• Title/Summary/Keyword: Underground Structures

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An Experimental Study on the Earth Pressure on the Underground Box Structure (지하 박스구조물에 작용하는 토압에 관한 실험적 연구)

  • 김은섭;이상덕
    • Journal of the Korean Geotechnical Society
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    • v.15 no.4
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    • pp.235-246
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    • 1999
  • Some of the underground structures such as subway tunnels are constructed by open cut method, in which the ground is excavated, a structure installed, and after that the excavated space is backfilled. In this case, because of their narrow and constrained boundary conditions, the earth pressure induced by self-weight of the backfilled soil acting on the underground structures is different from that of the classical theory. The vertical and horizontal earth pressures acting on upper slab and side wall of the underground structures constructed by open cut method are affected by the backfill geometry. The laboratory model tests were performed in the conditions of a variety of the shapes of backfill geometry and wall friction. And their results were compared with those from theories. As a result, it was observed that the distribution of the earth pressure acting on the underground structure is affected by the shapes of backfill geometry, the width of backfill, the angle of excavation and the wall friction.

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A study on the regulation of durability standard of underground structures monitoring sensors (지하구조물 계측센서의 내구연한 기준에 대한 규정 분석 연구)

  • Woo, Jong-Tae
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.1
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    • pp.73-81
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    • 2018
  • The purpose of this study is to research the regulation of durability standard of underground structures monitoring sensors. The durability criteria for construction monitoring sensors of domestic construction companies, the standard years of contents such as buildings on the income tax implementation regulations, and the standards of the Public Procurement Service for construction monitoring and construction machinery were analyzed. The durability criterion on products such as the inclination meter and the strain gauge, which are purchased from the Public Procurement Service prior to installation on the underground structure, is 8 to 10 years. It is considered that the monitoring sensor installed in the paperboard and the concrete structure at the time of construction will have considerably shortened service life rather than the useful life of the product itself due to various adverse factors such as groundwater influence and compaction.

Seismic Fragility of Underground Utility Tunnels (지하 공동구 시설물의 지진취약도 분석)

  • Lee, Deuk-Bok;Lee, Chang-Soo;Shin, Dea-Sub
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.5
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    • pp.413-419
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    • 2016
  • Damage of infrastructures by an earthquake causes the secondary damage through the world at large more than the damage of the structures themselves. Amomg them, underground utility tunnel structures comes under the special life line: communication, gas, electricity and etc. and it has a need to evaluate its fragility to an earthquake exactly. Therefore, the destruction ability according to peak ground acceleration of earthquakes for the underground utility tunnels is evaluated in this paper. As an input ground motion for evaluating seismic fragilities, real earthquakes and artificial seismic waves which could be generated in the Korean peninsula are used. And as a seismic analysis method, response displacement method and time history analyzing method are used. An limit state which determines whether destruction is based on the bending moment and shear deformation. A method used to deduct seismic fragility curve is method of maximum likelihood and the distribution function is assumed to the log normal distribution. It could evaluate the damage of underground utility tunnels to an earthquake and could be applied as basic data for seismic design of underground utility tunnel structures.

Flexural Behavior of FRC with Composite Waterproof Sheet (복합방수시트로 보강된 섬유보강콘크리트 휨거동)

  • Kim, Byoungil
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.215-216
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    • 2023
  • Leakage in the structure due to the irregular flow of groundwater in the underground structure penetrates into internal spaces such as underground parking lots and basement through underground walls, which is expensive in terms of maintenance of the building. In this study, various composite waterproofing methods installed on the outer walls of underground structures were selected to evaluate the structural performance of composite specimens due to bending behavior through experiments and analysis on bending test behavior on concrete attachment surfaces.

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An Efficient Dynamic Workload Balancing Strategy Design of the Wireless Reading/Management System for the Corrosion Monitoring of Underground Structures (지하 구조물 부식 감시를 위한 무선 검침/관리 시스템 설계)

  • Kwan, Yong-Kwang
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.7
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    • pp.95-102
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    • 2014
  • There are a variety of structures below the surface are buried. In particular, if It is experiencing problems in the city gas pipe or electrical wire, our safety would be greatly jeopardized. Therefore, the underground structures which encounter a variety of pollutants are highly sensitive to corrosion. So if you are not identify the degree of corrosion, it can lead to large accidents such as gas leakage. Until now, person visit directly every underground structure to measure and record manually, but This approach requires a lot of human and material resources and the continuity of management. Therefore, the research to find out the risk factors quickly via the continuous management is needed, and in this paper the structures management systems in the vehicle being moved by combining ICT underground structures for state information wirelessly collects and analyzes system is proposed.

A comparative study on the behavior of dynamic analysis and pseudo-static analysis considering SSI of a tall building and an adjacent underground structure (초고층 빌딩과 인접 지하구조물의 SSI를 고려한 동적해석과 유사정적해석의 거동 비교 연구)

  • You, Kwang-Ho;Kim, Seung-Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.4
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    • pp.671-686
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    • 2018
  • Recently, earthquakes have occurred near Gyeongju and Pohang and the social demands are thus being increased for seismic analysis of tall buildings and their adjacent underground structure in big cities. Since most of the previous seismic analysis studies considered a tall building and an adjacent underground structure separately, however, they lack the analysis on dynamic mutual behavior between two structures. Therefore, in this study, a dynamic analysis with a full soil-structure interaction was performed for a complex underground facility with a tall building and an adjacent underground structure constructed on the bedrock with a surface layer. To improve the reliability, in particular, a pseudo-static analysis was performed and compared with the dynamic analysis results. It is comprehensively concluded that the analysis of adjacent underground structures being considered is more conservative than that of not considered.

A Study on the Design of Anode Shape using BEM (BEM(경계요소법)을 이용한 양극형상 설계 연구)

  • Lee, H.G.;Bae, J.H.;Kim, D.K.;Ha, T.H.;Choi, S.B.;Jeong, S.H.
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.3169-3171
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    • 2000
  • Most metal structures such as gas pipelines. oil pipelines, hot water pipelines and power cables etc. are buried in underground. Normally. metal structures corrode in underground by the electrochemical reaction. Then, metal structures need to be protected against corrosion. Cathodic protection is one of useful methods to protect metal structures against corrosion. In this paper we do the design of anode shape using Boundary Element Method. So we analysis the current density of anode surface and the potential distribution in the electrolyte. Therefore we seek to maximize the anode life and the safety of metal structures.

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Vibrational characteristic of FG porous conical shells using Donnell's shell theory

  • Yan, Kai;Zhang, Yao;Cai, Hao;Tahouneh, Vahid
    • Steel and Composite Structures
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    • v.35 no.2
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    • pp.249-260
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    • 2020
  • The main purpose of this research work is to investigate the free vibration of conical shell structures reinforced by graphene platelets (GPLs) and the elastic properties of the nanocomposite are obtained by employing Halpin-Tsai micromechanics model. To this end, a shell model is developed based on Donnell's theory. To solve the problem, the analytical Galerkin method is employed together with beam mode shapes as weighting functions. Due to importance of boundary conditions upon mechanical behavior of nanostructures, the analysis is carried out for different boundary conditions. The effects of boundary conditions, semi vertex angle, porosity distribution and graphene platelets on the response of conical shell structures are explored. The correctness of the obtained results is checked via comparing with existing data in the literature and good agreement is eventuated. The effectiveness and the accuracy of the present approach have been demonstrated and it is shown that the Donnell's shell theory is efficient, robust and accurate in terms of nanocomposite problems.