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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Korean Society of Hazard Mitigation
Journal Basic Information
Journal DOI :
Korean Society of Hazard Mitigation
Editor in Chief :
Moo Jong Park
Volume & Issues
Volume 10, Issue 6 - Dec 2010
Volume 10, Issue 5 - Oct 2010
Volume 10, Issue 4 - Aug 2010
Volume 10, Issue 3 - Jun 2010
Volume 10, Issue 2 - Apr 2010
Volume 10, Issue 1 - Feb 2010
Selecting the target year
Determination of the Allowable Load for Trussed Web Beam
Kim, Myeong-Han ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 1~5
The efficient beam members for modern greenhouse need to be much lightweight with the required flexural and buckling strength. To confirm the applicability and practicality of the trussed web beam recently proposed for column and beam members of greenhouse, the flexural behavior and buckling characteristics were analyzed by the finite element approach. On the basis of analytical studies, the member design process was presented considering the lateral and local buckling behavior. Also, two improved alternatives which were capable of retaining the lateral and local buckling effectively were suggested.
Moment Gradient Factor for Lateral Torsional Buckling Strength of Monosymmetric Stepped I-beam Subjected to Uniform Moment
Gelera, Kathleen Mae ; Park, Jong-Sup ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 7~13
Stepped I-beams having increased moment of inertia at one end (singly stepped beam) or both ends (doubly stepped beams) can often be seen in construction of bridges due to material economy and easy fabrication of the section. This paper presents the results of the parametric study of lateral torsional buckling of monosymmetric stepped I-beams with constant depth subjected to uniform moment. Design recommendations were made based on the finite element results of the models having different combinations of monosymmetric ratio, stepped length ratio, flange thickness ratio and flange width ratio. The proposed approximation is acceptable based on the parameters given having mostly conservative results. The proposed equation can be further used to extend the study to different loading conditions.
Evaluating the Load Carrying Capacity of Aged Bridges in Consideration of the Functional Deterioration of Point Parts
Yang, Seung-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 15~21
Structural analysis used to evaluate the load carrying capacity of a bridge should implement behavioral characteristics similar to the actual behaviors of the structure through loading tests, but it is not feasible in many cases due to the behavioral characteristics of points, inadequate modeling method in structural analysis, errors in loading tests, changes in strength and rigidity resulting from cross-sectional damage, etc. This problem can be more serious if bridge bearings have been damaged or were not installed and, consequently, the bearings do not function properly. This study produced results similar to actual behaviors using a structural analysis model built with support moment derived from the difference
between measured deflection obtained by confining the cantilever segment of a solid beam and calculated deflection under a unrestrained condition. When the load carrying capacity of a bridge in operation was evaluated in consideration of the confinement condition of supports, the result was 15~19% lower than load carrying capacity calculated by the existing method.
A Study on Measuring and Calibration Method using Time Domain Reflectometry Sensor under Road Pavement
Cho, Myung-Hwan ; Lee, Yoon-Han ; Kim, Nak-Seok ; Park, Joo-Young ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 23~30
The research presents moisture content measuring and calibration method of road pavement, especially asphalt concrete pavement for performance evaluation or remaining life prediction using Time Domain Reflectometry(TDR) sensor, CS616 made by campbell INC. Before calibration test of CS616, accomplished a sensor verification tests. Verification test items were covering depth and interference effect of two CS616 sensors, temperature effects between
and compaction ratio effects. Covering depth and interference effects between two CS616 sensors were just small and the effects of temperature and compaction ratio effected a Volumetric Moisture Contents at
under disregard appeared with the fact that was possible. Also, obtained the calibration equation of the subgrade and subbase course,
showed above of all 0.9.
Gradation Curve of Aggregate using Digital Image Process
Hwang, Tak-Jin ; Cho, Jae-Yoon ; Lee, Kwan-Ho ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 31~37
Shape conversion coefficient and equivalent diameter for changing 2D image to 3D image by the Digital Image Process(DIP) have been suggested and modified particle size distribution curve has been showed. Couple of aggregates, like two different marine aggregates and two different crushed stones, have been employed. The measured flatness ratios of each aggregate were 0.30, 0.36, 0.47 and 0.83, respectively. Also, the conversion shape coefficients of each aggregate were determinded as 0.77, 0.78, 0.84 and 0.92. The size of aggregate has been modified by multiplying the shape conversion coefficient and the aggregate size from DIP. The modified gradation curve with modified volume and weight of aggregate has been suggested. Within the limited test results, DIP is one of useful to get the particle shape of aggregate with limitation of measuring errors and to apply the particle distribution curve.
