• Journal of Korean Society of Steel Construction
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• v.9 no.3 s.32
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• pp.309-321
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• 1997

The prediction of the dynamic response of a bridge resulting from passing vehicles across the span is a significant problem in bridge design. In this paper. the static and dynamic experiments are performed to understand the dynamic behavior of an actual two-span steel plate girder bridge. The road surface roughness of the roadway and bridge deck is directly measured by Intelligent Total Station. Numerical scheme to obtain the dynamic responses of the bridges in consideration of measuring road surface roughness and 3-D vehicle model is also presented. The bridge and vehicle are modeled as 3-D bridge and vehicle model, respectively. The main girder and concrete deck are modeled as beam and shell elements, respectively and rigid link is used for the structure between main girder and concrete deck. Bridge-vehicle interaction equations are derived and the impact factors of the responses for different vehicle speeds are calculated and compared with those predicted by several foreign specifications.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.29-36
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• 2007

Despite the role of tunnels in today's roadway environment, the study on tunnel lighting is still scant. Drivers passing through a tunnel face some difficulties caused by the visual differences between outside and inside of the tunnel. The whitehole phenomenon at a tunnel exit-zone severely decreases the driver's visibility in the daytime. A probeam lighting is generally recommended for the prevention of it. This paper simulates an exit-zone with a whitehole phenomenon to verify the effect of probeam lighting. Even though the tunnel lighting is important, it is not easy to consider enough number of lighting alternatives at the stage of tunnel design due to the complexity of tunnel conditions. This paper is expected to contribute improving the visibility in tunnels, especially at the exit-zone.

• International Journal of Highway Engineering
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• v.5 no.2 s.16
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• pp.1-14
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• 2003

This study is a fundamental research for developing self-deicing function of snow-melting asphalt concrete for roadway pavement. The objective of this study is to develop technology of making self-snow-melting asphalt pavement and evaluate properties of the asphalt concrete containing deicers. Asphalt concrete with deicers and CRM was produced by dry process. The $\alpha$-deicer, CRM and F-deicer were used for sand asphalt mixtures of thin-layer pavement on the existing pavement. The $\alpha$-deicer, $\beta$-deicer, CRM A, CRM B and C were used for 13mm dense-graded mixtures on surface course. Penetration grade of 60-80 asphalt was used for asphalt mixtures. Marshall mix-design, indirect tensile strength, freezing and thawing test, analysis of extracted water were carried out to evaluate performance of self deicing function of asphalt mixtures. The study result showed that snow-melting asphalt mixtures had not only good mechanical characteristics and good snow-melting function, but also chemically safe in environmental point of view.

• Tunnel and Underground Space
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• v.15 no.5 s.58
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• pp.378-386
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• 2005

Jook-Ryung roadway tunnel was constructed by drill-blast after pilot tunnelling by 2 TBMS. nis report analyzes the data for TBM performance in the total length of 7.3 km for the two pilot tunnels. Net penetration rates were recorded as high as 2.3 m/h and 2.0 m/h for the two different directions while degrees of operation were $31.4\%$ and $33.3\%$, respectively. The cutter lives for No.2 tunnel were evaluated $200\~280\;m^3/c$ and around 400 m/set as high as for Meraker 10 km tunnel in Norway. The relationship between net penetration rate and characteristics of rock mass which were obtained by RMR and TSP measurement, coincides with the prior studies. This kind of evaluation is expected to be used to design TBM tunnelling and to help to perform the TBM operation effectively

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.47-56
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• 2008

Generally, accident exposure at intersections is relatively higher than that at roadway segments due to more possibility of merging, diverging, turning, crossing, and weaving maneuver. Furthermore, the traffic accident rate at intersections has been rapidly increasing since 1990's. Since there is more opportunity of conflict at unsignalized intersection, frequency and severity of traffic accident are more severe than signalized intersections. The purpose of the study is to analyze factors causing vehicle crashes and provide intersection design guidelines to improve intersection safety. For this study, vehicle to vehicle crash data of 116 rural 3 legs unsignalized were collected and field surveys were conducted for traffic and geometric conditions. Ordered probit models were developed to analyze the severity of crashes. It was found that weather, obstacles in minor roadsides, presence of major exclusive right lane, presence of major road crosswalk, difference between posted speed of major road and minor road, land-use around intersections, shoulder width of major road, ADT of major road are significant factors for intersection safety.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.53-63
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• 2008

