• 한국도로학회:학술대회논문집
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• 2008.10a
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• pp.271-277
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• 2008

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.113-126
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• 2017

PURPOSES : This study proposes standards for rural access road pavement section and thickness design considering existing access road construction conditions; the study also proposes a complementary policy that can be used for design convenience. METHODS : Various literature review and case studies had been performed in terms of rural access road section and thickness design, both domestically and internationally, and this was followed by domestic rural access road field surveys. KPRP and KENLAYER were used to analyze the commonalities and predict the remaining life. Data on real cost is used to select an appropriate construction method through economic analysis. RESULTS : The economic efficiency of concrete pavement ($15{\times}15$) was the highest in terms of economic efficiency of performance life and traffic volume. In the case of asphalt pavement, it is considered that the most economical method is to implement micro-surfacing method four times as a preventive maintenance method (once every 10 years and 4.5 years for asphalt concrete pavement and MS construction method, respectively). Repairable asphalt pavement is advantageous for areas where heavy vehicles are expected to pass. In the case of other general areas, it is considered economical to place concrete ($15{\times}15$) pavement. However, as analytical results on its performance life are unavailable, it is to be considered for study in the future. CONCLUSIONS : This study proposed interim design guidelines based on various domestic and international design guidelines and case studies. However, in order to develop the final design criteria applicable to the field, it is necessary to (a) estimate the bearing capacity of the lower level of the pavement at various sites, (b) estimate the daily traffic volume, (c) implement advanced low-cost pavement technologies, and (d) propose maintenance standards and techniques for long-term performance.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.382-390
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• 2012

Global warming has been hot issue world wide. Korea has been dealing with the global issue under the slogan of low carbon and green-growth such as setting national greenhouse gas (GHG) reduction targets and allocation to each industrial sector. Infrastructure construction, in which enormous social overhead capital (SOC) is input, has great role as one of the actions. Road is one of the representative infrastructure and large amount of resources is utilized in its construction, operation and maintenance stage. The estimation methodology of life cycle carbon emissions was developed and applied to a case study of highway currently under construction in this study. Also, total carbon emissions of all the highway in South Korea at present (2009) and cumulative carbon emissions from 2009 to 2020 were estimated using the results of case study.

• International Journal of Highway Engineering
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• v.19 no.3
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• pp.65-70
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• 2017

PURPOSES : Pavement Management System contains the data that describe the condition of the road. Under limited budget, the data can be utilized for efficient plans. The objective of this research is to develop a mixed integer program model that maximizes remaining durable years (or Lane-Kilometer-Years) in road maintenance planning. METHODS : An optimization model based on a mixed integer program is developed. The model selects a cluster of sectors that are adjacent to each other according to the road condition. The model also considers constraints required by the Seoul Metropolitan Facilities Management Corporation. They select two lanes at most not to block the traffic and limit the number of sectors for one-time construction to finish the work in given time. We incorporate variable cost constraints. As the model selects more sectors, the unit cost of the construction becomes smaller. The optimal choice of the number of sectors is implemented using piecewise linear constraints. RESULTS : Data (SPI) collected from Pavement Management System managed by Seoul Metropolitan City are fed into the model. Based on the data and the model, the optimal maintenance plans are established. Some of the optimal plans cannot be generated directly in existing heuristic approach or by human intuition. CONCLUSIONS:The mathematical model using actual data generates the optimal maintenance plans.

• International Journal of Highway Engineering
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• v.15 no.3
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• pp.17-22
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• 2013

PURPOSES: Current theories for composite structures are too difficult for design engineers for construction. The purpose of this paper is to demonstrate to the practicing engineers, how to apply the advanced composite materials theory to the road structures. METHODS: Some laminate orientations have decreasing values of $D_{16}$, $B_{16}$, $D_{26}$ and $B_{26}$ stiffnesses as the ply number increases. The plate aspect ratio considered is from 1 to 5. In order to study the effect of $M_x$ on the equilibrium equations, two cases are considered. $M_x$ term is considered or neglected. RESULTS: Most of the road structures have high aspect ratios, for such cases further simplification is possible by neglecting the effect of the longitudinal moment terms. CONCLUSIONS: Most of the road structures have plate aspect ratios higher than 2. It is concluded that, for all boundary conditions, neglecting the longitudinal moment($M_x$) terms is acceptable if the aspect ratio (a/b) is equal to or higher than 2. This conclusion gives good guide line for design of the road structures.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.95-98
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• 2003

