• Title/Summary/Keyword: surrounding rock

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Oxygen and Hydrogen Isotopic Compositions of the Hwacheon Granite (화천화강암의 산소와 수소 동위원소 조성)

  • Park Young-Rok;Ko Bokyun
    • The Journal of the Petrological Society of Korea
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    • v.13 no.4
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    • pp.214-223
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    • 2004
  • Oxygen and hydrogen isotopic compositions of the Jurassic peraluminous Hwacheon granite were measured, and compared with those of other Jurassic peraluminous Daebo granite in Korea. $\delta$$\^$18/O values for quartz and feldspar of the Hwacheon granite range from 8.2 to 10.6 and 5.8 to 9.0$\textperthousand$, respectively. Whole rock $\delta$$\^$18/O values for banded biotite gneiss country rocks surrounding the Hwacheon granites range from 8.1 to 9.4$\textperthousand$. Whole rock and biotite $\delta$D Values for Hwacheon granite range from -84 to -113 and -107 to -113$\textperthousand$, respectively. Whole rock $\delta$D values for banded biotite gneiss country rocks range from -76 to -100$\textperthousand$. Both $\delta$$\^$18/O and $\delta$D values of the Hwacheon granite are characterized by low values compared to the 'normal' values for the fresh peraluminous granitic rocks. Low $\delta$$\^$18/O values of the Hwacheon granite resulted from fluid-rock interaction for a long period. Isotopic modelling result renders that a relatively low-$\delta$$\^$18/O fluid below -1$\textperthousand$ was involved in subsolidus isotopic exchange under a relatively high fluid/rock ratio (<-6). The fluid of meteoric origin has experienced a modification of oxygen isotopic composition as a result of fluid-rock interaction with the Hwacheon granite and surrounding metapelitic country rocks.

A Trend of Back Ground Surface Settlement of Braced Wall Depending on the Joint Dips in Rocks under the Soil Strata (복합지반 굴착 시 암반층 절리경사 각도별 흙막이 벽체 배후 지표침하의 경향)

  • Bae, Sang-Su;Lee, Sang-Duk
    • Journal of the Korean Geotechnical Society
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    • v.32 no.11
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    • pp.83-96
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    • 2016
  • The surface settlement of the back ground of a braced wall due to the ground excavation has the great influence on the safety of the surrounding area. But it is not easy to predict the settlement of the surrounding area due to proud excavation. Estimation of the settlement of the surface ground induced by the deformation of the braced wall is performed by FEM and empirical method (Peck, Clough etc). In this research, surface settlement of the back ground braced wall depending on the joint dips in rocks during excavating the composit ground was measured at the large scale model test (standard: $0.3m{\times}0.3m{\times}0.5m$). The scale of model test was 1/14.5 and the ground was excavated in ten steps. Earth pressure on the braced wall and ground surface settlement on the back ground of a braced wall were investigated. The surface settlement during the excavation depended on the joint dips in rocks on of the ratio of rock layer. Maximum earth pressure and maximum surface settlement were masured at the same excavation step. In accordance with the increase of the rock layer dips and rock layer ratio, the ground surface settlement increased. The maximum ground surface settlement was 17 times larger at 60 degree joint dips in rocks than that of the horizontal ground conditions. And the position of the maximum surface settlement by empirical method was calculated at the point, which was 17%~33% of excavation depth. In accordance with the increase of the rock layer dips and rock layer ratio, the ground maximum surface settlement increased. The ground surface settlement of composite ground is smaller than that of the empirical.

Types and Historical Transition of Korean Traditional Seokgasan (한국 전통 석가산의 유형과 역사적 변천)

  • Yoon, Young-Jo;Yoon, Young-Hwal
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.3
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    • pp.83-97
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    • 2010
  • Seokgasan which is artificial rock mountain had been developed into one of the axes of traditional rock landscape of Goryo period and Joseon period as the central component of Korean traditional landscaping, but the legacy was cut off at the present. In the middle of the Goryo period, the Seokgasan made by piling rocks which were started from replicating miniature landscape has been developed into presenting the symbol and Seokgasan so it faced the new transition period of traditional rock garden culture. Seokgasan so it as small knoll, the Korean traditional Seokgasan was made differently the the surrounding landscape with big Seokgasan in China which overwhelms so it harmonize the surrounding landscape to build Korean style of the Seokgasan. This study is the objective investigation based on the old literature and the field remains, so it aims to so it comprehend the type of Seokgasan and developmental forms. At the result of investigation, 5 types of Seokgasan such as rocks piling on a pond, piling rocks, rocks in a pond, rocks on a ground, rock in a pot etc. has been developing in addition to the rocks which the oddly shaped rock is piled up as the basic framework. Among those, the piling rocks on a pond of Seokgasan which means water flows in Seokgasan is the representative Seokgasan which has been continued since the middle of the Goryo period until the end of the Joseon period. This study is expected to be the foundation which will succeed to legacy of Seokgasan tradition which was cut off and to develop by recovering historical landscaping value and identity of Seokgasan.

