• Title/Summary/Keyword: 연약대

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Soil Property of Coastal Soft Ground Considering Geological Property (지질학적 특성을 고려한 해안연약지반의 토질특성)

  • 송무영;김팔규;김연천;류권일
    • The Journal of Engineering Geology
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    • v.7 no.3
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    • pp.217-227
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    • 1997
  • The purpose of this study is to analyze the correlation of soil properties in coastal soft ground. For the purpose of this study, several coastal soft ground areas were selected. Many large scale construction works are being executed and will increase continuously in these soft ground areas. So, soil property in these areas is very important. The grounds forming coastal areas are affected by seawater movement. So, most of these areas consist of alluvium stratum. Therefore, soil properties of eastern and southern coastal areas are very complex. Many laboratory tests were executed with disturbed and undisturbed soil samples. Undisturbed samples were taken by using thin walled tubes and transported into the laboratory with caution, so as not to disturb the sample. The consistent rate of fine-grained content in these areas is over 90%. Also, these areas contain higher water content and clay content. Therefore, knowing these soil properties, it is possible to safely design fabrics and constructions.

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A Study on Consolidation Settlement Calculation of Cutting Soft Clay as Fill Material (절취 연약점성토의 성토재 활용에 따른 압밀침하량 산정에 관한 연구)

  • Yonghee Park
    • Journal of the Korean GEO-environmental Society
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    • v.25 no.4
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    • pp.5-12
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    • 2024
  • In the case of creating a site in the reclaimed land (public waters), due to the nature of the coastal sedimentary ground, large-scale construction materials are required, It is necessary to utilize soft clay, which is inevitably generated during construction of the complex, as a fill material in terms of resource recycling and economic aspects (reducing the amount of embankment required). In this study, changes in the consolidation characteristics of cut-out disturbed soft clay due to the recycling of soft clay soil were identified, and a consolidation settlement design plan was proposed. Through the results of the consolidation test of the study site, the change in consolidation characteristics (compression index reduction, precede load uncountable) due to disturbance (cutting) was confirmed, the method of calculating (consolidation settlement) the filling clay layer as the composite target layer (consolidation target layer, loading load layer) was analyzed as a result consistent with the actual behavior.

A Study on the Dynamic p-y Curves in Soft Clay by 1 g Shaking Table Tests (1g 진동대 실험을 이용한 연약 점성토 지반에서의 동적 p-y 곡선 연구)

  • Han, Jin-Tae;Yoo, Min-Taek;Choi, Jung-In;Kim, Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • v.26 no.8
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    • pp.67-75
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    • 2010
  • In this study, a series of 1 g shaking table tests were carried out for a single pile in soft clay with various input acceleration amplitudes and frequencies. Based on the results, dynamic p-y curves were drawn and, in turn, the dynamic p-y backbone curve was formed by connecting the peak points, corresponding to the maximum soil resistance, of the dynamic p-y curves. In order to represent the p-y backbone curve numerically, Matlock's p-y formulations for clay was used to find the initial stiffness ($k_{ini}$) and the ultimate capacity ($p_u$) of the clay, both of which are required to formulate the p-y backbone curve as a hyperbolic function. The suggested p-y backbone curve was verified through comparisons with currently available p-y curves as well as other researchers' centrifuge test results and numerical analysis results.

Engineering Geology of Soft Marine Sediments along the Western Coastal Area of korea (한국 서해안의 연약한 해성 퇴적층에 관한 지질공학적 고찰)

  • 송병무
    • The Journal of Engineering Geology
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    • v.4 no.1
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    • pp.79-90
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    • 1994
  • Development of industries and increasing population demand civil engineering projects of various types and sizes to be looated along the ooastal aaaas where extremely soft marine sedirnents are encountered. These sediments present settlement and stability problems, among others, and consequently, cost increase and schedule delay are resulted.Insulfident understanding of the basic nature of the soft formations dulling design and construction phases result in catastrophicfailures all too often. In order to provide safe and economic solutions to these problems, utilization of various related disciplines should be made for analyses. However, this paper will primarily rely in portions of paleoclimatology, sedimentology, and soil mechanics to define the problems and to provide basic understanding of the sediment, and the directions and methodology for the analyses.

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A Study on the Underground Structure of Underground Storage Cavern by Seismic Surveying (탄성파측양에 의한 지하저장시설의 지하구조조사에 관한 연구)

  • Yeu, Bock-Mo;Kwon, Hyon;Kim, Joong-Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.2 no.1
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    • pp.34-45
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    • 1984
  • The condition of underground basic rock and the location of cavern site can be found by means of seismic surveying is one of the physical exploration methods by which the prelimirary investigation of underground storage constructions are made in order to maximize the use of a land. This study is valuable in the point of showing a method for the decision of the property of a underground facilities estabilishment, by analying the elastic wave velocity and the distribution of a lower velocity zone and by grasping the weak zone of the basic rock.