Even though accident frequencies in roadway segments have been decreasing since 2000, there has been increasing the number of vehicle crashes at intersections. Due to this increase, safety problems at intersection recently started to be regarded as significant issues. The purpose of this study is to analyze the effects of road conditions, traffic operational conditions, and other influencing condition on intersection safety. Then a traffic accident frequency prediction model to evaluate the safety at intersections was developed based on the correlations between influencing factors and vehicle crashes. In this research, critically significant factors affecting vehicle crashes at rural four-legs signalized intersections were investigated. It was found that Poisson regression was the best fit method to developing a accident frequency modeling using the collected data in this study. Through this study, it was concluded that exclusive left turn lane, crosswalk, posted speed, lighting, angle, and ADT are significant influencing factors on the intersection safety.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.114-120
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• 2018

Recently, the plate girder bridge is offen designed a temporary bridge for underground roadway construction have not interrupt railroad operation. The integral support plate girder bridge which have longitudinal girder and cross-girder is improved workability and reduction cost and of construction time. The cross beam of the integral support plate girder bridge has a normal box shape to distribute load on the main girde to end both side girder. In this study, On the change to the web distance of the cross box shows characteristics of related to the stresses and displacements on the flange and web plate. Afterward, the various analysis contributed to the safety improvement of crossbeam of the integral support crossbeam plate girder bridge.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.31-41
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• 2019

More than 90% of roadway in the world are paved as asphalt concrete pavement due to its excellent properties compared with other paving materials; excellent riding quality, flexibility, anti-icing property and easy maintenance-ability. In this study, to make best use of the softer property of the asphalt mixture, the flexible sand asphalt mixture (FSAM) was developed for pedestrian ways. The mix design was conducted to prepare FSAM using PG64-22 asphalt, screenings (sand) less than 5mm, crumb rubber, hydrated lime and limestone powder without coarse aggregate. The deformation strength ($S_D$), indirect tensile strength (ITS) and tensile strength ratio (TSR) tests were conducted to make sure durability of FSAM performance. The impact energy absorption and flexibility were measured by drop-boll test and the resilient modulus ($M_R$) test. The impact energy absorption of FSAM was compared with normal asphalt pavement, concrete pavement, stone and concrete block for pedestrian way. As a result of drop-boll test, FSAM showed higher impact energy absorption compared with other paving materials with the range of 18% to 43%. Impact energy absorption of FSAM increased with increasing test temperature from 5 to $40^{\circ}C$. The results of $M_R$ test at $5^{\circ}C$ showed that the flexibility of FSPA was increased further, because the $M_R$ value of the sand asphalt was measured to be 38% lower than normal dense-graded asphalt mixture (WC-1). Therefore, it was concluded that the FSAM could provide a high impact absorbing characteristics, which would improve walking quality of the pedestrian ways.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.201-213
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• 2021

Recently, personal mobility has been spreading and using increasing, but the pedestrian environment is getting worse and accidents are also rapidly increasing. Therefore, this study conducts a status survey related to the elements of pedestrian disturbances in personal mobility and identifies the problems. The following measures are presented to improve the pedestrian environment for the mobility handicapped through expert opinion surveys. The movement of individual mobility means in the walking space is prohibited, and the speed limit shall be stipulated to enable the mobility handicapped to walk safely and conveniently. Parking spaces will have to create obstacle zones in the parking area next to the roadway or at the border of sidewalks and roads, and regulations are needed to collect illegally parked vehicles. It is necessary to switch from the existing automobile-oriented road to the road structure considering the use of low and medium-speed vehicles.

• Journal of the Korean Geotechnical Society
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• v.24 no.12
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• pp.41-52
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• 2008

This paper concerns the load carrying capacity of back-to-back reinforced soil wall for use in roadway and railway construction. Two test conditions, designed with due consideration of the FHW A design guideline, were first developed and a number of cases having different reinforcement lengths were tested under a surchage loading until failure. The results indicated that for cases in which two sides of reinforcements do not overlap, the wall behavior was similar to those of single wall. For cases in which the reinforcements overlap each other, on the other hand, the load carrying capacity of the wall significantly decreased when reinforced with reinforcement layers having lengths less than 50% of the wall height.