• Title/Summary/Keyword: bedrock

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Studies on the Characteristics of Modified Landscape and the Transformational Processes of Ongnyucheon in Changdeok Palace (창덕궁 옥류천의 수경(修景) 특성과 변천과정)

  • Jung, Woo-Jin;Kim, Hyung-Suk;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.3
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    • pp.42-56
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    • 2012
  • This study was carried out to investigate the construction characteristics and the landscaping design skill for Wiyiam at Ongnyucheon(玉流川) in the rear garden of Changdeok Palace focusing on constructing technique, space composition and transformational process of the site. The results of this study were summarized as follows; First, Wiyiam of Ongnyucheon was constructed as garden ornament which was modified the huge bedrock into the shape of the mountain. The waterfall of Wiyiam was originally made of torrent which water flowed into the bottom, but it was reconstructed to take the effect of Inak(離落: the method to drop water from high place) by carving rock into square shape at the era of King Gojong(高宗). Second, main characteristics of Wiyiam appeared in Donggwoldo was the hill built up with a square pond and ground at the back of Wiyiam and the profound scenery of mountains and stream from the view of Wiyiam. Also, pavilions such as Soyojeong(逍遙亭), Cheongujeong and Taegeukjeong(太極亭) built in Ongnyucheon seemed to be constructed as the spots to appreciate the view and waterfall sound of Wiyiam. Also the spots were not bounded by the function of creating special water systems such as Cheongujeong pond and Taegeukjeong pond and showed the outstanding landscape design skill to make people feel unusual interest from each spot. On the other hand, this study considered that the evening scenery of Wiyiam, beautiful sound of falling water, unusual water system with beautiful plant materials were landscaped for the function of the psychological peace and stability to the appreciators. Lastly, the extreme change of space composition in Ongnyucheon was assumed as a strategy to improve the existing poor drain environment by confirming that the mountain stream and wall of Soyojeong were removed and drainage in both side of Soyojeong was installed in the 21th year of King Gojong's reign(1884).

Monitoring of a Time-series of Land Subsidence in Mexico City Using Space-based Synthetic Aperture Radar Observations (인공위성 영상레이더를 이용한 멕시코시티 시계열 지반침하 관측)

  • Ju, Jeongheon;Hong, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1657-1667
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    • 2021
  • Anthropogenic activities and natural processes have been causes of land subsidence which is sudden sinking or gradual settlement of the earth's solid surface. Mexico City, the capital of Mexico, is one of the most severe land subsidence areas which are resulted from excessive groundwater extraction. Because groundwater is the primary water resource occupies almost 70% of total water usage in the city. Traditional terrestrial observations like the Global Navigation Satellite System (GNSS) or leveling survey have been preferred to measure land subsidence accurately. Although the GNSS observations have highly accurate information of the surfaces' displacement with a very high temporal resolution, it has often been limited due to its sparse spatial resolution and highly time-consuming and high cost. However, space-based synthetic aperture radar (SAR) interferometry has been widely used as a powerful tool to monitor surfaces' displacement with high spatial resolution and high accuracy from mm to cm-scale, regardless of day-or-night and weather conditions. In this paper, advanced interferometric approaches have been applied to get a time-series of land subsidence of Mexico City using four-year-long twenty ALOS PALSAR L-band observations acquired from Feb-11, 2007 to Feb-22, 2011. We utilized persistent scatterer interferometry (PSI) and small baseline subset (SBAS) techniques to suppress atmospheric artifacts and topography errors. The results show that the maximum subsidence rates of the PSI and SBAS method were -29.5 cm/year and -27.0 cm/year, respectively. In addition, we discuss the different subsidence rates where the study area is discriminated into three districts according to distinctive geotechnical characteristics. The significant subsidence rate occurred in the lacustrine sediments with higher compressibility than harder bedrock.

