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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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International Journal of Highway Engineering
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Journal DOI :
Korean Society of Road Engineers
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Volume & Issues
Volume 12, Issue 4 - Dec 2010
Volume 12, Issue 3 - Sep 2010
Volume 12, Issue 2 - Jun 2010
Volume 12, Issue 1 - Mar 2010
Selecting the target year
Development of an incident impact analysis system using short-term traffic forecasts
Yu, Jeong-Whon ; Kim, Ji-Hoon ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 1~9
Predictive information on the freeway incident impacts can be a critical criterion in selecting travel options for users and in operating transportation system for operators. Provided properly, users can select time-effective route and operators can effectively run the system efficiently. In this study, a model is proposed to predict freeway incident impacts. The predictive model for incident impacts is based on short-term prediction. The proposed models are examined using MARE. The analysis results suggest that the models are accurate enough to be deployed in a real-world. The development of microscopic models to predict incident effects is expected to help minimize traffic delay and mitigate related social costs.
Multi-directional Pedestrian Model Based on Cellular Automata
Lee, Jun ; Bae, Yun-Kyung ; Chung, Jin-Hyuk ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 11~16
Various researches have been performed on the topic of pedestrian traffic flow. At the beginning, the modeling and simulation method for the vehicular traffic flow was simply applied to pedestrian traffic flow. Recently, CA based simulation models are frequently applied to pedestrian flow analysis. Initially, the square Lattice Model is a base model for applying to pedestrians of counterflow and then Hexagonal Lattice Model improves its network as a hexagonal cell for more realistic movement of the avoidance of pedestrian conflicts. However these lattice models express only one directional movement because they express only one directional movement. In this paper, MLPM (the Multi-Layer Pedestrian Model) is suggested to give various origins and destinations for more realistic pedestrian motion in some place.
A Case Study on the Traffic Operational Guidance for Temporary Closure of Climbing Lane; Focusing on Nakdong JC at Jungbunaeryuk Expressway
Choi, Yoon-Hyuk ; Lee, Seung-Jun ; Bae, Young-Seok ; Ko, Han-Geom ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 17~28
A climbing lane is installed to separate low-speed traffic from high-speed traffic if drastic traffic capacity reduction is expected due to a large number of vehicles that slow down in the upward section. Existing studies on climbing lanes have focused on the designation, location of starting and ending points, and installation method of climbing lane with regard to road design standards. However, in terms of traffic operation, it was known that the climbing lanes cause traffic congestion due to the increase of traffic volumes. In this regard, this study aims to establish traffic operational guidance as to how much effects temporary closure of climbing lanes can have on traffic improvement according to the volume-capacity ratio, grade, and composition of trucks. A test section of simulated climbing lane was selected in Nakdong JC bound for Masan(136.9K~133.3K, 3.6km, 3.7%) on Jungbunaeryuk expressway to conduct VISSIM analyses, microscopic traffic simulation based on such control variables as traffic volume(v/c), grade and the trucks ratio. As a result of the analyses, it has been found that v/c and the ratio of trucks are the key variables for efficient traffic management of climbing lanes in order to relieve traffic congestion via climbing lane. If ratio of trucks are more than 50% and when v/c would be 0.8, both climbing lane would be closed and non-operated regardless of grade and ratio of trucks when v/c is 1.0. With the increased traffic due to a five-day work week system, continued peak hours during the weekday, increased and various patterns of congestion on expressway, this study would be expected to contribute to facilitating researches on flexible operational standards for road facilities.
Effectiveness Analysis on the Installation of Right-Turn Bypass Lane in Roundabout
Lim, Jin-Kang ; Kim, Kyung-Hwan ; Park, Byung-Ho ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 29~37
This study deals with the Right-Turn Bypass Lane in Roundabout. The purpose of the study is to comparatively analysis the effectiveness questions on the installation of right-turn bypass lane in roundabout. In pursuing the above, this study analyzed after and before of the right turn bypass lane plan by VISSIM software. The right turn bypass lane is formed by control type of yield and control type of joint were compared and analyzed the effects of the operation. The main results analyzed are as follows. First, after Right-Turn Bypass Lane is Installed, the traffic volume rate of the right-turn increasing by average delay time per vehicle is on the gradual decrease, maximum average about 28% with the fact that decreases. Second, control type of yield and control type of joint are both average delay time per vehicle decreasing by the traffic volume rate of the right-turn is on the gradual increase. Control type of joint was analyzed with the fact that has the maximum average about 18% delay decrement efficiency.
