• 한국안전학회지
• /
• 제13권3호
• /
• pp.135-142
• /
• 1998

This paper is to investigate the failure surface and modes in a soil mass by a excavation of the model ground. To study the failure surface for the excavated slope, centrifugal model tests were performed by changing the angle of the excavated slope(50, 75, $90^{\circ}$) and the ground condition($D_r$=60, 90%, dry and submerged ground). Excavation was simulated during the centrifuge tests by operating a valve that allowed the zinc chloride solvent to drain from the excavation. Results of model tests were compared with those obtained with theoretical solutions using limit equilibrium analysis method. The results of model tests show that, there is a failure to create a straight line in the low angle of excavated surface and a create a circle as the angle increases. Also, as the angle of excavated surface is increasing, the angle of the failure surface increases. The failure length in the submerged ground increases approximately 1.10~1.34 times more than that of the dry ground.

• 대한원격탐사학회지
• /
• 제38권4호
• /
• pp.365-374
• /
• 2022

Mining activity causes environmental pollution and geological hazards such as ground subsidence or landslide of which continuous monitoring is necessary. In this study, the activity on the Fushun West Open-Pit Mine (FWOPM), one of the largest open-pit coal mines in Asia located in Fushun, Liaoning Province, China, was analyzed by using a time-series Sentinel-1 InSAR coherence dataset. By using the difference between the two Digital Elevation Models (DEM) of the area, it was possible to confirm that there was a stockpiling activity in the western area of the FWOPM while excavation activity in the eastern area. By using RGB composite images using the yearly-averaged InSAR coherence images, the activity of the mine was confirmed by period, which was confirmed by Google Earth optical images. As a result, it was possible to confirm three landslides and the related activities on the northwest slope and the dumping activity on the west slope of FWOPM.

• 제어로봇시스템학회논문지
• /
• 제7권9호
• /
• pp.733-740
• /
• 2001

네트워크와 RF 통신이 가능한 감시용 로봇에 대해 소개한다. 이 로봇은 4 바퀴와 4개의 링크로 구성된 메카니즘으로 인하여 자유로운 위치 조절이 가능하며, 이미지와 데이터를 RF를 통하여 전송하는 기능을 지니고 있다. 또한 네트워크 상에서 데이터와 카메라 이미지가 전송된다. 이 로봇은 로봇 주위에 일어나는 상황을 모니터링하고 4개의 암 구조를 통하여 넓은 영역을 확보한다. 이 로봇은 4개의 링크를 통하여 무게 중심을 조정하여 경사지에서의 안정성을 보장한다.

• Smart Structures and Systems
• /
• 제5권6호
• /
• pp.663-679
• /
• 2009

The use of Micro-Electro-Mechanical Systems (MEMS) accelerometers in geotechnical instrumentation is relatively new but on the rise. This paper describes a new MEMS-based system for in situ deformation and vibration monitoring. The system has been developed in an effort to combine recent advances in the miniaturization of sensors and electronics with an established wireless infrastructure for on-line geotechnical monitoring. The concept is based on triaxial MEMS accelerometer measurements of static acceleration (angles relative to gravity) and dynamic accelerations. The dynamic acceleration sensitivity range provides signals proportional to vibration during earthquakes or construction activities. This MEMS-based in-place inclinometer system utilizes the measurements to obtain three-dimensional (3D) ground acceleration and permanent deformation profiles up to a depth of one hundred meters. Each sensor array or group of arrays can be connected to a wireless earth station to enable real-time monitoring as well as remote sensor configuration. This paper provides a technical assessment of MEMS-based in-place inclinometer systems for geotechnical instrumentation applications by reviewing the sensor characteristics and providing small- and full-scale laboratory calibration tests. A description and validation of recorded field data from an instrumented unstable slope in California is also presented.

