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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 13, Issue 6 - Dec 2013
Volume 13, Issue 5 - Oct 2013
Volume 13, Issue 4 - Aug 2013
Volume 13, Issue 3 - Jun 2013
Volume 13, Issue 2 - Apr 2013
Volume 13, Issue 1 - Feb 2013
Selecting the target year
An Experimental Study on Structural Behavior of New Shape Weak-Axis Connection through Monotonic Loading Test
Cho, Han Sol ; Lee, Tae Gyu ; Hwangbo, Chan ; Kim, Sang Seup ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 1~8
DOI : 10.9798/KOSHAM.2013.13.5.001
Although much researches are performed on the strong axis steel connection of H-shape beam-to-column, there is little researches on the weak-axis steel connection. New shape weak-axis connection has a simple shape with the less spot of welding points, and it has advantage about showing the obvious flow of strength in connection points. Therefore, this research performed monotonic loading test by making weak-axis connection in full-scale test specimens. The experimental results of weak-axis connection are evaluated by applying criterion of connection performance that suggested in the AISC and Eurocode No.3.
Inspection of the Specific Buildings Using the Wind-Induced Disaster Risk Index
Lee, Youngkyu ; Lee, Chuljoo ; Ahn, Seungil ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 9~16
DOI : 10.9798/KOSHAM.2013.13.5.009
The wind-induced disaster risk index (WRI) is developed to inspect the safety against windstorm for the specific buildings, approximately 34,000 buildings, distributed over South Korea. WRI for a specific building is based on the wind damage band which calculates an average damage probability with the strong wind exerted on it and makes the damage probability take an variation due to its characteristics. The strong wind is defined as the wind speed extracted from the wind hazard map that is a set of 10-min averaged winds of 100-yr return period over South Korea. The building characteristics is invested by three categories including 4 of the environmental variables, 5 of the roof variables, and 8 of the wall variables. We took a survey for 724 of the specific buildings. According to the results of WRIs for the sample in the corresponding rate zones for wind and flood insurance, the more the rate zone is high, the more WRIs increase in general. In comparison of WRIs to occupancy, WRIs show a tendency of increasement in the order of apartment, commercial, and industrial buildings.
Development and Tests for Adjustable Bearings Using Wedges to Adjust Elevation
Choi, Eunsoo ; Tae, Ghiho ; Baek, Joon-Ho ; Eo, Yoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 17~24
DOI : 10.9798/KOSHAM.2013.13.5.017
This study provides an idea of adjustable bearing using wedges, which adjusts elevation of a superstructure during construction and/or in service. Adjustable bearings can release developed stress in a superstructure causing from settlement and so on. This study prepares a wedged adjustable bearing and assess its performance from a few static loading tests. A tolerance of the bearing to adjust elevation is estimated to be 0.42 mm, which is in good performance. The deformation of 2.0 mm occurs due to loading of 1470 kN and the deformation is removed with releasing the loading. Thus, any residual deformation is not remained. Finally, finite element analyses are conducted to estimate stress in the sole plate of the adjustable bearing, which is distributed uniformally.
Hygro-Thermo-Mechanical Analysis of Concrete under High Temperature
Rhee, Inkyu ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 25~33
DOI : 10.9798/KOSHAM.2013.13.5.025
In reality, a concrete structure develops critical damage from a fire disaster. This is because the physical high gradient changes in the form of thermal stress and pore pressure; it is elevated by moisture migration among dissimilar material properties as well as irreversible chemical reaction of its constituents. This paper explores two main hypotheses for spalling: restrained thermal deformations and vaporization of the free pore water with an aid of finite element method. Eventually, the combined problem with pore pressure and thermal deformation under constrained conditions are discussed for the sake of analyzing the recent experimental findings. The heterogeneous model (representative volume element; RVE) problem of aggregate inclusions in an elastic matrix bonded by different thermal, hygral, and elastic properties was considered. Since these multiple processes occur on different scales, the binding rule of these processes was basically taken as an additive relation in the form of a strain format for simplicity. Finally, the total strain was evaluated according to the contributions of thermal strain, hygral strain, strain by pore pressure, and the elastic strain at the material points. The right-hand side of the stiffness equation was finally introduced in the environmental strain driven initial load.