Investigation of Minimum Number of Drop Levels and Test Points for FWD Network-Level Testing Protocol in Iowa Department of Transportation
Kim, Yong-Joo ; Lee, Ho-Sin(David) ; Omundson, Jason S. ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 39~46
In 2007, Iowa department of transportation (DOT) initiated to run the falling weight deflectometer (FWD) network-level testing along Iowa highway and road systems and to build a comprehensive database of deflection data and subsequent structural analysis, which are used for detecting pavement structure failure, estimating expected life, and calculating overlay requirements over a desired design life. Iowa's current FWD networklevel testing protocol requires that pavements are tested at three-drop level with 8-deflection basin collected at each drop level. The test point is determined by the length of the tested pavement section. However, the current FWD network-level program could cover about 20% of Iowa's highway and road systems annually. Therefore, the current FWD network-level test protocol should be simplified to test more than 20% of Iowa's highway and road systems for the network-level test annually. The main objective of this research is to investigate if the minimum number of drop levels and test points could be reduced to increase the testing production rate and reduce the cost of testing and traffic control without sacrificing the quality of the FWD data. Based upon the limited FWD network-level test data of eighty-three composite pavement sections, there was no significant difference between the mean values of three different response parameters when the number of drop levels and test points were reduced from the current FWD network-level testing protocol. As a result, the production rate of FWD tests would increase and the cost of testing and traffic control would be decreased without sacrificing the quality of the FWD data.
Improvement of Vehicle Classification Method using Vehicle Height Measurement
Oh, Ju-Sam ; Jang, Kyung-Chan ; Kim, Min-Sung ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 47~51
A vehicle classification data is essential for traffic road planning and pavement. In this study, the vehicle height, vehicle criteria for classification applied to measure the height of the car driving has devised a way to install equipment. It is capable of measuring the vehicle height was confirmed to field experiments, the measurement system is obtained to the vehicle length and height data. In this experiment, results showed the accuracy of 88.6% compared to classification data using the discriminant function obtained from video replaying. The height of vehicle applying the classification criteria can be utilized to determine the vehicle class.
Evaluation of Early age Performance of Geogrid-reinforced Asphalt Pavements
Yeo, Hyun-Dong ; Kim, Gwang-Duk ; Kwon, Soo-Ahn ; Jeong, Jin-Hoon ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 53~60
Geogrid-reinforced asphalt pavement is a pavement type applicable to overlay for repair in addition to new construction. The geosynthetic materials are placed between the asphalt layers to stop or delay propagation of the cracking existing at lower layers and to reduce the rutting. In this study, the cracking, rutting, IRI, and deflection were investigated to compare the performance between geogrid-reinforced asphalt pavement and ordinary or polymer modified asphalt pavement. Based on field conditions, the 11 sections were classified into 3 groups; sections proper to compare, sections with restrictions to compare, sections with difficulties in comparing, and the data was statistically analyzed. Larger resistance to rutting and increased IRI were measured at the geogrid-reinforced asphalt pavement sections comparing to the ordinary or polymer modified asphalt pavement sections. However, the deflections of the pavements were similar and the resistance to the cracking could not be compared because of short pavement lives.
A Study on the Accuracy of Traffic Demand Forecasting in National Highway
Jeon, Woo-Hoon ; Lim, Kang-Won ; Cho, Hye-Jin ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 61~70
The purpose of this study is to analyze the accuracy of traffic volume forecast by comparing an estimated to real traffic volume. For this study, total 10 sections of national highways, which are planned in 1980s and 1990s, were selected and traffic analysis data for highway construction were collected. In addition, targeted 10 sections were categorized into network-related and -unrelated sections. In the analysis of inaccuracy between the estimated and real traffic, for network-related sections, appeared to have lower inaccuracy. As time goes on after traffic open, inaccuracy between the estimated and real traffic appeared to be lower. In various section lengths, the longer the section length, the higher the inaccuracy is. Using 3 years passed data after traffic open, national highway have lower inaccuracy than expressway. However, the traffic analysis according to traffic open time resulted in little change of the inaccuracy.
