• Journal of the Korean Geotechnical Society
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• v.38 no.6
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• pp.41-47
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• 2022

Permeable pavement technology allows the penetration of rainfall into the roadbed, thereby reducing surface runoff and enhancing water quality. The water quality can be improved by adding a filter layer to the permeable pavement. This study analyzes the permeability performance and particulate-matter removal efficiency of a bottom ash-silica sand filter. The performances of five filters with bottom ash and silica sand as the basic materials were evaluated on particulate matter sized 60 ㎛ or smaller. The pure silica sand sample and pure bottom ash sample delivered an average removal efficiency of around 70%. The removal efficiency of the mixed sample was approximately 90%, exceeding the recommended reduction rate (80%) at non-point pollution reduction facilities. In future work, the filter performance should be further verified on permeable pavement.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.12
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• pp.1353-1359
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• 2007

Water quality constituents, and particle size distributions were characterized in urban bridge road runoff, Bridge road runoff contains significant loads of micro-particles, heavy metals and organic constituents. Bridge road runoff was monitored on four sites of four and six lanes bridge road areas along with traffic volume. A total seven storm events were monitored to characterize the bridge road runoff. The quantity of road runoff and quality constituents, including chemical oxygen demand(COD), suspended solids(SS), total nitrogen(T-N), ortho-phosphorus$(PO_4-P)$, total phosphorus(T-P), and particle size distribution were analyzed. The results indicate that the concentrations of SS, COD, T-N and T-P ranges were $35\sim2,390$ mg/L, $40\sim1,274$ mg/L, $0.03\sim21.25$ mg/L, and $0.05\sim4.58$ mg/L, respectively. And the results showed that the mean range of particle size and $D_{90}$ for bridge road runoff were $4.75\sim14.05{\mu}m$ and $17.33\sim58.15{\mu}m$, respectively.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.511-521
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• 2018

Despite the limitations and difficulty in the application of CALINE3 model for air dispersion prediction of roads and tunnels construction businesses in South Korea, the model is being used in all roads construction projects. This study compared the predicted values of CALINE3 and AERMOD model that is suggested by the US EPA, to the values of GRAL model, a Lagrangian particle tracking model developed in Europe, by applying the models to the existing roads of the urban areas. The result showed low relevance to the actual measurement value in the case of CALINE3 model, thus displaying a low trusted value when applying to the urban areas. In the case of using AERMOD model, the predicted values were overly expressed compared to the actual measurement value, thus leading to the need of adding a No2 conversion method to the model in the future. In the case of GRAL model, a Lagrangian particle tracking model, the relevance between the actual and predicted values were high as the model considers the surrounding topography and the buildings all together, thus confirming that the model can be used for air dispersion prediction of the roads in the urban areas. Lastly, the result of this study testing the air prediction models in Jeongneung Measuring Station points that it is necessary for the future studies to expand the testing areas and test the validity of the models continuously.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.173-180
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• 2019

This study was conducted to understand factors affecting TSS and heavy metals transport on the road, parking lot and roof. During storm events, heavy metals, which were mostly attached to TSS, were also transported when TSS was washed off in the road, parking lot and roof. This finding may be supported by the significant correlations between TSS load and total and soluble heavy metals load including Cr, Fe, Cu, and Pb (Pearson r value: 0.52 to 0.73; probability p value<0.01). Generation and transport of TSS and heavy metals were greater in the road and parking lot compared to the roof due to vehicular activities, slope and greater catchment areas of these sites. It was found that TSS transport during peak flows of storm events ranges from 65% to 75% implying that by controlling peak flows, TSS transportation to nearby water bodies may be decreased. Depending on the target TSS and heavy metal reduction, sizing of low impact development (LID) technologies and green infrastructures (GI) such as infiltration trench, tree box filter, and rain garden may be calculated. Future researchers were recommended to assess the limitations of the systems and determine the design considerations for these types of facilities.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.145-154
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• 2018

In this study, three pilot-scale wetland systems were built for treating stormwater runoff from asphalt road. Each of the system consists of a settling tank and a vertical flow wetland packed with 25%, 50%, and 75% woodchip as treatment media. According to the analysis of the distributions of particle size, it was found that solids ranging in size $0.52-30{\mu}m$ were predominant in the stormwater runoff. After 24-hours settling, those coarser than $20{\mu}m$ were significantly detained. Further retention, especially for the finer-sized fraction, occurred in the wetland through internal recirculation during the dry day periods. As a primary media of the wetland, woodchip showed a high filtration and attachment capacity for the particulates in pre-settled stormwater, whereas overall amount of solids in the wetland effluent increased due to the detachment of woody elements from the media. This was observed mainly during the initial 75 days of operation, and the size and detachment rate were found to be strongly related with the woodchip packing ratio. The mechanism involving woody particle detachment was modeled as a first-order form. In addition, water quality factors and operational parameters affecting the detachment were analyzed and discussed.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.111-120
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• 2010

