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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 15, Issue 6 - Dec 2015
Volume 15, Issue 5 - Oct 2015
Volume 15, Issue 4 - Aug 2015
Volume 15, Issue 3 - Jun 2015
Volume 15, Issue 2 - Apr 2015
Volume 15, Issue 1 - Feb 2015
Selecting the target year
An Experimental Study on Bending and Seismic Performance of New Concept Hybrid Composite Beam
Kim, Sung Bae ; Kang, Min Joung ; Cho, Seong Hyun ; Kim, Sang Seup ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 1~12
DOI : 10.9798/KOSHAM.2015.15.4.1
Recently, high rise buildings and long span buildings are being constructed, studies on composite structure systems have been progressing in various fields. Therefore, this study suggested the new concept hybrid composite beam and performed the monotonic and cyclic tests to evaluate the bending and seismic performance of the new concept hybrid composite beam by creating 6 bending specimens and 2 beam-to-column connection specimens. The bending performance test results showed that the capacity of the beam was stably increased in proportion to the depth of beams and the thickness of steel plates. Also, enough maximum moment was secured compared to nominal moment. The seismic performance test results showed that the maximum moment is above the plastic moment and the connection is intermediate moment frame.
Improvement Plane of the Facilities Management Manual to Prevent safety Accidents in School
Moon, Sang-Deok ; Ock, Jong-Ho ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 13~22
DOI : 10.9798/KOSHAM.2015.15.4.13
The purpose of this study is to derive the improvement direction of school facilities management manual that is currently being used for school safety accidents prevention to provide basic data for future research directions for the safety of school facilities. The study was performed qualitatively through focus group interviews of facilities expert group, facility administrators group and safety researcher group, focusing on the manual of the education office in the form of a checklist. Main findings derived from the interviews are as follows: 1) Most of the manual are for visual inspections so that it may lead to cursory facility inspection and the configuration is complicated, so an integrated management system using smart devices needs to be developed. 2) Safety management training is required for facilities managers, students and school staffs. 3) It is effective for disaster accident prevention but not suitable for safety accidents that occur during school life. 4) Management of the design phase is required for prevention of school safety accidents, and safety accident management database is needed for development of the design factors that can be applied to the design development stage.
Development of a Rainfall Time Distribution Considering Characteristics of Temporal Variability of Extreme Rainfall Events
Cho, Hyungon ; Kim, Gwangseob ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 23~29
DOI : 10.9798/KOSHAM.2015.15.4.23
In this study, a new approach to design the time distribution of probable rainfall is suggested to reflect the characteristics of the temporal variability of extreme rainfall events. Time of rainfall concentration and quantile characteristics of the intense rainfall period are analyzed to form the time distribution of designed storms. The developed approach was applied for Seoul to verify its applicability with Huff method, Yen & Chow method, and SCS method. Traditional approaches have limitations that the temporal distributions of rainfall using Huff method and the Yen & Chow method are too smooth to reflect extreme storms. The temporal distributions of rainfall using the SCS method is over concentrated at center. The suggested method demonstrated that it illustrated well of the characteristics of time distribution of extreme rainfall events.
Analyzing the Effects and Costs of Flood Protection Measures at the Urban Catchment Scale
Park, Changyeol ; Shin, Sang Young ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 31~43
DOI : 10.9798/KOSHAM.2015.15.4.31
Extreme weather and urban development have increased flood disaster risk. This study sets flood protection measures at the urban catchment scale and analyzes the effects and cost of the measures. Three scenarios to mitigate flood risk are developed by considering drainage system improvements, water storage installations, and building flood protection measures. The costs of measures and flood reduction effects were compared by each scenarios. The result shows that structural measures have effective for the design rainfall, yet it is not effective for the local heavy rainfall. Also, the cost-effectiveness of building flood protection measures increases remarkably to reduce the residual risk of flood damage. This result indicates that, as local heavy rainfall increases, a combined set of flood protection measures at the catchment scale could be helpful to mitigate urban flood risk more fundamentally.
Hydrologic Risk Analysis Based on Extreme Drought Over the Korean Peninsula Under Climate Change
Kim, Nam-Sung ; Kim, Jong-Suk ; Jang, Ho-Won ; Lee, Joo-Heon ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 45~52
DOI : 10.9798/KOSHAM.2015.15.4.45
This study analyzed the regional characteristics of extreme drought events in each of the medium-scale basins in the Korean Peninsula by using the Standardized Precipitation Index(SPI), one of the typical drought indexes, and analyzed hydrologic risk by season and basin in consideration of the exceedance probability of all the observational data. According to the results of estimating SPI with the observational rainfall data (1976-2010) and analyzing severe droughts' time and space characteristics as well as tendencies, spring droughts are more serious in the Korean Peninsula. In addition, according to the results of analyzing average hydrologic risk by using 4 GCMs for five major rivers' basins in the Korean Peninsula, about short-term mid-term droughts, basin regions weak for droughts are expected to increase in the Korean Peninsula. It is expected that the method for analyzing basins' hydrologic risk in consideration of extreme droughts suggested here in this study will show high applicability in predicting droughts in the Korean Peninsula according to the climatic change and establishing practical coping strategies.