A preliminary numerical analysis on the behaviour of tunnel under construction in fracture zone considering seismic load (지진 하중을 고려한 단층파쇄대에서의 시공 중 터널 거동 분석에 관한 수치해석적 연구)

  • Oh, Dong-Wook;Hong, Soon-Kyo;Kim, Dae-Kon;Lee, Yong-Joo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.2
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    • pp.279-299
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    • 2019
  • Recently occurred earthquake Gyeongju and Pohang served as a momentum to remind that Korean peninsular is not a safety zone from earthquake anymore. The importance of seismic design, therefore, have been realized and researches regarding design response spectrum have been actively carried out by many researchers and engineers. Current tunnel seismic design method is conducted to check safety of tunnel structure by dynamic numerical analysis with condition of completed lining installation, so, it is impossible to consider safety of tunnel behavior under construction. In this study, therefore, dynamic numerical analysis considering seismic wave propagations has been performed after back analysis using results from field monitoring of tunnel under construction in fractured zone and 1st reinforcement (shotcrete, rockbolt) behaviour are analyzed. Waves are classified by period characteristic (short and long). As a result, the difference depending on period characteristic is minor, and increasements of displacement are obtained at crown displacement due to seismic wave is 28~31%, 14~16% at left side of tunnel in the fractured zone, 13~27% at right side of tunnel in the bed rock, respectively. In case of shotcrete axial force is increased 113~115% at tunnel crown, 102% at left side, 106~110% at right side, respectively. Displacement and axial force of rockbolts which are selected by type of anchored grounds (only fractured zone, fractured zone and bed rock, only bedrock) are analyzed, as a result, rockbolt which is anchored to fractured zone and bed rock at the same time are weaker than any other case.

Brutal sorigeuk of the use of educational view of (잔혹소리극 <내다리내놔>의 가치 교육적 활용에 대한 고찰)

  • Kim, Jeong Sun
    • (The) Research of the performance art and culture
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    • no.32
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    • pp.595-628
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    • 2016
  • Pansori of a creative group pansori 2006 demonstration factory floor sound brutal sorigeuk the home of is a legend 'deokttaegol' in pansori, a creative for adaptation to remakes Work is. Evil Twin 'deokttaegol' called "Give me my leg back" in of Ghost Stories, broadcast on a kbs of lines from breakneck work is considered to be a pronoun. Sound and shadow play and playing drums and payments sentiments of the cruelty I've come across in this 'Give me my leg back' audience to be deployed to the cruel is formed by the center. Based on emotional horror of cruelty. When I was little, ever heard of Korean Ghost Stories, a bedrock of the main feeling revulsion of value in a short time and is contained in a story of filial piety, while in education, to the target Provided. Done in our lives using genre called 'pansori' sentiment and efficient learning can move about the value education can know. Sound and stories, many carefree a stimulus such as Pansori is a great gesture can be a means of education. Valued with any information, work is performed in pansori, depending upon efficient and the various, education and made an emotional cultivation resulting from the value. In my life friendly, our own via a variety of materials that can easily access many values and sentiments, and to culture for each age group on languages and customs Each age groups and instructive preferred allowing them access through their rhythm, pansori, access to the target is persistent about it with curiosity and interest. Can have interest. This wealth not belong to the traditional pansori and new together private and to the tune called creative work for the Pansori. Therefore, our language and customs, their poems span a friendly, the pansori and created using the vocabulary for each age group creative content is educational effects if used in education It is expected to be big thing. These effective approach for each age group and based on the vocabulary by the content easily understood lessons by causing only a smoothly acquired Can to provide an opportunity. Therefore, the Pansori of a creative education is important to take advantage of educational value.

Natural Baseline Groundwater Quality in Shingwang-myeon and Heunghae-eup, Pohang, Korea (포항시 신광면 및 흥해읍 일대 지하수의 배경수질 연구)