An Estimation Procedure for Concrete Modulus by Using Concrete Strength Relationships in the LTPP Test Sections
Yang, Sung-Chul ; Cho, Yoon-Ho ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 39~46
Concrete strength relationship between various strength properties was presented through experimental data from concretes made from different sources of coarse aggregates and fine aggregates, and different amount of cement contents. In the strength relationship were included compression-flexure, compression-split tension, compression-modulus and flexure-split tension. A total of 61~81 data sets were analyzed while each data set is composed of 3 to 4 experimental test data. Using the proposed strength relations, a procedure to reliably estimate modulus values from the LTPP field test section was suggested. Core specimens were taken from 10 LTPP sections on the expressway as well as 4 sections on the national road. Then compressive strengths and modulus were determined in the lab. Finally concrete modulus was averaged with the estimated values by using the derived relationship and experimental values.
Air-Void Structure of Very-Early Strength Latex-Modified Concrete Using Ultra-Fine Fly Ash
Choi, Pan-Gil ; Park, Won-Il ; Yun, Kyong-Ku ; Lee, Bong-Hak ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 47~53
Very-early strength latex-modified concrete (VES-LMC) was developed with a focus on workability, strength development and long-term durability that would allow for opening a bridge to traffic only 3 hours after concrete placement, which would be useful when repairing concrete bridge deck overlays. However, even though usage of latex in VES-LMC improves the durability, it has a disadvantage that it produces lots of entrained air. Therefore, specific plan is necessary since it is weak for freezing and thawing in air-void structure. In the present study ultra-fine fly ash (UFFA) was used. Test results are follows ; Air content of VES-LMC UFFA (VES-LMC using UFFA) concrete was decreased since major pozzolan reaction was happened in one day. It was also found that total air content of concrete was decreased with pozzolan reaction since air content in 28 days was the same with one day air content. The addition of calcium hydroxide increased entrained air which is smaller than size of 200
. It was effective to improve the air-void structure of VES-LMC since spacing factor can be confirmed as smaller than size of 200
using more than 15% of UFFA.
The effects of compact city development on public transportation commuting -The cases of 54 medium and small-sized cities in korea
Lee, Kyung-Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 55~60
The purpose of this study is to analyze compact city planning indicators that have influence on public transportation commuting of residents in the 54 medium and small-sized cities. In the study, land use and transportation infrastructure of cities and other socio-demographic variables are used as explanatory variables in a causal model. 96,552 subjects from 54 cities in korea are selected as the final sample, and a statistical analysis is carried out by applying Random Intercept Logit Model. Analysis shows that a high level of density and jobs-housing balance in the city results in more public transportation commuting. And higher access to bus and subway station influence commuting, so subway & bus stop are important factors to increase public transportation commuting
An Analysis on the Order of Priority in Disaster Management Policy
Kim, Jin-Dong ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 61~68
Korea is constructing the disaster management system to prevent various disasters and minimize damages. In spite of these efforts, however, Korea lately suffered from a number of diverse disasters. These disasters once again lead to the questions and criticisms concerning the effectiveness of the disaster management system. So research into how to quantify the disaster management system is very significant in securing the right of the people to lead a safe life, keeping human life and properties from being injured. The purpose of this study is to prioritize policies which can be considered for establishing and operating disaster management system. To do that, this study conducts a questionnaire survey, targeting for 282 fire man. The survey includes various factors according to four stages in disaster management process: prevention, preparedness, response and recovery. The method used is AHP(Analytic Hierarchy Process) technique using expertchoice 2000. Results of the analysis are as follows. At the first stage of analysis, prevention is found as the most significant factor. The other significant factors are response, preparedness, and recovery factor in order. At the second stage of analysis, share of role among disaster facilities is the most significant factor. Reorganization of disaster facilities and connection of law are significant in order.
