• Title/Summary/Keyword: road structure

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Computational Model for Hydrodynamic Pressure on Radial Gates during Earthquakes (레디얼 게이트에 작용하는 지진 동수압 계산 모형)

  • Phan, Hoang Nam;Lee, Jeeho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.5
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    • pp.323-331
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    • 2019
  • In this study, a computational model approach for the modeling of hydrodynamic pressures acting on radial gates during strong earthquakes is proposed. The use of the dynamic layering method with the Arbitrary Lagrangian Eulerian (ALE) algorithm and the SIMPLE method for simulating free reservoir surface flow in addition to moving boundary interfaces between the fluid domain and a structure due to earthquake excitation are suggested. The verification and validation of the proposed approach are realized by comparisons performed using the renowned formulation derived by the experimental results for vertical and inclined dam surfaces subjected to earthquake excitation. A parameter study for the truncated lengths of the two-dimensional fluid domain demonstrates that twice the water level leads to efficient and converged computational results. Finally, numerical simulations for large radial gates with different curvatures subjected to two strong earthquakes are successfully performed using the suggested computational model.

An Analysis on Micro-climate Characteristic of Apartments in Beijing, China Using ENVI-met Simulation (ENVI-met를 이용한 중국 베이징 아파트 하절기 미기후 특성 분석)

  • Wu, Jin-Dong;Lee, Jun-Hoo;Yoon, Seong-Hwan
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.8
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    • pp.169-176
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    • 2019
  • The purpose of this study was to analyze outdoor thermal comfort of apartments planning characteristic of pedestrian height in Beijing, China. Selecting 322 apartment complexes with more than 1000 households and more than 10 buildings(including 10 buildings), mainly in Chaoyang District and Tongzhou District to select 32 basic layout types and then 12 typical layout types were select in 32 basic layout types. Finally, the simulation was conducted for the 12 typical layout types using the micro-climate model ENVI-met to evaluate the wind environment, the thermal environment and the comfort. The results of this study as follows: In the parallel arrangement, it has the best outdoor thermal comfort of Slab-East-Parallel(S/E/P). Next is Slab-South-Parallel(S/S/P), Tower-South-Parallel(T/S/P) in turn. In the stagger arrangement, Mixture-South-North and South Stagger-1(M/S/NSS-1) has the best outdoor thermal comfort and Slab-South-North and South Stagger(S/S/NSS), Tower-South-North and South Stagger(T/S/NSS), Mixture-South-North and South Stagger-3(M/S/NSS-3), Mixture-South-North and South Stagger-4(M/S/NSS-4), Mixture-South-North and South Stagger-2(M/S/NSS-2) in turn. In the cluster arrangement, Mixture-Mixture-Cluster-2(M/M/C-2) has the best outdoor thermal comfort and Mixture-Mixture-Cluster-3(M/M/C-3), Mixture-Mixture-Cluster-1(M/M/C-1) in turn. Due to the low wind speed and high air temperature, it is necessary to consider the layout types that can form the wind road at first, such as Mixture-South-North and South Stagger-1(M/S/NSS-1), Slab-South-North and South Stagger(S/S/NSS) and so on.

A measure for activating BIM by actual application analysis of integrated utilization process of quantity, process(4D), and construction cost(5D) in view of life-cycle

  • Lee, Jae-Hong;Kim, Tae-Young
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.12
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    • pp.1-15
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    • 2020
  • In this paper, we propose a novel method for converting the existing 2D processes in the design and construction phase of civil engineering, to the future BIM-based processes. First, we compare and analyze the actual application processes of the outputs of the existing 2D method and the outputs of the 3D BIM method, for the whole process of BIM design of earthworks and road structures and integrated utilization of quantity, process(4D) and construction cost(5D), in view of life-cycle. The proposed method acquire the outputs of the design phase integrating IFC international common standard file information and CBS/OBS/WBS standard classification scheme information, and acquire the outputs of the construction stage by using an integrated utilization module for quantity, process(4D) and construction cost(5D). Ultimately, we intend to commercialize the step by step technologies for BIM design and construction in civil engineering by using the proposed method.

