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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Civil Engineers
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Journal DOI :
Korean Society of Civil Engeneers
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Volume & Issues
Volume 34, Issue 6 - Dec 2014
Volume 34, Issue 5 - Oct 2014
Volume 34, Issue 4 - Aug 2014
Volume 34, Issue 3 - Jun 2014
Volume 34, Issue 2 - Apr 2014
Volume 34, Issue 1 - Feb 2014
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Estimation of Dynamic Vertical Displacement using Artificial Neural Network and Axial strain in Girder Bridge
Ok, Su Yeol ; Moon, Hyun Su ; Chun, Pang-Jo ; Lim, Yun Mook ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1655~1665
DOI : 10.12652/Ksce.2014.34.6.1655
Dynamic displacements of structures shows general behavior of structures. Generally, It is used to estimate structure condition and trustworthy physical quantity directly. Especially, measuring vertical displacement which is affected by moving load is very important part to find or identify a problem of bridge in advance. However directly measuring vertical displacement of the bridge is difficult because of test conditions and restriction of measuring equipment. In this study, Artificial Neural Network (ANN) is used to suggest estimation method of bridge displacement to overcome constrain conditions, restriction and so on. Horizontal strain and vertical displacement which are measured by appling random moving load on the bridge are applied for learning and verification of ANN. Measured horizontal strain is used to learn ANN to estimate vertical displacement of the bridge. Numerical analysis is used to acquire learning data for axis strain and vertical displacement for applying ANN. Moving load scenario which is made by vehicle type and vehicle distance time using Pearson Type III distribution is applied to analysis modeling to reflect real traffic situation. Estimated vertical displacement in respect of horizontal strain according to learning result using ANN is compared with vertical displacement of experiment and it presents vertical displacement of experiment well.
Estimation of Live Load Moment for Concrete Unfilled Steel Grid Deck Using Main Bearing Bar Distribution Factor
Park, Young hoon ; Kim, Sung Hoon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1667~1676
DOI : 10.12652/Ksce.2014.34.6.1667
Because of the different flexural rigidity between longitudinal and transverse direction, orthotropic plate theory may be suitable for describing the behavior of composite deck. The ratio of flexural rigidity between longitudinal and transverse direction affects the live load moment. Because of the ratio of flexural rigidity of concrete unfilled steel grid deck has a direct relationship with main bearing bar spacing, it is concluded that the study for the distribution factor which is effected by main bearing bar spacing and aspect ratio is needed. In this study, evaluate the live load moment of concrete unfilled steel grid deck using the AASHTO LRFD Bridge Design Specification and presents the distribution coefficient equation for concrete unfilled steel grid deck.
Comparative Study on the Flexural Performance of Concrete Reinforced with Polypropylene and Steel Fibers
Cho, Baiksoon ; Lee, Jong-Han ; Back, Sung Yong ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1677~1685
DOI : 10.12652/Ksce.2014.34.6.1677
Short discrete fibers compounded with concrete can enhance the tensile resistance and ductility of concrete. Recently, the effectiveness of the reinforcement has increased according to the increasing length of steel fiber. However, the lengthening of steel fiber requires reducing the ratio of the fiber content to remain the workability and quality of concrete. Thus, the present study evaluated the flexural performance of fiber reinforced concrete with less than l.0% fiber volume ratios of steel fiber, 30mm and 60mm long, and polypropylene fiber, being evaluated as a good reinforcing material with chemical stability, long-term durability, and cost effectiveness. Concrete with more than 0.25% steel and 0.5% polypropylene fibers improved the brittle failure of concrete after reaching cracking strength. Concrete reinforced with polypropylene exhibited deflection-softening behavior, but that with more than 0.5% polypropylene delayed stress reduction and recovered flexural strength by 60 to 80% after cracking strength. In conclusion, concrete reinforced with more than 0.75% polypropylene could improve structural flexural performance. In particular, energy absorption capacity of reinforced concrete with 1.0% polypropylene fiber was similar to that with 0.5% and 0.7% steel fibers.