The Sagged Cable Tension Estimation Technique Using FOA
Jang, Han-Teak ; Ryu, Duck-Yong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 35~41
DOI : 10.9798/KOSHAM.2013.13.5.035
This paper introduces the tension estimating technique using FOA(Fast Optimization Algorithm) for a major member of cable stayed bridge and compares the existing techniques. FOA is overcoming the disadvantages of LOA(Local Optimization) that is the local convergence and GOA(Global Optimization Algorithm) that is the problem of premature convergence. The existing methods are divided into the mechanical methods and the dynamics methods based on the natural frequency and they have been recently proposed the SI(System Identification) methods using the FE model and identification technique. Excepting that the sagged cable have a large sag, in the cases of conventional method using a mathematical model, the taut string theory and Triantafyllou & Gringfogel`s proposed equation have the error less than 5%, the beam model using the linear regression equation hase the error less than 1%, Shinke et al.`s proposed equation is certificated the tension estimation errors less than 4%. SUA(Senstivity Updating Algorithm), DE(Differential Evolutionary) have the estimated tension value that have errors less than the 0.5%. GAs(Genetic Algorithm) has the errors less than 2%,
less than 3%, hGA less than 5%. It is that the proposed technique using proposed FOA has resolved the weak of existing techniques and shorten analysis time. It seems that errors are less than 0% and the proposed technique has been estimated the exact tensions.
Risk based Bridge Management Method considering Value of Bridges
Sun, Jong-Wan ; Park, Kyung-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 43~50
DOI : 10.9798/KOSHAM.2013.13.5.043
In order to efficiently and reasonably use a limited budget for bridge maintenance, a systematic decision-making method is proposed considering the performance of individual bridges and their direct and indirect values. The typical bridge performance is expressed with the risk level which is based on the risk rate evaluated with the condition state and safety factor of the bridge. The replacement value of the bridges is estimated by considering the sum of direct reconstruction cost and potential value depending on several traffic conditions around the bridges. Final representative risk of each bridge is defined as risk grade which is determined form the risk matrix combining the risk level and replacement value. A number of actual bridge structures are considered to demonstrate the applicability and verification of the proposed method. From the results, the method can be expected to lead a quantitative decision-making in maintenance phase of bridges.
Behaviors of Steel Pipes for Ocean Resource Extraction Considering Ovality
Mha, Ho-Seong ; Cho, Kwang Il ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 51~57
DOI : 10.9798/KOSHAM.2013.13.5.051
The ovality arising from production or installation can affect the responses of the steel pipes for ocean resource extractions. Ultimate strengths and the stresses occurring during installation are examined to see the effect of the ovality with various values upon the responses by using the detailed FEM analysis using shell elements. From results, the ultimate strength for bending moment decreases from 1% to 3% as the ovality increases from 0% to 6%, while the ultimate strength for the pressure decreases from 43%to 55%. The influence from the locating positions of steel pipes are also evaluated, showing that the stresses increases as the ovality increases. At the vessel, where the members are mainly under tensile forces, the stress varies at 0.01%. At the sagbend and seabed, the pressure exceeds the ultimate strength in the case of the ovality over 4%. It can be concluded that the ovality affect the pipe more highly under pressure than under bending moments or tensions. From results, steel pipes with the ovality over a standard criteria can create serious safety or stability problems. More rigorous attentions on ovality are desired to produce and install the steel pipes in the ocean.
Analysis of Negative Moment for RC Slab Bridges with Various Skew Angles
Mha, Ho-Seong ; Cho, Kwang Il ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 59~65
DOI : 10.9798/KOSHAM.2013.13.5.059
Negative moments of two-span continuous RC slab bridges with various skew angles and span lengths are studied through the time history analysis for moving vehicle. Responses of bridges are evaluated by FEM time history method used in the previous study, which was verified by comparing the measured data. The velocity of moving vehicle is selected as 60 km/h, since the variation of the vehicle velocity does not show noticeable effect upon the response displacements. From the result of negative moments for various values of the skew angels, the maximum moments occur at the skew angle around
. It can be said that the bridge with middle range of skew angles show the biggest load effect compared to those with small angle or straight bridges(
skew angle). It is also found that the rate of increment of negative moment also increases as the span length increases. The better design for skewed bridges could be possible as response analysis for the more various loading conditions and bridge types would be conducted in the future.
A Numerical Study on Economic Design of Prefabricated Sewage-Pipe Plastic Foundation
Kang, Sung-Yong ; Park, Jong-Sup ; Lee, Kwan-Ho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 67~74
DOI : 10.9798/KOSHAM.2013.13.5.067
Improper backfill materials and compaction controls under pipelines have become one of the major causes of failure in many sewage pipeline systems. A study on backfill materials and compaction controls has been considered for a long time. However, structural supporters under the pipe were recently concerned because of pipeline repair and maintenance. This paper presents a prefabricated plastic foundation for supporting a sewage pipe system and increasing the performance function of the pipes. Several analytical models for the plastic foundations were investigated using finite-element program, ABAQUS, for checking safety and determining economic design. Comparing with the results of analyses, some of economic design sections based on the sizes of pipe diameters, 300mm and 600mm, were recommended. These results could be applied to a pipeline system with a prefabricated plastic foundation.
