• The Journal of Engineering Geology
• /
• v.33 no.3
• /
• pp.475-487
• /
• 2023

We surveyed the distribution of soil layers on Dongdo and Seodo of Dokdo and measured the physical properties of the soils. To investigate the distribution of soil layers, the soil depth was measured directly in accessible locations, and visual observations of inaccessible locations were carried out using drones and boats. Soil depths ranged from 3 to 50 cm, and most soil layers had depths of 10~20 cm. Based on these results, a map of the soil layer was drawn using 5 cm intervals for soil depth. To analyze the soil characteristics of Dokdo, soil samples were collected from 13 locations on Dongdo and 13 locations on Seodo, in consideration of various geological settings. According to the results of grain size distribution tests, sand contents were >75%, and soil from Seodo contained more gravel-sized particles than that from Dongdo. Using the unified soil classification system (USCS) and textural classification chart of the United States Department of Agriculture (USDA), most of the soil samples from Dokdo are classified as sand, and some are classified as loamy or clayey sand. In addition, well-graded loamy or clayey sands are more common in Dongdo, and poorly graded sands with gravel are more common in Seodo. These results are expected to be important for studying soil characteristics on Dokdo.

• Journal of the Korean Geosynthetics Society
• /
• v.9 no.1
• /
• pp.1-11
• /
• 2010

The soil mechanical characteristics according to geologic conditions were investigated in the study area. The geology of study area was consisted of Ingok Tuff, Yuchi Conglomerate and Dado Tuff. Yuchi Tuff covered about 80% of the study area. The disturbed and undisturbed soils were sampled from the conglomerate area, Tuff area and Shale area, and then a series of the laboratory soil tests was performed. The soils sampled from the conglomerate area have a large dry unit weight and a low permeability relatively, while the soils sampled from tuff and shale areas have a small dry unit weight and a high permeability. It is proven that the soil permeability is highly affected by the effective grain size and the silt and clay content. That is, the soil permeability is increased with increasing the effective grain size, and the soil permeability is decreased with increasing the silt and clay content.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.5C
• /
• pp.303-312
• /
• 2006

This study is to evaluate the mechanical characteristics of flowable backfill and offer a guide line of mixture proportion based on soil types for constructing underground power utilities. Flowable backfill is known as soil-cement slurry, void fill, and controlled low-strength material(CLSM). The benefits of CLSM are reduced equipment costs, faster construction, re-excavation in the future, and the ability to place materials in confined spaces, which are narrow parts or perimeters of underground power cables nearly impossible for compaction. The flowable slurry mixed with 17 soils and 6 accelerated mixtures in the laboratory were evaluated for flowability and unconfined compressive strength to meet the target values of this study.

• 건강소식
• /
• v.29 no.9 s.322
• /
• pp.38-39
• /
• 2005

옛부터 송이가 나는 자리는 자식에게도 가르쳐주지 않는다고 할 정도로 송이는 귀한 음식으로 통했다. '송이'는 소나무 뿌리에서 자라는 버섯이라 해서 붙은 이름. 지표 온도와 일교차, 습도 등 자생조건이 까다로워 인공재배가 불가능한 것으로 알려져 있는데, 현재 우리나라 자연 송이의 산지는 봉화와 양양을 대표로 꼽는다. 특히 봉화 지영의 마사토라는 토질에서 자라난 송이는 향이 진하고 맛이 쫄깃해 전국 최고로 치고 있다. 가을 초반부터 중반까지만 맛볼 수 있어 이 때를 놓치면 1년을 기다려야 한다.

• The Korea Beekeeping Bulletin
• /
• s.338
• /
• pp.23-31
• /
• 2008

양봉관리 방법이 양봉 농가마다 조금씩 차이가 난다. 그것은 봉장이 다르고 또한 토질과 기후도 다르가. 그리고 환경 조건도 다르며 따라서 양봉가의 성격과 양봉의 상태도 강군과 약군으로 달라지기 때문에 관리방법도 다르기 마련이다. 1월 양봉관리는 작년을 결산하고 새해는 더욱더 알찬 계획을 세워 풍성하게 수확을 할 수 있는 준비 하는 달이다. 1월의 봉군 관리는 봉군의 상태와 환기에 중점을 두어야 한다.