The Road Cross Section Evaluation With The Rotational Laser Scanner
Lee, Jun Seok ; Yun, Duk-Geun ; Sung, Jung-Gon ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 71~78
The road safety depend on many road factors like vertical alignment, horizontal alignment and road cross section angle. These data are hardly to get with drawings, and the real data are differ from drawings because of road pavement overlay, etc. To get these data, so many time and cost are needed, moreover it is dangerous work in heavy traffic road. In this study we obtained the road safety data with RoSSAV(Road Safety Survey & Analysis Vehicle) of Korea Institute of Construction Technology in accordance with traffic flow, and make analysis of road safety with the vertical alignment, horizontal alignment and road cross section angle data. We derived the safety improvement method in Young-dong accident prone spot and described detail method in this paper.
Analysis on the effectiveness of roundabout at the diamond interchange using VISSIM
Kim, Tae-Young ; Kim, Kyung-Hwan ; Park, Byung-Ho ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 79~86
This study deals with the roundabout installed at the diamond interchange. The goal is to analyze the relative effectiveness of roundabout to signalized intersection. In pursuing the above, this study gives the particular attentions to comparing the performances using VISSIM software. The main results analyzed are as follows. First, the single and double roundabouts are analyzed to have the rapid change of delay in the case of total entering vehicles of more than 2,400pcph for directional rate 10:5:5, 2,800pcph for 10:8:2, and 4,400pcph for 10:2:8. Second, the roundabouts are evaluated to be more effective than signalized intersection in the case of total entering vehicles of less than 4,000pcph for directional rate 10:5:5, and 4,400pcph for 10:2:8. In the case of directional rate 10:8:2, double roundabout of total entering vehicles less than 5,600pcph is analyzed to be more effective than signalized intersection. Finally, the performance of double roundabout is analyzed to be very similar to that of single roundabout in the case of total entering vehicles less than 4,400pcph. However, the double roundabout is evaluated to be more effective than single in the case of total entering vehicles more than 4,400pcph.
Characteristics of Rutting and Moisture Susceptibility of R-EPDM Modified Asphalt Mixtures
Jo, Young-Jin ; Han, Joung-Min ; Noh, Young-Jin ; Choi, Se-Hyu ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 87~92
This study evaluates the laboratory properties of asphalt binder and mixture modified with R-EPDM(Recycling Ethylene Propylene Dien Monometer), which consists of R-EPDM as a main ingredient that is an industrial by-product made by manufacturing waste EPDM below 50 mesh as an additive. Superpave system was used to determine the PG(Performane Grade) and evaluate the property of R-EPDM modified binder. OACs(Optimum Asphalt Contents) of R-EPDM modified asphalt mixtures were determined by Superpave mix design using gyratory compactor and wheel tracking test and moisture susceptibility test were carried out with R-EPDM modified asphalt mixtures at OACs. The results from these tests, rutting-resistance and freezing and thawing resistance by moisture susceptibility of R-EPDM modified asphalt mixtures were superior to one of general asphalt mixtures(AP-5).
Development of Trip Generation Type Models toward Traffic Zone Characteristics
Kim, Tae-Ho ; Rho, Jeong-Hyun ; Kim, Young-Il ; Oh, Young-Taek ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 93~100
Trip generation is the first step in the conventional four-step model and has great effects on overall demand forecasting, so accuracy really matters at this stage. A linear regression model is widely used as a current trip generation model for such plans as urban transportation and SOC facilities, assuming that the relationship between each socio-economic index and trip generation stays linear. But when rapid urban development or an urban planning structure has changed, socio-economic index data for trip estimation may be lacking to bring many errors in estimated trip. Hence, instead of assuming that a socio-economic index widely used for a general purpose, this study aims to develop a new trip generation model by type based on the market separation for the variables to reflect the characteristics of various zones. The study considered the various characteristics (land use, socio-economic) of zones to enhance the forecasting accuracy of a trip generation model, the first-step in forecasting transportation demands. For a market separation methodology to improve forecasting accuracy, data mining (CART) on the basis of trip generation was used along with a regression analysis. Findings of the study indicated as follows : First, the analysis of zone characteristics using the CART analysis showed that trip production was under the influence of socio-economic factors (men-women relative proportion, age group (22 to 29)), while trip attraction was affected by land use factors (the relative proportion of business facilities) and the socio-economic factor (the relative proportion of third industry workers). Second, model development by type showed as a result that trip generation coefficients revealed 0.977 to 0.987 (trip/person) for "production" 0.692 to 3.256 (trip/person) for "attraction", which brought the necessity for type classifications. Third, a measured verification was conducted, where "production" and "attraction" showed a higher suitability than the existing model. The trip generation model by type developed in this study, therefore, turned out to be superior to the existing one.