An Experimental Study for Bond Stress between DFRCC and Carbon FRP Plank Used as a Permanent Formwork
Park, Chan-Young ; Yoo, Seung-Woon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1687~1694
DOI : 10.12652/Ksce.2014.34.6.1687
Recently FRP of carbon fibers is utilized as a repairing and reinforcing material for concrete structures. In this study, the bond performance between CFRP planks and ductile fiber reinforced cementitious composites was evaluated in order to develop a new system of concrete bridge deck to take advantage of the FRP planks of carbon fiber using as a permanent formwork. In order to strengthen the bonding between the FRP and cast-in-place concrete, an epoxy resin circulated in the market generally was fitted with a silica sand. The bond stress of ordinary concrete appeared in 2.11~5.43MPa and the bond stress of ductile fiber reinforced cementitious composites DC1 (RF4000) and DC2 (PP) respectively were 3.91~5.60MPa, 2.92~5.21MPa and the average bond stress of DC3 (RF4000+RSC15) and DC4 (PP+RSC15) were 4.80~5.58MPa, 5.57~5.89MPa.
Seismic Fragility Analysis of Reinforced Concrete Bridge Piers According to Damage State
Jeon, Jeong Moon ; Shin, Jae Kwan ; Shim, Jae Yeob ; Lee, Do Hyung ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1695~1705
DOI : 10.12652/Ksce.2014.34.6.1695
In the present study, a total of 275 tested specimens (149 of non-seismically designed and 126 of seismically designed) for reinforced concrete bridge piers with circular section have been investigated in order to suggest drift limits probabilistically according to damage states in seismic fragility analysis. Thus, quantitative damage states of the piers have been evaluated depending on details of the piers. Nonlinear time-history analyses have been conducted for a damaged bridge in terms of using the suggested drift limits. Then, seismic fragility analysis for a reinforced concrete bridge structure has been conducted using both suggested and existing drift limits. Comparative analyses have revealed that median values by the suggested limits is smaller than those by the existing limits. This implies that seismic performance of the structure can be overestimated when the existing limits are used.
Structural Performance of Pre-tensioned Half-depth Precast Panels
Kim, Dong Wook ; Shim, Chang Su ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1707~1721
DOI : 10.12652/Ksce.2014.34.6.1707
Half-depth panels were developed with the merits of CIP (Cast In Place) decks and precast decks for constructability and fast construction. In this paper, details of half-depth panels with pre-tensioning were suggested. For evaluation of structural performance, five half-depth panel specimens were fabricated and static tests were conducted. The cross-sections of these specimens were composed of pre-tensioned half-depth panels and pre-tensioned two-span half-depth panels. Test parameters were the amount of the prestressing force and the longitudinal reinforcements. Static tests on simply-supported slabs showed that ultimate strength was 1.55 times greater than calculated nominal strength. The flexural strength was only 10 % increased and the influence on crack width control was negligible when the member of tendons was increased twice. For two-span continuous specimens, the ultimate strength increased 1.2 times and 1.38 times respectively as the reinforcement was additionally provided. The verified half-depth panels by this research can be effectively utilized for the fast replacement or construction of bridges.
A Study on Measurement of Prestressing Force in PSC Girder using Electrical Resistance Strand Meter
Han, Jong Wook ; Lee, Kyu Wan ; Jung, Dae Sung ; Kim, Choong Eon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1723~1730
DOI : 10.12652/Ksce.2014.34.6.1723
The use of strand wire in structure has been increased by the recent development of construction technologies. Until now, in spite of difficult problems in measuring strand stresses within PSC girders, indirect estimation with a load cell or accelerometer has been often used. In this paper, the electrical resistance strand meter for effective measurement of strand stresses is proposed with experiments considering material, location and thickness of sensor. The reliability and feasibility of the strand meter is enhanced through the experiment with 29.9m PSC girder.
