• Title/Summary/Keyword: rock foundation

Search Result 231, Processing Time 0.024 seconds

Numerical Analysis of Offshore Wind Turbine Foundation Considering Properties of Soft layer in Jeju (제주 연약지층 특성을 고려한 해상풍력기초의 수치해석적 연구)

  • Yang, Ki-Ho;Seo, Sang-Duk;Cho, Yee-Sun;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
    • /
    • v.12 no.4
    • /
    • pp.45-56
    • /
    • 2013
  • Recently, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. Jeju island has optimum condition for constructing a wind energy farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can not support sufficiently the structure. In this paper, the settlement and stress distribution is predicted by numerical analysis when the mono-pile base are constructed on various soft layer between stratified structure. To determine the settlement of the pile foundation supported on stratified rock layer, the geological investigation at the 3 regiions and the results of laboratory experiments of the stratified rock layer is required.

A Study on Behavior Analysis of Large-diameter Drilled Shaft by Design Methods in Deep Water Depth Composite Foundation (대수심 대형 복합기초에서 설계기법에 따른 대구경 현장타설말뚝의 거동 분석 연구)

  • Han, Yushik;Choi, Yongkyu
    • Journal of the Korean GEO-environmental Society
    • /
    • v.16 no.1
    • /
    • pp.5-16
    • /
    • 2015
  • In the long span bridge construction, construction cost portion of large scale marine foundation is about 40% (KICTEP, 2007). In this study, designs for deep water depth large composite foundation of a super long span cable-stayed girder bridge of prototype were performed by three design methods (ASD, LRFD, Eurocode) and the behaviors of a large diameter drilled shaft were analyzed and the 3D numerical analysis was performed. As a result, the soft rock socket lengths in allowable stress design estimation method were the longest. The soft rock socket lengths estimated by the design approach 2 among Eurocode and the LRFD were similar. The longer the socket length socketed in the soft rock was, the smaller the axial force acting on a large-diameter drilled shaft head was and the smaller the settlement of drilled shaft was.

The Case Study of Rock Treatment Method for the Fractured Rock Foundation of Underground Roadway Structure (기반암의 파쇄대 특성을 고려한 지하차도 기초 보강사례)

  • Yoon, Ji-Nam;Yang, Sung-Don;Lee, Geun-Ha;Park, Sa-Won;Jung, Hun-Chul
    • Tunnel and Underground Space
    • /
    • v.18 no.2
    • /
    • pp.125-133
    • /
    • 2008
  • The rock treatment methods for improving bearing capacity and reducing settlement of the underground roadway structure foundation on fractured rock was studied in this paper. Also, effective reinforcement scheme was evaluated by numerical analysis for the application to the practical construction. Various in-situ and laboratory tests were executed systematically at Yeongi-goon, Ohoongchungnam-do, Korea, for the purpose of defining the physical and mechanical properties of rock. Consequently the effective treatment methods insuring the bearing capacity of fractured rock were proposed. In addition, the adequate reinforcing depth of the comparatives measure, such as double rod, triple rod injection methods and micropile, were investigated from the case study. Finally, the most effective construction scheme with the consideration of safety and economical aspects were proposed by using numerical analysis(Plaxis ver. 8.2).

Geotechnical treatment for the fault and shattered zones under core foundation of fill dam (단층 및 파쇄대가 분포하는 Fill Dam 기초의 보강대책)

  • 김연중;최명달
    • The Journal of Engineering Geology
    • /
    • v.2 no.1
    • /
    • pp.19-35
    • /
    • 1992
  • aThe elastic properties of the fault zone (width; 3~12m), the shattered zone (width; over 40m) and the fresh rock zone distributed under the core foundation of fill dam in granitic gneiss have widely different range. The deformation moduli of the fresh rock zone, the fault zone and the shattered zone obtained from in situ rock tests - Plate Load Test and Bore Hole Deformation Test - show a range of $42,000~168,000kg/\textrm{cm}^2,{\;}963~2,204kg/\textrm{cm}^2{\;}and{\;}1,238~2,098kg/\textrm{cm}^2$, respectively. The differential settlements hetween the fault zone and the fresh rock zone are expected after the dam construction. Therefore, the displacement of foundation and concrete fill are evaluated using FEADAM 84 program of finite element analysis. The geometric distribution of discontinuifies obtained from the site mapping and drilling is considered in the finite element analysis. The analysis shows that the differential settlements between the fault zone and the fresh rock zone is about 6cm, while that of concrete fill is within 0.5cm.