Investigation on Water Leakage-Induced Tunnel Structure and Ground Responses Using Coupled Hydro-Mechanical Analysis (수리역학 연계해석을 이용한 누수로 인한 터널 구조물 및 지반 거동의 분석)

  • Dohyun Park
    • Tunnel and Underground Space
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    • v.33 no.4
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    • pp.265-280
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    • 2023
  • Water leakage in tunnels is a defect that can affect tunnel stability and the ground movement by changing the stress and pore water pressure of the surrounding ground. Long-term or large-scale water leaks may lead to damage of tunnel structure and the surrounding environment, such as tunnel lining instability and ground surface settlement. The present study numerically investigated the effects of water leakage on the structural stability of a tunnel and the ground behavior. The tunnel was assumed to be under undrained conditions for preventing the inflow of the surrounding water and leaks occurred in the concrete lining after completion of the tunnel construction. A coupled hydro-mechanical analysis using a TOUGH-FLAC simulator developed in Python was conducted for assessing the leakage induced-behavior of the tunnel structure and ground under different conditions of the amount and location of water leak. Additionally, the effect of hydro-mechanical coupling terms on the results of coupled response was investigated and discussed.

Study on bearing capacity of combined confined concrete arch in large-section tunnel

  • Jiang Bei;Xu Shuo;Wang Qi;Xin Zhong Xin;Wei Hua Yong;Ma Feng Lin
    • Steel and Composite Structures
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    • v.51 no.2
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    • pp.117-126
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    • 2024
  • There are many challenges in the construction of large-section tunnels, such as extremely soft rock and fractured zones. In order to solve these problems, the confined concrete support technology is proposed to control the surrounding rocks. The large-scale laboratory test is carried out to clarify mechanical behaviours of the combined confined concrete and traditional I-steel arches. The test results show that the bearing capacity of combined confined concrete arch is 3217.5 kN, which is 3.12 times that of the combined I-steel arch. The optimum design method is proposed to select reasonable design parameters for confined concrete arch. The parametric finite element (FE) analysis is carried out to study the effect of the design factors via optimum design method. The steel pipe wall thickness and the longitudinal connection ring spacing have a significant effect on the bearing capacity of the combined confined concrete arch. Based on the above research, the confined concrete support technology is applied on site. The field monitoring results shows that the arch has an excellent control effect on the surrounding rock deformation. The results of this research provide a reference for the support design of surrounding rocks in large-section tunnels.

Application Case of Test of Revegetation Measures on Design of Slopes Revegetation and Tentative Instruction on Construction Work -With a Case of Slopes Along the National Road Between Gimcheon and Eomo - (비탈면 녹화 설계 및 시공 잠정 지침 적용사례 -김천어모구간 국도비탈면을 중심으로-)

  • Jeon, Gi-Seong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.4
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    • pp.83-94
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    • 2007
  • Test application of revegetation measure was made on the roadside slope damaged by Gimcheon-Eomo national road improvement project in a bid to prevent the soil from being washed out as well as to restore the ecological environment, and the survey for assessing the effect of slope revegetation measures was conducted, beginning Sep 7 through Sep 20, 2006. In the wake of comprehensive reviewing and evaluating the surrounding topographic environment, physical and chemical characteristics of soil, germination of revegetation plants, analysis of bio mass, covering ratio and the plants appeared, revegetation measure C was found to have been most effective and desirable for further application in the area. Viewing the specific applicability by the area, revegetation measure C and C-1 appeared to be appropriate for blasting rock slope and ripping rock slope as they are efficient in preventing the slope from being washed out and in early revegetating. And revegetation measure B deemed to be effective to blasting rock slope or ripping rock slope as an alternative. And for cut slope, vegetation measure C-2 was judged to be more effective than measure D or E, while measure C-3 would be appropriateto embankment slope.