  • Lee, Hyun A;Lee, Hyunjoo;Kwon, Eunhye;Park, Jonghoon;Woo, Nam C.
    • The Journal of Engineering Geology
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    • v.30 no.4
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    • pp.469-483
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    • 2020
  • The results of long-term groundwater level and quality monitoring can be used not only as the basic data for evaluating the impact of various disasters including climate change and establishing responses, but also as key data for predicting and managing geological disasters such as earthquakes. Some countries use groundwater level and quality monitoring for researches to predict earthquakes and to assess the impacts of the earthquake disaster. However, a few cases in Korea report on individual groundwater quality factors (i.e., dissolved ions) observed before and after the earthquakes, being different from other countries. To establish the abnormality criteria for groundwater quality in Pohang, groundwater samples were collected and analyzed five times from 14 agricultural or private wells existing in Shingwang-myeon and Heunghae-eup. As a result of the analysis, it was found that Ca2+ was the dominant cation in Shingwang-myeon, while Na+ was the dominant cation in Heunghae-eup. The elevated NO3- concentration in Shingwang-myeon is contributed to the agricultural activity in the area. A high concentration of Fe was detected in a well on Heunghae-eup; the concentration exceeded the drinking water standard by nearly 100 times. Relatively higher dissolved ions were observed in the groundwater of Heunghae-eup, and it is considered as the result of the flow velocity difference and water-rock reaction accompanying the difference in bedrock and sediment characteristics. The groundwater of Shingwang-myeon appeared to be most affected by the weathering of granite and silicates, while that of Heunghae-eup was mainly affected by the weathering of silicates and carbonate. The background concentrations (baselines) of groundwater Shingwang-myeon and Heunghae-eup was identified through the survey; however, the continuous monitoring is required to monitor the possible changes and the repeatability of seasonal variation.

Report on Extended Leak-Off Test Conducted During Drilling Large Diameter Borehole (국내 대구경 시추공 굴진 중 Extended Leak-Off Test 수행 사례 보고)

  • Jo, Yeonguk;Song, Yoonho;Park, Sehyeok;Kim, Myung Sun;Park, In-Hwa;Lee, Changhyun
    • Tunnel and Underground Space
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    • v.32 no.5
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    • pp.285-297
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    • 2022
  • We report results of Extended Leak-Off Test (XLOT) conducted in a large diameter borehole, which is drilled for installation of deep borehole geophysical monitoring system to monitor micro-earthquakes and fault behavior of major fault zones in the southeastern Korean Peninsula. The borehole was planned to secure a final diameter of 200 mm (or more) at a depth of ~1 km, with 12" diameter wellbore to intermediate depths, and 7-7/8" (~200 mm) to the bottom hole depth. We drilled first the 12" borehole to approximately 504 m deep and installed American Petroleum Institute standard 8-5/8" casing, then annulus between the casing and bedrock was fully cemented. XLOT was carried out for several purposes such as confirming casing and cementing integrity, measuring rock stress states. To that end, we drilled additional 4 m long open hole interval to directly inject water and pressurize into the rock mass using the upper API casings. During the XLOT, flow rates and interval pressures were recorded in real time. Based on the logs we tried to analyze hydraulic conductivity of the test interval.

A Study on the Fengshui Shapes of the Four Propitious Sites Recorded in The Canonical Scripture (『전경』에 기록된 사명당(四明堂)의 풍수 물형(物形) 연구)