Behavior Evaluation of Thin Bonded Continuously Reinforced Concrete Overlay on Aged Jointed Concrete Pavement(2)
Ryu, Sung-Woo ; Cho, Yoon-Ho ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 101~110
In this paper, it has been studied about the CRCO to maintain or rehabilitate the aged JCP. The CRCO and JCO was constructed at useless section of Seo-Hae-Ahn express highway in South Korea. The performance evaluation was conducted. Especially, it was focused on the roll of longitudinal reinforced steels inserted into the CRCO. On crack survey results from field construction section, the reflection cracks at joint of the existing pavement occurred in CRCO. However, due to the constraints of longitudinal reinforced steels, crack width was small. Total crack length and quantity in the CRCO more than that in the JCO. And crack spacing in the CRCO was narrower than it in the CRCP. Through the bonding strength test results, if the cold milling and cleaning as well as surface treatment is applied, there will be no debonding problem at interlayer in the early age. From analysis of the horizontal behavior at the joint, the longitudinal reinforced steels constrained crack width which became wider than initial state over time. Also, that steel in the CRCO reduced the horizontal movement due to temperature variation(4 times than that in the JCO). But, if interface is debonded, the roll decreased. Vertical VWG data showed that CRCO did not occur debonding problem at steel location, but there was some problem in JCO. It was confirmed by field coring. The tensile strain appeared in the CRCO, But the compressive strain occurred in the JCO in early age. Through the FWD test result, deflection in the CRCO was less than that in the JCO. And K value in the CRCO was greater than it in the JCO.
Evaluation of Fundamental Properties of Warm-mix Recycled Asphalt Concretes
Kim, Nam-Ho ; Kim, Jin-C. ; Hong, Jun-P. ; Kim, Kwang-W ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 111~120
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
2 warm-mix additives
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.
A Basic Experimental Study on Vibration Power Generation Using Bridge Vibration
Jo, Byung-Wan ; Lee, Yun-Sung ; Kim, Yung-Ji ; Yoon, Kwang-Won ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 121~129
Through this paper, we studied on the basic concept of vibration-induced power generation for urban infrastructures. Since the travelling of automobiles on the bridge cause vibration, it is possible to convert the vibration energy into green-electric energy by utilizing magnetic induction technology. In this paper we define the concept of green-bridge vibration power generation system which contains the concept of magnetic induction technology and propose a vibration power generation device for converting the bridge vibration energy into the electric energy. Also, an experiment was held by applying the vibration power generator on a real bridge. The results showed the applicability and effectiveness of the vibration power generator.
Evaluation of Pollutants Concentrations and Runoff Characteristics in Highway Rest Area
Kim, Jeong-Hyun ; Kang, Hee-Man ; Ko, Seok-Oh ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 131~137
The stormwater runoff from rest areas in highways are known as more polluted compared to highways because of more vehicle activities. This study is performed to find pollutant characteristics in the rest areas in the magnitude of statistical pollutant concentrations during storms. Washoff characteristics of pollutants from rest areas by monitoring of rainfall, runoff rate and runoff samples were evaluated. High concentrations of pollutants in runoff were observed at the beginning of runoff and rapid decrease thereafter, indicating that first-flush effects are clearly occurred. Event Mean Concentrations(EMCs) of TSS, COD, TN, and TP are estimated to be in the range of 31.04-127.11mg/L, 35.5-369.5mg/L, 2.62-9.86 mg/L, and 0.53-1.96mg/L, respectively. Heavy metals in runoff showed relatively high values, possibly due to the abrasion of brake pad or tire while cars are slowly moving for parking. EMCs of total Pb, total Cu, and total Ni are in the range of
, respectively. Pollutant loading per rest area calculated by using EMC, flowrate and target area is also described for each pollutant.
