• Title/Summary/Keyword: Road Capacity

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In the middle of a perfect storm: political risks of the Belt and Road project at Kyaukphyu, Myanmar

  • Morris, David
    • Journal of Contemporary Eastern Asia
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    • v.20 no.2
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    • pp.210-236
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    • 2021
  • China's Belt and Road Initiative infrastructure connectivity and other projects are presented in much of the discourse as a grand strategy to trap developing nations in debt, to exert asymmetric power and construct a new world economic order. The asymmetric relationship between China and Myanmar might therefore be expected to generate a range of political risks for stakeholders. Myanmar itself presents a "perfect storm" of problems, with dysfunctional governance, civil conflict, under-development and growing economic dependence on China. The Kyaukphyu port project and associated Special Economic Zone in Myanmar's troubled Rakhine state is investigated as a case study of risks on the Belt and Road. While worst case fears China might seize military control of the port appear unlikely, at least in current conditions, empirical observation indicates the complexity on the ground generates an array of other risks - as well as opportunities, should conditions allow. Further, despite challenges and constrained capacity, Myanmar governments have demonstrated agency, including by re-negotiating control and costs of the Kyaukphyu project. The case underlines that conditions are more complicated than simply China's asymmetric power. A sceptical approach is taken to normative discourses in order to build inductive understanding of how stakeholders and local experts perceive dynamics underway. A political risk approach is deployed to develop a framework to identify, analyse and assess risks for actors in relation to the Kyaukphyu project. The research findings are presented on an interim basis, given current constraints on field interviews due to the current crisis.

Loading capacity evaluation of composite box girder with corrugated webs and steel tube slab

  • He, Jun;Liu, Yuqing;Xu, Xiaoqing;Li, Laibin
    • Structural Engineering and Mechanics
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    • v.50 no.4
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    • pp.501-524
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    • 2014
  • This paper presents a type of composite box girder with corrugated webs and concrete filled steel tube slab to overcome cracking on the web and reduce self-weight. Utilizing corrugated steel web improves the efficiency of prestressing introduced into the top and bottom slabs due to the accordion effect. In order to understand the loading capacity of such new composite structure, experimental and numerical analyses were conducted. A full-scale model was loaded monotonically to investigate the deflection, strain distribution, loading capacity and stiffness during the whole process. The experimental results show that test specimen has enough loading capacity and ductility. Based on experimental works, a finite element (FE) model was established. The load-displacement curves and stress distribution predicted by FE model agree well with that obtained from experiments, which demonstrates the accuracy of proposed FE model. Moreover, simplified theoretical analysis was conducted depending on the assumptions which were confirmed by the experimental and numerical results. The simplified analysis results are identical with the tested and numerical results, which indicate that simplified analytical model can be used to predict the loading capacity of such composite girder accurately. All the findings of present study may provide reference for the application of such structure in bridge construction.

Determination of Base Capacity Values for Short-Term Freeway Work Zone (고속도로 단기공사구간 기본용량 결정에 관한 연구)

  • Kim, Sang Gu;Hong, Gil Seong
    • Journal of Korean Society of Transportation
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    • v.31 no.1
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    • pp.37-46
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    • 2013
  • Lane closure in freeway work zone due to maintenance and repair of freeway facilities results in abrupt change of traffic flow. Sudden change of traffic flow results strong interactions among vehicles, and reduces capacity compared to the ordinary traffic condition. Such capacity reduction is likely to cause congestion, traffic queues, and economic loss cost. This study aims to determine the base capacity for a short-term freeway work zone that can be used to establish a work zone schedule in advance without any traffic impact. First, the research collected detector data and schedule data of road works on all freeways in Korea. Second, the research determined 23 study sites finding the capacity values of work zone after matching two kinds of data. All study sites had varying characteristics regarding traffic flow being adjacent to work zone during road works. The capacity values were reviewed in terms of lane closure configuration, the types of work, and design speed. Finally, research proposed capacity values for a short-term freeway work zone with the design speeds of 100 kph, 120 kph and 1,700 pcphpl, 1,750 pcphpl, respectively.

