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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 11, Issue 6 - Dec 2011
Volume 11, Issue 5 - Oct 2011
Volume 11, Issue 4 - Aug 2011
Volume 11, Issue 3 - Jun 2011
Volume 11, Issue 2 - Apr 2011
Volume 11, Issue 1 - Feb 2011
Selecting the target year
Characterization of Fiber Connectivity in Fire-resistant High Strength Concrete using Percolation Theory
Shin, Young-Sub ; Han, Tong-Seok ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 1~6
DOI : 10.9798/KOSHAM.2011.11.1.001
To improve fire-resistance of a high strength concrete against explosive spalling under elevated temperature, fibers can be mixed with concrete to provide flow paths of evaporated water within concrete to the free surface. The fiber-mix concrete approach is effective against explosive spalling when the flow path generated from melting fibers at the elevated temperature is interconnected to transport high pressurized evaporated water from the inside concrete to the free surface. The percolation theory can identify the connectivity of the fibers and provide an estimate of the fire-resistance of concrete by investigating layout of fibers. In this study, the correlation between percolation theory and explosive spalling of fiber-mixed high strength concrete is analyzed and the connectivity of the fiber in concrete is stereologically investigated by using virtual specimens of fiber-mixed high strength concrete.
Peak Factors for Bridges Subjected to Asynchronous Multiple Earthquake Support Excitations
Yoon, Chong-Yul ; Park, Joon-Seok ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 7~13
DOI : 10.9798/KOSHAM.2011.11.1.007
Accurate response analysis of long span bridges subjected to seismic excitation is important for earthquake hazard mitigation. In this paper, the performance of a typical four span continuous reinforced concrete bridge model subjected to asynchronous multiple seismic excitations at the supports is investigated in both the time and frequency domains and the results are compared with that from a relevant uniform support excitations. In the time domain analysis, a linear modal superposition approach is used to compute the peak response values. In the frequency domain analysis, linear random vibration theory is used to determine the root mean square response values where the cross correlation effects between the modal and the support excitations on the seismic response of the bridge model are included. From the two sets of results, a practical range of peak factors which are defined to be the ratio of peak and the root mean square responses are suggested for displacements and forces in members. With reliable practical values of peak factors, the frequency domain analysis is preferred for the performance based design of bridges because of the computational advantage and the generality of the results as the time domain analysis only yields results for the specific excitation input.
Structural Performance Analysis of New Type CFTA Girder Bridge
Lee, Ji-O ; Jeong, Min-Chul ; Park, Kyung-Hoon ; Kong, Jung-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 15~22
DOI : 10.9798/KOSHAM.2011.11.1.015
In this research, static load test is performed to verify the arch effect and structural performance of CFTA(Concrete-Filled and Tied steel tubular Arch) girder, and FE(Finite Element) analysis is performed to investigate validity of the test result. CFTA girder is designed to maximize the benefit of each material, such as steel plate, filled concrete and PS tendon. Static load test is performed based on the frame-analysis result of 12m sample miniature model. The result of static load test is that structural performance and safety of CFTA girder are confirmed and there is different deflection mode with other structural form result from arch effect. FE analysis with ABAQUS is also performed to show the validity of the truck collision safety and static load test.
An Experimental Study on the Comparison of Operating Temperatures in Thermal Detector due to Tunnel Fire
Roh, Hyeong-Ki ; Park, Kwang-Young ; Im, Seok-Been ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 23~27
DOI : 10.9798/KOSHAM.2011.11.1.023
Due to the rapid development of construction technology with effective land utilization in this nation, many tunnels were and are being built across the country. However, the smoke and the heat generated from tunnel fire are the most important critical factors which may results in both massive personal injury and property damage, especially, due to the closed surrounding of the tunnel. Considering this particular nature of the tunnels, this study aims to install a fire detection system using an optic fiber cable to measure the temperature changes, compare, and analyze the resulted values with the times of temperature changes of the sensor by performing fire simulations under the same condition as a real fire test. From the results, it has been found that the temperature sensor detects a fire occurrence and generates an alarm within one minute after ignition for both a real fire test and a fire simulation alike, and also that the characteristics of temperature changes of the sensor has close relations with the speeds of the currents inside the tunnel. In addition, considering the tunnel fires can affect the evacuation efficiency and the fire extinguishing activities of the fire brigade inside the tunnel, the temperature sensor must be able to search and find the locations and directions of the fires correctly.