An Inter-comparison of Active and Passive satellite Soil Moisture Products in East Asia for Dust-Outbreak Prediction
Kim, Hyunglok ; Choi, Minha ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 53~58
DOI : 10.9798/KOSHAM.2015.15.4.53
In this study, three of satellite soil moisture datasets were inter-compared using Global Land Data Assimilation System (GLDAS) soil moisture over East Asia in summer (June, 2013) to evaluate soil moisture data for global-scale analysis. The applied satellite sensors are Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) on Soil Moisture and Ocean Salinity (SMOS), Advanced Microwave Scanning Radiometer 2 (AMSR2) on GCOM-W, and Advanced Scatterometer (ASCAT) on MetOp-A. While the ASCAT soil moisture was found to be most correlated with GLDAS soil moisture in the non-desert parts of study area, SMOS-retrieved soil moisture data showed most reliable result in dry regions(desert and semi-desert). In the future study, soil moisture derived from SMOS will be uses for dust-outbreaks prediction research.
Comparison of Characteristics and Spatial Distribution Tendency of Daily Precipitation based on the Regional Climate Models for the Korean Peninsula
Kim, Jungho ; Park, Moojong ; Joo, Jingul ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 59~70
DOI : 10.9798/KOSHAM.2015.15.4.59
This study compares the quantitative characteristics and the spatial distribution tendency of daily precipitation data depending on the regional climate models based on the HadGEM2-AO (coupled atmosphere ocean model of Hadley centre global environmental model version 2) and RCP 4.5/8.5 scenarios. For this purpose, HadGEM3-RA, RegCM4, SNURCM, GRIMs, and WRF models were used to make the climate change ensemble scenario data for 2021~2090 years. According to the results from the quantitative comparisons in this study, it is found that the difference of amount of precipitation, the number of days with precipitation, and daily maximum precipitation are obviously different depending on the regional climate models. When considering time series of years, an average difference among the regional climate models dominantly affects overall time series trend in terms of annual precipitation, annual number of days, and average daily precipitation. In the results of spatial distribution tendency, the trend is decided by amount of daily precipitation forecasted in both area of east coast and of south coast, also, the characteristics of the regional climate models could be classified by spatial distribution tendency of the regional climate models.
Characteristics of Forest Fires at Yeongdong in Gangwondo since 1990s
Kim, Seung-Soo ; Lee, Myung Woog ; Lee, Jong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 71~77
DOI : 10.9798/KOSHAM.2015.15.4.71
The incidence and the area of forest fires at Yeongdong in Gangwon-do were increased in 2000s compared to 1990s. However, few research have tried the increase of forest fires depending on the effect of the variation of weather on meteorological factor. Precipitation, duration of precipitation, and relative humidity at Yeongdong were decreased during warning period of forest fires in 2000s, whereas mean temperature and days of minimum humidity were increased, and days of precipitation and mean wind velocity did not much change. To see the effect of the incidence of forest fires, multiple regression analysis was applied for dependent variable (occurrences and area of forest fires) and independent variable (precipitation, duration of precipitation, relative humidity, days of minimum humidity, mean temperature and mean wind velocity). The analysis results showed that the incidence of forest fire was highly affected by days of minimum humidity and mean wind velocity, and the area of forest fire was affected by mean wind velocity.
A Study of Capacity Planning for Urban Sediment Control Device
Kal, Byung Seok ; Lee, Jung Min ; Kang, Du Kee ; Kim, Ji Hye ; Jeon, Byoung Hoon ; Park, Kwang Hee ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 79~86
DOI : 10.9798/KOSHAM.2015.15.4.79
Recently, the urbanization aspects lift the foot and around the settlements in the valley while it increases the risk of the need of large scale landslides and debris flow. In this study, we review the storage device design capacity for controlling urban runoff sediment. Capacity for control was calculated by dividing the ordinary management capacity and sediment runoff sediment sediment spill disaster management capacity. Normal capacity is used to manage the sediment amount was calculated based on RUSLE official capacity was needed during a disaster is determined by the scenario.