Wind Stability Analysis of an Over-Sea Cable Stayed Bridge Considering In-site Turbulence Properties
Shin, Hyun Seop ; Kim, Byeong Cheol ; Yhim, Sung Soon ; Lee, Young Ho ; Song, Jae Joon ; Hwang, Yoon Koog ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 75~82
DOI : 10.9798/KOSHAM.2013.13.5.075
The safety as well as serviceability of over-sea bridges can be threatened by excessive vibration, because the bridge should endure harsh condition such as high-speed wind during the expected life time. The buffeting, which is typical wind induced vibration, is hard to be estimated without verifying the exact wind properties. This study investigates a method for improving an accuracy of the buffeting analysis of a cable stayed bridge by considering in-site turbulence property. The two-year, 100 Hz, wind and acceleration data measured by integrated measurement system is used to analyze the properties of the wind and the structure more accurately. The buffeting analysis considering an effect of in-site wind turbulence is performed by using measurement-based model. The method calculating limit speed of serviceability is considered to be reliable, because the result from the analysis has enough similarity with the measured one. It is expected that the serviceability evaluation criteria of each bridge can be more reasonably determined considering wind properties, if enough data is stored on the system.
Infiltration and Stability Analysis of Weathered Granite Slope considering Rainfall Patterns
Lee, Ji Sung ; Kim, Yun Tae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 83~91
DOI : 10.9798/KOSHAM.2013.13.5.083
Many slope disasters occur in many parts of the world during rainy season. Rainfall is one of the significant factors related to the landslides which cause a considerable damage to society. The rainfall-induced landslides in unsaturated slopes generally have shallow failure and are triggered by decrease in matric suction during rainfall. In this paper, effects of rainfall patterns on slope stability of the unsaturated weathered soil were investigated. Landslides inventory consisted of 106 landslides data from 1999 to 2011 was used to induce two rainfall patterns: strong major rainfall(SMR) pattern and strong antecedent rainfall(SAR) pattern. SMR pattern is a rainfall type in which the major rainfall of the landslide event day provides a key role on the landslide occurrence. SAR pattern is that the antecedent rainfall of the 1-antecedent day gives an important role on the landslide occurrence. Constant rainfall pattern was also used for comparison in numerical analysis. Combined seepage and stability analyses were performed to study the stability of slope subjected to various rainfall patterns. The results of numerical analysis indicated that variation of factor of safety of weathered granite slope depended on rainfall pattern, rainfall intensity and soil permeability.
Laboratory Soil Box Tests for Compaction Characteristics of Foundation Soils using Nondestructive and Penetration Tests
Kim, Kyu-Sun ; Woo, Wontaek ; Lee, Changho ; Lee, Woojin ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 93~101
DOI : 10.9798/KOSHAM.2013.13.5.093
The paper describes the use of the nondestructive and penetration tests such as the Soil Stiffness Gauge (SSG), the Dynamic Cone Penetrometer (DCP), and the Time Domain Reflectometry (TDR) for evaluating the compaction characteristics of foundation soils. A comprehensive laboratory experimental program was conducted for the SP, SW-SM, SM, CL soil specimens. The SSG, DCP, TDR, plate load test (PLT), California Bearing Ratio (CBR) test, and the sand cone test were performed for compacted soil specimens with various water contents. The interpreted results show that the nondestructive and penetration tests can quickly and quantitatively evaluate the compaction characteristics of soils with similar performance. The TDR can measure the water content of soils with high accuracy when testing soils with a water content of less than 15%. The results show that the SSG modulus is approximately two times higher than the PLT modulus. The SSG and DCP measurements have a log-log correlation between the soil stiffness and the shear strength of soils.
Evaluation of Relationship between Tensile Force of Anchor and Safety Factor of Slope through Numerical Analysis
Kim, Young Sang ; Lee, Cheol-Ju ; Sung, Hyun-Jong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 103~109
DOI : 10.9798/KOSHAM.2013.13.5.103
Main reasons making the slope reinforced with anchors unsafe are rise of ground water table due to heavy rainfall and sudden reduction of initial tensile force due to damage of anchor head. In this research, numerical analysis was carried out to evaluate the safety of slope reinforced by anchors from the monitoring result of tensile force. Limit equilibrium analysis and 3D finite element analysis were carried out to model the sudden reduction of initial tensile force and increase of tensile force due to soil movement, which was caused by rise of ground water table. From the numerical analysis, it was found that the increase of tensile force due to rise of ground water table comes with nonlinear decrease of safety factor and reduction of initial tensile force due to damage of anchor head accompanied with linear decrease of safety factor. From the results, it can be concluded that safety of the slope can be evaluated indirectly by monitoring the tensile force of anchor using FBG sensor embedded tendon.
Earth Pressure Distribution on Short Pile during Overturning Failure
Lee, Su Hyung ; Lee, Sung Jin ; Lee, Seong Hyeok ; Lee, Jin Wook ; Lee, Seung Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 111~115
DOI : 10.9798/KOSHAM.2013.13.5.111
Earth pressures acting on a short rigid foundation during overturning failure were measured by a real-scale load test. A cast-in-place concrete foundation with square section of 1.0 m width and 2.2 m embedded depth was equipped with 11 earth pressure cells. Moment was applied to the pole supported by the foundation until overturning failure occurred. Earth pressure distribution between the foundation and soil was compared with those from the existing theories to verify their validities. In the measurement result, increase of earth pressure on the upper foundation was found in comparison with the theories, that was caused by the soil compaction at the ground surface. A Simplified distribution of vertical soil pressure on the foundation for the reasonable design was proposed.