The effects of introduction of diesel passenger cars on the ventilation requirements for road tunnels (경유승용차 도입이 터널 소요환기량에 미치는 영향분석)

  • Kim, Hyo-Gyu;Song, Seok-Hun;Kim, Nam-Young;Lee, Chang-Woo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.9 no.3
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    • pp.309-321
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    • 2007
  • Since the first diesel passenger car hit the local road in late 2005, the share of diesel cars is growing significantly; possibly up to the level as in the western Europe. In this study, the effects of introduction of diesel passenger cars on the ventilation rate and facility capacity are analyzed for the three individual cases with different basic exhaust rate based on the vehicle age, the vehicle class percentage and the smoke exhaust rate. The target tunnel for this comparative study is a typical 2 km-long 2-lane highway tunnel. Case 1 assuming the current local design standards and the diesel vehicles comprising 40% of the total passenger cars on the road required more ventilation rate and facility capacity than in the case only with the current standards. Case 2 which is the real tunnel currently in the designing stage taking into account the vehicle age but ignoring the diesel vehicle ratio, and Case 3 on the contrary considering the both factors show similar level of ventilation characteristics as EURO-3 emission regulation. Application of the emission standard set by the Ministry of Environment for newly manufactured vehicles in the current local tunnel design standard indicates higher requirements than for EURO-2 regulation, whereas the emission standard came into effect in 2006 results in the ventilation characteristics similar to EURO-4. This study aims at providing fundamental information for assessing the basic emission rate and determining the optimal ventilation rate and facility capacity considering the growing percentage of diesel cars and gradually decreasing level of smoke emission forced by the relevant laws.

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Effects of foam core density and face-sheet thickness on the mechanical properties of aluminum foam sandwich

  • Yan, Chang;Song, Xuding
    • Steel and Composite Structures
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    • v.21 no.5
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    • pp.1145-1156
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    • 2016
  • To study the effects of foam core density and face-sheet thickness on the mechanical properties and failure modes of aluminum foam sandwich (AFS) beam, especially when the aluminum foam core is made in aluminum alloy and the face sheet thickness is less than 1.5 mm, three-point bending tests were investigated experimentally by using WDW-50E electronic universal tensile testing machine. Load-displacement curves were recorded to understand the mechanical response and photographs were taken to capture the deformation process of the composite structures. Results demonstrated that when foam core was combined with face-sheet thickness of 0.8 mm, its carrying capacity improved with the increase of core density. But when the thickness of face-sheet increased from 0.8 mm to 1.2 mm, result was opposite. For AFS with the same core density, their carrying capacity increased with the face-sheet thickness, but failure modes of thin face-sheet AFS were completely different from the thick face-sheet AFS. There were three failure modes in the present research: yield damage of both core and bottom face-sheet (Failure mode I), yield damage of foam core (Failure mode II), debonding between the adhesive interface (Failure mode III).

A Study on Evaluation of Sidewalk / Roadway Pavement Using Stone Block (스톤 블럭을 이용한 보.차도 포장의 적용성 평가)

  • Yoon, Won-Sub;Kim, Jong-Kook;Park, Sang-Jun;Cho, Chul-Hyun;Chae, Young-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.259-266
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    • 2008
  • Recently, the maintenance period of sidewalk pavement proposed in Ministry of Construction & Transportation to be extended by more than 10 years. Therefore it takes many interests in Durability and the maintenance. Beside sidewalk pavement, block pavement happened problems in parking and road less than 20km/hr about bearing capacity and durability, the maintenance. It interests about importance of environmentally friendly sidewalk pavement. It compared engineering characteristics about strength and durability through general pavement comparison with stone block pavement. It estimate bearing capacity in actual si-tu site and test site. It experimented plate bearing test and field density test. It verified about durability of pavement by construction availability of geosynthetics that is constructed by purpose of filter. Stone block pavement evaluated about application of sidewalk/road pavement on the basis of result.