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Failure Prediction for Weak Rock Slopes in a Large Open-pit Mine by GPS Measurements and Assessment of Landslide Susceptibility (대규모 노천광 연약암반 사면에서의 GPS 계측과 위험도평가에 의한 파괴예측)

  • SunWoo, Choon;Jung, Yong-Bok;Choi, Yo-Soon;Park, Hyeong-Dong
    • The Journal of Engineering Geology
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    • v.20 no.3
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    • pp.243-255
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    • 2010
  • The slope design of an open-pit mine must consider economical efficiency and stability. Thus, the overall slope angle is the principal factor because of limited support or reinforcement options available in such a setting. In this study, slope displacement, as monitored by a GPS system, was analyzed for a coal mine at Pasir, Indonesia. Predictions of failure time by inverse velocity analysis showed good agreement with field observations. Therefore, the failure time of an unstable slope can be roughly estimated prior to failure. A GIS model that combines fuzzy theory and the analytical hierarchy process (AHP) was developed to assess slope instability in open-pit coal mines. This model simultaneously considers seven factors that influence the instability of open-pit slopes (i.e., overall slope gradient, slope height, surface flows, excavation plan, tension cracks, faults, and water body). Application of the proposed method to an open-pit coal mine revealed an enhanced prediction accuracy of failure time and failure site compared with existing methods.

Effect of Electro-Osmosis Method on Marine Clay with Preloading (선행하중이 작용하는 해성점토지반에 전기삼투공법의 효과)

  • Kang, Hongsig;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.2
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    • pp.53-58
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    • 2015
  • The Pre-loading method has been widely used for the soft ground stabilization but long construction times and the transport of large quantities of fill material are required. To shorten the construction periods, the vertical drain method is generally applied simultaneously. But the high costs of the fill materials along with environmental damages remain as the main difficulties to apply this method. Therefore, a complimentary way to reduce both the height of the embankment and the consolidation time is needed. In this study, the electro-osmosis method, which is able to shorten the consolidation time and minimize the damage of the environment, was performed with a model test. The results show that as the voltage increases the consolidation settlements, consolidation drainage and shear strength also increase while the water content decreases.

A study on analysis method for the prediction of changes in ground condition ahead of the tunnel face (터널 막장 전방의 지반 변화 예측을 위한 해석기법에 관한 연구)

  • Kim, Young-Sub;Kim, Chan-Dong;Jung, Yong-Chan;Lee, Jae-Sung;You, Kwang-Ho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.6 no.1
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    • pp.71-83
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    • 2004
  • The purpose of this study is to present an analysis method for the prediction of the changes m ground conditions. To this end, three dimensional convergence displacements are analyzed in several ways to estimate the trend of displacement changes. Three-dimensional arching effect is occurred around the unsupported excavation surface including tunnel face when a tunnel is excavated in a stable rock mass. If the ground condition ahead of tunnel face changes or a weak zone exists, a diagnostic trend of displacement change is observed by the 3 dimensional measurement and numerical analysis. Therefore, the change of ground condition and the existence of a weak zone ahead of tunnel face can be predicted by monitoring 3-dimensional absolute displacements during excavation, and applying the methodology (the ratio of L/C, $C/C_o$, etc.) presented in this study.

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Application of Gold Exploration Using Three-dimensional Resistivity Inversion in Sambo mine (3차원 전기비저항 역산 방법을 이용한 삼보 광산에서 금광 탐사)

  • Park Jong-Oh;Kim Hee-Joon;Song Moo-Young;You Young-June
    • The Journal of Engineering Geology
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    • v.15 no.1
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    • pp.19-27
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    • 2005
  • The Sambo mine is located in Hae-je Myeon, Moo-an Gun, Chollanamdo, which consists of host gneiss and rhyolite possessing quartzite veins with other compositions such as gold, silver, and sublimated sulfur. The ore grade estimated from the core was 0.05~10.9g/t or less in gold and 0.05~389g/t or less in silver, indicating a partial mineralization. The purpose of this paper is to understand the subsurface structures and the distribution of mineralized bodies in the Sambo mine using a combined method of Schlumberger, Wenner, and Dipole-di-pole resistivity surveys on the surface and the resistivity tomography survey in boreholes. The result of three-dimensional resistivity inversion showed that the mineralized body is extended to 240m long in the N10°~20°E direction, with 30m wide and 80 m thick from the surface. The low resistivity zones (<1,000ohm-m) determined from the resistivity image were in good agreement with the mineralized bodies and weak zones identified from the logged cores.