Factors Affecting Posttraumatic Stress of Emergency Medical Personnels
Baek, Mi-Lye ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 29~35
DOI : 10.9798/KOSHAM.2011.11.1.029
This study not only investigates emergency medical personnel's posttraumatic stress(PTS), social support, work burden, and coping style but also identifies related factors which were exerted influence on PTS and active coping method of emergency medical personnels among the firefighters. The data were gathered from 143 emergency medical personnels who were receiving training. The data were collected by IES-R, consisting of twenty-two questions that determine the level of PTS, method used in Cho's research(2000) that deal with work burden, method used in Oh's article (2006) relating to social support, and sixty-two questions that deals with coping methods. Then the data gathered were analyzed using SPSSWIN 14.0 program. PTS of general characteristics showed significant difference in age, marriage status, education, and position. High risk group of PTS was 74(51.7%). Work burden, active and passive coping method, and three symptoms in PTS are significantly high(p=0.000) in high risk group. PTS was correlated with work burden(r=0.508, p=0.000), active coping method(r=0.375, p=0.000), and passive coping method(r=0.505, p=0.000) but not with social support. Related factors of PTS were work burden(0.371) and passive coping method(0.366). Also related factors of high risk group of PTS were work burden(odds ratio=1.064, 95% confidence interval:1.031-1.103) and passive coping(odds ratio=1.050, 95% confidence interval:1.022-1.080). Related factors of active coping method were PTS(0.392) and social support(0.158). To minimize the PTS of emergency medical personnels, the new policy should decrease their work burden and passive coping method and strengthen the social support to encourage active coping method.
A Study on Meteorological Elements Effecting on Large-scale Forest Fire during Spring Time in Gangwon Young-dong Region
Lee, Si-Young ; Kim, Ji-Eun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 37~43
DOI : 10.9798/KOSHAM.2011.11.1.037
In this study, we analyzed the meteorological elements, when large forest fires were occurred, The rate of precipitation was 13% of annual average precipitation. Especially, the stronger wind speed, lower humidity and rainfall than average annual record were the distinct feathers on the year when large forest fire occurred in east coast area in Kangwon region. The average, maximum and maximum instantaneous wind speed was 5.9 m/s, 11.3 m/s and 20.9 m/s when large forest fires occurred. The average, maximum and maximum instantaneous wind speed on large fire occurred were 1.8 m/s, 3.0 m/s and 6.9 m/s faster than and average wind speed when whole forest fires occurred. The results indicated that the large forest fire occurrence had a close correlation with meteorological elements.
Effect of Weight of Fire-protective Clothing for Physical Balance and Agility after Maximum Physical Activity
Bang, Chang-Hoon ; Huh, Man-Dong ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 45~49
DOI : 10.9798/KOSHAM.2011.11.1.045
The aim of study intends to investigate effect of weight of fire-protective clothing for physical balance and agility after maximum physical activity and to provide the base data for the safety of firefighter. For evaluation of static and dynamic-balance, the closed-eyes foot balance and the beam-walking were performed respectively. For evaluation of static and dynamic-agility, the whole body reaction and the side-step were carried out. This study demonstrates that after maximum physical activity, the weight of fire-protective clothing effects on physical static-balance and dynamic-agility and suggests that it could be useful for actual safety field studies of firefighters.