Estimation of Runoff Coefficient through Infiltration Analysis by Soil Type
Lee, Jaejoon ; Kwak, Changjae ; Park, Heeseob ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 87~96
DOI : 10.9798/KOSHAM.2015.15.4.87
Some existing methods of runoff coefficient have a problem to produce subjective value such a runoff coefficient in rational formula. In this study a new method to estimate the runoff coefficient is suggested through the infiltration analysis based on the comparative results of the existing runoff coefficient method. The effect of rainfall intensity and soil characteristics to runoff coefficient is also analyzed by the FFC-COBRA model and effective rainfall separation method based on NRCS CN. Parameters affected to estimate runoff coefficient are chosen, and effects of each parameter are analyzed after applying various cases.runoff coefficient is simulated after supplying the condition of land use and soil type at the actual watershed(Seolma-cheon catchment) area for determining suitability of new method to estimate the runoff coefficient. This result shows that runoff coefficient in this study is not only in the range of runoff coefficient, but also over the upper limit of 0.10~0.22 at 'forest, etc' from ASCE. Therefore, runoff coefficient in rational formula has to modify an upward adjustment in Korea. A new method to estimate runoff coefficient by infiltration analysis can be used practical purpose in domestic circumstances.
Development of Scenarios and Correlated Response Measures to Mt. Baekdu Volcano Eruption
Park, Jae Eun ; Kim, Hye Won ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 97~106
DOI : 10.9798/KOSHAM.2015.15.4.97
In recent years, signs of a forthcoming Mt. Baekdu volcano eruption such as earthquakes, generation of volcanic gases, and rising temperature of spring water around the mountain have increased. If the Mt. Baekdu volcano were to erupt at a similar magnitude of that which occurred 1,000 years ago, the impact of its damage would affect not only the surrounding areas of Mt. Baekdu, such as China, North Korea, South Korea, and North East Asia, but also other regions around the world. To cope with such a mega-disaster, it is necessary to secure contingency capabilities and disaster preparedness against various possible scenarios. Accordingly, the present study aims to identify the potential damage and implications of such a volcano disaster, as well as the issues related to response measures, through a case analysis of local and international large volcano disasters. The analysis will evaluate the features of volcano eruptions in each case and the contingency capabilities that were in place in order to establish a Mt. Baekdu contingency system to pre-emptively cope with volcano disasters. Furthermore, the present study analyzes the damage effects of possible situations resulting from a volcano disaster using causal loop diagrams. Four scenarios of a Mt. Baekdu volcano eruption were developed based on the above analysis results, and major contingency tasks for each stage of the eruption (start, expansion, peak, and extinction) according to the scenarios were proposed.
Identification on Carbon Oxide and Smoke Release Change of Aging Wire Cables
Park, Youngju ; Lee, Haepyeong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 107~113
DOI : 10.9798/KOSHAM.2015.15.4.107
In this study, outer cover of temperature aging(used for 29 years, 14 years, 10 years) cables were prepared for comparative thermal characteristics and retardant characteristics to predict combustive pattern of power cables(CV-Cable) that are being used in sealed environment of common utility tunnel. ISO 5659(smoke density), UL 94(flame retardancy), and NES 713(toxic gas) standards were followed for tests for analysis of smoke generation characteristics and flame retardant characteristics. As result of research, total smoke release of 29 passed years, 14 passed years, and 10 passed years were shown a
, respectively in which tendency of increasing total smoke release was shown as used years increased. Also, maximum smoke density was identical to 924Dm by passed years and was shown to be 6.16 times higher than the smoke density performance standard of flame retardant cables which is 150Dm or lower. Toxic index was shown to be 2.7, 1.7, and 0.6 for 29 passed years, 14 passed years, and 10 passed years, respectively in which 29 passed year cable showed more than 4 times higher toxic index that 10 passed year cable.
A Study on the Vertical Fire Spread of Buildings(Focusing on Fire Plume Behavior in Vertical Shafts)
Shin, Yi Chul ; Park, Kye Won ; Yoo, Yong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 115~121
DOI : 10.9798/KOSHAM.2015.15.4.115
Model experiments are conducted on a vertical shaft with openings spaced uniformly in the vertical direction along the vertical shaft and on a vertical shaft where one opening is present in the bottom floor and another one floor above. Study of these models helps to elucidate phenomena such as the stack effect by working from fundamental knowledge of the behavior of hot air flows in vertical shafts. The following results were obtained: (1) the temperature distribution within the vertical shaft decreases from the lower part toward the upper part inside the vertical shaft; and (2)
have a largely proportional relationship, independent of the opening conditions and the position of the fire source. Furthermore, a prediction formula for the temperature distribution inside the vertical shaft is derived from the results.
Numerical Study on the Prediction Method of Flashover in a Compartment
Sung, Kun Hyuk ; Choi, Moon Soo ; Hong, Sung Ho ; Park, Kye Won ; Ryou, Hong Sun ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 123~128
DOI : 10.9798/KOSHAM.2015.15.4.123
In building fires, irradiation from walls and the fire plume increases burning rates, then fire spreads throughout a compartment within a few minutes due to flashover phenomena. Many researchers have experimentally suggested empirical correlations and conditions for the flashover which applications are limited in specific spaces or vents. Therefore, it is necessary to investigate prediction of the flashover using numerical results. The objective of this study is to numerically investigate the prediction method of flashover by estimating oxygen concentrations and mean flame surface at the compartment which size is
. In the results, flashover occur at 70s and the minimum required heat release rate is about 4.14 MW.