A Study on the Support System of Large Caverns Under High Initial Stress (과지압 하에 있는 대규모 지하공동의 지보 시스템에 관한 연구)

  • 박연준;유광호;최영태;김재용
    • Tunnel and Underground Space
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    • v.14 no.2
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    • pp.154-166
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    • 2004
  • A numerical stability analysis was conducted on the large oil storage caverns excavated in a rock mass under high initial horizonal stress. The behaviors of the surrounding rock mass, rockbolts, and shotcrete were analyzedr and stability of the support members were assessed. For a proper support system design, the effect of the modelling technique, cavern shape and rockbolt length on the stability of the cavern was investigated. Results show that installation timing of supports and the change in cavern shape due to stepwise excavation affect the stress induced in support members. Also found was desperate need for a numerical technique which can properly reflect the behavior of the steel fiber reinforced shotcrete.

Traditional Korean landscape garden with special attention (역사적 문화환경의 창조 -고대정원문화를 중심으로-)

  • 민경현
    • Journal of the Korean Professional Engineers Association
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    • v.18 no.2
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    • pp.54-65
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    • 1985
  • Korean Landscape Garden may be described according to its stage of development. In the primitive agricultural era, the garden was preceded by vegetable yards and at this time rock arranging (Soo-Sok garden) was initiated together with the megalithis culture of dolmens, heavenly altars and tumuli. In the early Three Kingdom period palace gardens were built on a grand scale and toward the end of fourth century temple garden were introduced along with Buddhism. These gardens evolved to the flourishment of "HWAGE"(terraced gardens) rock arrangements of ZEN, early KOR-YO period. Especially since the middle of KOR-Yo period the "IM-CHUN"(forest and pond) garden became popular, while during Cho-Son period "HWAGE" in the back yard, pond and pool garden and "IM-CHUN" style country villa became fashionable. The Korea traditional Landscape garde may be characterized that first it is a nature Landscape style, which makes the maximum accomodation with the surrounding nature. Secondly, the Korean garden is built creatively by utilizing the elements of its climate and topography, Kogu-Ryo, Paik-Je great-Kaya and Sil-Ra had developed original a castle town plans and beautiful gardens rock arrangements which precede the equivalent style of China and set the prototype for Japan. The Landscape art of waterfalls and rock arrangements at An-Ap-Chi garden of 7th century has no equals in China and set the origin of pond style of Japanese garden.

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Technologies of Underground Thermal Energy Storage (UTES) and Swedish Case for Hot Water (지하 열에너지 저장 기술 및 스웨덴 암반공동내 열수 저장 사례)

  • Park, Doh-Yun;Kim, Hyung-Mok;Ryu, Dong-Woo;Choi, Byung-Hee;SunWoo, Choon;Han, Kong-Chang
    • Tunnel and Underground Space
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    • v.22 no.1
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    • pp.1-11
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    • 2012
  • Thermal energy storage is defined as the temporary storage of thermal energy at high or low temperatures for later use in need. The energy storage can reduce the time or rate mismatch between energy supply and demand, and thus it plays an important role in conserving energy and improving the efficiency of energy utilization, especially for renewable energy sources which provide energy intermittently. Underground thermal energy storage (UTES) can have additional advantages in energy efficiency thanks to low thermal conductivity and high heat capacity of surrounding rock mass. In this paper, we introduced the technologies of underground thermal energy storage and rock caverns for hot water storage in Sweden.

A Study on Regional Revitalization by Creating a Landmark of Ulsanbawi in Goseong-gun, Gangwon-do (울산바위 랜드마크 조성을 통한 지역활성화 방안 연구)

  • Suhr, Myong-Suk
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.313-319
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    • 2020
  • The Misiryeong East-West road opened in July 2006, after the opening of the Expressway between Seoul and Yangyang in June 2017, has led to a recession caused by a decrease in the number of visitors to nearby region, leading to the emergence of economic crisis in the surrounding region. Against this background, in order to revitalize the Healing Road in Misiryeong, we study to find a way to revitalize the region by creating a landmark in Ulsanbawi Rock. In order to create a landmark of Ulsanbawi Rock, an observation cafe, exhibition facilities, and convenience facilities were built, and a monorail was used to view Ulsanbawi Rock, and a healing plaza, resting area, and outdoor performance hall were installed to promote the local economy.