Numerical Analysis for the Pullout Behavior and Failure Mechanism of Ground Anchor
Park, Byung-Soo ; Shim, Do-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 69~76
This study is an numerical study of predicting the behavior of anchor embedded in weathered rocks, subjected to uplift loads, about ultimate pullout capacity and the failure mechanism. Factors influencing the behavior of anchors were investigated by reviewing the data about in-situ anchor tests performing numerical modelling with changing the bondage length of anchor, diameter of anchor body and diameter of tendon, and by correlations between those factors were evaluated to apply them to predict the behavior of anchors. As results of numerical analysis, a linear relationship between bondage length, diameter of anchor body and diameter of tendon with ultimate pullout capacity was obtained on the one hand, from the result of numerical analysis changing the Young's modulus of weathered rock, this parameter was found to influence to load-displacement and ultimate pullout capacity within the range of 10%, which was not so significant to affect.
A Study of Economic Aspects on 3-D Scanning Measurement during Tunnel Construction
Choi, Won-Il ; Park, Geun-Young ; Cho, Kook-Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 77~81
D&B(Drill & Blast) method in tunnel construction requires accurate and rapid measurement of the ground movement, which is essential for feedback analysis. Case study and adaptability of IT technique for tunnel survey are discussed in this paper. The application of laserscannig and existing light wave instrument method in the field of tunnel construction were reported in several advanced country including Austria and Japan. Survey for the shoulder movements by IT survey method was conducted at a subway construction site and the results were compared to the conventional method. Also, the economic aspects of laserscannig method were analyzed using measured data which were categorized by expenses, frequency, interval and period in the field of construction. Therefore IT survey solution may contribute to execute more economic and safe construction
A Experimental Study on the Depth of Scour to Formula Estimated of the Pattern Pier
Baek, Kyung-Won ; Park, Soo-Jin ; Lee, Yeong-Seop ; Choi, Han-Kuy ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 83~90
This study was intended to compare and evaluate the value obtained from the existing formula for calculating the depth of scour and the valey from experimental model through the investigation of hydraulic characteristics and pier data in the area of rivers at Gangwon Province, and the sensitivity analysis, which is a statistical method, of the elements affecting the scour of the pier was carried out. As a result, a deviation between the values of existing formulas and experimental model reached about 1.09%
63.98%, indicating that existing formula was found not to be appropriate at the rivers in Gangwon Province. A sensitivity analysis was carried out based on value obtained from experimental model and consequently, the elements affecting the scour were size of pier accounting for 64% and water depth accounting for 36%. Finally, a formula for calculating the scour of the pattern piers at the rivers in Gangwon Province was developed using the regression analysis.
Decision of the Representative Moving Direction of a Storm Event
Yoo, Chul-Sang ; Park, Chang-Yeol ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 91~102
This study analyzed methodologies for determining the representative direction of a storm event. The mean direction, median direction, and modal direction of von Mises distribution were considered as representative directions. In addition, the results with and without considering the storm moving distance were also compared. As results, the modal directions of von Mises distribution were found to explain the directional characteristics of a moving storm much better than other methods. Also, it was found that the storm moving distance has a significant effect on the determination of representative directions of a moving storm, whose uncertainty can also be decreased significantly by considering the moving distance.
Estimation of Small Hydropower Resources and Development of Geographic Information System
Heo, June-Ho ; Park, Wan-Soon ; Yun, Jung-Hwan ; Jeong, Sang-Man ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 103~110
Small hydropower is one of the many types of new and renewable energy, which South Korea is planning to develop, as the country is abundant in endowed resources. In order to fully utilize small hydropower resources, there is a need for greater precision in quantifying small hydropower resources and establish an environment in which energy sources can be discovered using the small hydropower geographic information system. This study has given greater precision to calculating annual electricity generation and installed capacity of small hydropower plants of 840 standard basins by inquiring into average annual rainfall, basin area and runoff coefficient, which is anticipated to promote small hydropower resources utilization. Small hydropower geographic information system was also established by additionally providing base information on quantified small hydropower resources and analysis function and small hydropower generator status, rivers, basin, rainfall gauging station, water level gauging station etc., all of which were not provided by the domestic hydropower Resources Map System. Established GIS small hydropower energy system can be used to basic information for active uses of small hydropower energy which is scattered to the entire country.