A Study on the Fire Resistance of the Fire Damper
Choi, Dong Ho ; Seo, Hee Won ; Park, Soo Young ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 129~133
DOI : 10.9798/KOSHAM.2015.15.4.129
On the domestic side, a fire damper must be installed on the position that the duct for ventilation and air conditioning penetrates a fire compartment. This fire damper closes automatically in fire condition within a given period and prevents the flame and smoke spread. But there are no performance criterion and evaluation method for evaluating the fire resistance of the fire damper. Therefore there is a possibility that the fire spread through the duct, due to the fire damper having no fire resistance performance. In this study, the domestic fire damper was assessed with respect to the flame and smoke spread performance and the basic information for performance criterion and evaluation method was suggested.
A Research for Detour Simulation of Reaction Risk Factor
Park, Il Gyu ; Kim, Jin Su ; Rie, Dong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 135~139
DOI : 10.9798/KOSHAM.2015.15.4.135
In line with the building becoming larger, higher and deeper, risk of life safety has been increasingly growing. The law on performance-based design took effect beginning in 2007 to enhance life safety. Risk assessment requires fire analysis program and evacuation simulation. Evacuation simulation uses
algorithm makes possible the shortest-path evacuation but is not able to detect risk factors and bypass evacuation which results in unstable evacuation. Though it may be able to reduce the evacuation time by passing risk factors, practical simulation for spatial safe evacuation is unachievable. This study is intended to use MAS program that makes possible bypass evacuation by detecting risk factors, thereby performing simulation that leads to safe evacuation for the people.
A Study on the Necessity and Plan of On-site Flame Resistant Inspection System Improvement
Kim, Hwang Jin ; Lee, Sung Eun ; Kim, Hae Hyung ; Roh, Young Sup ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 141~145
DOI : 10.9798/KOSHAM.2015.15.4.141
According to the regulation, interior materials of a Specific Fire fighting property that can cause casualties when fire breaks out should be treated with flame resistant. When the interior used woods and plywoods, a flame resistant treater applies the flame resistant paint on-site and has to submit the sample to the district fire station for its performance test. In many cases, however, the sample submitted does not match the one used on-site, requiring improvement of the flame resistant inspection system. Therefore, the study suggests a non-destructive on-site inspection using FT-IR and XRF as a way to identify problems occurring from the current flame resistant inspection system and address them.
An Experimental Verification on the Long-Term Performance of FRP Reinforcing Bars using Mechanical Anchorage System
Oh, Hongseob ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 147~154
DOI : 10.9798/KOSHAM.2015.15.4.147
This paper is dealt with an experimental results to examine the tensile strength, long-term performance such as the fatigue and tensile creep performance of GFRP and AFRP reinforcing bar. The anchorage method for test on the tensile and long-term performance was adopted with compression type mechanical anchorage system based on the ASTM specification. From the cyclic loading test on the AFRP and GFRP reinforcing bar, the fatigue endurance limit on the two million loading cycles of two different bars are almost 25% of initial tensile strength. The creep rupture test on GFRP bar was conducted and the creep rupture does not occur if sustained stress is limited to 55% of the short term strength.
Embankment Dams as a Protection Against Vibrations
Kim, Dong Woo ; Huh, Young ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 155~162
DOI : 10.9798/KOSHAM.2015.15.4.155
Due to the increased requirements of industrial facilities with respect to prevalent ground motions and to establish more effective anti-vibration measures, reflecting soil-embankment dam interaction is required so that the transfer characteristics of vibration induced by a embankment dam can be well identified. The same holds for urban areas with the always increasing impact of traffic of all kinds on residential areas. Sources of vibrations might be other industrial sites, road and rail traffic, among others. Usually, before vibrations are considered as a problem, noise protection measures have already been implemented in the project., therefore noise barriers are a common object along railway tracks, designed to absorb or reflect sound. They are made from virtually any kind of materials like concrete, alloy, steel, and timber. Occasionally, soil embankments are used as barriers, too. Numerical investigations, presented in this paper, show that at the same time, the latter can also act effectively as a vibration barrier.
Numerical Analysis of Blast-Resistant Capacity of Beam-Column Connections
Lim, Kwang-Mo ; Yoon, Young-Soo ; Lee, Joo-Ha ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 163~168
DOI : 10.9798/KOSHAM.2015.15.4.163
As the increase of explosive accidents and terrorism, demands of blast-resistant capacity in structures would be increased to prevent those situation. Therefore, various studies on blast-resistant structures should be performed. In this study, behavior of beam-column connections is investigated. Base specimen was designed according to the design criterion of beam-column connections. To determine the effects of reinforcement details, flexure, shear and diagonal bar were considered as variables. LS-DYNA, nonlinear finite element program, is selected to the numerical analysis of specimens. The analysis results included failure shape of specimens, deflection, support rotation and stress of reinforcements. In conclusion, specimen which was reinforced with additional flexure bars did not show significant differences as contrasted with base specimen. The diagonal reinforcements are more effective to resist the blast loads than additional flexure reinforcements because safety of connection was enhanced due to the transfer of plastic hinge region in case of reinforcing diagonal bars. In the specimen which is reinforced with additional shear bars, outstanding behavior was observed. In the structures subjected to blast loads, therefore, it is should be considered to not only flexural performance but also shear forces.
