간행물

한국도로학회논문집 KCI 등재 International journal of highway engineering

권호리스트/논문검색
이 간행물 논문 검색

권호

제21권 제6호 (2019년 12월) 16

1.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES : Almost every design method for airport concrete pavements considers only traffic loading and not environmental loading. This study proposes a mechanistic design method for airport concrete pavements, that considers both environmental and traffic loading simultaneously. METHODS: First, the environmental loading of concrete pavements in Korean airports was quantified. FEAFAA, a finite element analysis program for airport pavements, was used to calculate the maximum tensile stress (MTS) of the slab, caused by both environmental and traffic loadings. The factors that influence the MTS were identified via sensitivity analysis, and an MTS prediction model was developed using the statistical analysis program SPSS. The ratio of MTS to the tensile strength of slab was calculated using the prediction model. The fatigue model under the AC 150/5320-6E and AC 150/5320-6F standards of the FAA was corrected to make it suitable for the predicted stress-strength ratio. RESULTS : The MTS prediction model and corrected fatigue model were used to redesign the slab thickness and joint spacing of airport concrete pavements originally designed using the AC 150/5320-6D standard, which empirically considers traffic loading only. As a result, different slab thicknesses and joint spacings were redesigned with consideration for environmental loading, specifically the weather conditions of airports. . CONCLUSIONS: The slab thickness and joint spacing can be mechanistically designed at the same time, whereas previously, only the slab thickness was designed, and the joint spacing was determined empirically.
4,200원
2.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: This study proposes a cohesive shrinkage particle model that can be used to simulate a variety of dynamic behaviors and phase changes of construction materials, including road subsidence and debris flow, and phase change curing, via discrete element method (DEM). METHODS : From the perspective of DEM modeling, the water-content-dependent characteristics of soil particles and related modeling techniques are reviewed from literature. The static friction, cohesion, and particle size change are considered as the major parameters that should be reflected in DEM modeling for a more realistic simulation. The relationships of water content with cohesive force and particle radius, as determined from experimental test results in the relevant study, are utilized to develop the cohesive shrinkage model. For each water content value, the snapshot in simulation is compared to that in the experimental study. RESULTS: The numerical simulation shows very good agreement with the experimental test in terms of overall sample radius and thickness change due to drying. However, the local curling of soil sample in the DEM simulation does not perfectly match that in the experimental test. CONCLUSIONS : The cohesive shrinking particle model seems to be good enough for simulating the volumetric and phase changes of soil samples due to drying. However, it seems necessary to consider both bonding and cohesive contact models in DEM modeling because the only cohesive contact model exhibited limitations in the simulation of curling and crack development.
4,000원
3.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES : The Ministry of Land, Infrastructure and Transport (MOLIT) and its subordinate agencies have recently established various policies for the application of BIM and are implementing these policies, and are increasing project orders with the application of BIM. Developed countries where they have earlier adopted BIM provide BIM standards and guidelines at the national level to support BIM implementation by private-sector constructors. Domestic BIM standards and guidelines, however, have been lacking details on upper-level standards that have to be presented by ordering agencies, thereby limiting the practical application thereof. This study aims to provide BIM practice manual development measures to ensure the facilitation of the writing of BIM outputs and their delivery in the road sector. METHODS: This study first analyzed domestic BIM standards and guidelines, and examined BIM processes in the existing BIM guidelines to determine the major works required in each stage of the implementation of road construction projects. Further, the study determined those matters that were required in working BIM but were not specified in existing BIM guidelines. Those derived contents have been reflected in the definition of the configuration system in the table of contents of the BIM practice manual, and in the contents on the road sector, and the details of each configuration system have been specified. RESULTS : The proposed BIM practice manual for the road sector is a technical guide on BIM guidelines published by public ordering agencies, and provides the basic requirements and methods required for the writing of BIM models. Further, the manual provides working procedures and detailed methods for writing BIM to enable working-level staffers on BIM projects to construct BIM data. The proposed BIM practice manual was configured with considerations for domestic civil-sector BIM technology levels and will be further developed and improved according to the development of domestic BIM technology. CONCLUSIONS : In an effort to respond to the changing domestic construction technology environment, and to apply and activate BIM, this study analyzed domestic BIM standards and guidelines, and defined a working BIM manual configuration system and its detailed configuration method. The findings and improvements are presented as a BIM practice manual on development measures in the road sector. This manual is expected to minimize the repetitive trials and errors and design errors in the construction of road-sector BIM models, to improve the productivity and efficiency in the creation of BIM outputs and their delivery, and to enhance the quality and utilization of the outputs. Further, the proposed manual is expected to provide and share information on the practical cases for BIM, to bolster the capabilities of design engineering, to ensure the linkage with relevant agencies, and thus to expand the diffusion of BIM in a virtuous cycle.