Experimental Study on Structural Behavior of Precast PSC Curved Girder Bridge
Kim, Sung Jae ; Kim, Sung Bae ; Uhm, Ki Ha ; Kim, Jang Ho Jay ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1731~1741
DOI : 10.12652/Ksce.2014.34.6.1731
Recently, many overpasses, highway, and advanced transit systems have been constructed to distribute the traffic congestion, thus small size of curved bridges with small curvature such as ramp structures have been increasing. Many of early curved bridges had been constructed by using straight beams with curved slabs, but curved steel beams have replaced them due to the cost, aesthetic and the advantage in building the section form and manipulating the curvature of beams, thereby large portion of curved bridges were applied with steel box girders. However, steel box girder bridges needs comparatively high initial costs and continuous maintenance such as repainting, which is the one of the reason for increasing the cost. Moreover, I-type steel plate girder which is being studied by many researchers recently, seem to have problems in stability due to the low torsional stiffness, resulting from the section characteristics with thin plate used for web and open section forms. Therefore, in recent studies, researchers have proposed curved precast PSC girders with low cost and could secured safety which could replace the curved steel girder type bridges. Hence, this study developed a Smart Mold system to manufacture efficient curved precast PSC girders. And by using this mold system a 40 m 2-girder bridge was constructed for a static flexural test, to evaluate the safety and performance under ultimate load. At the manufacturing stage, each single girder showed problems in the stability due to the torsional moment, but after the girders were connected by cross beams and decks, the bridge successfully distributed the stress, thereby the stability was confirmed. The static loading test results show that the initial crack was observed at 1,400 kN when the design load was 450 kN, and the load at the allowable deflection by code was 1,800 kN, which shows that the safety and usability of the curved precast PSC bridge manufactured by Smart Mold system is secured.
Effect of Latex and Mineral Additive on Durability of Remicon LMC
Choi, So Yeong ; Choi, Yoon Suk ; Heo, Hyeong Seok ; Yang, Eun Ik ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1743~1751
DOI : 10.12652/Ksce.2014.34.6.1743
It is well known that latex modification can lead to enhancement compressive and flexural performance, tensile bond strength, chloride penetration resistance and freezing-thawing resistance for concrete. For these, many studies for LMC pavement have been widely conducted more than those for conventional pavement concrete. However, due to several problems such as noise and construction cost, new approaches for LMC have been executed to improve the performance of LMC. Recently, Remicon LMC was developed in order to solve the problems of LMC. In this study, the durability of Remcion LMC was compared with latex and mineral additive mixing ratio. From the results, when latex and mineral additive were mixed in Remicon LMC, compressive, flexural and bond strength were satisfied with Korea Highway Construction Guide Specification. And, it showed that the qualitative effect of latex and mineral additive mixing ratio on the durability of Remicon LMC was investigated experimentally. Also, the latex mixed in Remicon LMC must be at least 8%, in order to ensure the durability equivalent or higher than conventional LMC.
Feasibility Calculation of FaSTMECH for 2D Velocity Distribution Simulation in Meandering Channel
Son, Geunsoo ; You, Hojun ; Kim, Dongsu ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1753~1764
DOI : 10.12652/Ksce.2014.34.6.1753
Numerical flow simulation models in the riverine environments have been widely utilized for analyzing flow dynamics in various degrees in researches and practical applications. However, most of the simulated results have been validated based on the data from indoor experimental models or very limited in-situ measurements. Therefore, it has been required to more accurately validate the performance of the numerical models in terms of the detailed field observations. In particular, it was also hard to validate the performances of the existing numerical models in the real meandered river channels that encompass more sophisticated flow and geometric structures. Recently, advancements of the modern flow measuring instrumentations such as acoustic Doppler current profilers (ADCPs) enabled us to efficiently acquire the detailed flow field in the broad range of river channels, thus that it became to be possible to accurately validate any numerical models with the field observations. In this study, based on the detailed flow measurements in a actual meandered river channel using ADCP, we validated FaSTMECH model in iRIC in terms of water surface elevation, which is relatively new but began to get highlighted in the research areas. As the validation site, a meandering channel in River Experiment Center of KICT was chosen, which has 6.5 m of width, 0.38m of flow depth, 1.54 m3/s of flow discharge, 0.61 m/s of mean flow velocity, and 1.2 of sinuosity. As results, whereas the FaSTMECH precisely simulated water surface elevation, simulated velocity field in the bend did not match well with ADCP dataset.