Development of Load Carrying Capacity Evaluation Model Based on Bridge Frequency Response
Roh, Hwasung ; Ryu, Minkwan ; Park, Kyung-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 169~176
DOI : 10.9798/KOSHAM.2015.15.4.169
The current method evaluating a load carrying capacity of bridges requires numerical structural analysis model and vehicle passing test in field on the bridges. Here, the numerical model such as finite element model of the bridges needs to reflect their current health state each evaluation time. Also, the field test requires a traffic closing, which frequently leads to traffic jam. Furthermore, the peak impact factor should be decided considering all possible vehicle speeds on the bridges. However, such all vehicle speeds cannot be considered since the testing-truck driver cannot make these all vehicle speeds during the test. Therefore, in this study, a new model is proposed as an alternative to the current method, which is based on the frequency-peak impact factor response spectrum and requires the fundamental frequency of bridges. This paper explains in details the framework of the model, using a simply-supported beam bridge as an example.
Hazard Assessment of Post-Fire Debris Flow Induced by Rainfall
Chung, Jae-won ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 177~183
DOI : 10.9798/KOSHAM.2015.15.4.177
Wildfires denude vegetation on hillslopes, reduce soil permeability. and produce water-repellent soils that increase surface runoff. This process consequently increases soil erosion and soil movement during rains, and it makes burned areas more susceptible to debris flows. For appropriate debris flow mitigation strategies in burned areas, it should be prioritized to identify the areas with debris flow potential. This paper presents statistical models to estimate debris flow volumes in burned areas, based on existing data measured from the western United States Debris flow hazards was then mapped using the estimated volumes and probabilities of debris flows. The study area is located in California, U.S. where wildfires occurred in September 2014. Its debris flow hazards were assessed in response to three design rainfalls(2-, 10-, and 25-year recurrence intervals). To determine if statistical models can be applied to Korea, it is necessary to measure and compile data of post-fire debris flows. When the perimeters of burned areas are provided, debris flow hazards can be promptly mapped for making effective mitigation decision.
Characteristics of Engineering Properties in Rock According to Weathering
Byun, Ji-Hwan ; Hong, Seungseo ; Yoon, Hyung-Koo ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 185~192
DOI : 10.9798/KOSHAM.2015.15.4.185
The Korea peninsula is surrounded by the sea on three sides and thus, the rock is easily weathered due to salt. Furthermore, the external force, erosion and thawing-freezing are also influence on the weathering of rock. The objective of this study is to estimate the characterization of weathering caused by the chemical and mechanical factors by using elastic wave. The specimen is extracted by drilling machine in the field of Icheon, Gyeonggi-Do of tunnel construction site and five specimens are selected to perform the experiment. The samples are fitted into a cylindrical shape for enhancing the measurement of elastic wave. Chemical and mechanical affections are performed by using salty water of high concentration and slake durability test, respectively. The initial average P-wave and S-wave velocity are 3828 m/s and 2211 m/s and then the P and S-wave velocity is reduced to 2601 m/s and 1371 m/s. And the porosity of rock increases from 0.59%~1.95% to 0.46~1.43% due to the weathering. The relationship between elastic wave velocity and weathering index is also suggested and thus, the result may be applied to provide the degree of weathering by using elastic wave.
Mechanical Properties of Porous Polymer Concrete Used Volcanic Ash as Filler for Permeability Pavement
Kim, Youngik ; Park, Sungyong ; Lim, Hyuntaek ; Kim, Jungmyeon ; Lee, Chungwon ; Kim, Yongseong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 193~201
DOI : 10.9798/KOSHAM.2015.15.4.193
Most roads are paved with impermeable materials such as asphalt concrete and cement concrete, problems arise such as increased flooding due to rainwater flowing into city rivers and the depletion of underground water. In recent years there has been a great deal of ongoing research concerning water permeability and drainage in pavements in an effort to prevent flood damage and secure underground water resources. Accordingly, in this research, a porous polymer concrete was developed for permeable pavement by using unsaturated polyester resin with a high binding force, recycled aggregate as coarse aggregate, volcanic ash, fly ash and blast-furnace slag as filler, and its physical and mechanical properties were investigated. Regardless of the type of filler and amount of binder in use, the standard void ratio of 8% specified in the mixture of permeable asphalt was exceeded in any and all mixes, and the void ratio tended to decrease as the amount of binder increased. In PC-VA, PC-FA and PC-BS mixes, compressive strength and flexural strength increased as the amount of binder increased, and the standard compressive strength for permeable concrete of 18 MPa was exceeded. In PC-VA, PC-FA and PC-BS mixes, the permeability coefficient of the porous polymer concrete depending on the amount of binder was
, respectively. In all mixes after 300 cycles of freezing-thawing, no change occurred to the surface of the porous polymer concrete, regardless of the amount of binder.