4,300원
4.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES : The feasibilities of cohesive elastoplastic contact model and discrete element method (DEM) for asphalt concrete mixture compaction process were evaluated. METHODS : The contact models that were used to simulate the dynamic behavior of construction materials were reviewed. The characteristics of cohesive elastoplastic models were discussed from the perspective of integration with existing contact models. Two asphalt mixtures that were fabricated with specific aggregate gradations and binder contents were compacted according to the Superpave gyratory compaction specification. The parameters for the model were determined via trial-and-error method. The heights of the specimens were plotted with respect to number of gyrations. The results of the laboratory tests were compared to those of numerical simulations. The displacement of particles in asphalt mixture specimen was also visualized to understand the effect of gyratory compaction on asphalt mixture specimen. RESULTS : The DEM model exhibited a significant friction coefficient dependency on compaction degree and slop. The DEM model with parameters determined through trial and error demonstrated reasonable simulation results in terms of specimen height at a gyration number. CONCLUSIONS: Even though a little discrepancy was observed between the results of the experimental test and numerical simulation, a combination of DEM with cohesive elastoplastic contact model seems to be applicable for the simulation of asphalt mixture compaction in laboratory. However, the model needs to be enhanced to be used for more realistic compaction processes, including heat transfer, phase change, and vibratory loading.
4,000원
5.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: In this study, a numerical parametric study was performed to evaluate the effect of angular velocity and weight of wheel, and density of road-bed particles on corrugation development. METHODS : Discrete element method coupled with rigid body dynamics was applied to simulate a wheel-running circular table with variations in independent parameters, such as wheel angular velocity, wheel weight, and particle density. The position profiles for travel distance from origin were compared and analyzed to confirm if the trend from numerical analysis agrees with the analytical solution. RESULTS: The angular velocity of the wheel exhibits a clear inverse relationship with the development of corrugation even though the weight of wheel does not demonstrate clear trends for both long-wave and short-wave corrugation. The density of road-bed particles is observed to have clear proportional effect on corrugation development. The movement of corrugation to the running direction, which was observed in previous research, is also observed for various conditions. CONCLUSIONS : The parametric study using discrete element method with rigid body dynamics clearly exhibits good agreement with analytical solution for initiation of corrugation. The coupled method is confirmed to supply additional information that cannot be delivered by analytical solution only.
4,200원
6.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES : This study aimed to estimate road pavement life expectancy using Bayesian Markov Mixture Hazard Model, to support infrastructure asset management. In addition, the life expectancies for the pavement condition index were compared among regional construction and management administrations. METHODS : Eleven years of National Highway road pavement monitoring data fused with ESAL (Equivalent Single Axle Loads), SNP (Structural Number of Pavement, an indicator of structural capacity), and average low temperature, total rainfall, and de-icing were used for the deterioration modeling. Deterioration modeling was performed through the Bayesian Markov Mixture Hazard Model. RESULTS : The expected life expectancy of the crack was estimated at 12.28 to 18.51 years, rut depth was estimated at 15.93 to 25.3 years, and the International Roughness Index was estimated at 10.44 to 14.33 years. It was also confirmed that the heterogeneity factor proposed in the Bayesian Markov Mixture Hazard Model could be used to analyze group characteristics and differences in the benchmark. CONCLUSIONS: This study provided important information in that it compared the life expectancies and structural characteristics of the pavement condition indexes among regional construction and management administrations. Based on this result, it is expected that a pavement structure design and maintenance strategy suitable for deterioration characteristics among regional construction and management administrations will be established.