Applicability Evaluation of Probability Matching Method for Parameter Estimation of Radar Rain Rate Equation
Ro, Yonghun ; Yoo, Chulsang ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1765~1777
DOI : 10.12652/Ksce.2014.34.6.1765
This study evaluated PMM (Probability Matching Method) for parameter estimation of the Z - R relation. As a first step, the sensitivity analysis was done to decide the threshold number of data pairs and the data interval for the development of a histogram. As a result, it was found that at least 1,000 number of data pairs are required to apply the PMM for the parameter estimation. This amount of data is similar to that collected for two hours. Also, the number of intervals for the histogram was found to be at least 100. Additionally, it was found that the matching the first-order moment is better than the cumulative probability, and that the data pairs comprising 30 to 100% are better for the PMM application. Finally, above findings were applied to a real rainfall event observed by the Bislsan radar and optimal parameters were estimated. The radar rain rate derived by applying these parameters was found to be well matched to the rain gauge rain rate.
Prediction of Local Scour Around Bridge Piers Using GEP Model
Kim, Taejoon ; Choi, Byungwoong ; Choi, Sung-Uk ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1779~1786
DOI : 10.12652/Ksce.2014.34.6.1779
Artificial Intelligence-based techniques have been applied to problems where mathematical relations can not be presented due to complicatedness of the physical process. A representative example in hydraulics is the local scour around bridge piers. This study presents a GEP model for predicting the local scour around bridge piers. The model is trained by 64 laboratory data to build the regression equation, and the constructed model is verified against 33 laboratory data. Comparisons between the models with dimensional and normalized variables reveals that the GEP model with dimensional variables predicts better. The proposed model is now applied to two field datasets. It is found that the MAPE of the scour depths predicted by the GEP model increases compared with the predictions of local scours in laboratory scale. In addition, the model performance increases significantly when the model is trained by the field dataset rather than the laboratory dataset. The findings suggest that apart from the ANN model, GEP model is a sound and reliable model for predicting local scour depth.
Sensitivity Assessment of Meteorological Drought Index using Bayesian Network
Yoo, Ji-Young ; Kim, Jin-Young ; Kwon, Hyun-Han ; Kim, Tae-Woong ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1787~1796
DOI : 10.12652/Ksce.2014.34.6.1787
The main purpose of this study is to assess the sensitivity of meteorological drought indices in probabilistic perspective using Bayesian Network model. In other words, this study analyzed interrelationships between various drought indices and investigated the order of the incident. In this study, a Bayesian Network model was developed to evaluate meteorological drought characteristics by employing the percent of normal precipitation (PN) and Standardized Precipitation Index (SPI) with various time scales such as 30, 60, and 90 days. The sensitivity analysis was also performed for posterior probability of drought indices with various time scales. As a result, this study found out interdependent relationships among various drought indices and proposed the effective application method of SPI to drought monitoring.
A Method of Estimating Conservative Potential Amount of Groundwater
Chung, Il-Moon ; Kim, Nam Won ; Lee, Jeongwoo ; Lee, Jeong Eun ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1797~1806
DOI : 10.12652/Ksce.2014.34.6.1797
By far, groundwater management has been conducted by 'safe yield' policy based on the estimation of annual average of groundwater recharge throughout the world. However, as groundwater recharge show spatiotemporal variation, dynamic analysis must be carried out to evaluate the sustainable groundwater resources. In this study, an integrated surface-groundwater model, SWAT-MODFLOW was used to compute the spatial distribution of groundwater recharge in Gyungju region. Frequency analysis is adopted to evaluate the existing values of potential amount of groundwater development which is made by the 10 year drought frequency rainfall multiplied by recharge coefficient. The conservative methods for estimating recharge rates of 10 year drought frequency in subbains are newly suggested and compared with the existing values of potential amount of groundwater development. This process will promote the limitations for existing precesses used for computing potential amount of groundwater development.