A Simplified Analysis Model for Seismic Analysis of Pile-Supported Cylindrical Liquid Storage Tank Considering Fluid-Structure-Soil Interaction
Kim, Jae-min ; Son, Il-min ; Kang, Bo-rim ; Yun, Chung-bang ; Chung, Myung-jin ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 203~214
DOI : 10.9798/KOSHAM.2015.15.4.203
In this paper, a couple of simplified analysis models are proposed for seismic response analysis of LNG storage tank including dynamic effects of the FSSI (Fluid-Structure-Soil Interaction). For this purpose, a closed-form added mass function is proposed for cylindrical tank based on the Haroun's added mass model for a flexible tank. The proposed model is verified with the Haroun's flexible broad and tall benchmark tanks. In addition, a shear building model is employed to facilitate seismic wave input through layered soil medium. Moreover, some discussions are made on the number of modes required in the calculation of the sloshing height. Finally, all of these features are integrated into a single system to develop simplified analysis models for seismic response analysis of LNG storage tank including dynamic effects of the FSSI. A numerical example dealing with the large-scale LNG storage tank on a flexible soil is given to demonstrate effectiveness of the proposed approach. Fundamental impulsive frequency, base shear force, overturning moment, and sloshing height obtained by the proposed procedure are compared to those by a refined FSSI analysis. Numerical results indicated that the present study is accurate and simple enough to replace simplified techniques commonly employed in practice.
Evaluation of Flood Damages Using Principal Component Analysis
Azotea, Marc Sinan B. ; Necesito, Imee V. ; Cheong, Tae Sung ; Yu, Insang ; Jeong, Sangman ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 215~220
DOI : 10.9798/KOSHAM.2015.15.4.215
Despite the growing economy of Korea, natural disasters such as floods are still knocking the economic ladder. The counteractions made by flood disasters that were also induced by typhoons have caused significant damages to properties and human life. In this regard, the searches for the primary parameters that are affecting the flood damage amount were focused in this study. The data used in this study is flood damage from the 485 facilities in Gunsan City which were further divided based on the facility type. It identifies what type of parameter variable namely: flood damage, flood depth, flood duration, inundation area, family income and land price greatly affects or are relevant to each facilities being classified using Principal Component Analysis (PCA). Results from the Principal Component Analysis (PCA) show the relationship that exists among the variables and that it had narrowed down to which parameter was correlated to flood damage. This paper used the eigenvector and eigenvalue of the data matrix in order to compute the principal component. The result of the total variance in the flood damage of residential, commercial and agricultural facilities using the eigenvector and eigenvalue were calculated to be 0.691, 0.626 and 0.700, respectively. Significant level of Principal Component Analysis greater than 0.5 and less than -0.5 must be attained for relativity variables to exist and as for this study it proves that flood depth was the most significant among the rest.
Prediction of Local Scour Development in Downstream due to Operation Rule of Movable Weir Gate
Lee, Jae Young ; Kim, Ki Young ; Son, Shin Hye ; Shin, Dong Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 221~230
DOI : 10.9798/KOSHAM.2015.15.4.221
A numerical model was applied to couple computation module of local scour depth by improving the numerical problem to implement internal boundary condition and entering field test data of bed material in order to examine on stability of hydraulic structure located downstream. The local scour development in the vicinity of foundation of hydraulic structures was predicted occurring by variation of hydraulic conditions in downstream due to various operation rule under the frequency flood condition. The verification of the model was performed by applying a historical flood event and operation rule of movable weir gate under different flooding scenarios and short and long-term variation of pier scour depth were simulated. It was found that overflow at fixed weir dependent upon gate operation of movable weir effects on the time development of the local scouring around bridge foundation and then it enables optimal gate operation rule to reduce local scour depth around pier for flood season.