A Study on the Reinforcement of Bridge Foundation in the Limestone Cavity
Lee, Sang-Chul ; Ryu, Chang-Yeol ; Cho, Kook-Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 51~57
DOI : 10.9798/KOSHAM.2011.11.1.051
Irregular distributions of limestone cavity in Gang-Won province area may cause unexpected accidents from reduced serviceability or failure of structure. It is requested that an appropriate ground reinforcement method should be used to improve bearing capacity of structure, and the method should also be satisfied with environmental requirements. Among several methods used for foundation constructions in cavity area, Rod Jet Pile(RJP) method has been widely used. While the RJP method was used to improve bearing capacity for the railway bridge foundations, water pollutions of drinking water as well as fishery located adjacent to this project area were occurred. The main reason of the water pollution was cement runoff used in cement mortar during injecting material in RJP method. Laboratory tests were performed to prevent water pollution. The compaction mortar method using low movable material was selected for this project. The quality of water at a fishery adjacent to the site and the compressive strength of cores taken from the construction site were measured. Test results show that the water pollutions was minimized, and the average compressive strength of foundation material was over 5 MPa. As a result of this study, compaction mortar method can be used to ensure the bearing capacity of foundation and to prevent environment pollutions.
Dynamic Behavior of Buried Pipelines Constructed by Domestic and USA Specifications
Jeon, Sang-Soo ; Kim, Jae-Min ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 59~66
DOI : 10.9798/KOSHAM.2011.11.1.059
Lifeline Damages induced by earthquake loading brings not only a structure damage but the communication problems by the interruption of various energy utilities such as electric power, gas, and water resources. Earthquake loss estimation systems in USA and Japan, called as HAZUS (Hazard in US) and HERAS (Hazards Estimation and Restoration Aid System), respectively, have been established for the purpose of efficient responding to the earthquake hazard. Sufficient damage records are required to establish these systems. However, there are insufficient data set of damage records obtained from previous earthquakes in Korea. In this study, according to the construction specifications of the pipelines in both Korea and USA, the behavior of both ductile and brittle pipelines embedded in dense sand overlying various soils, such as clay, sand, and gravel were examined with respect to the pipeline characteristics under various earthquake loadings. The applicability of pipeline damage prediction used in HAZUS program to Korea has been investigated.
Analysis of Flow Duration Characteristics due to Environmental Change in Korea River Basin
Lee, Jae-Joon ; Kim, Young-Jun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 67~75
DOI : 10.9798/KOSHAM.2011.11.1.067
The purpose of this study is to evaluate the flow duration characteristics of Nakdong, Seomjin and Geum river due to environmental change. The water level gauging stations of Nakdong, Seomjin and Geum river were selected to analyze the change of flow duration. The construction period of multipurpose dam was considered to analyze flow duration characteristics. As the result of this study, it show that ninety-five day flow, normal flow, low flow and drought flow were increased by multipurpose dam construction at all stations except a Jukpo gauging station. Especially, improved effect of flow duration in downstream part was bigger than that in upstream and midstream part. The coefficients of river regime of Nakdong, Seomjin and Geum river were decreased and also coefficients of flow duration were decreased after the multipurpose dam construction. However decline of coefficient of flow duration was smaller than coefficient of river regime because coefficient of flow duration is less affected by maximum discharge and minimum discharge than coefficient of river regime, It was confirmed that multipurpose dam on upstream and midstream has a useful effect for improving the flow duration characteristics.
Estimation of Probable Maximum Flood by Duration using Creager Method
Kang, Boo-Sik ; Ryu, Seung-Yeop ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 77~84
DOI : 10.9798/KOSHAM.2011.11.1.077
The methods of the rational formula and Kajiyama formula have been widely used for estimating the peak flood for design to all kind of hydraulic structure. However, there are many limitations and we have to apply these methods to ungauged basin. These methods require to calculate the Probable Maximum Precipitation (PMP) before determining the Probable Maximum Flood (PMF). Creager's method (Creager et al., 1945) is a kind of estimation of specipic flood and this method provided nonlinear equations based on relationship between the drainage area and PMF in order to calculate the PMF of multipurpose dams over medium-sized. But this method has not much applied in Korea. Creager's coefficient is not clear about its application because this method has never been applied to dams in Korea. Based on the PMP for rainfull-runoff models with the PMF of small and larger dams in this research, the range and standard of Creager's coefficients with parameters are proposed to apply basin areas in Korea.
