• Proceedings of the Korea Contents Association Conference
• /
• 2018.05a
• /
• pp.499-500
• /
• 2018

최근 지반이 가라앉아 지면에 구멍이 발생하는 싱크홀(Sink Hole)의 발생이 빈번하게 발생하고 있으며, 이에 대한 피해사례도 증가하고 있다. 이를 예방하고 대응하기 위하여 국가적으로 대대적인 지반조사를 하고 있으며 해당 지반을 탐사하기 위하여 지표투과레이더와 내시경 등을 활용한 방법을 사용하고 있다. 본 논문에서는 현재까지 가장 효율적인 방법으로 알려진 지표투과레이더의 데이터를 그래프 형태로 표현하고 분석하여 효과적으로 탐사를 할 수 있는 시스템을 제안한다.

• Journal of Korea Society of Industrial Information Systems
• /
• v.13 no.2
• /
• pp.28-34
• /
• 2008

This paper reports the problem in the previous routing protocol, EAR, and proposes an energy aware routing protocol to solve the problem in it. Proposed routing protocol considers the number of hops, the possibility of node exhaustion, and the node energy amount at the same time from the source to the sink. Thereby, it could efficiently solve the potential network separation problem and the sensing hole problem in EAR. Proposed routing protocol could remove the problems in the previous routing protocols but it still gets the advantages in them.

• Journal of the Korean Geosynthetics Society
• /
• v.15 no.2
• /
• pp.55-64
• /
• 2016

The construction of the road NATM tunnel, which undergoes the weathered zone of the mountain, was in process with the reinforcement methods such as the rock bolt, shotcrete depositing, and the multi step grout with large diameter steel pipe. The collapse from the ceiling, and on the ground surface area(sink hole), of which were measured to be 25m from the ground surface($V=12m(W){\times}14m(L){\times}5m(H)=840m^3$), as well as excessive displacements in the tunnel, had occurred. In order to execute the necessary reconstruction work, the causes of the surface collapses were inspected through the field investigation, in-situ tests, and numerical analysis. As a result, several proper solutions were suggested for both internal and external reinforcements for the tunnel. As a result of numerical analysis, the collapsed zone of the tunnel was reinforced up to 0.5D~1.0D laterally by the cement grouting on the ground surface, 0.5D longitudinally by the multi step grout with large diameter steel pipe in tunnel. With further reinforcement implemented by rebars in lining, the forward horizontal boring was executed to the rest of the tunnel to evaluate the overall status of the tunnel face. Appropriate reinforcement methods were provided if needed.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.7 no.1
• /
• pp.37-43
• /
• 2019

This research studied production of lightweight filling production for sink hole restoration utilizing various industrial by-products(2kinds of fly ash, petro-cokes CFBC ash, blast furnace slag fine particle). For this purpose, the mixed raw material properties(compressive strength) behaviors according to the blending ratio of industrial by-products were examined by applying the experimental design method and statistical analysis was performed using the commercial program MINITAB. Compressive strengths of industrial by-products were strongly dependent on blast furnace slag powder. Compressive strength(3days aging) was 3~11MPa depending on the amount of blast furnace slag powder used. The use of CFBC fly ash was evaluated to have the least effect on compressive strength. In addition, the compressive strength and the coefficient of permeability were measured by preparing foamed concrete for the experimental batch 1 condition in the mixture experimental design. In this case, the bulk density is 0.9 to 1.0, the apparent porosity is 30 to 50%, the compressive strength(3days old) is 1 to 2MPa, and the permeability coefficient is $10^{-2}$ to $10^{-3}cm/sec$.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.3
• /
• pp.449-461
• /
• 2017

The uncertain existence and insufficient information of underground structures, such as pipe lines and cable tunnels, is causing many problems related to route plan, design, construction of new underground structures. The theoretical equations that is able to predict the location, size, and direction of underground structures through electric field analysis are suggested at the previous study (Ryu., 2015). Three field tests were performed for predicting the location, size, and direction of underground structures and the existence and size of sink-hole. Prediction results were reflected at the design and follow-up measures were performed.

• Tunnel and Underground Space
• /
• v.27 no.6
• /
• pp.366-376
• /
• 2017

In this paper, we investigated the subsidence possibility and countermeasures according to the current mining method through investigation of the subsidence condition in operation mine. Most of the metal mine were broken, investigating to subsidence pattern of the Sink-hole. Coal mines are becoming more and more deep, investigating to Trough type subsidence patterns in existing mining areas. History of nonmetallic mines have not been developed for over 30 years, but large and small ground deformation problems have been investigated. Mining also has ground subsidence functionality due to time dependence by relying more heavily on empirical methods than technical methods. Therefore, it is necessary to carry out the various researches on systematic development method and prevention of subsidence of nonmetallic mines.

• ETRI Journal
• /
• v.43 no.3
• /
• pp.414-426
• /
• 2021

In the task of data routing in Internet of Things enabled volatile underwater environments, providing better transmission and maximizing network communication performance are always challenging. Many network issues such as void holes and network isolation occur because of long routing distances between nodes. Void holes usually occur around the sink because nodes die early due to the high energy consumed to forward packets sent and received from other nodes. These void holes are a major challenge for I-UWSANs and cause high end-to-end delay, data packet loss, and energy consumption. They also affect the data delivery ratio. Hence, this paper presents an energy efficient watchman based flooding algorithm to address void holes. First, the proposed technique is formally verified by the Z-Eves toolbox to ensure its validity and correctness. Second, simulation is used to evaluate the energy consumption, packet loss, packet delivery ratio, and throughput of the network. The results are compared with well-known algorithms like energy-aware scalable reliable and void-hole mitigation routing and angle based flooding. The extensive results show that the proposed algorithm performs better than the benchmark techniques.

