• Title, Summary, Keyword: Ground investigation

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Laboratory investigation on deep excavation-induced ground movements (축소모형실험을 이용한 지반굴착시 주변 지반 거동 연구)

  • Yoo, Chung-Sik;Lee, Soung-Woo;Lee, Bong-Won
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.1476-1483
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    • 2005
  • This paper presents the results of small scale model tests on the behavior of propped wall and ground movements during deep excavation. Small scale model tests were performed in order to investigate the effects of various influencing factors on the deep excavation, such as stiffness of ground and unsupported span length. The results of model tests indicated that the wall behavior is significantly influenced not only by the stiffness of ground but by the over-excavation, and that the wall behavior can be reduced by decreasing the unsupported span length and increasing the stiffness of ground.

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A Study on Development of a Ground-Source Heat Pump System Utilizing Pile Foundation of a Building (건물 기초를 이용한 지중열 공조시스템의 개발에 관한 연구 (2))

  • Ryozo, Ooka;Hwang, Suk-Ho;Kentaro, Sekine;Yosuke, Shimawaki;Nam, Yu-Jin
    • Proceedings of the SAREK Conference
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    • pp.155-160
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    • 2005
  • To purpose of this research is to develop the numerical model for simulating performance of ground heat exchanger with high prediction accuracy. This paper describes the development of a numerical model that simulates the heat transfer between ground and circulation water in ground heat exchanger. Furthermore, we propose the estimating technique of soil properties, such as thermal conductivity, heat capacity and hydraulic conductivity, based on ground investigation. Comparison between experiment and numerical analysis based on the model developed above was conducted under the condition of the experiment in 2004. The result of analysis agreed well with the experimental result.

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Case Studies on Investigation Technologies on Embankments (제방의 조사 기술에 관한 고찰)

  • Yang, Tae-Seon;Kim, Jin-Man;Choi, Bong-Hyuck;Kim, Ju-Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.680-688
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    • 2008
  • On behalf of hazard mitigation, cases of investigation methods on levee are described. In general, failures of levee are caused by piping, water leakage through ground under the levee in Kimpo, Ilsan etc. Several phenomena against levees should be protected through consideration of analysis and quality control stage during construction. In this paper, protection methods against failures should be investigated by case studies.

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Flow Analysis Approach to Triggering Phenomenon of Ground Sinking in a Metropolitan Area (도심지 지반함몰의 초기발생현상에 대한 흐름해석적 접근)

  • Jo, Young-Seok;Jang, Yeon-Soo
    • LHI Journal of Land, Housing, and Urban Affairs
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    • v.8 no.1
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    • pp.13-22
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    • 2017
  • In this study, triggering mechanism of ground sinking was analyzed through groundwater flow analysis on the basis of a case of the ground sinking occurred in Yongsan in 2015. The results of geotechnical investigation performed before and after the ground sinking were analyzed for the accurate understanding of geological features in the study area. The numerical groundwater flow analysis was performed to evaluate the influence of the flow behavior from the surrounding area toward the excavated site using software of Visual MODFLOW. As a result, it was found from the geotechnical analysis that the strata of sedimentary layer along the sunken area in the vertical direction was mixed significantly after the ground sinking compared with the status of the soil condition before the ground sinking. Piping was occurred at the toe of cut-off wall in the sandy gravel layer, and this phenomenon was predicted by the numerical flow analysis. Sequential ground displacement scenario of the ground sinking was derived from the geotechnical in situ test and numerical flow analysis performed in this study.

Development of the Side Scan Sonar Using the Multi-beam Sensors : Sensor Design (멀티빔 센서를 이용한 사이드 스캔 소나 개발 : 센서 설계)

  • Chang, Yu-Shin;Keh, Joong-Eup;Jo, Heung-Gi;Lee, Man-Hyung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.10
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    • pp.581-586
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    • 2005
  • The multi-beam side scan sonar system uses the towfish installed sonars, it is an equipment that search images of the bottom surface of the sea in real time. It is a typical equipment that is related to a sea investigation such as a geological survey, seabed communication cable and power line cable placing repair investigation, fish breeding ground investigation, sea purification, relic and mineral investigation, and mine and submarine search. Recently, it is used to sea purification and geological survey that require information of the correct surface of the seabed. Therefore, this research develops multi-beam sensors for a side scan sonar that supply various information with the fast scan speed and correct high resolution that is not a simple underwater investigation equipment.