Estimation of Post Evaluation Index of Natural Disaster Prevention Projects using Structure Equation Modeling
Heo, Bo Young ; Song, Jai Woo ; Yoon, Sei Eui ; Lee, Seung Oh ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1807~1814
DOI : 10.12652/Ksce.2014.34.6.1807
Natural disaster has been hard to prevent the occurrence of itself, thus in order to reduce the economic damages and loss casualties, it is important to be prepared in cases that the disasters should occur in advance. Interest of the related project to prevent various natural disasters has been grown along with an investment in Korea. Along with this movement, when investments related to natural disaster prevention projects were built on, the post evaluation that can verify the ripple effects of those investments on the community should be emerging as an essential task. For evaluating the effects of public investment projects such as natural disaster prevention projects in this study, the related researches would continue through qualitative analyses, for example, cost-benefit analysis. Even the qualitative analysis alone cannot fully explain the effects of those projects, the diverse methods of analyzing and evaluating those effects might not have been presented in those fields. For the post evaluation of natural disaster prevention projects through the qualitative analysis, this study derived subjects that had effects on the post evaluation of natural disaster prevention projects. Also, employing the structural equation modeling (SEM), the causation between post evaluation subjects and the effects of projects were quantitatively analyzed, and the weighting factors of evaluation items were calculated respectively. Based on these results, post evaluation index formula was proposed for the natural disaster prevention projects in Korea.
Estimating Geotechnical System Response Probability of Internal Erosion Risk in Fill Dam using Event Tree Analysis
Noh, Kyung-Lyun ; Lim, Jeong-Yeul ; Mok, Young-Jin ; Jung, Young-Hoon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1815~1829
DOI : 10.12652/Ksce.2014.34.6.1815
Recently frequent collapse of old fill dams has taken place, which increases social awareness in the safety of the infrastructure. Fill dams in Korea has been incautiously regarded as safe once the fill dam is considered to have a full capacity to retain a conservative design flood determined by government authorities. However, developed foreign countries has been managing their fill dams by introducing systematic risk assessment techniques over a long period of time. In this study, the system response probabilities of the deteriorated old fill dams in Korea were systematically evaluated and analyzed by using the internal erosion toolbox based on the event tree analysis technique. The probability of the existence of flaw and the magnitude of the hydraulic gradient through a potential crack can significantly influence the geotechnical system response probability. The results of this study show that the probability of the existence of flaw and the magnitude of the hydraulic gradient through a potential crack can significantly influence the geotechnical system response probability and the risk of the deteriorated fill dam can be quantitatively assessed.
Preparation of Probabilistic Liquefaction Hazard Map Using Liquefaction Potential Index
Chung, Jae-won ; Rogers, J. David ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1831~1836
DOI : 10.12652/Ksce.2014.34.6.1831
Probabilistic liquefaction hazard map is now widely needed for engineering practice. Based on the Liquefaction Potential Index (LPI) calculated from liquefied and non-liquefied cases, we attempted to estimate probabilities of liquefaction induced ground failures using logistic regression. We then applied this approach for the regional area. LPIs were calculated based on 273 Standard Penetration Tests in the floodplains in the St. Louis area, USA and then interpolated using cokriging with the covariable of peak ground acceleration. Our result shows that some areas of
, due to soft soil layers and shallow groundwater table, appear probabilities of ground
Designing Questionnaires for Better Reliable Survey: Case Study of Using Railway Safety Culture Survey Data
Lim, Kwangkyun ; Kim, Sigon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1837~1844
DOI : 10.12652/Ksce.2014.34.6.1837
The study of safety culture estimate has received a wide attentions in many other industries, rather in the contexture of railroad stands at an initial phase. A factor analysis and internal reliability test were conducted to check if the survey results are reliable by looking at how the factors are dimensioned and how the questionnaires are sub-grouped in accordance with such factors, and further if there are any other common attributes being extracted as a new factor. The designed 5 factors were expanded to 7 through the test, and they were renamed accordingly. The questionnaires are reorganized according to the new 7 factors. It implicates that thorough investigation of the common attributes is important in reducing the gaps between interviewers' and interviewees' understanding. Moreover, the results of internal reliability test represent the new design of questionnaire is reasonably acceptable with the high reliable values. We expect such approaches can be applied for the railway culture survey study to be more reliable and applicable.