  • Shin Young-dae
    • Journal of the Daesoon Academy of Sciences
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    • v.41
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    • pp.133-178
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    • 2022
  • This study investigates if four propitious sites (四明堂, sa myeongdang) identified in Daesoon Jinrihoe's The Canonical Scripture correspond with the orthodox descriptions of dragon, energy hub, sand, and water (龍穴砂水, yong hyeol sa su) which are held by Fengshui as conditions necessary for that specific designation. In this study, these conditions, based on the shape of the site-formations, were observed via through on-site surveys and the application of the theories presented by traditional books on Fengshui. First, the dragon veins (龍脈, yongmaek) of the energy hub of the Five Immortals Playing Baduk (五仙圍碁穴 oseonwigi- hyeol) on Mount Hoemun in Sunchang consists of solid soil, is like a spiderweb, rises and lays prone, winds in every direction, and looks almost disconnected while actually remaining connected. Second, the Fengshui characteristics of the energy hub of Worship Held by Buddhist Monks from Abroad (胡僧禮佛穴, hoseungyebul- hyeol) on Mount Seungdal in Muan is that the branching feet (枝脚 jigak) support the mountain range by forming a valley to the left and right of the dragon veins that stretch from the peak of Mount Seungdal. Also, the direction-changing helm (橈棹 yodo) supports the mountain range solidly can be said to be well-developed. It is likewise noted that there is an excellent change in dragon veins in that exhibit curvature that spans being high, low, rising, and lying. This makes it appear as though the dragon is wriggling back and forth. Third, the state of the energy hub of Celestial Maidens Weaving Silk (仙女織錦穴, seonnyojikgeum-hyeol) on Sonryong Ridge in Jangseong County demonstrates overall harmony between mountain and water as it is near Mount Ju and Mount An and has a solid water outlet to which it is tightly fastened such that its energy does not leak out. Meanwhile, the positioning of its blue dragon of the east, red phoenix of the south, white tiger of the west, and black tortoise of the north is so intimate that its long flow can be said to be spinning. The Songryong Ridge area where energy hub was formed between soil and bedrock is the right land for a great favored location as it corresponds with Fengshui logic in an exemplary manner. Fourth, the Fengshui characteristics of the energy hub of Subjects Receiving the Imperial Command (群臣奉詔穴, gunshinbongjo-hyeol) at Baerye-jeon Field in Taein can be described as embracing the village snuggly as it centers around Mount Wangja, and its blue dragon and white tiger respond to each other. Additionally, a clear distinction between host and guest is noticeable in the positions of Mount Ju and Mount An. The flowing body of water in front of the village wraps around that village as a Horizontal Water Formation (橫水局, hoengsuguk), and vigorous vapor from the earth draws breath as the yin-yang energy of the landscape courses through the earth. As dragon veins, the range of the mountain, are like the blood vessels within the human body and the dragon is compared to the limbs, the energy hub of Subjects Receiving the Imperial Command at Baerye-jeon Field in Taein can be identified as a favored location that was formed directly by the sky and earth.

Analysis of Crustal Velocity Structure Beneath Gangwon Province, South Korea, Using Joint Inversion of Receiver Functions and Surface Wave Dispersion (수신함수와 표면파 분산의 연합 역산을 사용한 강원도 지역 하부의 지각속도구조 분석)

  • Jeong-Yeon Hwang;Sung-Joon Chang
    • Economic and Environmental Geology
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    • v.56 no.3
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    • pp.277-291
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    • 2023
  • To analyze the crustal velocity structures beneath 21 broadband seismic stations in Gangwon Province, South Korea, we first applied the H-κ stacking method to 139 teleseismic event data (Mw ≥ 5.8 and the epicentral distance of 30° - 90°) occurring between March 18, 2019 and December 31, 2022 to estimate the Moho depths and Vp/Vs ratios beneath each station. The Moho depths and Vp/Vs ratios from the H-κ stacking method range from 24.9 to 33.2 km depth and 1.695 - 1.760, respectively, and the estimated Vp/Vs ratios were applied to the joint inversion of receiver functions and surface wave dispersion to obtain 1-D crustal velocity models beneath each station. The resulting Moho depths range from 25.9 to 33.7 km depth, similar to the results from the H-κ stacking method. Moho depth results from the both methods are generally consistent with Airy's isostasy. The 1-D crustal velocity models confirm that the existence of 2 km thick low-velocity layers with P-wave velocities of 5 km/s or less at some stations in the Taebaeksan basin, and at the stations CHNB and GAPB in northern Gangwon Province, which are located above the Cenozoic sedimentary layer. The station SH2B, although not overlying a sedimentary layer, has a low P-wave velocity near the surface, which is probably due to various factors such as weathering of the bedrock. We also observe a velocity inversion with decreasing velocity with depth at all stations within 4 - 12 km depths, and mid-crustal discontinuities possibly due to density differences in the rocks at around 10 km depth below some stations.