  • PDF

The Study on Seismic Stability Evaluation Model for Rock Foundation of Nuclear Power Plant (원전 기초지반의 지진안정성 평가 모델 연구)

  • Hwang, Seong-Chun;Jang, Jung-Bum
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.9 no.4 s.44
    • /
    • pp.1-10
    • /
    • 2005
  • The purpose ol this study Is to suggest a proper analysis model that can evaluate seismic stability for local rock foundation of nuclear power plant. Sliding Analysis, Pseudo-static Analysis and Dynamic Analysis methods are used for analysing NPP rock foundation with the conditions like acting directions of input earthquake, boundary conditions, width and depth of analysing model, and modeling methods of weakness fault zones. As the results of study, Pseudo-static Analysis for lateral roller and dynamic analysis for transfer boundary condition showed good results, and analysing ranges of width and depth were 5 times of structure width and over 2 times ol structure depth.

Application of D-ROG technology for restoration of the subsided building (침하건물 복원을 위한 정밀 다점 주입공법의 적용)

  • Lee, Ju-Hyung;Koh, Hyo-Seog;Hong, Jin-Pyo;Park, Jae-Hyun;Cho, Sam-Deok
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.03a
    • /
    • pp.405-410
    • /
    • 2009
  • This paper presents a case study that achieved both of serviceability and safety of the building through soil reinforcement and restoration around foundations subjected to serious differential settlement using D-ROG method. The building which has one basement floor and three ground floors is founded on soft ground and differential settlement occurred to the maximum extent of 678mm. The foundation type of the building is a independent mat foundation. Soil profiles consist of landfill layer, alluvial layer, weathered rock, and soft rock. The bearing layer consisting of gravel and weathered rock is located 16.0~17.0m below the bottom of the building. As a result of soil reinforcement and restoration, the recovery ratio of more than 90% can be attained with the maximum set-up of 657mm.

  • PDF

Design criteria of rock socked pile in South Korea (국내 암반에 근입된 현장타설말뚝의 설계기준 수립)

  • 이풍희;김종흔;전경수
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2002.06a
    • /
    • pp.31-42
    • /
    • 2002
  • The Design criteria are different from one another due to the different engineering properties of rock in the every nation. Most of the test results of the rock-socketed piers were loaded two times of the design load capacities because they would be used in the foundation of the bridge or the building. So we have much difficulties in study of the load capacities of the rock-socketed piers by the test result in Korea. When we design the rock-socket piers, every designer uses the different formula, and makes different results. Recently the demand of the large bridges and the huge buildings has been increased. The adequate design criterion of the rock-socketed pier is urgently needed to design them reasonable. In this paper we analyzed the various design criteria and proposed the adequate design criterion which is based on the test results of the rock-socked piers in Korea.

  • PDF

Behavior of Electric Transmission Tower with Rock Anchor Foundation (암반 앵커기초로 시공된 송전철탑 구조물의 거동특성에 관한 연구)

  • Kim, Kyoung-Yul;Hong, Sung-Yun;Lee, Dae-Soo
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2010.09a
    • /
    • pp.605-614
    • /
    • 2010
  • In this paper, the initial behavior of transmission tower was analyzed. This tower was firstly constructed by rock anchor foundation in domestic 154 kV transmission line and wireless real-time monitoring system was installed to obtain the measured data for analysis of the structure behavior. For this purpose, 16 strain gauges was installed in anchors of foundation and strain gauges, clinometers, anemoscope and settlement sensors was installed at superstructure. As the results, the main factor which influence the behavior of superstructure is wind velocity, wind direction, rainfall and temperature change. Especially, the uplift load at stub of transmission structure revealed about 35.4 percentages of design load. Hereafter the long term stability will be analyzed.

  • PDF

A Study on the Transmission Tower Foundation Design and Construction Method - A Focus of Cylindrical Foundation - (가공 송전 철탑기초 설계 및 시공 방법 연구 - 심형기초를 중심으로 -)

  • Jang, Suk-Han;Kim, Hee-Kwang;Lee, Kang-Hyeon;Han, Kyung-Soo;Ham, Bang-Wook;Chung, Ki-Sun
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.6
    • /
    • pp.1031-1034
    • /
    • 2007
  • Electric transmission lines pass through a variety of area. Foundation supporting the conductors and tower are selected properly in accordance with external load, for example dead load, wind load, snow load, construction load etc, and topography and geology condition. Typical types of foundation are as follows: pad foundation for small load and hard soil or rock in mountainous area, pile foundation for medium or large load and soft soil in plain field area. This paper introduced cylindrical foundation design & construction for large load and mountainous area. This foundation failure mode against pulling-out show splitting failure by tensile force toward circumferential direction.