• 터널과지하공간
• /
• 제19권3호
• /
• pp.248-260
• /
• 2009

직접 개발 형식의 해외자원개발과 관련하여 단순 자본 투자에서 직접 개발로 변화하고 있다. 대규모 노천 석탄광산에서의 사면 안정성과 관련하여 지하수 유동 체계 분석과 사면 보강공으로서의 수평 배수공 타당성을 인도네시아 Pasir 탄광을 대상으로 검토하였다. 본 연구에서는 지하수 체계를 특징짓기 위해 지하수 수위 분석, 현장 투수 시험, 추적자 실험 등 다양한 현장 실험 및 계측을 수행하였다. 특히, 중부 지역의 상부에 위치한 SM강과의 연계성을 분석에 중점을 두었다. Guelph 투수계수를 활용하여 투수계수를 측정하였으며, 사암이 이암이나 탄층보다 투수성이 매우 높은 것으로 나타났다. 지하수 수위 분석 결과 사암층과 협재되어 많은 균열을 포함한 얇은 탄층이 주된 지하수 유동 경로 역할을 히는 것으로 나타났다. 추적자 시험 결과 SM강이 인근 지하수계에 미치는 영향은 강 바닥의 지층구조에 따라 다른 것으로 파악되었다. 수평 배수공의 효과를 파악하기 위한 2차원 지하수 유동 해석 결과는 폭이 좁은 탄층이 협재되어 있는 지층과 사암층이 주된 지하수 유동 경로이며, 충분한 심도로 수평 배수공 시공시 사면 안정화에 효과가 있는 것으로 파악되었다. 따라서 수평 배수공의 시공 위치와 시공 심도의 결정을 위해서는 지층 구조의 파악이 선행되어야 한다.

• 한국환경생태학회지
• /
• 제28권4호
• /
• pp.450-456
• /
• 2014

본 연구는 우리나라 정맥의 마루금 등산로 훼손실태를 파악하고 관리방안을 수립하고자 수행되었다. 등산로의 훼손정도를 파악하기 위하여 물리적 인자 12가지를 조사하고 조사자가 등산로의 건전여부를 정성적으로 평가하였다. 그 결과 한남금북정맥 마루금 등산로의 훼손 정도는 평균노폭이 78cm, 최대침식깊이의 평균값은 6.4cm, 평균경사는 20.8%였으며, 금북정맥 마루금 등산로의 훼손 정도는 평균노폭이 73cm, 최대침식깊이의 평균값은 7.3cm, 평균경사는 20.0%로 나타났다. 낙남정맥 마루금 등산로의 훼손 정도는 평균노폭이 73cm, 최대침식깊이의 평균값은 6.7cm, 평균경사는 17.7%이며, 금남정맥 마루금 등산로의 훼손정도는 79cm, 최대침식깊이의 평균값은 6.7cm, 평균경사는 19.7%로 비교적 양호한 편이었다. 위와 같은 결과를 백두대간 및 국립공원의 훼손 실태와 비교하여 볼 때, 정맥의 훼손은 양호한 편이라고 할 수 있다. 그러나 일부 도심권을 통과하는 지역과 관광지 주변의 등산로는 훼손이 심화된 것을 확인할 수 있었다. 따라서 향후 이용객의 증가가 예상되는 지역에 대해서는 보다 자세한 모니터링과 적극적인 관리가 요망된다.

• 한국농공학회논문집
• /
• 제58권5호
• /
• pp.81-90
• /
• 2016

Due to droughts and water shortages causing severe damage to crops and other vegetations, much attention has been given to efficient irrigation for upland farming. However, little information has been known to measure soil moisture levels in a field scale and apply their spatial variability for proper irrigation scheduling. This study aimed to characterize the spatial variability and temporal stability of soil water contents at depths of 10 cm, 20 cm and 30 cm on flat (loamy soil) and hill-slope fields (silt-loamy soil). Field monitoring of soil moisture contents was used for variogram analysis using GS+ software. Kriging produced from the structural parameters of variogram was applied for the means of spatial prediction. The overall results showed that the surface soil moisture presented a strong spatial dependence at the sampling time and space in the field scale. The coefficient variation (CV) of soil moisture was within 7.0~31.3 % in a flat field and 8.3~39.4 % in a hill-slope field, which was noticeable in the dry season rather than the rainy season. The drought assessment analysis showed that only one day (Dec. 21st) was determined as dry (20.4 % and 24.5 % for flat and hill-slope fields, respectively). In contrary to a hill-slope field where the full irrigation was necessary, the centralized irrigation scheme was appeared to be more effective for a flat field based on the spatial variability of soil moisture contents. The findings of this study clearly showed that the geostatistical analysis of soil moisture contents greatly contributes to proper irrigation scheduling for water-efficient irrigation with maximal crop productivity and environmental benefits.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 추계 학술발표회
• /
• pp.569-580
• /
• 2008