Physical Properties of Volcanic Rocks in Jeju-Ulleung Area as Aggregates (제주도 및 울릉도에서 산출되는 화산암의 골재로서의 물성 특징)

  • Byoung-Woon You;Chul-Seoung Baek;Kye-Young Joo
    • Economic and Environmental Geology
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    • v.57 no.2
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    • pp.205-217
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    • 2024
  • This study evaluated the physical characteristics and quality of volcanic rocks distributed in the Jeju Island-Ulleung Island area as aggregate resources. The main rocks in the Jeju Island area include conglomerate, volcanic rock, and volcanic rock. Conglomerate is composed of yellow-red or gray heterogeneous sedimentary rock, conglomerate, and encapsulated conglomerate in a state between lavas. Volcanic rocks are classified according to their chemical composition into basalt, trachybasalt, basaltic trachytic andesite, trachytic andesite, and trachyte. By stratigraphy, from bottom to top, Seogwipo Formation, trachyte andesite, trachybasalt (I), basalt (I), trachybasalt (II), basalt (II), trachybasalt (III, IV), trachyte, trachybasalt (V, VI), basalt (III), and trachybasalt (VII, VIII). The bedrock of the Ulleung Island is composed of basalt, trachyte, trachytic basalt, and trachytic andesite, and some phonolite and tuffaceous clastic volcanic sedimentary rock. Aggregate quality evaluation factors of these rocks included soundness, resistance to abrasion, absorption rate, absolute dry density and alkali aggregate reactivity. Most volcanic rock quality results in the study area were found to satisfy aggregate quality standards, and differences in physical properties and quality were observed depending on the area. Resistance to abrasion and absolute dry density have similar distribution ranges, but Ulleung Island showed better soundness and Jeju Island showed better absorption rate. Overall, Jeju Island showed better quality as aggregate. In addition, the alkaline aggregate reactivity test results showed that harmless aggregates existed in both area, but Ulleungdo volcanic rock was found to be more advantageous than Jeju Island volcanic rock. Aggregate quality testing is typically performed simply for each gravel, but even similar rocks can vary depending on their geological origin and mineral composition. Therefore, when evaluating and analyzing aggregate resources, it will be possible to use them more efficiently if the petrological-mineralological research is performed together.

Distribution Characteristics of Land and River Aggregate Resources in Yeongam Area by Deposition Period (영암지역 육상 및 하천 골재의 퇴적 시기별 분포 특성)

  • Jin Cheul Kim;Sei Sun Hong;Jin-Young Lee;Ju Yong Kim
    • Economic and Environmental Geology
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    • v.57 no.2
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    • pp.243-251
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    • 2024
  • In this study, a surface geological survey was first conducted to investigate aggregate resources in the Yeongam area of Jeollanam-do, and a drilling survey was conducted in the lower part of the surface, which was difficult to identify through a surface geological survey, to determine the spatial distribution of aggregates. Drilling sites were selected considering the topographical development and Quaternary alluvium characteristics of the study area, and river aggregate drilling surveys were conducted at a total of 5 points and land aggregate drilling surveys were conducted at a total of 28 points. Borehole core sediments were classified into seven sedimentary units to determine whether they could be used as aggregates, and optically stimulated luminescence dating was performed on representative boreholes to measure the depositional period for each sedimentary unit. As a result of the study, most of the Yeongam area had a very wide river basin, so it was estimated that there would be a large amount of aggregate, but the amount of aggregate was evaluated to be very small compared to other cities and counties. Most of the unconsolidated sedimentary layers in the Yeongam area are composed of blue-grey marine clay with a vertical thickness of more than 10 m. The sand-gravel layer corresponding to the aggregate section is distributed in the lower part of the marine clay, thinly covering the bedrock weathering zone. This is because the amount of aggregates themselves is small and most of the aggregates are distributed at a depth of 10 m below the surface, which is currently difficult to develop, so the possibility of developing aggregates is evaluated to be very low. As a result of dating, it can be seen that the blue-grey marine clay layer is an intertidal sedimentary layer formed as the sea level rose rapidly about 10,000 years ago. The deposition process continued from 10,000 years ago to the present, and as a result, a very thick clay layer was deposited. This clay layer was formed very dominantly for about 6,000 to 8,000 years, and the sand-gravel layer in the section where aggregates deposited in the Pleistocene period can exist was measured to have been deposited at about 13.0 to 19.0 ka, and about 50 ka, showing that it was deposited as paleo-fluvial deposits before the marine transgression process.