Characteristics of Dynamic Shear Behaviors of the Interface in Waste Landfill Sites
Park, Innjoon ; Kwak, Changwon ; Park, Junboum ; Han, Jajung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 117~123
DOI : 10.9798/KOSHAM.2013.13.5.117
The number of the waste landfill site increases continuously in recent years. Various types of geosynthetics have been utilized in the waste landfill site for encapsulating, isolating, protecting, and so on. Geosynthetics compose the interface with soil and affect the shear behaviors of waste landfill system. The chemical aggressors in the leachate also play a critical role in the interface and it is known that the dynamic loading is able to accelerate manifestation of the effects of chemical attack. In this research, numerical analysis was conducted considering shear stress degradation in the geosynthetic-soil interface due to dynamic load with chemical effect. Cyclic simple shear test results was reviewed and applied to the numerical modeling as well. Consequently, the stability of waste landfill site could be overestimated without considering the shear stress degradation of interface.
Examination on the Method for Evaluating the Allowable Axial Bearing Capacity of a Single Pile subjected to Machine Vibration by 3D Numerical Analysis
Ha, Ik Soo ; Han, Jin-Tae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 125~131
DOI : 10.9798/KOSHAM.2013.13.5.125
In this study, the applicability of the method for evaluating the axial bearing capacity of a single pile subjected to machine vibration, which is generally applied in Korea, is examined. Firstly, the 3D model for the load-displacement behavior of a single pile, which is one of the group pile supporting a rotating machine, was constituted. In the constituted numerical model, the soil-pile interaction was considered by using the empirical formulae for evaluating axial bearing capacity and conducting the repeated numerical analyses. After the model was statically loaded to the allowable bearing load in static numerical analysis, the axial vibration due to machine vibration was added to the pile top in dynamic numerical analysis. From these procedures, the additional axial dynamic load caused by machine vibration was computed. From the analysis results, it was found that the additional dynamic load caused by machine vibration was about 13% of the allowable static load and it was thought that the domestic design concept, assuming that the additional dynamic load due to machine vibration equals to the allowable static load, is excessively conservative.
Study on Hazard of Roadside Slopes based on Discontinuities by Faulting and Wetness Index in Ga-Ji Mountain Provincial Park
Kim, Honggyun ; Kim, Seung-Hyun ; Lee, Jong-Hyun ; Ok, Young-Seok ; Koo, Ho-Bon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 133~140
DOI : 10.9798/KOSHAM.2013.13.5.133
This study is targeted at national road #24 located in Ga-Ji Mt. provincial park, Gyeongsangnam-do. Study area is divided into two domains of A and B to study exposure characteristics and hazard of roadside slopes for each location. The east of Seoknam Tunnel is domain A and the west of that is Domain B. In domain A,
trending vertical joints develop systematically. These are considered as fractures by Riedel Shear(R-Shear) and conjugate Riedel Shear(R`-Shear) respectively caused by movement of Moryang Fault adjacent to domain A. Domain B contains relatively more massive rocks than domain A and has road-direction sheeting joints, which are capable of causing plan failure. The result of wetness index analysis shows higher index in domain B, indicating more effect of water in this domain. Domain A shows high frequency of rockfall by rectangular released rock, which is caused by vertical joints accompanied by Moryang Fault. Slopes located in domain B show high hazard and consequence because of poor joint pattern and much water flow. Therefore, it is necessary to set up long-term countermeasures for stability of slopes, considering features of each domain.
Application of Determination Method of Monitoring Location in Pilot Plant for Water Distribution System
Kwon, Hyuk Jae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 141~147
DOI : 10.9798/KOSHAM.2013.13.5.141
In this study, determination method of pressure monitoring location in water distribution system was suggested and applied to the pilot plant for the experimental verification. Monitoring location was estimated by two methods such as pressure contribution analysis and pressure sensitivity analysis. Pressure change due to change of demand was calculated for each junctions. Results of the calculation were used to determine which junction has high pressure sensitivity and pressure contribution to another junctions. Furthermore, results of analysis were compared with the results of experiment. Real leakage was reproduced and pressure change was measured in pilot plant. Pressure change was measured by four pressurer sensors with five different sensor locations. From the results, it was found that the results of determination methods of monitoring location are well matched with the results of experiment.