Assessment of Continuous Simulations of Rainfall Runoff Models Based on Soil Moisture Accounting Models at Guem River Catchments, Korea
Chang, Hyungjoon ; Lee, Hyonsang ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 231~242
DOI : 10.9798/KOSHAM.2015.15.4.231
This study assesses a relationship between catchment groups and model performance of nine Conceptual Rainfall Runoff models at 22 Guem river sub catchments. Three catchment groups (H1, H2 and H3) are derived from Hydrological distance measuring based on three catchment characteristics (i.e. Area, slope and SCS-CN). 9 CRR models, which are combined from 3 Soil Moisture Accounting models (Probability Distributed Model, Catchment Wetness Index model, Modified Penman type model) and 3 Routing models (2-conceptual reservoirs in parallel, 2-conceptual reservoirs in parallel with Macro-pre Approach, 3-conceptual reservoirs in parallel) in Rainfall-Runoff Modeling Toolkit. The models are calibrated and validated in the period of 2006-2012 and 2001-2005 respectively. The model performance in Nash Surcliffe Efficiency is compared in terms of model structures and catchment groups. The results show that there is no significant relationship between catchment groups and model structures and suggest one group for Guem river region. However, PDM-SMA Models show generally good performances in calibration, validation and Number of calibrated model parameters. PDM with 2PAR model is recommended as a rainfall runoff model for Guem river region.
Application of Numerical Modelling for the Prediction of Sediment Deposits after Sejong Weir Installation
Kim, Hayong ; Park, Jihong ; Park, Woncheol ; Hong, Ilpyo ; Jeong, Sangman ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 243~249
DOI : 10.9798/KOSHAM.2015.15.4.243
Hydraulic characteristic of rivers are changed due to installations of structures such as weirs. Erosion of sediments in the upstream and downstream portion of the weir results to change in river beds. In this study, a comparison between the actual changes in the riverbed of Sejong weir, about 600m upstream and the downstream section of the Geum River was made. Comparison between the actual result and simulation of two-dimensional model of flow characteristics using SED-2D were done. Assessments on the change in river beds were also made to identify the applicability of the model. This study also analyzed the long term bed fluctuation patterns and models were constructed based on its weir construction time of 1, 5, and 10 years respectively. As a result, a trend similar to the actual variation patterns was found. However, changes in the Sejong weir upstream river bed tend to be largely deposited especially in the concave section. The low value of flow rate is attributed to the topographical characteristics that were due to the intensive accumulation phenomenon occurring in the eye of stagnant zones. In addition, the authors believe that the time required to stabilize the three kinds of deposit is more than 10 years and will also take 5 years to reach its state of equilibrium to mitigate the accumulation of eroded materials occurring in the prime section.
Depositional Behavior of Fine-Grained Particles with Varying Cohesiveness
Choi, In Ho ; Kim, Jong Woo ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 251~259
DOI : 10.9798/KOSHAM.2015.15.4.251
The purpose of this paper is to examine the effect of their cohesiveness on the deposition behavior of fine-grained sediments with varying cohesiveness, through laboratory experiments. Laboratory studies are realized in a small annular flume with a free water surface, where the flow is driven by the rotating inner cylinder. Sediment material is using silica particle, which is the main mineral components of clay that affect sedimentation. Results show that the deposition rate of silica increases more rapidly at pH4.2 than at pH6.8 with decreasing bed shear stress due to the effect of the cohesiveness. Silica particle is not deposited above the bed shear stress of
in distilled water. The minimum shear stress of silica occurs under the bed shear stress of
. Thus, the settling velocity ranged from approximately 0.0003~0.006 mm/s under variable pH value and shear stress.
Characteristics of Daily Precipitation Data Based on the Detailed Climate Change Ensemble Scenario Depending on the Regional Climate Models and the Calibration
Kim, Jungho ; Joo, Jingul ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 261~272
DOI : 10.9798/KOSHAM.2015.15.4.261
This study examines characteristics of daily precipitation data resulted from the detailed climate change detailed ensemble scenarios for four regional climate models with the calibration implementation in South Korea. After calibrating, the number of days with precipitation was decreased by 12.9~33.9% depending on the regions and the regional climate models, but the trend of the spatial distribution was similar with the un-calibrated. Annual average precipitation had no change between before and after calibration. Correlation coefficients between observed data and predicted data for the number of days with precipitation and average daily precipitation of 73 gauge stations are 0.64~0.78 and 0.57~0.79 respectively. Thus, their correlation is high enough to say that they are related. It is expected that the results in this study will be useful to figure out the characteristics and the spatial distribution trend of daily precipitation data based on the detailed climate change ensemble scenarios for four regional climate models before using the daily precipitation data.
1-day Probable Maximum Precipitation in accordance with AR5 RCPs in Korea
Sim, Kyu Bum ; Lee, Okjeong ; Kim, Sangdan ; Kim, Eung Seok ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 273~280
DOI : 10.9798/KOSHAM.2015.15.4.273
In this study, the PMP is estimated by statistical methods using future climate change scenarios, AR5 RCP 2.6/4.5/6.0/8.5 future rainfall data, provided by Korea Meteorological Administration. Future PMP values have been estimated into two types. One is a moving average 1-day PMP(SMP) and the other is a cumulative average PMP(CMP). The trend of PMP values has been analyzed through the first-order linear regression. This analysis shows that the PMP will be increasing and the rise of Seoul and Busan is relatively more obvious than the increase in other regions.