The theoretical foundation and ideological character of Cho Soang's threefold equalitarianism (조소앙(趙素?) 삼균주의(三均主義)의 사상적 토대와 이념적 성격)

  • Lee, Sangik
    • The Journal of Korean Philosophical History
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    • no.30
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    • pp.87-121
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    • 2010
  • Soang excavates the idea of equality in our national indigenous thoughts and the theoretical structure of threefold egalitarianism in our traditional Confucianism. He also digests diverse Western thoughts and introduces some of them into his theory. At first sight, his theory looks like an assembly of diverse Western thoughts. However, he always justifies it with our traditions. Even if his theory and political position fails in his time, it gives us valuable instructions. First, if the failure of his political center position means an opening road toward Korean division, his political position must be a future guide for the reunification of Korean peninsula. Second, if the bi-polarization is a serious disease of our society, then his view of egalitarianism must be a efficient guide for curing our society. Third, as European Union shows us, the kingly view of world family is a feasible guide for realizing world peace in future.

Physical Model Test for Wave Overtopping for Vertical Seawall with Relatively Steep Bottom Slope for the Impulsive Wave Condition (상대적으로 급한 경사 수심을 갖는 직립식 호안에서 충격파 조건에 대한 월파량 산정 수리실험)

  • Young-Taek Kim;Jong-In Lee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.35 no.2
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    • pp.33-40
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    • 2023
  • Wave overtopping rate is one of the most important design parameters for coastal structures. In this study, the physical model tests for measuring the wave overtopping have been conducted with the foreshore slope in front of the seawall. The bottom seabed for the coastal road area was fabricated at the wave flume for two areas in the East sea areas. The wave overtopping rate was measured for various water depths and wave conditions in each coastal area. In particular, the impulsive wave conditions were compared with the previous research and the similar trends of wave overtopping was observed. It could be known that the effect of foreshore slope was significant and should be concerned for applying theses formula like EurOtop.

Hydraulic and Numerical Tests on Wave Overtopping for Vertical Seawall with Relatively Shallow and Steep Sloped Water Depth (상대적으로 수심이 낮고 급한 전면 경사를 갖는 직립식 호안에서의 월파량 산정에 관한 수리 및 수치 실험)

  • Young-Taek, Kim;Hyukjin, Choi;Hwangki, Lee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.34 no.6
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    • pp.258-265
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    • 2022
  • In Korea, the hydraulic model tests for measuring the wave overtopping have been almost conducted with no bottom slope or single slope condition in Korea. In this study, the bottom seabed for the coastal road area was fabricated at the wave flume and the wave overtopping was measured. The overtopping rate was also measured with the numerical modelling by OLAFoam. The measuring data were compared with EurOtop manual. It could be known the the influence of the foreslope in front of the vertical wall was significant and the these effects should be concerned when designing the coastal structures. And also it could be known that OLAFoam could be used to predict the wave overtopping rate for the complex bottom topography.

Review of fire resistance evaluation and fire resistance method of concrete segment lining for fire in tunnel (터널 내 화재발생에 대한 콘크리트 세그먼트 라이닝의 내화성 평가 및 내화방법에 대한 고찰)

  • Moorak Son;Juhyun Cheon;Youngkeun Cho;Bumjoo Kim
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.25 no.2
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    • pp.121-139
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    • 2023
  • Various tunnels such as road, subway, and railway are under construction and operation. Various types of linings are used for structural stability of tunnel structures, and concrete segment linings are mainly installed in TBM tunnel construction. In this paper, when a fire occurs in a tunnel, the impact on the concrete segment lining, which is the structure in the tunnel, and related standards, fire resistance evaluation and fire resistance method are investigated through literature review and related contents are presented. Through this, it is intended to provide an information for practitioners to secure the safety of concrete segment linings against tunnel fires.