A Study on Disaster and Safety Management Measures to Establish the National Park
Song, Chang-Young ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 149~155
DOI : 10.9798/KOSHAM.2013.13.5.149
Korea National Park have been in the ongoing development since Jirisan National Park was designated in 1967. However, disaster and safety management of the National Park research on infancy, and according to the type of disaster, a disaster of national park considering the characteristics of studies are lacking. Accordingly, in this study national park status and problems of disaster and safety administration, national disaster management review criteria were based on this mountain, coastal, city park, according to the characteristics of each natural disaster, and human and social risk factors such as type of disaster identification, evaluation, and research and analysis on the important risks were calculated. All National Park`s top three key risk items are classified as a human disaster was derived, risk analysis matrix medium mountain parks and waterfront park, city park, with a low degree of risk of death or`ve found a good level of hundreds of accidents, injury cases, including the National Park of this efficient and systematic management of disasters and safety of long-term measures for the establishment is deemed necessary.
A Case Study on the Regional Application of PRISM Precipitation
Hwang, Seok Hwan ; Ham, Dae Heon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 157~167
DOI : 10.9798/KOSHAM.2013.13.5.157
This research evaluated the adaptability of PRISM (Parameter-elevation Regressions on Independent Slopes Model) which is one of the key methods to specify spatial precipitation by considering topographic or geographic features. The analyzed PRISM daily precipitation data were provided by Korea Meteorological Administration (KMA) with RCP scenario data. And KMA produced and provided grid PRISM data of 1 km resolution based on KMA`s Automatic Synoptic Observation System (ASOS) and Automatic Weather System (AWS) data of recent 11 years (2000-2010). To analyse, we latticed (
) the data using KMA`s AWS (also ASOS) stations (515 stations) as well as Ministry of Land, Infrastructure and Transport (MLIT)`s stations (567 stations), then calculated the areal precipitation of target basin. And compared it with areal precipitation of PRISM data. The analysis period is 2 years of 2008 and 2010 and we extracted and used the only storm event of which MLIT`s data were observed to be satisfactory. As a result, in case of PRISM data, we were able to confirm improvement in detailed accuracy aspect for some inland areas near Mt. Jiri where density of stations is scarce. However, excluding a few regions, variability among regions and storm events were larger than gridded data only based on KMA network and simple interpolation method. In a nationwide perspective, it is difficult to concluded that PRISM data has high accuracy compared to grid precipitation based on only ground observation network.
Quantitative Evaluation for Regional Vulnerability of Precipitation Networks
Hwang, Seok Hwan ; Ham, Dae Heon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 169~183
DOI : 10.9798/KOSHAM.2013.13.5.169
This research was conducted to analyze the quantitative vulnerability of spatial estimation of precipitation for precipitation observation network of Korea Meteorological Administration (KMA). We compared the amount of precipitation of GRD(K) which were gridded data only using KMA`s observation network and GRD(A) which were gridded data using both KMA and Ministry of Land, Infrastructure and Transport (MLIT)`s observation network. we used a multi-quadric interpolation method(MQI) to make a gridded data. We compared the observation densities as a schematic analysis and areal precipitation as a quantitative analysis. As a result, regions where the relative deviations (GRD(K) compared to GRD(A)) are large were located at south of the axis which lines across from Mt. Juwang, Gaya, Deokyu and Mt. Naejang at east to Mt. Wolchool at west. In addition, based on north and south axis which lines across Mt. Deokyu at mid region of South Korea to Mt. Jiri, areas were separated into west regions where GRD(K) were estimated to be bigger than GRD(A) and east regions where GRD(K) were estimated to be smaller than GRD(A). In other words, GDR(K) and GRD(A) showed the biggest gap in regions near or southern the Sobaek mountain range and the Noryung mountain range. Thus, these areas were evaluated as the most vulnerable in case of using KMA`s observation network only.
A Study on the Current Condition and Development Plan of Disaster Relief in Korea
Seo, Jung Pyo ; Cho, Wonchul ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 185~193
DOI : 10.9798/KOSHAM.2013.13.5.185
Major disaster relief in Korea is administered on the basis of the Disaster Relief Act which mainly aims for the relief of victims affected by natural disasters. There is, however, a growing need for the comprehensive relief that can cope with all kinds of disasters because the possibility of new and complex disasters always happens amid social, economic, and environmental changes, including low fertility, population aging, multiculturalism, and climate change. At the same time, due to the increasing numbers of elderly people and foreign workers, the establishment of laws and systems protecting the disaster minority has become an urgent task. Futhermore, several problems which relate to disaster relief funds and donations should be resolved. They must be delivered to the disaster victims promptly. And the poor management of the disaster relief supply which is focused on disaster relief kits only and the problem of the temporary housing facility should also be improved. Lastly, the short duration of disaster relief education and training, the neglect of cultivating disaster relief professionals and R&D, and the limitation of disaster relief management regarding to volunteering activities are pointed out. In this study, the development plan for relief activities were discussed by investigating and analyzing the problems involved in raws and legal system, relief resources and supplies, relief systems currently being operated.