Logging for a Stone Column Using Crosshole Seismic Testing
Kim, Hak-Sung ; Mok, Young-Jin ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 139~145
An integrity testing for stone columns was attempted using crosshole S-wave logging. The method is conceptionally quite similar to the crosshole sonic logging (CSL) for drilled piers. The critical difference in the logging is the use of S-wave rather than P-wave, which is used in CSL, because swave is the only wave sensing the stiffness of slower unbounded materials than water. An electro-mechanical source, which can generate reversed Swave signals, was utilized in the logging. The stone column was delineated using the S-wave travel times across the stone column, the S-wave velocity profile of the crushed stone(
-profile) and that of surrounding soil(
-profile). In the calculation of
-profile of the crushed stone, its friction angle and Ko (coefficient of lateral earth pressure at rest) are recommended to be used. The calculation of the column diameter is not much affected by the values of friction angle and Ko.
A Prediction Model of Resilient Modulus for Recycled Crushed-Rock-Soil-Mixture
Park, In-Beom ; Mok, Young-Jin ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 147~155
A prediction model of resilient modulus(
) was developed for recycled crushed-rock-soil mixtures. The evaluation of
, using the "orthodox" repeated loading tri-axial test, is not feasible for such a large-size gravelly material. An alternative method was proposed hereby using the subtle different modulus called nonlinear dynamic modulus. The prediction model was developed by utilizing in-situ measured shear modulus(
) and its reduction curves of modeled materials using the large free-free resonant column test. A pilot evaluation of the model parameters was carried out for recycled crushed-rock-soil-mixture at a highway construction site near Gimcheon, Korea. The values of the model parameters(
) were proposed as 9618, 0.47, 0.0135, and 0.8, respectively.
Experimental Analysis of Prestressed Approach Slab Behavior
Park, Hee-Beom ; Eum, In-Sub ; Kim, Seong-Min ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 157~164
This research was conducted to analyze the behavior of Single-PTAS (Single Post-Tensioned Approach Slab) under tensioning and environmental loads by performing field tests when the demonstration Single-PTAS was being constructed. The temperature measurement sensors were installed at different depths, and the displacements in the approach slab under environmental loads and tensioning were measured using displacement transducers. As an experimental result, an abrupt change in the longitudinal displacement due to tensioning was not observed. The daily temperature change in the approach slab was negligible where the depth is over about 35cm. The temperature gradient in the approach slab adjacent to bridge was smaller than that adjacent to pavement. The patterns and magnitudes of vertical displacements were directly related to the temperature gradient at the measuring location. The behavior of Single-PTAS was very similar to that of concrete pavement. Therefore, a new design methodology for approach slabs is needed to include the pavement concept and to overcome drawback of current design procedures based on the simple beam concept.
Evaluation of Pavement Rehabilitation Using Precast Concrete Slabs and Slab Connection methods
Cho, Young-Kyo ; Oh, Han-Jin ; Hwang, Ju-Hwan ; Kim, Seong-Min ; Park, Sung-Ki ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 165~174
This study was conducted to evaluate the feasibility of expedite repairing of concrete pavements using precast concrete pavement method and to investigate the effectiveness of slab connection methods. In the demonstration construction, four slabs of jointed concrete pavements were replaced with the precast slabs. First, precast concrete slabs were designed and fabricated, then existing slabs were cut and removed, and finally precast slabs were installed. The slabs were leveled and pockets, holes, and space between the slab bottom and the underlying layer were grouted. From the demonstration construction, details about the design and construction of the precast pavements for repairing of pavements were evaluated. In addition, the slab connection methods such as pocket and hole connection methods were applied in the construction and the slab curling behaviors at the joints that include those connection methods were compared. The results showed that both slab connection methods were applicable, and the hole connection method was superior.
Crash Worthiness of a Post with Clip-type Slip Base Subject to Side Impact
Ko, Man-Gi ; Kim, Kee-Dong ; Kim, Kyoung-Ju ; Sung, Jung-Gon ; Yun, Duk-Geun ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 175~186
When a rigid post is exposed to traffic, it is hazardous not only to head-on impacts but also to side impacts. Clip-type slip base is an effective measure to reduce the severity of head-on impacts and side impacts as well because of its multi-directional release mechanism. Side impact tests were conducted and the results were analysed to demonstrate the hazardousness of a rigid post to a side impact and the crash worthiness of a post having clip-type slip base. For that, side impact test standard was made adapting the NCHRP Report 350, and 820kg-50km/h side impact tests were made for posts of D101.6mm(t=4.2mm) with and without slip base. Additionally, 35km/h side impact to the same post with slip base was conducted to check whether the clip-type slip base release mechanism works properly to the low impact speed. The tests revealed that the rigidly connected post was very hazardous to side impact while the post with the clip-type slip base reduced the impact severity tremendously.