Formulation and Evaluation of Railway Optimal Alignment Design Model
Kim, Jeong Hyun ; Shin, Youngho ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1845~1850
DOI : 10.12652/Ksce.2014.34.6.1845
Railway operators have given a lot of efforts to determine the railway route of the minimum cost. In order to determine the optimal alignment, the alignment should be allocated satisfying the design criteria on various geographical condition with the minimum earth works. The determination of the optimal railway alignment is a kind of combination optimization because that must consider various design elements. This study developed a numerical model to determine the optimal railway alignment with the minimum construction cost. The problem was analyzed by the genetic algorithm, and the concept of the optimal alignment was established with the results from the analyses. The methodology was applied to a fictitious rail construction section and the result was evaluated. This methodology is meaningful considering the fact that the cost for energy is greater than that of the construction.
A Study on Calculation of Sectional Travel Speeds of the Interrupted Traffic Flow with the Consideration of the Characteristics of Probe Data
Jeong, Yeon Tak ; Jung, Hun Young ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1851~1861
DOI : 10.12652/Ksce.2014.34.6.1851
This study aims to calculate reliable sectional travel speeds with the consideration of the characteristics of the probe data collected in the interrupted traffic flow. First, in order to analysis the characteristics of the probe data, we looked into the distribution of the sectional travel times of each probe vehicle and compared the difference in the sectional travel speeds of each probe vehicle collected by DSRC. As a result, it is shown that outliers should be removed for the distribution of the sectional travel times. However, The comparison results show that the sectional travel speeds from the DSRC probe vehicles are not significantly different. Finally, based on the distribution characteristics of the sectional travel speeds of each probe vehicle and the representative values counted during a collection period, we drew the optimal outlier removal procedure and evaluated the estimation errors. The evaluation results showed that the DSRC sectional travel speeds were found to be similar to the observed values from actually running vehicles. On the contrary, in the case of the sectional travel speeds of intra-city bus, it was analyzed that they were less accurate than the DSRC sectional travel speeds. In the future, it will be necessary to improve BIS process and make use of the travel information on intra-city buses collected in real time to find various ways of applying it as traffic information.
A Study on the Re-examination of Parking Requirements for Discount Stores and the Utilization Plan of Parking Space
Jung, Hunyoung ; Lee, Hyeryeong ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1863~1871
DOI : 10.12652/Ksce.2014.34.6.1863
This study conducted parking demand-supply analysis of 13 big discount stores' in Busan using qualitative and quantitative methodologies. Based on the analysis, we reexamined the parking requirements in discount stores and suggested effective use plan of established parking lots. We found that all big discount stores in the study had more parking spaces than actual parking demands. Also, there are differences of parking occupancy rate by their location types. Third, even if the minimum standard for parking provision in the stores is reduced by up to 20%, they would be adequate to respond current parking demands. Thus, we suggest to consider different parking standards depending on location types. Finally, in order to utilize surplus parking spaces, this study suggests to examine whether parking with various purposes besides shopping is permitted or not.