4,200원
7.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: The objective of this study is to develop an external lighting traffic sign system for better visibility. METHODS: To develop an external lighting traffic sign system, we selected an installation location and an appropriate angle of view for the luminaire. Using these parameters, we developed an external traffic sign system based on field installation results on the lighting and reflector. The economic benefit is then compared with the cost, an analysis that is necessary for both internal and external lighting traffic signs. RESULTS: Through experiments on the number of luminaires necessary to improve illuminance deviation and visibility, it was confirmed that the illuminance was improved roughly 2 to 3 times by the use of two luminaires. The protruding height (H) of the luminaire is 1.0 m, in consideration of the differences in brightness and driver visibility between the top and bottom, and the angle of view of the luminaire is applied at 120 degrees of high-brightness and low-brightness difference. The lower illuminance is lowered because of the diffusion of light according to the angle of view of the luminaire, due to the longer protruding length of the external lighting type traffic sign. To improve from this problem, the experiment was performed with the application of the reflecting plate, the lower illuminance of the sign was lowered, and the upper and lower illuminance ratio was improved. This solution was confirmed to be effective. As a result of reviewing the economic feasibility of the external illuminated traffic sign system, the cost reduction effect was determined to be about 39.8%. CONCLUSIONS: The results of this study were used to develop a balanced combination of the optimum housing and lighting installation angle for external lighting traffic signs. The use of this technology requires further research under various site conditions.
4,000원
8.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: The objective of this study is to evaluate the durable performance of combined organic and inorganic hybrid mortar as repair material (HRM mortar) for concrete road facilities via comparison with that of cement repair materials (IRM mortar). METHODS : To produce HRM mortars, inorganic materials as binder and 2 mineral fillers were adopted. The ratio of main resin versus hardener was fixed at 1:2. For comparison, IRM mortars made with cement repair materials were also manufactured. Compressive, flexural, and bonding strengths were measured at predetermined periods. For durability assessment, the scaling resistance, freezing & thawing resistance, rapid chloride penetration resistance, and acid attack resistance of those mortars were experimentally monitored. RESULTS: The durability performances of HRM mortars, especially with respect to freezing & thawing, rapid chloride penetration and acid attack, were identified to be much better than those of IRM mortars. This result implies that HRM is a highly promising and versatile material because of its excellent durability. CONCLUSIONS: It is concluded that the application of the combined organic and inorganic hybrid mortars is possibly an option for the repair of concrete road facilities exposed to aggressive environments.
4,000원
9.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES : For compaction control on the subgrade layer, the simple and economical test DCPT (Dynamic Cone Penetrometer Test) is being applied to the Korea Pavement Design Guide. However, compaction control is now difficult and to conduct in the field and is not performed in practice because the compaction degree is evaluated via the field density test as a pretreatment step when the compaction management process is evaluated by DCPT at the same time. Therefore, this study tried to propose a method considering an evaluation for the compaction degree using DCPT, via laboratory tests and field tests. METHODS: The in-situ DCPT tests were conducted according to the types of subgrade soils in the field. Afterward, the field density tests for the compaction degree (R) of field samples and the experiments using DCPT were performed simultaneously in a self-made test container in the lab. RESULTS: Through the DCPT test, compaction degree evaluation from the correlations proposed in this study was determined to be possible. Additional field tests could verify the proposed correlations between compaction degree with DCPT PR on the subgrade. CONCLUSIONS: For the evaluation of the subgrade compaction degree using dynamic CPT, the correlations between compaction degree and DCPT PR on the subgrade layer are proposed from laboratory tests and field tests using DCPT and field density tests.
4,200원
10.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: This study developed a new backfill method for mini trenching. The purpose of this study is to evaluate the performance of the new backfill method in the field. METHODS: In this study, asphalt pavement was created to verify mini trenching. Trenching test sections were then made in various trench widths in the asphalt pavement. The trench widths were 10 cm, 15 cm, 20 cm, and 25 cm. For the trenching test section, a general backfill method and new backfill method (2-layer SCB) were devised and applied. To evaluate the test section, a vehicle loading test and FWD (falling weight deflectometer) test were performed. RESULTS : In the vehicle loading test, the duct vertical strain of the general section was up to 22 times larger than that of the 2-layer SCB section. According to the results of the FWD test, the D0 deflection of the 2-layer SCB section was smaller than that of the general section. These results indicate that 2-layer SCB has a good structural performance. With the use of FWD data, BLI (base layer index) and MLI (middle layer index) were analyzed. BLI is an indirect index for evaluating base layer. The BLI of the 2-layer SCB section was smaller than that of the general section, because the bottom layer (cellular mortar) of the 2-layer SCB is superior to that of the general section. MLI, on the other hand, is an indirect index for evaluating subbase layer. As the trench width increases, MLI increases. The MLI of the 2-layer SCB section was smaller than that of the general section. These results indicate that the damage is relatively greater when the trench width increases and that the 2-layer SCB strengthens a relatively weakened subbase. CONCLUSIONS: In this study, the performance of the 2-layer SCB was analyzed. The results of the study showed that good performance was obtained when 2-layer SCB was applied to a mini trenching section.
