• Title/Summary/Keyword: Pavement surface damage

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Determination of Volume Porosity and Permeability of Drainage Layer in Rainwater Drainage System Using 3-D Numerical Method (3차원 수치해석기법을 이용한 우수배수시스템 배수층의 체적공극과 투수도 결정)

  • Yeom, Seong Il;Park, Sung Won;Ahn, Jungkyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.449-455
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    • 2019
  • The increase in impermeable pavement from recent urbanization has resulted in an increase in surface runoff. The surface runoff has also increased the burden of the existing drainage system. This drainage system has structural limitations in that the catchment area is reduced by the waste particles transported with the surface runoff. In addition, the efficiency of the drainage system is decreased. To overcome these limitations, a new type of drainage system with a drainage layer was developed and applied. In this study, various volume porosity and permeability of the lower drainage layer were simulated using ANSYS CFX, which is a three dimensional computational fluid dynamics program. The results showed that the outlet velocity of the 35% volume porosity was faster than that of the 20% and 50% cases, and there was no relationship between the volume porosity and drainage performance. The permeability of the drainage layer can be determined from the particle size of the material, and a simulation of five conditions showed that 2 mm sand grains are most suitable for workability and usability. This study suggests appropriate values of the volume porosity and particle size of the drainage layer. This consideration can be advantageous for reducing and preventing flood damage.

Durability Evaluation of a Buried Expansion Joint of Buried Folding Lattice Type (BFL형의 매설형 신축이음장치의 내구성 평가)

  • Jwa, Yong-Hyun;Park, Sang-Yeol;Kim, Seok-Hyun
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.9-20
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    • 2011
  • Most of domestic expansion joint system was applied by exposed expansion joint system. There are cases where it is damaged by driving. As the result noise and impact happened, and the social cost due to frequent repair works is increasing. So based on the Asphalt Plug Joint(APJ) system that applied in the United States and Europe, new buried expansion joint system was lately developed a system of Buried Folding Lattice Joint(BFLJ) that changed substructure. In this research, we have tested for durability and flexibility performance of buried expansion joint system that based on the type of asphalt mixture. Also we have evaluated for durability of BFLJ system against vehicle load using accelerated pavement testing. As a result of the experiment, the developed BFLJ system gives high flexibility performance and resolves transformation concentration along the joint section more than APJ system. Also it could be seen that the BFLJ system could overcome the disadvantages of APJ and prevent early damage. Because surface deflection of BFLJ system against vehicle load was measured low, and sub system in the buried expansion joint system was not damaged against vehicle load.

Proposed Pre-Processing Method for Improving Pothole Dataset Performance in Deep Learning Model and Verification by YOLO Model (딥러닝 모델에서 포트홀 데이터셋의 성능 향상을 위한 전처리 방법 제안과 YOLO 모델을 통한 검증)

  • Han-Jin Lee;Ji-Woong Yang;Ellen J. Hong
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.4
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    • pp.249-255
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    • 2022
  • Potholes are an important clue to the structural defects of asphalt pavement and cause many casualties and property damage. Therefore, accurate pothole detection is an important task in road surface maintenance. Many machine learning technologies are being introduced for pothole detection, and data preprocessing is required to increase the efficiency of deep learning models. In this paper, we propose a preprocessing method that emphasizes important textures and shapes in pothole datasets. The proposed preprocessing method uses intensity transformation to reduce unnecessary elements of the road and emphasize the texture and shape of the pothole. In addition, the feature of the porthole is detected using Superpixel and Sobel edge detection. Through performance comparison between the proposed preprocessing method and the existing preprocessing method, it is shown that the proposed preprocessing method is a more effective method than the existing method in detecting potholes.

Analysis of the under Pavement Cavity Growth Rate using Multi-Channel GPR Equipment (멀티채널 GPR 장비를 이용한 도로하부 공동의 크기 변화 분석)

  • Park, Jeong Jun;Kim, In Dae
    • Journal of the Society of Disaster Information
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    • v.16 no.1
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    • pp.60-69
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    • 2020
  • Purpose: Cavity growth process monitoring is to periodically monitor changes in common size and topography for general and observational grades to predict the rate of common growth. The purpose of this study is to establish a systematic cavity management plan by evaluating the general and observational class community in a non-destructive method. Method: Using GPR exploration equipment, the acquired surface image and the surrounding status image are analyzed in the GPR probe radargram in depth, profile, and cross section of the location. The exact location is selected using the distance and surrounding markings shown on the road surface of the initial detection cavity, and the test cavity is analyzed by calling the radar at the corresponding location. Result: As a result of monitoring tests conducted at a cavity 30 sites of general and observation grade, nine sites have been recovered. Changes in scale were seen in 21 cavity locations, and changes in size and grade occurred in 13 locations. Conclusion: The under road cavity is caused by various causes such as damage to the burial site, poor construction, soil leakage caused by groundwater leakage, waste and ground vibration. Among them, indirect factors could infer the effects of groundwater and localized rainfall.