Evaluation of Seismic Performance of Valve Chamber System by Shaking Table Tests (진동대 실험을 통한 밸브실 시스템의 내진성능 평가)

  • Young-Soo Jeong;Kyeong-Seok Lee;Jin-Seok Yu;Hyung-Chae Jeong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.1
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    • pp.46-52
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    • 2024
  • The structural safety of expansion joints for piping systems has been drawing attention owing to ruptures and leaks of water pipes caused by earthquakes and road subsidence at soft ground. In general, metal bellows are installed as expansion joints to prevent various damages in the piping system. In this study, the seismic performance of a valve chamber system was evaluated by performing earthquake shaking table tests. To validate the benefits to structural safety of metal bellows in connecting steel pipes to valve chambers, the seismic tests were conducted on expansion joints (bellows) and general pipping, and the results were compared for durability. Strain gauges were attached to measure the effects of the input motion. As a result of the shaking table test, it was confirmed that the strain of the valve chamber structure and inflow or outflow steel pipes were decreased in 1/100, 1/20 by applied to the expansion joints.

Geographical Structure of View Point in the Landscape Experience on Mountain in Yangsan City (경관체함이 발생하는 조망점의 지리구조에 관한 연구;양산시 소재 산지를 대상으로)

  • Kang, Young-Jo;Cha, Young-Chae;Cha, Myeong-Sook
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.3
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    • pp.75-84
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    • 2008
  • The purpose of this research is to find the visual characteristics and geographic structure in a landscape of mountains in Yangsan City. In order to carry out this study, 40 view points of 6 mountains in Yangsan City were selected to experience the mountainscape. The results are as follows. The mountainscape of Yangsan City was confirmed from the view point to the object of view as ranging in middle distance reverse, the angle of elevation 11${\sim}13^{\circ}$ which give the impression of confronted to the mountain, and the horizontal angle 50${\sim}90^{\circ}$ which gives the impression of vastness. This shows that mountainscapes are perceived impressively when seeing the mountain with the meaning to feel the texture of the mountain as a confrontational relationship rather than a pictorial relationship. The geographic structure of the view point which occurs in scenes of impressive experience is classified into eight types and its characteristics are investigated. The first type is corridor, and it emerges in a long narrow linear structure made from the surrounding environment with buildings or street trees. The second is tunnel in which a vision and light hidden while passing underneath a bridge, high-level road, or inside a tunnel can be seen. Third, the maze is formed by the mountain shape. The hill spur emerges when the direction of traffic changes after turning the coner of a building or mountain edge. The hill ground emerges at the top of a hill slope. Next, parallel emerges when the observer and the mountain are in the same direction of process. Confrontation occurs when confronting an isolated mountain. Finally, the view point emerges when passing through major points such as a bridge or square and the boundary of a village or city. This research arranged visual conditions that create impressive mountainscapes. Geographic characteristics in terms of Types that make possible to experience mountainscapes were described. The results of this research will be basic data collected for the management and preservation of mountainscapes and for landscape effect evaluation. Furthermore, this research suggests theoretical evidence to preserve and manage geographic structures that create view experiences as well as to preserve the landscape in terms of view points.

The Effects of the Urban Spatial Structure on Traffic Congestion Costs (도시의 형태가 교통혼잡비용에 미치는 영향연구)

  • Lee, Tae-Kyung;Won, Jae-Mu
    • International Journal of Highway Engineering
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    • v.13 no.3
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    • pp.147-156
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    • 2011
  • Since the urbanization process has been taking place, negative outcomes such as environmental pollution and traffic congestion have produced as well. Reflecting the phenomenon, our study assumed that physical structure of urban form were implicit in relation to both economic performance and cost. It can be interpreted that as the urban space has been growing bigger, economic performances such as regional product output, economy of scale and the effect of agglomeration economies are increased. On the contrary, the negative effects such as environmental pollution and traffic congestion were incurred as economic loss and expenses. It means that even though economic performance can help increase regional product output, we should consider the loss on economic expenses which are paid for social problems such as environmental pollution and traffic congestion, which are caused by urbanization. Therefore, this study aims to statistically validate the relationship between traffic congestion as the most representative economy costs and physical characteristics of urban in a large city such as Seoul and to suggest its implications. As a result of model development for empirical analysis, GRDP(0.604), the population(0.582), employment GINI coefficients(0.296), population GINI coefficients(0.254) in order led to congestion cost. We can come to the conclusion that in case of scale factor such as the population, if the population tends to concentrate, urban becomes more crowded and that if GINI coefficients (the population, employment) which are variable on inequality according to region have the disparity with surrounding areas, congestion cost is caused a lot on account of movement related with employment. In addition, this phenomenon was caused if both the population and employment were geographically biased on one side.