• Title/Summary/Keyword: Road Tunnel

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Study of the Effect of the Point-to-Point Speed Enforcement System Using a Comparison-Group Method (비교그룹방법을 이용한 무인구간속도위반단속시스템 설치 효과 분석)

  • Yun, Il-Soo;Park, Sung-Ho;Oh, Bong-Sik;Oh, Young-Tae
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.177-185
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    • 2011
  • In order to reduce traffic accidents at long road sections involving high risks of traffic accidents, including tunnels, bridges or curves, the National Police Agency have decided a tentative installation and operation of an automated point-to-point speed enforcement system based on cameras at January, 2007. The first system was established at the direction to Kangreung of Dunnae Tunnel at December, 2007. Currently, the automated point-to-point speed enforcement system operates at 11 sections including eight sections on expressways and three sections on national highways. However, there have been few researches on the effects of the system upon the reduction of traffic accidents in a scientific way. To this end, this research effort was initiated to evaluate the effect of the automated point-to-point speed enforcement system on traffic safety by comparing the number of traffic accidents before and after the installation of the system using a comparison-group(C-G) method. Three-year-long traffic accident data for the expressways were collected in order to evaluate the system. As a result, the installation of the system was found to reduce traffic accidents by 49.97% in average.

A study on evaluation of flexural toughness of synthetic fiber reinforced shotcrete (구조용 합성섬유 보강 숏크리트 휨인성 평가에 관한 연구)

  • Moon, Kyoung-Sun;Kim, Seog-Jin;Kim, Yeon-Deok;Min, Byeong-Heon;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.3
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    • pp.433-452
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    • 2019
  • This study deals with shotcrete reinforcing performance according to the amount of synthetic fiber (PP fiber) and proper evaluation method. The shotcrete compressive strength, flexural strength and flexural toughness were tested by setting the mixing amounts of steel fiber ($37.0kg/m^3$) and synthetic fiber (PP fiber) as parameters ($5.0kg/m^3$, $7.0kg/m^3$ and $9.0kg/m^3$). Particularly, circular panel flexural toughness test (Road and Traffic Authority, RTA) was performed to evaluate the shotcrete energy absorption capacity. As a result, the compressive strength and the bending strength of the steel fiber reinforced shotcrete were large, but the flexural toughness of the synthetic fibe (PP fiber) reinforced shotcrete was large. Therefore, synthetic fiber (PP fiber) reinforced shotcrete is considered to have a reinforcing effect comparable to that of steel fiber reinforced shotcrete. Analysis of the relationship between the flexural toughness and the energy absorption capacity of synthetic fiber (PP fiber) reinforced shotcrete revealed that the energy absorbing ability is exhibited at a flexural toughness lower than the allowable standard (3.0 MPa). (Class A: 2.55 MPa = 202J, Class B: 2.72 MPa = 282J, Class C: 3.07 MPa = 403J). As a result of this study, it can be concluded that the actual shotcrete support performance can be evaluated by evaluating the support performance of the shotcrete measured at less than the allowable standard (3.0 MPa) at the actual tunnel site.

Studying the Comparative Analysis of Highway Traffic Accident Severity Using the Random Forest Method. (Random Forest를 활용한 고속도로 교통사고 심각도 비교분석에 관한 연구)

  • Sun-min Lee;Byoung-Jo Yoon;WutYeeLwin
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.156-168
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    • 2024
  • Purpose: The trend of highway traffic accidents shows a repeating pattern of increase and decrease, with the fatality rate being highest on highways among all road types. Therefore, there is a need to establish improvement measures that reflect the situation within the country. Method: We conducted accident severity analysis using Random Forest on data from accidents occurring on 10 specific routes with high accident rates among national highways from 2019 to 2021. Factors influencing accident severity were identified. Result: The analysis, conducted using the SHAP package to determine the top 10 variable importance, revealed that among highway traffic accidents, the variables with a significant impact on accident severity are the age of the perpetrator being between 20 and less than 39 years, the time period being daytime (06:00-18:00), occurrence on weekends (Sat-Sun), seasons being summer and winter, violation of traffic regulations (failure to comply with safe driving), road type being a tunnel, geometric structure having a high number of lanes and a high speed limit. We identified a total of 10 independent variables that showed a positive correlation with highway traffic accident severity. Conclusion: As accidents on highways occur due to the complex interaction of various factors, predicting accidents poses significant challenges. However, utilizing the results obtained from this study, there is a need for in-depth analysis of the factors influencing the severity of highway traffic accidents. Efforts should be made to establish efficient and rational response measures based on the findings of this research.

