• Title/Summary/Keyword: Foundations of Geometry

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A Study on Applicability and External / Internal Stability of true MSEW abutment with slab (순수형 보강토교대의 슬래브교에 대한 적용성 및 외적/내적 안정성 검토)

  • Park, Min-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.263-274
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    • 2018
  • In this study, the applicability and external/internal stability of a MSEW abutment with a slab were investigated. Structural analysis of slab bridges between 10 ~ 20.0 m and thicknesses of 0.7 ~ 0.9 m was carried out to calculate the reaction forces due to dead and live loads acting on the bridge supports. The slab bridge with a length of 20.0 m satisfied the allowable contact pressure of 200 kPa for the true MSEW abutment. Because the external stability of the true MSEW abutment was dominated by the geometry of the MSE wall, the change in the factor of safety due to the load of the super-structure is small. Because the stiffness of the foundations is fixed and the load of the super-structure is increased, the factor of safety of the bearing capacity was reduced. As the load of the super-structure was increased, the horizontal earth pressure of the true MSEW abutment increased greatly. As a result, the pullout and fracture of the uppermost reinforcement, which are the factors of safety, did not meet the design criteria. Therefore, it is necessary to increase the pullout resistance and the long-term allowable tensile force of the reinforcement placed on the top of the reinforced soils to ensure efficient design and performance of a true MSEW abutment.

Analysis of Load Sharing Ratio of Piled Raft Foundation by Field Measurement (현장 계측을 통한 말뚝지지 전면기초의 하중분담률 분석)

  • Jeong, Sang-Seom;Lee, Jun-Hwan;Park, Jong-Jeon;Roh, Yang-Hoon;Hong, Moon-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.33 no.8
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    • pp.41-52
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    • 2017
  • In this study, field measurements were investigated to analyze the load sharing ratio and behavior of piled raft foundation. The field measurements were performed for about 300 days from the start of construction. The geometry of the raft is $3.1m{\times}3.1m$, and the pre-cast and pre-bored pile is 23 m in length and 0.508 m in diameter. Based on the field measurements, the load-settlement relationship of the piled raft foundation was obtained, and the load sharing ratio of the pile was converged to 70% at ultimate loading condition. The load sharing ratio of the pile increased as the settlement increased, and this is because the surface friction of the weathered soil, which is at the lower ground, was significantly increased. Based on the results of the field measurements, load transfer curves were obtained and applied to a numerical analysis by using load transfer method.

Development of Pre-Service and In-Service Information Management System (iSIMS) (원전 가동전/중 검사정보관리 시스템 개발)

  • Yoo, H.J.;Choi, S.N.;Kim, H.N.;Kim, Y.H.;Yang, S.H.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.4
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    • pp.390-395
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    • 2004
  • The iSTMS is a web-based integrated information system supporting Pre-Service and In-Service Inspection(PSI/ISI) processes for the nuclear power plants of KHNP(Korea Hydro & Nuclear Power Co. Ltd.). The system provides a full spectrum coverage of the inspection processes from the planning stage to the final report of examination in accordance with applicable codes, standards, and regulatory requirements. The major functions of the system includes the inspection planning, examination, reporting, project control and status reporting, resource management as well as objects search and navigation. The system also provides two dimensional or three dimensional visualization interface to identify the location and geometry of components and weld areas subject to examination in collaboration with database applications. The iSIMS is implemented with commercial software packages such as database management system, 2-D and 3-D visualization tool, etc., which provide open, updated and verified foundations. This paper describes the key functions and the technologies for the implementation of the iSIMS.