If slope height was more than 20 meters, we conducted an analysis of stereographic projection and limit equilibrium at this slope. We proposed reduction of slope face angle and reinforcement of rock bolt depending on analysis. Blasting design : Standard pattern based on result of local test blasting was made for blasting design. Vibration criterion was set for less than 3.0mm/s because of outworn buildings and inhabitants opinions. Production blasting and Controlled blasting has been done as Construction standard pattern. After Vibration Monitoring has been done, so that we can control of complement. "Bidding Document" and AASHTO 2001 "A Policy on Geometric Design of Highways and Streets" were so for design criteria of earthwork but they were different actual design criteria and left something to be desired in Afghanistan. Therefore, although "Bidding Document" and "AASHTO 2001" were basic design criteria, domestic design criteria was reflected in this design criteria for complement by discussion with supervisor. Drainage design : For stability ratio, ditch of arch block and stonework was designed by rainfall data for the 13 years and discussion with supervisor. Pavement was designed as flexible pavement. Because these days in Afghanistan postwar repair works, especially urgent repairing of roads and newly making of roads, are very highly in progress, I think that Afghanistan is the region about which our construction technical experts should have great concerns.

• 한국환경복원기술학회지
• /
• 제23권6호
• /
• pp.187-200
• /
• 2020

Despite the eco-friendly route plan, road slopes were collapsed due to road construction, resulting in human and property damage. To solve this problem, the Ministry of Land, Transport and Maritime Affairs established guidelines in 2009 to conduct a test-bed for slope recording considering the conditions of the site and the ecological environment, and divided them into recording quality and economic evaluation. The following results were obtained by analyzing 183 construction methods of cut-soil sections at 60 sites from 2012 to 2018 for road slope afforestation research. Straw net+seedspray, vegetation media spray method 1T, 3T were used the most, and vegetation media spray method 3T(patent) was excellent in quality, and straw net+seedspray was excellent in economics. As a result of analyzing the market unit price and the construction unit price, vegetation media spray method submitted the construction unit price at up to 60% lower than the market unit price. As a result of the analysis of the key factors of the greening method evaluation, the economic assessment had the greatest influence on all evaluation items. Problems in the evaluation method of revegetation were first identified as problems in the allocation of points and secondly as problems in the evaluation criteria. As for the improvement of the economic assessment criteria, the method was proposed to evaluate the same method based on market unit price when the same method was constructed, and not to conduct an economic assessment if there was a difference in market unit price between methods, or to add weight to the scores. Based on the monitoring data of 60 road slopes, this study drew up problems and improvement measures. However, with regard to scoring, research on appropriate scoring is needed by examining the current status.

• 지질공학
• /
• 제32권3호
• /
• pp.339-350
• /
• 2022

경주시 골굴사 신생대 응회암에서는 다양한 형태의 타포니가 다수 발달한다. 응회암은 풍화변질되어 있는데, 석영, 장석류, 운모, 버미큘라이트, 녹니석, 스멕타이트와 제올라이트 광물인 아날사이트 등으로 구성된다. 타포니는 초기 단계에서는 각력이 제거된 동공이나, 응회암 결정 입자의 풍화변질에 의해 형성된 미세 동공에서부터 시작하여 점차 확대된다. 타포니는 사면의 반대방향으로 약하게 경사지면서 발달한다. 타포니의 상관계수는 폭-높이 0.839, 폭-깊이 0.900, 높이-깊이 0.856인데 서로 밀접한 관련성이 있다. 타포니 벽체가 제거되면 반달형이나 신장된 타포니로 되는데, 작은 동공들이 횡적으로 병합되면서 확대된다. 커다란 타포니 동공들은 암반 사면에 비하여 내부가 비어있기 때문에 암반의 강도가 더 낮다. 따라서 타포니 사면의 강도, 동공의 비율, 체적, 합병 양상에 대한 지속적인 모니터링이 요구된다.