Acid Drainage and Damage Reduction Strategy in Construction Site: An Introduction (건설현장 산성배수의 발생현황 및 피해저감대책)

  • Kim, Jae-Gon
    • Economic and Environmental Geology
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    • v.40 no.5
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    • pp.651-660
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    • 2007
  • Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

Recycle Possibility of the Stone-Dust in Quarry as Subbase Layer Materials of the Road (도로 보조기층재로서 채석장 석분토의 재활용가능성 분석)

  • Kim, Kyeong-Su;Song, Young-Suk
    • The Journal of Engineering Geology
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    • v.17 no.2 s.52
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    • pp.279-287
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    • 2007
  • An ore of stone obtained from quarry lose its about 60% such as the muck and the stone-dust during the process of making the architectural block, the crushed aggregate and so on. A part of the muck is only reutilized for the crushed aggregate as road pavement materials, while the most of the muck in the shape of powder is mixed with water and then it is deposited in a sludge tank. The muck in the shape of powder is called the stone-dust. If the stone-dust is discharged and sprayed, an ecosystem will have terrible damage because the seepage of surface water, the flow of ground water and the movement of air are not occurred smoothly by packing the void of soils. As the Waste Management Law (2003) in Korea, the stone-dust is sorted out the industrial waste and the most of that is dumped in ground. Therefore, the establishments of an efficient recycling plan are necessary through the improvement of engineering properties of the stone-dust. To investigate the possibility of recycle and improvement for the stone-dust, the stone-dust and natural soils are sampled from six quarries in Korea. The various soil tests are performed by use of the mixed soils with the stone-dust content ratio. As the result of various soil tests, the recycle possibility of the stone-dust is analyzed as subbase layer materials of the roads.

A Study on Design Standards of a median strip in City considering Traffic Safety (교통안전을 고려한 도심형 중앙분리대 설치기준 마련에 관한 연구)

  • Kim, Jong-Min;Kim, Jang-Wook;Noh, Kwan-Sub;Kim, Kyung-Tae
    • International Journal of Highway Engineering
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    • v.14 no.1
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    • pp.35-43
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    • 2012
  • The Government is implementing the safety measures for pedestrian in living zone to decrease the traffic accident casualties in half. It is urgently to study the guideline because it contains to make the guideline of a median strip in City to prevent the violation of central line and jaywalking on the main contents. So, this study analyzed the pedestrian accidents and the violation of central line, and studied the type of a median strip, the installation guideline through studying the minimum crossing. Consequently, this study found out that a median strip which revised the attention inducement stick to decrease jaywalking could not have the strong prevention function of a crash barrier, so if it happens separation after the collision between vehicles, it induced the secondary accidents, and could take negative effects on traffic safety. In consideration of driving safety, this study analyzed that if it installs a median stirp, it has to ensure one meter, and such a thing could prevent the separation of lane or damage of facilities. However, if it is hard to ensure the space because of narrow road width, it could install a median strip in case of installing the road surface mark 0.5m. And the installation of the attention inducement stick or a median strip on the central line could be possible to induce the violation of central line, thus it is desirable not to install only anythings but also raised pavement markers.

Evaluation of Deicing Performance and Effects of Deicers of the Winter Season (동절기의 융빙제들의 융빙 성능 및 영향 평가)

  • Doh, Young-Soo;Lee, Byeong-Duck;Choi, Kwang-Soo;Kim, Kwang-Woo
    • International Journal of Highway Engineering
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    • v.10 no.3
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    • pp.149-158
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    • 2008
  • This study was estimated on performance of deicers, corrosion inhibitors and low corrodible deicer used for removal of snow or ice on the road and on influence on structure. The weight loss rate after freezing and thawing of low corrodible deicer is lower than one of deicer, corrosion inhibitors and these combination. Relative dynamic elastic modulus of all except water, low corrodible deicer and NaCl+JF-1004 was radically reduced after freezing and thawing 150 cycles. And concretes after freezing and thawing were showed severe surface damage. It was found that individual use of low corrodible deicer and corrosion inhibitors had a problem of field application because of lack of early ice melting effect and considerably low durability. Products combined with NaCl was showed rapid weight loss by metal corrosion. Therefore, It will need to circumspectly select combination of deicers having low effect on concrete pavement and bridge if possible.

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The Verification Of Green Soil Material Characteristics For Slope Protection (사면 보호를 위한 녹생토 재료 특성 검증)

  • Lee, Byung-Jae;Heo, Hyung-Seok;Noh, Jae-Ho;Jang, Young-Il
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.6
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    • pp.681-692
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    • 2017
  • In recent years, large-scale construction projects such as road pavement construction and new city construction have been carried out nationwide with by the expansion of social overhead facilities and base on the economic development planning, resulting in a rapid increase in artificial slope damage. The existing vegetation-based re-installation method of the slope surface greening method reveals various problems such as lack of bonding force, drying, and lack of organic matter. In this study, research was carried out using vegetation-based material and environmentally friendly soil additives, were are used in combination with natural humus, Bark compost, coco peat, and vermiculite. Uniaxial compressive strength was measured according to the mixing ratio of soil additives and the strength was analyzed. Experiments were carried out on the characteristics of the soil material to gauge the slope protection properties by using the soil compaction test method wherein the soil and the soil additive materials are mixed in relation to the soil height, the number of compaction, the compaction method (layer) and the curing condition. As a result of the experiment, excellent strength performance was demonstrated in soil additives using gypsum cement, and it satisfied vegetation growth standards by using performance enhancer and pH regulator. It was confirmed that the strength increases with the mixing of soil and soil additive, and the stability of slope protection can be improved.