4,200원
11.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: The purpose of this study is to analyze characteristics of concentrations of fine particulate matter (PM2.5) among 3 different types of bus stops, specifically partially closed bus stop with front & back partition, partially closed bus stop with back partition, and bus stop with open space (referred to as bus stop types Ⅰ, Ⅱ, and Ⅲ, respectively) at urban roadside, using the Anderson-Darling test as statistical method. METHODS: For the purpose of this study, first of all, data on concentrations of PM2.5 on the 3 types of bus stops at urban roadside were acquired for certain days, with different levels of air quality index (AQI). Secondly, this study accomplished the data processing of removing outliers from acquired data, and the Anderson-Darling test was conducted to estimate probabilities of occurrence for concentrations of PM2.5 in the 3 types of bus stops. RESULTS : The average concentrations of PM2.5 for AQI‘ Very High’for bus stop types Ⅰ, Ⅱand Ⅲare 46-179㎍/m3, 66-194㎍/m3, 42- 134㎍/m3, respectively, and for AQI ‘High’for bus stop typesⅠ, Ⅱ and Ⅲ are 16-71㎍/m3, 26-84㎍/m3, and 14-69㎍/m3, respectively. Furthermore, probabilities of occurrence for concentration levels of PM2.5 in AQI were estimated for given measurement dates using the Anderson-Darling test as statistical method. As a result, for AQI ‘Very High,’the probabilities of occurrence for concentration levels ‘Very High’and‘ High’were determined more likely to occur regardless of bus stop type. With respect to each type of bus stop, the probabilities of ‘Very High’for bus stop type Ⅱ were 93.37% and 98.92%, higher than for the other bus stop types. For AQI ‘High’the probabilities of occurrence for concentration levels‘ Good’were found to be very low, at 0.00% to 3.07%, and occurred mainly for‘ Moderate’and‘ High’in this study. In particular, the probabilities of occurrence for concentration level‘ High’for bus stop type Ⅱwere analyzed to be greater than 90%, compared to those for the other bus stop types. CONCLUSIONS: Based on the result of this study, when PM2.5 is analyzed on certain days, probabilities of occurrence for concentration levels in AQI should be considered for each type of bus stop.
4,300원
12.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: The objective of this study is to evaluate the shear and tensile strength properties of adhesive road studs in asphalt and concrete pavements. METHODS: The 300 mm×300 mm×50 mm rectangular specimens were fabricated using asphalt and concrete mixture for installation of road studs. Four 140-mm-radius circular areas were milled on each specimen with depth of 5 mm to install the adhesive road studs. About 100 g of thermal melting adhesive was applied on the milled area, and then the road stud was bonded onto the surface of the asphalt and concrete mixture. Direct shear testing was conducted at a speed of 5 mm/min on the interface between road stud and asphalt and concrete materials. Tensile strength testing was also conducted on the prepared specimens by applying load with increase of 50 kPa per second. These tests were performed not only in dry condition but also in wet condition to determine the effect of moisture on the shear and tensile strengths. RESULTS : According to the shear testing results, the average shear strength of asphalt samples in dry and wet conditions are 0.509 and 0.234 MPa, respectively. From this testing, the shear strength of wet sample was found to be decreased by 50% with respect to that of the dry sample. Similar trends can be observed on the concrete samples. The average tensile strength of asphalt samples was 0.187 MPa at 1.5 mm of displacement in dry condition. The concrete sample has a 0.222 MPa average tensile strength, which is slightly higher than that of the asphalt sample because of the rough surface characteristics of the concrete sample. CONCLUSIONS: It is determined from this study that the shear and tensile strengths of road stud bonded on the surface of asphalt mixture are slightly lower than those on concrete samples. Regardless of the pavement type, the wet conditioning of the sample can decrease the shear and tensile strength by 50% those of the dry sample. In the future, the quality improvement of adhesive and increase of specific surface area should be considered to improve the bonding property between road stud and pavement surface.