Site Selection of Wildlife Passage for Leopard Cat in Urban Area using Space Syntax (공간구문론을 이용한 도시 내 삵 이동통로 적지선정)

  • Park, Jong-Jun;Woo, Dong-Geol;Oh, Dae-Hyun;Park, Chong-Hwa
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.1
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    • pp.92-99
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    • 2012
  • Many wildlife habitats have been destroyed and fragmented during the rapid industrialization and urbanization process in Korea. It is essential to connect these fragmented habitats to reduce road-kill of many types of endangered urban wildlife. The site selection for wildlife passages must take into account the behavior of the wildlife species for safe crossing utilizing many artificial barriers in urban areas. This study attempted to identify potential wildlife passage sites for the endangered and protected leopard cats of Gangseo Ecological Park in Seoul, Korea. A space syntax analysis, an analytical technique to objectively evaluate the spatial configurations related to passage selection, found that the integration value represents the accessibility and connectivity of spaces. In this paper, this means that the bigger the integration value, the more frequently the leopard cat passes through. The leopard cats were captured and radio-tracked for 72 hours once a month from March to June of 2009. The ArcGIS and Animal Movement of Hawth Tools were used to analyze the home range and movement paths, and Axwoman 4.0 was used to analyze space syntax. The daily average movement distance was $2.099{\pm}1.08km$. During the survey period, the leopard cats crossed over an urban expressway more than 20 times, running the risk of road-kill. The range of global integration values was 0.458~1.834, while that of the local integration was 0.210~6.061. Five sites that met across the leopard cats' movement routes and roads were selected to measure the local and global integrate values. Among these sites, the higher the integration value, the higher the road-kill possibility. Thus, two of five sites with high global and local integration values were suggested as potential wildlife passage sites for the leopard cats. Now, three tunnel passages are under construction at the suggested sites for which local integration value was highest (LI=4.369). Further studies are scheduled to verify these potential sites as suitable wildlife passages.

A Study on the Development of Rapidly Hardening Grouting Method for the Effective Filling in the Underground Cavity (지하공동의 효율적 충전을 위한 급결 충전 그라우트공법개발에 관한 연구)

  • Kim, Soo-Lo;Kim, Tae-Heok;Shin, Dong-Chun;Kwon, Hyun-Ho
    • Tunnel and Underground Space
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    • v.19 no.6
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    • pp.534-544
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    • 2009
  • The collapse of the underground cavity can cause the abrupt local subsidence of the ground surface. It can be hazardous to the stability of road and building for human activity. Therefore it is necessary to develop reinforcement methods for the filling of the underground cavity. This study was executed to improve the material quality and systems to fill the calcium-aluminate mineral $(C_{12}A_7)$ environmentally, and minimize the loss of filling materials for the steep underground cavity. Filling material which was developed in this study is composed of rapid hardening material and additives. The developed material had rapid hardening and non-separation ability in the water cavity condition, so it made the effective underground dam in the cavity with prevention of material loss when it was poured in the water cavity. Results of heavy metal leaching test for environmental assessment showed that it was environmentally suiTable material for the filling in the mine cavity.

Fog Generated Field Test for Criteria of Sign Size of Variable Speed Limit Signs (가변 제한속도 표지판 크기기준 정립을 위한 안개재현 현장실험)

  • Kim, Yongseok;Lee, Sukki;Kim, Soullam
    • International Journal of Highway Engineering
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    • v.18 no.6
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    • pp.87-96
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    • 2016
  • OBJECTIVES : A fog generated field test was conducted to analyze the relationship between different sizes of variable speed limit signs and the legibility distance under various fog density conditions. By using this study, appropriate sizes of signs can be selected depending on the density of fog. METHODS : An actual tunnel was selected as the area for this test, as other places cannot maintain the fog condition because of rapid air current. A total 121 subjects were recruited for this test, which took place over the course of four days. The test on the first day was conducted under normal weather conditions for comparison. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS : The test results show the relationship between the different sizes of signs and the legibility distance corresponding to the visibility distance due to both non-fog and fog generated conditions. According to the technical test results, appreciable amount of reduction in legibility distance due to fog was resulted in all sizes of signs. Moreover, the legibility distance is reduced proportionately with the decrease in the visibility distance due to fog. CONCLUSIONS : The results of this study can be used to select appropriate sizes of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.