EFFECTIVENESS ANALYSIS OF GROUND IMPROVEMENT TREATED BY DYNAMIC CONSOLIDATION (동압밀공법을 이용한 지반개량 사례연구)

  • 양정수;손준익
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.137-144
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    • 1992
  • This paper reports a case study of dynamic consolidation. The objective of the study is to evaluate the effectiveness of ground improvement at the site for Hyundai Petrochemical Compound constructed at Daesan-Myeon, Seosan-Gun in the western shores of Korea. The site ground was prepared by filling on the existing soft marine deposit which consists of a loose granular soil layer and a medium stiff clay layer. For the stabilization of site ground, the compaction was executed in three different procedures with same pounder weigh, drop height and imprint spacing. The post investigation showed that the object was successfully achieved indicating a significant increase of bearing capacity of the treated ground. In this study the effectiveness of dynamic consolidation is evluated for various factors the applied energy, temping sequences, the radial distance from the imprint location and the depth of bed rock.

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Ground Stability Assessement for the Mining Induced Subsidence Area (지하공동에 의한 지표침하지역의 지반안정성 평가)

  • 권광수;박연준;신희순;신중호
    • Tunnel and Underground Space
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    • v.4 no.2
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    • pp.170-185
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    • 1994
  • Surface subsidence is one of the problems caused by mined out caverns. Depending on the geologic conditions and mining methods, subsidence can occur in various forms. This report describes the ground stability assessment for the mining induced subsidence area where unfilled caverns still exist abandoned. Geologic features which could affect the stability of the ground were investigated and all the possible geophysical methods were employed to obtain data that could explain the state of the ground in question. Basic rock tests were conducted from the drill cores and rock mass classification was performed by core logging and borehole camera investigation. Numerical analyses were carried out to predict the ground stability using data obtained by various investigations. The result could have been more reliable if in-situ stress were measure and reflected in the numerical analysis.

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Investigation of the Downwash Induced by Rotary Wings in Ground Effect

  • Tanabe, Yasutada;Saito, Shigeru;Ooyama, Naoko;Hiraoka, Katsumi
    • International Journal of Aeronautical and Space Sciences
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    • v.10 no.1
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    • pp.20-29
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    • 2009
  • There are concerns about the influence of the gust wind caused by helicopters affecting the moving vehicles while hovering over the road during rescue activities. For the understanding of such complicated flow. numerical simulation of a rotor hovering above the ground has been carried out, changing the rotor/ground clearances. The rotor thrust is kept constant. and the rotor control is determined by trim adjustments incorporated into the CFD algorithm. Collective pitch angle and the required power decreases with the rotor/ground clearance which agrees with experience. Changes of the flowfield near the rotor with regard to the rotor height are investigated based on the calculated results.

Monitoring of Subsurface Temperature Variation as Geothermal Utilization (지종열 활용에 따른 온도변화 모니터링)

  • Lee, Tae-Jong;Shim, Byoung-Ohan;Song, Yoon-Ho
    • Transactions of the Korea Society of Geothermal Energy Engineers
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    • v.6 no.1
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    • pp.29-35
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    • 2010
  • Long-term temperature monitoring has been performed for ground heat exchanger at the Earthquake Research Center (ERC) building in Korea Institute of Geoscience and Mineral Resources (KIGAM). For the 3 years of monitoring, overall temperature increases are observed at various depths within a borehole heat exchanger. But monitoring of ground temperature variation at the monitoring well beforehand showed that geothermal utilization is not the only source for the temperature increase, Because various kinds of sources can cause the ground temperature change, more thorough investigation should be followed.

Aerodynamic Investigation of Three-Dimensional Wings in Ground Effect for Aero-levitation Electric Vehicle (공기부상 전동 운행체의 지면효과를 받는 3차원 날개에 대한 공력해석 연구)

  • Oh H. J.;Seo J. H.;Moon Y. J.;Cho J. S.;Yoon Y. H.
    • 한국전산유체공학회:학술대회논문집
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    • pp.196-201
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    • 2004
  • Aerodynamic characteristics of three-dimensional wings in ground effect for Aero-levitation Electric Vehicle(AEV) are numerically investigated for various ground clearances and wing spans at the Reynolds number of $2\times10^6$. Numerical results show that a sizeable three-dimensional flow separation occurs with formation of an arch vortex at the junction of main and vertical wings, and that this is conjectured a primary cause for the high lift-to-drag(L/D) reduction rate of the main wing, when the wing span is decreased. Improvements on L/D ratios of the wings with small spans are pursued by breaking the coherence of superimposed adverse pressure gradients at the wing junction.

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