Assessment of Rainfall Simulated on RCP Scenarios for Disaster Management
Park, Minkyu ; Park, Mujong ; Yoon, Jungsoo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 195~202
DOI : 10.9798/KOSHAM.2013.13.5.195
This study assessed the daily rainfall simulated on RCP(Representative Concentration Pathway) scenarios for disaster management. First, in the result that compared characteristic of the simulated daily rainfall with characteristic of the observed daily rainfall, annual rainfall and annual maximum daily rainfall estimated from the simulated daily rainfall was similar to those estimated from the observed daily rainfall. But monthly rainfall and rainy days of the simulated daily rainfall did not reflect the characteristic of the observed daily rainfall. And in the result that compared the simulated rainfall with the observed rainfall during 2000 yr~2011 yr, annual maximum daily rainfall and rainy days of the simulated rainfall was different from those of the observed rainfall. Finally, the simulated rainfall had smaller probability rainfall than the observed rainfall in certain rainfall point.
Developing the Humanity and Social Risk Index for Landslide Disasters in City
Choi, HyoungSun ; Lee, ChangWoo ; Kim, Kyongha ; Youn, Hojoong ; Kim, Geunyoung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 203~210
DOI : 10.9798/KOSHAM.2013.13.5.203
South Korea is one of the mountain-side urbanized countries with the high development demand by population centralization of the Seoul metropolitan region. South Korea has the humanity and social conditions of developing high-dense residential sites in mountain-side urbanized areas of large and medium size cities. However, there is lack of research for humanity and social damage of landslide disasters. This research is to identify humanity and social risks of landslide disasters, and to investigate a method rating the risk. This research computes basic units of buildings by classifying them, and identifies expected building resident indices derived from the GIS analysis process of our research. This research applies weight average staying times considering staying times and resident-user ratios in order to reduce analysis residuals. The five-stage classification of humanity and social risks for landslide disasters is developed the expected building resident indices of 0, 1~2, 3~7, 8~21 and 21+ stages.
Evaluation for Storm Events Recorded in Annals of Joseon Dynasty Using Qualitative Review
Choi, Jiyoung ; Park, Minkyu ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 211~217
DOI : 10.9798/KOSHAM.2013.13.5.211
In this study, A qualitative review on recording technology to the heavy rains and floods in Annals of the Joseon Dynasty was conducted. Annals of the Joseon Dynasty that includes all of the big storm in the Joseon Dynasty era, so it could be viewed as divided into a certain category, this will help to understand the nature such as the occurrence of extreme rain. The review was done concerning the recording usage such as the rainfall or flood terminology, the frequency of the article, the damage scale, the response of the government, so it set the standard to classify big rainfall events. Classification results shows that extremely big rain was estimated to occur around one in 30 years, big rain about one in five years and slightly big rain about one in two ~ three years. This return period was based on nation-wide scale, so this value which converted to the return period of a single location has the greater value. The classified extremely big rainfall events were compared with observed rainfall from Cheukwoogi(rainfall measuring device), the relationship between the recorded flood damage and the causing extremely big rain was explored.
The Relationship between Depression and Post Traumatic Stress Disorder among Firefighters
Jo, Seon Deok ; Park, Jae Bum ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 219~224
DOI : 10.9798/KOSHAM.2013.13.5.219
This study was aimed to investigate the relationship between depression and Post Traumatic Stress Disorder among firefighters. We re-analyzed the survey data conducted by Gyeonggi Provincial Mental Health Center from November 10th to 23th in 2010 with final sample size 4,446. The important factors to Post Traumatic Stress Disorder, like Sociodemographic, Job were analyzed thru Chi-square test. And the Relationship between Depression and Post Traumatic Stress Disorder were evaluated thru multiple logistic regression. The Beck Depression Inventory score was normality 70.9%(3,154), light-depression 16%(710), mid-level depression 9.2%(409), serious depression 3.9%(173) and Impact of Event Scale-Revised Korean version score was low 86.9%(3,862), high 13.1%(584). From the Sociodemographic perspective, there was significant correlation between Post Traumatic Stress Disorder and gender, age. In job characteristics, duration, number of performance, trauma experience, psychotherapy records influences on Post Traumatic Stress Disorder level. Depression was deemed to be an important factor in determining the Post Traumatic Stress Disorder level(OR 12.577, 95% CI
Characteristics of Forest Fires and Weathers in Domestic Over the Past 50 Years through the Statistics
Kim, Sung-Soo ; Lee, Jong Ho ; Lee, Myung Woog ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 225~231
DOI : 10.9798/KOSHAM.2013.13.5.225
The analytical results of the occurrences of forest fires with annual precipitation and durations, precipitation and durations during warned period of forest fire, drought warning in past 50 years showed that the occurrences had more relevance on precipitation and rained days during warned period of forest fire than annual precipitation and rained days a year. During 2000s, the annual precipitation and rained days a year and the precipitation and rained days during warned period of forest fire were larger than 1990s, but the occurrences of the fire were increased because of the larger number of drought warnings. According to monthly average precipitation during warned period of forest fire and the occurrences of forest fire in past 50 years, monthly average precipitation in February, March, November were consistently decreased, so the occurrences of forest fires expected to be increased. And the monthly average precipitation in December and May, increased continuously then the actual occurrences of forest fires were decreased. The monthly average precipitation in January, April were continuously decreased until 1990s, but were increased recently in 2000s. The riskiness of forest fire declined a little bit since 2000s due to the increased precipitation, but continuous cautions were required because of statistics of occurrence rates.