Calibration Method of Vehicle Weight Data from Weigh-In-Motion System According to Temperature Effects
Hwan, Eui-Seung ; Lee, Sang-Woo ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 187~196
The purpose of this study is to develop the calibration method for temperature effects to improve the accuracy of the Weigh-In-Motion(WIM) system for collecting long-term truck weight data. WIM system was installed at a location where the truck traffic volume is high and weight data has been collected from January 2010. In this study, as a calibration measure, the first axle weight of Truck Type 10, the semi tractor-trailer is used based on the fact that the first axle weight is relatively constant, independent of the cargo weight. From this fact, calibration equations are developed from the relationship between the axle weight and the temperature(daily mean, maximum and minimum). Analysis on calibrated weight data shows adequacy of the proposed calibration method. Results of this study can be used to improve the accuracy of the WIM system and to carry out more rational design of pavement and bridge structures.
Study on the Hazardousness of a Rigidly Connected Circular Post and Crash Worthiness of a Circular Post with Release Mechanism for Head-on Impacts Using Impact Simulation
Ko, Man-Gi ; Kim, Kee-Dong ; Kim, Kyoung-Ju ; Sung, Jung-Gon ; Yun, Duk-Geun ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 197~202
Post release mechanism is generally used to reduce the severity of the occupant of an errant vehicle impacting a roadside posts. The 820kg-50km/h head-on impact simulations were made using LS-DYNA program for the posts of 101.6mm Dia(t=4.0mm) with and without clip-type release mechanism. The simulation result was compared with impact test result to enhance the credibility of simulation model. The study shows that the high impact severity (THIV, PHD) and excessive deformation threatens the safety of the occupant when a car impacts a rigidly connected posts, while a post with clip-type slip base reduce the impact severity to a safe level.
A study on performance of the recycle asphalt mixtures using the foamed asphalt method
Park, Tae-Soon ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 203~209
The base asphalt mixtures that used the waste recycle asphalt correcting from the four different overlay construction sites in Seoul city were made using the foamed asphalt method. The sample mixtures were made in different ratio of the recycle asphalt and new asphalt material and the performance of the mixtures of the different ratio was investigated in the laboratory. The laboratory tests includes the Marshall test, the indirect tensile test, the resilient modulus test, the creep test and the wheel tracking test. The test of the recycle foamed asphalt mixtures(RFA) were compared with the those of the recycle hot mix asphalt(RHA) mixtures. The performance of the RFA is comparable to that of the RHA. On the other hand, the indirect tensile strength of the RFA in dry condition is lower than that of RHA and the indirect tensile strength of the RFA in wet condition is much lower than that of the RHA.
Modeling of Friction Characteristic Between Concrete Pavement Slab and Subbase
Lim, Jin-Sun ; Son, Suk-Chul ; Liu, Ju-Ho ; Jeong, Jin-Hoon ;
International Journal of Highway Engineering, volume 12, issue 4, 2010, Pages 211~218
Volume of concrete slab changes by temperature and moisture effects. At that time, tensile stress develops because the slab volume change is restrained by friction resistance between the slab and subbase, and then crack occurs occasionally. Accordingly, researchers have made efforts to figure out the friction characteristics between the slab and subbase by performing push-off tests. Lately, researches to analyze concrete pavement behavior by the friction characteristics have been performed by finite element method. In this study, The friction characteristics between the slab and subbase were investigated based on the friction test results for lean concrete, aggregate, and asphalt subase widely used in Korean concrete pavements. The energy method bilinearizing relation between nonlinear friction resistance and displacement were suggested. The friction test was modeled by 3-D finite element program, ABAQUS, and the model was verified by comparing the analyzed results to the test results. The bilinear model developed by the energy method was validated by comparing analysis results obtained by using the nonlinear and bilinear friction resistance displacement relation as input data. A typical Korean concrete pavement was modeled by ABAQUS and EverFE and analyzed results were compared to evaluate applicability of the bilinear model.