• Proceedings of the KSEG Conference
• /
• 2005.04a
• /
• pp.209-216
• /
• 2005

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.10
• /
• pp.15-24
• /
• 2010

In the case of underground power utilities pipe such as circular pipe, the most difficult problem is low compaction efficiency of the bottom of pipe inducing the failure of utilities. To overcome this problem, various studies have been performed and one of these is CLSM(Controlled Low Strength Materials) accelerated flow ability. But underground power utilities pipe backfill materials is also needed to have good thermal property that can dissipate the heat as rapidly as it is generated. So, in this study, we performed thermal resistancy test for various materials such as sand, weathered soil, clay and mixed soil to analyze the thermal characteristics of CLSM(Controlled Low Strength Materials) with accelerated flow ability for various conditions(water content, unit weight, void ratio, curing time) and to evaluate the applicability for backfill material of underground power utilities pipe. The test results of 16 specimens for thermal resistancy test showed good thermal property that maintained below $85^{\circ}C\;cm/W$.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.04a
• /
• pp.30-33
• /
• 2002

In this study, feasibility of using hydrogen peroxide as a chemical oxidant for in-situ treatment by EK-Fenton technology were investigated. Kaolinite, kaolinite/sand mixture and illitic soil spiked by phenol and phenanathrene were used and variation of electrochemical characteristics were examined by EK-Fenton test. For kaolinite that having low buffer capacity, hydrogen peroxide was injected effectively from anode reservoir. However illitic soil that having relatively higher buffer capacity had low hydrogen peroxide introducing efficiency. The test results showed that Hydrogen ions generated by current increased during the treatment decreased under pH 3 in the most of kaolinite specimen. Therefore, stabilized hydrogen oxide was injected more effectively in the kaolinite specimen. This study suggests that efficiency of hydrogen peroxide injection by EK-Fenton thechnoloty is dependent of variation of pH in the soil

• Journal of the Korean Geotechnical Society
• /
• v.16 no.5
• /
• pp.55-62
• /
• 2000

심층혼합처리공법에 의해 개량된 연약지반상에 사석제를 축조한 후 배면매립을 실시할 경우 사석호안의 변형거동을 관찰하기 위해 계측을 실시하였다. 개량지반상에 사석호안을 축조하기 위한 설계기준을 마련하기 위하여 유한요소법을 이용한 지반변형해석과 Bishop의 간편법을 이용한 사면안정해석을 실시하였다. 이들 해석을 사석제부, 연약지반부 그리고 뒷채음성토부의 토질조건 및 형상이 다른 여러 경우에 대하여 실시하여 그 결과를 서로 비교 분석하였다. 즉, 해석결과를 이용하여 사석제 정사부에서의 수평변위량과 침하？을 호안의 사면안정률과 연과지어 검토하였다. 본 연두결과 사석호안의 사면안전률 1.3보다 낮을 경우 상당히 큰 지반변형이 발생하는 것으로 나타났다.

• The Journal of Engineering Geology
• /
• v.17 no.4
• /
• pp.665-671
• /
• 2007

In this study, the soil characteristics and the landslide probability are investigated in East Island of Dok-do. The distribution and depth of soil layer were investigated and the soil samples were taken from the soil layer in East Island. As the results of field investigation, the soil layer was partly distributed in specific location and the soil depth was ranged from 1cm to 50cm. Also, the soil depth was mainly ranged about 10cm in the large part of soil layer. The soils were classed as the weathered residual soils and involved many organic contents such as rotten roots and leaves. The average of water contents is 23.2%, and the average of liquid limits is 42.2%. Also, the soils is non-plastic condition. Also, the soils were mainly classed as the poor graded sand including loam contents. Meanwhile, the landslide probability was investigated through a survey of the soil layer distribution in East Island. The soil depth was very shallow in the large part of the soil layer, and the distribution area of soil layer was small. Therefore, it may predict that the landslide probability is very low due to the dissatisfaction of landslide occurrence condition.