A Study on Water Level Rising Travel Time due to Discharge of Paldang Dam and Tide of Yellow Sea in Downstream Part of Paldang Dam
Lee, Jong-Kyu ; Lee, Jae-Hong ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 111~122
As the Jamsu-bridge and the floodplains of the Han River can be flooded during the rainy season, the exact prediction of the peak flood time is very important for mitigation of flood hazard. This study analyzes the effect of outflow of Paldang Dam and tide of Yellow Sea on the Han River. A target area is from the Paldang dam to Jeonryu gauging station. Water level of Jeonryu as a downstream boundary condition was estimated through multi linear regression analysis with outflow of Paldang dam and tide level of Incheon, because it was influenced by both a tide of Yellow Sea and outflow of Paldang dam. In this study, Water Level Rising Travel Time of the Jamsu-bridge and some floodplains in the Han River are estimated. Also, The second order polynomial expressions for relationships of outflow of Paldang Dam and Water Level Rising Travel Time were developed considering the outflow of Paldang dam and tide of Yellow Sea.
Study on a Scheme to Increase Flood Reduction Effect of Washlands
Baek, Chun-Woo ; Byeon, Chen-Il ; Kim, Do-Hyeon ; Ahn, Tae-Jin ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 123~133
Due to climate change and difficulty in construction of large dam, it is on the increase to use small hydraulic facilities such as washland for the flood control purpose. Since there can be many potential locations for washland in a basin, it is important for determination of optimal location to calculate flood reduction effect of washlands substantially and exactly. In this study, a new scheme to increase flood reduction effect of washlands is suggested. Suggested scheme uses sensitivity analysis of flood reduction effect depending on washland characteristics such as storage volume, spillway elevation and spillway width. The characteristics of the washland is determined by results of sensitivity analysis to maximize flood reduction effect at basin outlet and downstream of a washland. The methodology is applied to Anseong river basin to show its applicability and applied result is compared with those of another studies.
An Experimental Study on Soil Loss Rate of Recovery Soil Technique at High Water Revetment
Chae, Dong-Seok ; Kim, Young-Do ; Park, Jae-Hyeon ; Kim, Chul ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 135~141
Recently, to ensure the stability of flood control, instead of removal of concrete revetment, the vegetation mat method has been widely used on the recovery soil. However, the recovery soil method often failed to be stable against the flood, which caused the economic loss. In this study, the rate of soil loss and the velocity distribution on high water revetment are evaluated by the hydraulic experiments. The maximum difference of the soil loss rate was 52% depending on the vegetation. The reduction of the soli loss rate according to the vegetation is large when the revetment slope is steep. The maximum soil loss rate is 19.5% when there is no vegetation.
Analysis of Design Flood Change for the Small to Medium Size Rivers in Gyeonggi-do
Park, Sun-Hee ; Won, Jin-Young ; Song, Ju-Il ; Yoon, Sei-Eui ;
Journal of Korean Society of Hazard Mitigation, volume 10, issue 2, 2010, Pages 143~149
The river master plan was established every 10 years in Korea. The basin characteristics of 62 small and medium size rivers of which master plans were recently established during the past three years in Gyeonggi-do were investigated, and design rainfalls and design floods in the past and the latest were compared and analyzed. It was predicted that basin data and flood estimating method changed design flood. The quantitative amount of design floods were analyzed for 6 basins like Gungunchen etc. As the results, the increasing factors of design flood were the application of critical duration time, temporal time of rainfall and the increase of CN value. The decreasing factors of design flood were the application of Huff's rainfall distribution instead of Mononobe one and the ARF. The application of critical duration time increased flood about 60% whereas the application of Huff's rainfall distribution method estimated less flood than Mononobe about 62%. Considering critical duration time and changing rainfall distribution were the most important factors of increasing or decreasing design flood. However, trends of flood variation were differently analyzed by factors in 6 basins because characteristics of topography, weather, hydrology and hydraulic were different, now that correlations were not found between factors and flood variation. Flood variation is evaluated by complex effects of factors so new flood recalculated by reasonable methods should be considered as design flood.