Fog Generated Field Test for Luminance Criteria of Variable Speed-Limit Signs (가변속도형 표지 휘도기준 정립을 위한 안개재현 현장실험)

  • Kim, Yongseok;Lee, Sukki;Kim, Soullam
    • International Journal of Highway Engineering
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    • v.18 no.6
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    • pp.77-85
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    • 2016
  • OBJECTIVES : A fog generated field test was conducted to analyze the relationship between the luminance of variable speed-limit signs and the legibility distance under various fog density conditions. By using this study, appropriate luminance values can be selected depending on the density of fog. METHODS : An actual tunnel was selected as the area to conduct the test, as other places cannot maintain the fog condition because of rapid air current. Ninety-two subjects were recruited for this test, which took place during the course of three days. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS : The test results show the relationship between luminance values and the legibility distance corresponding to the visibility distance due to fog. According to the technical test results, lower luminance value such as $7000cd/m^2$ corresponds to less legibility distance compared to higher values such as $20000cd/m^2$ or $40000cd/m^2$. However, the amount of difference between $20000cd/m^2$ and $40000cd/m^2$ is negligible in our test. CONCLUSIONS : The results of this study can be used to select appropriate luminance of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.

Forward Vehicle Tracking Based on Weighted Multiple Instance Learning Equipped with Particle Filter (파티클 필터를 장착한 가중된 다중 인스턴스학습을 이용한 전방차량 추적)

  • Park, Keunho;Lee, Joonwhoan
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.4
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    • pp.377-385
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    • 2015
  • This paper proposes a novel forward vehicle tracking algorithm based on the WMIL(Weighted Multiple Instance Learning) equipped with a particle filter. In the proposed algorithm Haar-like features are used to train a vehicle object detector to be tracked and the location of the object are obtained from the recognition result. In order to combine both the WMIL to construct the vehicle detector and the particle filter, the proposed algorithm updates the object location by executing the propagation, observation, estimation, and selection processes involved in particle filter instead of finding the credence map in the search area for every frame. The proposed algorithm inevitably increases the computation time because of the particle filter, but the tracking accuracy was highly improved compared to Ababoost, MIL(Multiple Instance Learning) and MIL-based ones so that the position error was 4.5 pixels in average for the videos of national high-way, express high-way, tunnel and urban paved road scene.

Experimental study on usability of soil pavement using weathered granite soil and organic solidification agent (화강풍화토와 유기계 고화제를 이용한 흙포장의 사용성에 관한 실험적 연구)

  • Hwang, Sung-Pil;Jeoung, Jae-Hyeung;Lee, Yong-Soo;Lee, Tae-Hyung
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.4
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    • pp.11-21
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    • 2015
  • The method to replace asphalt and cement is needed to reduce the carbon emission on road. Polymeric material which is light and easy to handle while having complex function with less carbon emission would be highly effective when it replaced soil pavement containing cement. This study is intended to identify the usability of soil pavement containing organic solidification agent only through the field test. Pavement on bike trail still satisfied required bearing capacity coefficient in 3 months. Pavement after passing 1.6 bil units of bike through pavement acceleration test that simulated a long-term serviceability during a short-time still remained unaffected, demonstrating a long-term serviceability of soil pavement.

An Experimental Study on Electric Resistivity and Exothermic Property of Electrically Conductive Mortar using Amorphous Graphite (흑연을 혼입한 전기전도 모르타르의 전기저항 및 발열특성에 관한 실험적 연구)

  • Ahn, Hong-JIn;Kim, Sang-Heon;Choi, Soo-Kyung
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.3
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    • pp.247-255
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    • 2016
  • The exothermic property of electrical conductivity concrete would allow the heating system of house or snow melting system of tunnel, road or bridge deck. This study was performed on electric resistance, exothermic property and mechanical property of the mortar with graphite of carbon-based conductive material as a fundamental research for the heat conductive concrete development. As the results of this experiment, the increasement on the amorphous graphite substitution rate was found to decrease in the compressive strength, however, the electric resistance was found to be significantly lower. And, in order to demonstrate the exothermic property, the graphite was found to be included more than 15% of the total mortar volume. When low electric resistance obtained with a certain level of the graphite inclusion, exothermic value and applied voltage has a higher correlation, and the exothermic value and the square of the voltage appeared to be in a proportional relationship.