The objectives of the study are to analyze the impacts of rural road project on the social and economic activities of community people, offer basic data to perform evaluation of the project, and suggest future directions of the project. Research methodology adopted is a questionnaire method. There were interviewed 281 adult residents selected from 34 villages in Yeongdong-gun(mountainous), Miryang-si(middle), and Gochang-gun(plain). Results of the study are as follows: 1) Increase of income and land prices in mountainous and middle regions by the rural road project is higher than in plain; 2) Most inconvenient road expressed by the interviewee is the one linking farm and residence and 3) The problems of rural roads derived are narrowness, unpavement and partial pavement, unreliable maintenance, and long construction time. In order to meet the community needs on rural roads, it may be necessary that community people participate in the process of the project. And it is desirable to put priority on expanding and paving existing roads rather than constructing new one.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1147-1156
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• 2015

The result of responsibility supervision system which has been enforced for the last twenty (20) years since January, 1994 is evaluated, and keeps an eye out the process of unification and absorption of the system into the construction management (CM). As a baseline data for this study, the grade framework of construction engineer's ICEC introduced with CM is summarized. In this manuscript, the questionaire survey for CM and ICEC was conducted toward the target group of road field construction engineers and analyzed the outcome of the respondents' answers. 50% of the respondents have answered positively for the question about converting responsibility supervision to CM. 48% of the respondents from construction works field have answered positively for converting responsibility supervision system to CM while 38% of the respondents from engineers of supervision field have answered positively, less positive than the answers from works field engineers. 46% of overall respondents have answered, however, to maintain the present system of 40%, 40% and 20% on the survey to the question asking the opinion on the ways of calculating ICEC to use the rates : 40% of career, 40% of qualification and 20% of academic achievements. However, it appeared that engineers who have comparative advantages with academic achievements and career, and engineers with lower grade qualification demanded higher rate for career.

• International Journal of Highway Engineering
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• v.20 no.4
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• pp.21-26
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• 2018

PURPOSES : The objective of this study is to evaluate the application of soil stabilization method for soft shoulder construction in the iRoad Project of Sri Lanka. METHODS : Firstly, the quantitative analysis of soil strength improvement due to soil stabilization was done for soil samples collected from iRoad construction sites. Two types of soils were selected from iRoad Project sites and prepared for soil stabilization testing by the Road Development Authority. Secondly, the appropriate stabilizer was selected at given soil type based on test results. Two different stabilizers, ST-1 and ST-2, produced in Korea were used for estimating soil strength improvements. Finally, the optimum stabilizer content was determined for improving shoulder performance. The uniaxial compressive strength (UCS) test was conducted to evaluate the strength of stabilized soil samples in accordance with ASTM D 1633. The use of bottom ash as a stabilizer produced from power plant in Sri Lanka was also reviewed in this task. RESULTS : It is found from the UCS testing that a 3% use of soil stabilizer can improve the strength up to 2~5 times in stabilized soft shoulder soils with respect to unstabilized soils. It is also observed from UCS testing that the ST-1 shows high strength improvement in 3% of stabilizer content but the strength improvement rate with increase of stabilizer content is relatively low compared with ST-2. The ST-2 shows a low UCS value at 3% of content but the UCS values increase significantly with increase of stabilizer content. When using the ST-2 as stabilizing agent, the 5% is recommended as minimum content based on UCS testing results. Based on the testing results for bottom ash replacement, the stabilized sample with bottom ash shows the low strength value. CONCLUSIONS : This paper is intended to check the feasibility for use the soil stabilization technique for shoulder construction in Sri Lanka. The use of soil stabilizer enables to improve the durability and strength in soft shoulder materials. When applying the bottom ash as a soil stabilizer, various testings should be conducted to satisfy the specification criteria.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.568-569
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• 2011

As an answer for need for minimizing the road excavation of a box type tunnel, a method of vertical snake was developed, which is very economical and easy to construct. The reason why it is good is, the road excavation width, steel accessories, the road occupation space decreases with the technology. The pros and cons of 345kV XLPE $2,500mm^2$ horizontal and vertical snake are listed below. In this study, topics such as 345kV XLPE $2,500mm^2$ vertical snake construction standard and the development process of steel accessories, vertical snake construction procedure will be covered.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1175_1176
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• 2009

In comparison with different mass transportation systems, the streetcar is lower, both in speed and transportation capacity. However, it has the advantage of reducing the cost of construction, because it makes infrastructure simple, by using the road. It is proper in the city, where the population is few, to raise the efficiency of traffic. The convenience is high to passengers. On time accuracy and the commercial speed is influenced by operating condition. Generally that is organized into 21m degree in 6 quantity. All passengers in a streetcar are about 180 people. The maximum speed is 40~60km/h. When road traffic is considered, the speed can be reduced to 15km/h. To enhance the speed, the construction of a priority signaling system is necessary which is integrated with the road traffic operation information system. In order to develop a better Traffic Control System which is connected to a Traffic Control Center, a Priority Signaling System which incorporates Intersection Control Technics must be included.