• Journal of the Korean GEO-environmental Society
• /
• v.14 no.9
• /
• pp.13-19
• /
• 2013

The Chongok karst cave which is located in Donghae-city, has high tourist and educational value due to existence of many doline(sink hole). Whereas this cave is easy to approach for the tourists, because this cave is located near the downtown, a high environmental riskiness such as sewage flowing has been also involved. In study, we observed the variation of water quality with long-term monitoring and investigated the possibility of existence of impact factor to water eco-system and determined the proper long-term monitoring factor among many monitoring criteria. The groundwater quality was maintained in the range of about $14^{\circ}C$ in temperature, over 10mg/l in dissolved oxygen and 7-8 in pH, so the impact factor in water eco-system was not observed. The guide line to make sure of tourist safety was determined to 60mm/d as daily rainfall. The conductivity was suggested to main factor for long-term monitoring main factor and pH/turbidity was suitable for the supplementary factor. For the seasonal variation monitoring, ORP was recommended.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.331-331
• /
• 2016

기후변화의 영향으로 인하여 가뭄의 발생이 잦아지고 그 기간은 늘어나고 있다. 특히 2015년에는 충남 서부 지역에 제한급수가 실시되는 등의 피해가 발생하였으며, 올해에도 일부 지역에 가뭄 피해가 예상되고 있다. 이에 따라 가뭄에 대비하기 위한 방안의 하나로, 해수담수화 및 지하수와 같은 대체 수자원 개발의 요구가 높아지고 있다. 특히 지하수의 경우에는 단기간에 최소한의 비용으로 안전한 용수(用水)를 확보할 수 있다는 측면에서 그 효용성이 높다. 그러나 지하수 역시 지표수와 마찬가지로 한정된 자원이며 생성과정에 상당한 시일이 걸린다는 점을 고려할 때, 그 활용을 위해서는 다음과 같은 정책적 고려가 필요해 보인다. 우리나라 지하수는 개별법에 따라 5개 중앙부처 및 지자체에서 소관업무별로 관리하고 있어, 체계적 관리와 자료의 통합 연계에 어려움이 있다. 또한 기본법 성격을 지닌 "지하수법"에서도 지하수 관리 등에 대해 다른 법률에 특별한 규정이 있는 경우에는 해당 법률에 따르도록 규정하여(법 제4조), 합리적 제도 개선에 한계가 있다. "온천법" 등 타법에 의한 지하수 개발 이용관련 인허가 사항을 "지하수법"으로 일원화하여 기본법으로의 역할을 강화하고, 지역별 사업별 관리는 개별 계획을 수립하도록 하는 등 체계적인 지하수의 개발 보전 정책이 필요하다. 국내 지하수 사용은 주로 관정(管井) 개발을 통해 이루어지는데, 무분별한 신규 관정의 개발은 지하수 고갈, 지반침하(sink hole)와 더불어 지하수의 수질 악화를 야기할 수 있다. 관정 개발의 실패로 발생하는 실패공은 노후 관정 및 폐관정과 더불어 방치되는 경우가 많은데, 오염물질 유입으로 지하수를 오염시키는 주요 원인으로 작용한다. 오염된 지하수는 지표수에 비하여 수질을 복원하는데 오랜 시일과 노력이 필요하므로, 사용하지 않는 불용공(不用孔)을 원상 복구하는 등 지하수의 개발에서 사후조치에 이르기까지의 체계적인 관리가 필요하다. 국토교통부는 지하수에 대한 체계적인 관리를 위해, '지하수 기초조사', '지하수 수위변동 실태조사' 및 '지하수시설 전수조사'를 실시하고 있다. 그런데 지하수 기초조사는 "지하수법" 제5조에 근거하여 1997년부터 실시되고 있으나, 예산 및 인력 부족 등으로 20여년이 지난 지금까지도 조사가 마무리되지 못하고 있는 실정이다. 한편 지하수 수위변동 실태조사는 "지하수법" 제17조 등에 근거하여 시행되고 있는 반면, 지하수시설 전수조사는 근거 법률이 마련되어 미비하다. 지하수시설 전수조사는 전국의 모든 관정, 집수정(集水井), 지하댐(underground dam) 등의 지하수 시설을 대상으로 실시되므로, 조사의 방법, 대상, 시행 절차 및 주기 등에 대한 규정 마련을 통해 관련 자료를 지속적으로 보완 관리할 필요가 있다.

• Journal of the Society of Disaster Information
• /
• v.14 no.4
• /
• pp.399-408
• /
• 2018

Purpose: Recently, the ground subsidence has caused social problem, because it occurred life and economic damage. Method: Ground subsidence is different from a sink hole. Ground subsidence occurred cavities from loss of by groundwater flow, surface layer is collapsed due to relaxation and expansion. Results: According to the survey, the caused of ground subsidence are classified as ground cavities, surrounding ground relaxation and pipe joint failure. Conclution: Cavities of ground is mainly caused by cavities formed by rainfall induced infiltration of the heavy rainfall, loss of soil due to rise and fall of ground water level and repeated sewage runoff.