Rainfall Runoff Reduction Analysis for the Construction and Maintenance Costs of LID Facilities
Yeon, Jong Sang ; Kim, Sangdan ; Choi, Hyun Il ; Shin, Hyun Suk ; Kim, Eung Seok ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 281~287
DOI : 10.9798/KOSHAM.2015.15.4.281
This study analyzed the construction and maintenance cost efficiency of Runoff reduction at LID element techniques to analyze the applicability of LID. Using the improved SWMM 5.1 ver analyzed the runoff reduction efficiency of LID element technology. Construction and maintenance costs, the analysis was carried out using the values presented in Washington State University. Permeable pavement is analyzed the highest total runoff reduction efficiency and vegetation swale is analyzed the cheapest construction and maintenance costs. Bio-retention cell is analyzed the highest construction and maintenance cost efficiency of runoff reduction. As a result, Bio-retention cell to be applied in target area can be most effectively reduced runoff.
Effect of Climate Seasonality on Hydrological Partitioning of the Watershed
Park, Myungwoo ; Park, Yoonkyung ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 289~296
DOI : 10.9798/KOSHAM.2015.15.4.289
In this study, the seasonal effect of climate on the hydrologic partitioning of the watershed was analyzed using Horton index. Horton index is to serve as quantified value on hydrologic partitioning, and was estimated using the soil moisture probability density function in this study. The probability density of the soil moisture was stochastically simulated using the meteorologic data at Seoul, Daegu, Busan and Jeju observation site. As a result, it could be seen that the seasonality had an effect on reducing Horton index. Seasonality could be thought to inhibit the vegetation water use efficiency, considering positive relationship between Horton index and the vegetation water use efficiency. However, much more than usual precipitation in seoul with a wet climate and much less than usual precipitation in daegu with a dry climate tended to disappear to the influence of seasonality on Horton index.
Analysis of Relationship between Inundation Depth and Plant Habitat of Binae Wetland
Kim, Jungwook ; Hong, Seungjin ; Kim, Yonsoo ; Lee, Daewung ; Han, Yang Soo ; Kim, Hung Soo ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 297~307
DOI : 10.9798/KOSHAM.2015.15.4.297
In this study, we analyzed the flow duration of Binae wetland, which has a well-developed natural ecosystem and simulated the inundation depth of Binae wetland according to flow duration using HEC-RAS and RAS Mapper. Then, the plant habitats in inundation depth were analyzed. As a result, Salix koreensis Anderson inhabits from the area where the flooding did not occur to 0.8m below water level. Miscanthus sacchariflorus Benth inhabits from the area where the flooding did not occur to 0.4 m below water level. Artemisia princeps Pampanini-Erigeron canadensis L and Phragmites japonica steud inhabit from 0 to 0.4 m below water level. And Humulus japonicus inhabits from 0 to 0.8 m below water level. Here, plant habitats are analyzed by inundation depth and this study could be used as an idea for wetland design considering inundation depth. For more accurate research, methodology for the analysis of relationship between inundation depth and plants should be developed with accumulated data in long term.
The Improvement on the Empirical Formula of Stormwater Captured Ratio for Bio-retention Ponds
Yeon, Jongsang ; Sim, Kyubum ; Choe, Bogyeong ; Kim, Sangdan ; Im, Toehyo ; Kim, Eungseok ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 309~315
DOI : 10.9798/KOSHAM.2015.15.4.309
In this study, the formula of stormwater captured ratio taken into account both the weir and orifice of a bio-retention pond which is one of non-point pollutant control facilities is derived. EPA SWMM is applied to develop the formula according to different capacities of the facility. After a comparison with the formula being applied to an existing, the newly proposed formula will be calculated by intercepting more stormwater than the previous formula in the case that the pond has been installed in the same capacity. Since most of the pond may have a discharge process through an orifice, the proposed formula can be found to be able to reflect a more realistic than the previous formula. Therefore, it can be thought that the existing formular of rain captured ratio has underestimated the amount of intercepting stormwater.
Design of Water Quality Capture Volume for Infiltration Trench
Choe, Bogyeong ; Jo, Deokjun ; Lee, Jeonghoon ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 4, 2015, Pages 317~323
DOI : 10.9798/KOSHAM.2015.15.4.317
Recently, there has been growing interest in non-point pollutant sources management facilities based on LID concept that is to minimize the impact of urbanization. In this study the methodology for determining the water quality capture volume (WQCV) for infiltration trenches which are one of various LID facilities is proposed. The WQCV determined using the principle of diminishing returns is calculated by 18.55 mm, higher than the existing regulation. As the impervious area is increased by 20 percent, the WQCV is increased about 0.3 mm. Effect analysis of the drain time that is installing underdrain is expected to aid in the optimal design of the WQCV. In conclusion, it is shown that the WQCV which is usually applied to economics is closely related to the local precipitation pattern, drainage area imperviousness, and drain time applied to infiltration trenches.