This study evaluated strength properties of recycled asphalt concretes using warm-mix technology. Granite with maximum size of 13mm and penetration grade of 80-100 virgin binder were used for mixing in recycled mixtures. Mix design was performed using 20% and 30% RAP(coarse : fine= 6 : 4) contents. GPC, penetration, absolute viscosity and kinematic viscosity were measured for determining ratio of two warm-mix additives (Evotherm and Sasobit). Low-density polyethylene(LD) used as asphalt modifier for improving stiffness of recycled WMA mixtures in this study. Therefore, a total of 11 mixtures were prepared in this study; 8 warm-mix recycled mixtures(2 RAP contents${\times}$2 warm-mix additives${\times}$2 modifiers), 2 hot-mix recycled mixtures and 1 HMA virgin mixture(control). Deformation strength, indirect tensile strength, moisture sensitivity, permanent deformation by wheel tracking tests were measured out for evaluating fundamental properties of recycled asphalt concretes using warm-mix technology.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.195-202
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• 2011

This study develops a day-to-day dynamics modeling framework, incorporating a consistent drivers' travel time perception behavior and traffic information provision. Descriptive traffic information is updated and provided to the subscribers making a final decision on route choice. Nonsubscribers(not equipped any information devices) are assumed to obtain daily traffic information from their experience or friends or other public agencies. Drivers' route choice behavior is modeled based on boundedly-rational behavior rules. A microscopic traffic simulation model is adopted to evaluate the network system performance. Numerical experiments on a real world network have demonstrated the convergent property of the proposed model and the effectiveness of the consistent perception model.

• Land and Housing Review
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• v.13 no.3
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• pp.125-140
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• 2022

Road Deposited Sediment (RDS) is the solids formed from the wear of road, wear of vehicles, exhausts, and the input of the emissions from various sources out of the roads. RDS is seriously polluted by organic matter, nutrients, and metals. RDS plays an important role as the sink and the transport medium of the associated pollutants because RDS can be carried to the adjacent water system via stormwater runoff. In this regard, the heavy metals in RDS were investigated based on the publications. The contents of the metals in RDS were highly variable. The concentration of Cr, Ni, Cu, Fe, Zn, As, Cd, and Pb in urban RDS in various regions was in a range of 3.16-3,410, 1.15-1,382, 20.2-9,069, 2,980-124,853, 81-2,550, 2.3-214, 0.19-21.3, and 15.21-1,125 mg/kg, respectively. The anthropogenic enrichment of the metals in RDS was confirmed by the high concentration of Cu, Zn, Cd, and Pb. The contents of the metals were higher in industrial and traffic areas than in residential areas, while they were generally increased with decreasing particle size. It is believed that this study's results would contribute to quantifying the metals' load via RDS and establishing control strategies.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.43-52
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• 2014

PURPOSES : To solve problems in current compaction control DCPT(Dynamic Cone Penetrometer Test), highly correlated with various testing methods, simple, and economic is being applied. However, it、s hard to utilize DCPT results due to the few numerical analyses for DCPT have been performed and the lack of data accumulation. Therefore, this study tried to verify the validation of numerical modeling for DCPT by comparing and analyzing the results of numerical analyses with field tests. METHODS: The ground elastic modulus and PR(Penetration Rate) value were estimated by using PFC(Particle Flow Code) 3D program based on the discrete element method. Those values were compared and analyzed with the result of field tests. Also, back analysis was conducted to describe ground elastic modulus of field tests. RESULTS : Relative errors of PR value between the numerical analyses and field tests were calculated to be comparatively low. Also, the relationship between elastic modulus and PR value turned out to be similar. CONCLUSIONS : Numerical modeling of DCPT is considered to be suitable for describing field tests by carrying out numerical analysis using PFC 3D program.

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.405-416
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• 2018

In this research, the distribution of Platinum Group Elements (PGEs) at roadside dust in Daejeon, Korea was examined using an ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) technique. For the quality assurance of the determination, method validation based on its accuracy and precision was conducted using SRM (Standard Reference Material). It was found that the relative errors of Pt, Pd, and Rh against each SRM value were -0.7%, -10.0%, and -20.4%, respectively, while relative standard deviations for three elements were less than 10%. The concentrations of Pt, Pd and Rh in roadside dust averaged as $17.4{\pm}9.2{\mu}g/kg$, $283.6{\pm}20.5{\mu}g/kg$, and $7.3{\pm}2.8{\mu}g/kg$, respectively. The concentrations of Pt and Rh have significantly higher distribution patterns in the dust at roadside and underground parking lot than those in soil of the background or other urban area. The correlation analysis between concentrations of PGEs in roadside dust indicates that the distribution of Pt and Rh concentration were strongly affected by automobile sources.