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Analisys on Freezing Characteristics of Pavement Layer Using the Feild Pavement Model test (현장 모형 도로 축소 실험을 이용한 포장구성층의 동결 특성 분석)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Moon, Yong-Soo;Park, Jeong-Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1164-1171
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    • 2010
  • Korea is considered to be a seasonal frozen soil area that is thawed in the spring, and most of the area is frozen in winter as to the characteristic of geography. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this research, the evaluation of frost susceptibility on subgrade, ant-freezing layer, sub base was conducted by means of the mechanical property test and laboratory field road model downed scale experiment. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade, anti-freezing layer, sub base soils of highway construction site, were measured to determine the frost susceptibility.

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Evaluating Unsaturated Hydraulic Properties of Compacted Geomaterials in Road Foundations (II) : Numerical Analysis (다져진 도로기초 재료의 불포화투수특성 평가 (II) : 수치해석)

  • Sung, Yeol-Jung;Park, Seong-Wan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1D
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    • pp.83-90
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    • 2011
  • A need still exists that the unsaturated condition is to be considered when evaluating the infiltration and drainage capacity for compacted geomaterials in road foundation or embankments. For this reason, numerical analysis were used to analyze the time-dependent unsaturated infiltration and drainage condition depending on various geomaterial types. Therefore, laboratory data from the soil-water characteristic curve tests on geomaterials were adopted from previous studies. In addition, the unsaturated permeability was estimated using SWCC. Then the infiltration and drainage performance of unsaturated compacted soils were evaluated under various conditions based on the proposed method. The results demonstrated that the effect of initial suction and SWCC path on each material could be substantial and the proper application on analysis is very important to enhance the prediction on each capacity.

Analysis of Agricultural Working Load Experiments for Reduction Gear Ratio Design of an Electric Tractor Powertrain (전기구동 파워트레인의 감속기어비 설계를 위한 농용 트랙터의 작업 부하 분석)

  • Kim, Jung-Yun;Park, Yeong-Il
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.5
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    • pp.138-144
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    • 2012
  • Recent environmental issues such as exhaust gas and greenhouse effect make the agricultural machinery market takes into account the hybrid and electric propulsion technology used in automotive engineering. Generally the agricultural machinery, particularly an agricultural tractor, needs large load capacity and long continuous operating time comparing with conventional vehicles. In case of a pure electric tractor, it is necessary for considering large capacity batteries and long charging time. Therefore we take an AER extended PHEV (All Electric Range extended Plug-in Hybrid Electric Vehicle) power transmission system in developing an electric tractor in this study. First we propose a PHEV powertrain structure in order to substitute the conventional diesel engine equipped tractor. And we performed the road tests using a conventional mechanical tractor with various load conditions, which were classified and statistically treated real agricultural works. The test results were analysed with respect to the power characteristics of the power source. Finally using the test result, we designed two-stepped reduction gear ratios in the proposed an electric tractor powertrain for carrying out typical agricultural works.

Estimation of Road User Costs Caused by Work Zones and Economic Analysis in the Feasibility Study (도로공사로 인한 부(-)의 편익 반영 및 경제성 분석)

  • Lee, Seunghyeon;Lee, Jaeyoung;Choi, Keechoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.5D
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    • pp.461-465
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    • 2010
  • The objective of this study is to calculate road user costs that caused by the expansion work of metropolitan arterial highway and to analyze the costs that affect economic feasibility evaluation. "Taerung~Guri IC" section of Bukbu Expressway was selected as a case study. As a result, it shows that these costs could be a factor for determining economic feasibility for some projects. However, decreased capacity and free-flow speed are seriously different as period, type, length and traffic volume of work zones. These factors that decrease traffic capacity and free-flow speed should be deeply researched in the future.