The Effect of Viscosity Agent(Xanthan Gum) for Improving Extinguishing Performance of Water Mist
Kim, Seungil ; Shin, Changsub ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 233~237
DOI : 10.9798/KOSHAM.2013.13.5.233
Water is an economical extinguishing agent and has a variety of extinguishing effect. Since water does not adhere to the fire surface due to low viscosity, which causes to reduce extinguishing effect, secondary damage to unburned materials and loss of water. In this study, xanthan gum as a viscosity agent added to water and using water mist nozzle xanthan gum solution applied to wood crib fire and heptane fire to improve extinguishing performance. The results show that in case of wood crib fire in 0.2 MPa, flame suppression time and fire extinguishing time of xanthan gum 0.2% solution are 7.9 times, 2.9 times shorter than pure water, respectively. In heptane fire, fire extinguishing time of xanthan gum 0.025% solution is 5.2 times shorter than pure water in 0.2MPa, but extinguishing is failed after concentration of xanthan gum increase. Also, it is identified that water consumption decrease with extinguishing time and extinguishing performance of xanthan gum on wood crib fire and heptane fire improved according to increase of discharge pressure.
A Study on Characteristics Analysis for Detection Performance of a Video-based Automated Fire Detection System
Ku, Jae-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 239~245
DOI : 10.9798/KOSHAM.2013.13.5.239
Smoke detectors and flame detectors in detection ability of sensors is greatly limited by the ability to detect environmental impacts in case of fire have a problem in accurate fire detection. This study describes to analyze detection performance of a video-based automated fire detection system consisted of CCTV camera, a video-based fire alarm control station, CPU in order to enhance the fire detection performance. GMM(Gaussian Mixture Model) modeling for an intelligent motion detection is analyzed and the application of MHI(Motion History Image) technology is showed the improved fire detection performance. The fire detection performance is experimentally evaluated as a function of the fire source and detection distance. As a result, the fire detection time is found to increase with increased the detection distance and is analyzed with 10 sec at the detection distance of 15 m. Therefore, the video-based automated fire detection system developed showed good performance for automatic fire detection comparing with the detection time criteria of 30 sec for flame detectors.
A Study on the Fire Resistance Performance of the Steel Fire Doors Depending on Core Material
Seo, Hee Won ; An, Jae Hong ; Choi, Dong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 247~253
DOI : 10.9798/KOSHAM.2013.13.5.247
Fire doors are installed on the openings in buildings to protect fire spreading in the event of fire. In foreign countries, fire doors whose fire resistance performance is from 20 minutes to 180 minutes are installed depending on required fire resistance performance of where fire doors are installed. But, in Korea, it is difficult to protect fire spreading in the event of fire because fire doors only having integrity of 1 hour are installed regardless of the position of fire doors. Therefore, it is needed to improve the system related to fire doors by strengthening the required fire resistance performance depending on where fire doors are installed and introducing insulation performance. To do so, the performance verification of the existing fire doors must be done first. In this study, fire resistance performance of the steel fire doors which are used widely depending on core material was evaluated. As a result, most specimens had the integrity performance and secured insulation performance of around 10 minutes depending on core material.
A Study on the Non-linear Analysis of Concrete Barrier Subjected by Vehicle Corrison
Oh, Hongseob ; Kim, Young Hwan ; Sim, Jae-Won ; Oh, Kwang-ChinJin ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 255~261
DOI : 10.9798/KOSHAM.2013.13.5.255
Design of barrier should be consider the secondary accident caused by a fracture of road safety facilities as well as the safety of vehicles and passengers, but few researches have not conducted on the failure phenomenon of the safety facilities. In this study, the impact test of a 14-ton truck to a concrete barrier was conducted, and then analyzed non-linear behavior of a barrier by FEA. This work also investigates the fracture phenomena of concrete barriers on different detailing such as concrete strength and reinforcement of wire mesh. The collision tests revealed that local fracture with 50 cm in width and 15 cm in height was found in the upper part of a concrete barrier, and the result of analysis was well simulated the test. Also, the interpretations on the different parameters showed that, with respect to concrete strength, the higher the strength of a concrete barrier was, the lower the width of its local fracture and scaling damage was, and that the height of wire-mesh insignificant affected a reduction in local fracture width of a protection wall and its fracture height.