Expressway Travel Time Prediction Using K-Nearest Neighborhood
Shin, Kangwon ; Shim, Sangwoo ; Choi, Keechoo ; Kim, Soohee ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1873~1879
DOI : 10.12652/Ksce.2014.34.6.1873
There are various methodologies to forecast the travel time using real-time data but the K-nearest neighborhood (KNN) method in general is regarded as the most one in forecasting when there are enough historical data. The objective of this study is to evaluate applicability of KNN method. In this study, real-time and historical data of toll collection system (TCS) traffic flow and the dedicated short range communication (DSRC) link travel time, and the historical path travel time data are used as input data for KNN approach. The proposed method investigates the path travel time which is the nearest to TCS traffic flow and DSRC link travel time from real-time and historical data, then it calculates the predicted path travel time using weight average method. The results show that accuracy increased when weighted value of DSRC link travel time increases. Moreover the trend of forecasted and real travel times are similar. In addition, the error in forecasted travel time could be further reduced when more historical data could be available in the future database.
Deduction on The Problems and Improve The Way of The Successful Bidder Determination Method for Turnkey·Alternative Bid Construction
Park, Hong-Tae ; Lee, Yang-kyu ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1881~1891
DOI : 10.12652/Ksce.2014.34.6.1881
Full system of turnkey deliberation committee in 2010 was abolished and permanent Deliberation committee was introduced. So far, ordering organization selected the best method suitable for the design and comprehensive evaluation method in the turnkey bid construction. Comprehensive evaluation method have bid price design score coordination, weighted basis, the best design approach fixed amount, five successful bidder decision method in addition. Design deliberation branch committee in the successful bidder decision way configured and operated branch members of special design consultation committee, But main agent changed from committee deliberation pull system to permanent committee deliberation, as well as and The lobby burden was not improved. This similar to the past at the portion of the design deliberation and the way of the design deliberation in the turnkey bid construction. Therefore it is necessary to improve the design deliberation system. In other words, design score and technology competition should be adapted to determine a successful bid. This study suggested the operating system of the design deliberation, the decision method problems of the successful bidder and ways to improve the design deliberation.
Interaction Analysis between Construction Business Indicators and Business Performance Indicators of Specialty Contractors providing Labors
Kim, Nam-Sik ; Lee, Dong Wook ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1893~1899
DOI : 10.12652/Ksce.2014.34.6.1893
This study is to suggest strategies of specialty contractors that provide labors oriented engineering service by interaction analysis between construction business indicators and business performance indicators. For specialty contractors that mainly provides labor oriented engineering service, the amount of construction orders imposes lasting impact to the turnover ratio of current assets supposedly because they are operating current assets to secure labor. In other words, this type of specialty contractors are focused on mobilization of labor not materials or equipment. So, it is determined that they will be able to increase revenue by operating current assets to address current liabilities and labor mobilization.
Development of BIM based Maintenance Management Prototype System for Wastewater Treatment Plant
Um, Dong-Yong ; Choi, Jae-Ho ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1901~1910
DOI : 10.12652/Ksce.2014.34.6.1901
Current domestic and overseas BIM practice and research efforts show very few examples that design and construction BIM data could be successfully used for efficient operation and maintenance (O&M) of infrastructure in particular. This study takes public wastewater treatment plant requiring an enhancement of operation and maintenance capability into account to develop a prototype BIM-based maintenance management system. The system is designed and implemented following a typical system development procedure and validated by the system outputs per four scenarios being considered to be main maintenance activities: The research results are expected to contribute to the upgrade of current wastewater treatment plant maintenance level, which is more demanded as water-related regulation and policy direction changes to region-based large scale O&M and asset management adoption, and overseas market participation.
