학적 특성을 파악하였다.

• Geomechanics and Engineering
• /
• 제21권4호
• /
• pp.371-377
• /
• 2020

There are currently three common methods for selecting excavation supports in Polish hard coal mines. While many factors are considered when choosing appropriate support, these do not include layering or cracking in the excavation ceiling. Although global classifications of rock mass are rarely used in hard coal mines, they are utilised much more frequently during the construction of underground structures such as tunnels. Mining classifications of rock mass have been developed (e.g., in Germany) and they rely on a number of factors but are often related to local mining and geological conditions. This paper discusses the selected findings of a study carried out on seven excavation sites with diverse mining and geological characteristics. Based on the collected data, two indicators were developed to describe rock mass quality. The first indicator is referred to as the roof lithology index WL and describes the quality of the excavation roof in terms of its layering and lithology. The second indicator is the crack intensity factor n and represents the amount of cracks in an excavation's roof. The correctness of the developed indicators was supported by reliable data from the excavation in which the designed support did not fulfill its task but was changed at a later stage, after calculating the proposed indicators.