GIUH Variation by Estimating Locations
Joo, Jin-Gul ; Yang, Jae-Mo ; Kim, Joong-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 85~91
DOI : 10.9798/KOSHAM.2011.11.1.085
RV-GIUH must be applied at an outlet or a junction of highest order stream of a subbasin because the model was derived for basins following Horton's ordering system. However hydrograph is calculated at various locations which does not fit to the desirable points. Therefore, some guideline is required for RV-GIUH application in practice. This study would like to suggest the outlet location criteria for appling RV-GIUH at un-gauged basin. Locations were selected by moving to upstream from outlet of Sanganmi basin and unit hydrograph using derived and simple RV-GIUH were estimated at each location. As the results, the peaks of RV-GIUH in upstream were exaggerated because of distortion of length ratio and total stream length. To avoid this error, the location must be selected at 60% downstream of highest stream length. To apply RV-GIUH at various places, equations correcting distortion of total stream length were suggested. With the correcting equations, it can be possible that RV-GIUH is applied at 20% downstream of highest stream length. Application and precision of RV-GIUH will be improved through this research.
Functional Improvement of Floating Breakwaters with Long Wave Kinetics
Yoon, Jae-Seon ; Cho, Yong-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 93~99
DOI : 10.9798/KOSHAM.2011.11.1.093
In this study, a series of laboratory experiments are carried out to analyze fluid behaviors around multi-arranged (2 pieces) floating breakwaters with various parameters such as distance between structures, wave periods and steepness. The rate of wave transmission is shown to be affected directly by wave periods of incident waves and the breakwaters with multi-arranged structures show the highest rate of wave protection compared with other cases. The velocity fields around the breakwaters are measured by using the Laser Doppler Velocimetry system. The transmission coefficients are also measured in laboratory experiments. Finally, laboratory observed data are compared with numerical experimental results and analyzed in detail.
Investigation for Optimization of Ultrasonic Soil-Washing Process for Remediation of Diesel Contaminated Soil
Park, Beom-Guk ; Son, Young-Gyu ; Hwang, An-Na ; Khim, Jee-Hyeong ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 101~105
DOI : 10.9798/KOSHAM.2011.11.1.101
Determination of ultrasonic frequency and experimental design approach to optimization of ultrasonic soil-washing process for remediation of diesel contaminated soil were investigated. Ultrasonic frequencies of 35, 72, and 100 kHz were used for determination of optimal frequency.
program was used for experimental design of optimal washing condition. The optimal ultrasonic frequency was 35 kHz. Even though the number of cavitation bubble is little, however cavitation bubbles involving larger energy compared with high frequency was generated. Therefore, the removal efficiency at low frequency was higher than at high frequency. However the input energy has to be considered when the process is applied. The statistical tests from a factorial experiment shows that the application of ultrasound and mechanical mixing are the most important factor for design of an ultrasonic soil washing process. The lab-scale experiments are required to get the optimal condition of ultrasound and mechanical mixing for application of ultrasonic soil washing process.
Study of Degradation of Bisphenol A with
Powder in CPC System
Hwang, An-Na ; Park, Myung-Hee ; Lim, Beom-Guk ; Khim, Jee-Hyeong ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 1, 2011, Pages 107~112
DOI : 10.9798/KOSHAM.2011.11.1.107
In this study, photocatalytic degradation and mineralization of bisphenol A (BPA), which has been listed as one of endocrine disruptors, were carried out in the CPC system using
slurry and UVA irradiation. The degradation efficiency has been investigated under the controlled parameters including initial concentration (5, 10, 20 mg/L), dosage of
(0.1, 0.5, 1.0 g/L), UVA power (0, 80, 120 W) and temperature (0, 20, 30). At 10mg/L of initial concentration, BPA was degraded above 80% after 10min, BPA were degraded 97% and 49% at 20 mg/L and 30 mg/L, respectively. At
dosage was 0.1 and 0.5 g/L, the degradations of BPA showed similar trend and were about 70% after 1 hr, and the degradation of BPA was above 80% after 30 min at 1 g/L of
dosage. The increase of degradation seem to be due to the increase in the total surface area, namely number of active sites, available for the photocatalytic reaction as the dosage of photocatalyst increased. When the UVA power was 120 W, BPA was degraded rapidly above 60% after 10min of reaction time. To investigate the effect of temperature, carried out experiment controlled temperature, there were no significant differences depending on the temperature. After 1hr, the degradation of BPA were 46%, 67%, and 69% at 10, 20 and