Workspace Generation and Interference Optimization Algorithm by Work-type using 3D Model Object in a Construction Project
Kim, HyeonSeung ; Moon, HyounSeok ; Kim, ChangHak ; Kang, LeenSeok ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1911~1918
DOI : 10.12652/Ksce.2014.34.6.1911
The increase of input resources, such as labor and equipment, in a construction project causes workspace interference between activities and it influences on the productivity and quality of construction activities. To solve this problem, many studies related to the workspace interference have been performed, however they verified the workspace concerning with only the geometric location of activities or generated the shape of workspace by a whole object concept not separated units of detailed operations. It is difficult for project manager to reasonably analyze the workspace conflict, because the size of workspace cannot reflect the characteristics of an activity and input time of a resource. This paper presents a methodology that can generate three-dimensional models in order to optimize the workspace shape and size by considering with the characteristics of each activity and input time of each resource. The suggested method can be used for the active BIM system that optimizes the workspace conflict without additional construction duration and for the searching algorithm of optimized moving path for construction equipment.
Resilience Assessment of Dams' Flood-Control Service
Kim, Byungil ; Shin, Sha Chul ; Kim, Du Yon ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1919~1924
DOI : 10.12652/Ksce.2014.34.6.1919
Recently, due to the climate change, the frequency and intensity of extreme rainfall events have been continuously increased in regions of South Korea. As a consequence, safety issues have been raised especially in the hydrologic safety of old dams designed and constructed by the old standards. In general, for improving hydrologic safety of existing dams, two options are considered: 1) raising dam crest; and 2) constructing or expanding an emergency spillway. In this process, the main criteria of alternative selection are overtopping possibility and cost efficiency of each alternative. This approach is easy to implement but it is subject to major limitation for the proper evaluation of alternatives, overlooking downstream flood damages by any controlled flow of water that is intentionally released from dams to eliminate the possibility of overtopping. Therefore, this study suggests a framework for evaluating the dam safety strengthening alternatives in terms of a comprehensive flood control by applying the concept of resilience. The case study shows that the resilience-based evaluation framework which considering downstream flood damages is effective in the selection of dam safety strengthening alternatives.
A Study on Development of Diagnostic Index for Rural Areas
Mo, Hye-Ran ; Park, Hyung-Keun ; Jo, Jin-Hee ; Lee, Han-Soo ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1925~1935
DOI : 10.12652/Ksce.2014.34.6.1925
Initiatives for balanced growth are centered on urban centers and strictly based upon focused areas and quantitative economics, and thus have rather facilitated the urbanization while deteriorating rural areas' competitiveness. Although huge supports have been made by the central government to address this issue, the effects are very low, due to the limitation of top-down approaches. Recently, however, the demand of differentiated policies for rural communities increases while the necessity of diagnostic index tailored for individual municipalities is also highlighted. The present study investigates diagnostic indices discussed in the preceding studies and derives optimum ones suitable for rural area evaluation. To this end, an index pool was constructed and a set of indices was developed through experts interview and factor analysis. It is expected that the indices help planners effectively diagnose rural areas, and contribute to expand the applicability of 'Customized Diagnostic Technologies.'
A Study on the Mechanized Construction for Common Ducts in a Road Tunnel
Moon, Kyoung-Sic ; Kim, Sung-Keun ;
Journal of The Korean Society of Civil Engineers, volume 34, issue 6, 2014, Pages 1937~1944
DOI : 10.12652/Ksce.2014.34.6.1937
In recent years, common ducts have been installed and operated in the sidewalls of tunnels to prepare for emergencies in tunnel construction and maintenance. The installation of common ducts is done mainly by humans. Problems with cost increases are inherent in tunnel construction by humans due to the safety risks and the economic inefficiency of humans performing construction activities. Among the problems that arise are poor illumination due to the use of temporarily installed electricity, the risk of accidents due to the confined workspaces, and workers avoiding work tasks because of the poor environment in tunnel. Ideas for solving these problems were developed using a value engineering (VE) process, and mechanized construction was identified as a promising solution. To verify the effectiveness of mechanized construction of a common duct in tunnels, experimental construction work was carried out, and mechanized construction was proven to directly improve the constructability and economic efficiency of common duct construction. In addition, reducing human involvement in common duct construction in tunnels is expected to improve safety, and because of the continuous concrete placement technique used, the finish and appearance of the ductwork are improved.