4,000원
13.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES : This paper aims to summarize the findings of studies related to driving safety in long tunnels, and based on these findings, evaluate the risk in driving safety in consecutive tunnels. METHODS: After evaluating the risk in consecutive tunnels, it was verified that driving safety depends on the tunnel length of the consecutive tunnels and the interval between the tunnels. The experimental devices used in this study were a virtual driving simulator and PolyG-I system, measuring, driving speed and among driver's brain waves, theta wave that represents drowsiness or inner conscious states. RESULTS: The results of experiment I showed that, in consecutive tunnels, the variation of speed was higher and the theta wave increased at similar points in comparison with that for long tunnels, demonstrating the risk in consecutive tunnels. The results of experiment II revealed that the variation of speed was the highest in the shortest tunnel (250 m) and the risk of overspeeding was the highest in the longest tunnel (900 m). Additionally, among the consecutive tunnels, the longer tunnels significantly increased the overall theta wave in the tunnels, increasing the risk of drowsy driving. CONCLUSIONS: Of the three scenarios, it was concluded that safety was highest when the tunnel length was set to 600 m.
4,000원
14.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES : This study aims to create a pleasant environment by exploring ITS technology-based reduction measures to manage vehicles on the road, which are the main cause of traffic noise, while identifying the effects of traffic noise and various noise reduction measures. METHODS : A review of the literature identified the matters discussed mainly by reviewing the pre-examination and related statutes of traffic noise management measures at home and abroad. Furthermore, in the field investigation section, the variables affecting traffic noise (traffic volume, large vehicle mix rate, and driving speed) were investigated and the noise impact was analyzed using the three-dimensional (3D) noise prediction model (SounpdPLAN). RESULTS: The noise impact levels of the 3D noise prediction model were identified from various angles, such as horizontal and vertical, and traffic noise management measures for pre-real-time management and related DB utilization measures were proposed. CONCLUSIONS: Unlike the existing traffic noise management measures, which focus on follow-up management measures, it is believed that further research is needed to develop standards and related guidelines that meet regional characteristics by taking into account the characteristics of traffic noise and creating concrete and drawing action plans that can be used in future policies using ITS technology.
4,200원
15.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: This study aims to review the concept of emergency road networks through previous studies and propose a risk and resilience evaluation method for selecting an emergency road network in the event of an earthquake disaster in major highways in Daejeon. METHODS : Risk assessment in consideration of the possibility, exposure, and vulnerability of relatively weak spots and sections in the event of an earthquake disaster on major highways in Daejeon Metropolitan City, and responsiveness, mitigation, and accessibility for urgent response to disaster recovery and management. The emergency road network selection method was proposed by taking into account resilience evaluation. Five levels of links were classified using the P-I method and the overall scores were calculated by considering the weighting factors. RESULTS : In the selected emergency road network, the main roads located near major disaster prevention facilities (public institutions) and response facilities (firefighting and emergency facilities) exhibited a high priority during the earthquake. In addition, highways that emphasized the speed and connectivity between the local emergency road network and the surrounding suburbs exhibited a high priority. CONCLUSIONS : To designate the emergency road network in advance, evaluation of vulnerable facilities and exposure points in the event of a disaster needs to be considered, which can be used to establish a disaster safety plan, thereby ensuring speed and continuity in disaster response.
4,200원
16.
2019.12 구독 인증기관 무료, 개인회원 유료
PURPOSES: This study aims to suggest improvements to the management implementation plan for privately-financed roads. METHODS: We reviewed the establishment procedures and contents of the management implementation plan for expired businesses and analyzed the limits of detailed instructions. Additionally, we created a checklist including the needs of competent authorities to solve practical matters. Furthermore, we introduced the analytic hierarchy process (AHP) method to reflect aspects that were not covered in the detailed instructions. RESULTS: We suggested criteria for the decision-making structure system using the AHP method for efficient decision-making between the operation under government management and contracting-out. CONCLUSIONS: The proposed AHP method can consider other alternatives that are not proposed in the previous detailed instructions. However, further study is required with regard to the redundancy verification and appropriateness of weights of the evaluation items.
4,200원