Effect of Applied Stress of Unbonded PSC Tendon on Stress Wave Velocity
Kim, Byeong Hwa ; Lee, Il Keun ; Joh, Changbin ; Lee, Do Hyung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 263~268
DOI : 10.9798/KOSHAM.2013.13.5.263
This study experimentally investigates the effects of applied stress level on the stress wave velocity of unbonded PSC tendon. A set of longitudinal impact-echo tests with respect to several applied prestress levels are conducted for both unbonded prestressed strand and steel wire. The comparison results show that the longitudinal stress wave velocity is linearly proportional to the applied stress level in the case both strand and steel wire. However, the sensitivity of the longitudinal stress wave velocity to the applied stress level is very low. Based on the result of nondimensional analysis, it is postulated that the stress wave velocity is also affected by the tensile strength level.
Variation of Environmental Load Stresses in Continuously Reinforced Concrete Slab Track Depending on Steel Bar Arrangement
Kwon, Jong-Wook ; Cho, Young-Kyo ; Kim, Seong-Min ; Ahn, Suk-Jun ; Choi, Won-Il ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 269~276
DOI : 10.9798/KOSHAM.2013.13.5.269
This study was conducted to investigate the effects of steel bar locations in the continuously reinforced concrete slab track (CRCT) on the stress distribution and crack widths when the steel ratio was constant and the system was subjected to environmental loads. Three-dimensional finite element analysis models of CRCT were developed and the vertical temperature gradient that caused slab curling and the temperature drop were considered as environmental loads. The analysis results showed that even if the steel ratio was identical the stresses and crack widths of CRCT were affected by the steel bar arrangement.
Dynamic Analysis of Wheel Forces of KTX Vehicle Running with High-Speed on the PSC Bridge
Oh, Soon-Taek ; Lee, Dong Jun ; Lee, Jung Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 277~283
DOI : 10.9798/KOSHAM.2013.13.5.277
Dynamic analysis of wheel forces of KTX vehicle was carried out to compare the differences of wheel force (D.W.F.) and wheel force ratios (W.F.R.) on the road and bridge up to 450 km/h running speed, considering the interactions among vehicle/rail/bridge. An evaluation method of running safety of vehicles, lateral wheel force, derail factor, and offload factor are adopted for traffic safety of bridges.
A Study on the Reduction Methods of the Track Irregularity in High Speed Railway
Kang, Tae-Ku ; Yun, Kyung-Min ; Choi, Il-Yoon ; Lim, Nam-Hyoung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 285~290
DOI : 10.9798/KOSHAM.2013.13.5.285
The reduction strategies of the track irregularity in the bridge expansion joint zone are an important issue in the ballasted track on the high speed railway bridge. In general, the track irregularity on the railway bridge occurs at the expansion joint zone and is more spread across the bridge. This is due to the dynamic behavior from the train-induced dynamic impact and thermal expansion of the bridge. In this paper, field testing of the several methods for reducing the track irregularity on the bridge expansion joint zone such as the zero longitudinal restraint(ZLR), tied sleeper and ballast stabilizer is conducted. And then the progress of the track irregularity and the frequency of the maintenance work before and after the filed test construction are investigated.
Reliability Evaluation of the Speed Reduction Scheme in Korean High-speed Train based on the Reliability of the CWR Buckling
Kim, Myoung Soo ; Bae, Hyun Ung ; Choi, Jin Yu ; Lim, Nam Hyoung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 291~296
DOI : 10.9798/KOSHAM.2013.13.5.291
In order to prevent the track buckling in the hot summer and ensure the safety of the running train, as a part of the safety control plan for high-speed railway, the train speed restriction according to the rail temperature was introduced in 2004. However, the conceptual and theoretical background of train-speed restriction is unclear. In this paper, the buckling probability evaluation program( ProCWR) developed by this researchers was improved to take maximum and minimum buckling temperature into account for the calculation of allowable temperature. From the theoretical background of the international research and the buckling probability considering domestic railroad conditions, the validity and reliability of Korean high-speed train speed reduction scheme were investigated.
A Study on Urban Flood Vulnerability Assessment
Park, Moojong ; Song, Youngseok ; Joo, Jingul ; Park, Minkyu ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 297~305
DOI : 10.9798/KOSHAM.2013.13.5.297
Urban flood inundation by poor interior drainage systems causes annually the significant loss of life and properties in Korea. The inundation vulnerability assessment is important for policy establishment and priority decision of disaster management policy. In this study, an assessment model was developed for urban vulnerable areas. An assessment model was applied to arithmetic Urban flood vulnerability assessment and Urban flood vulnerability assessment using Promehtee(Preference Ranking Organization Method for Enrichment Evaluation). Assessment factors that directly affect urban flood were selected to lowland area, length of poor drainage sewer, and curve number. The results of assessment, inundation records are in concordance with arithmetic urban flood vulnerability assessment method about 75% and urban flood vulnerability assessment using Promehtee about 58.3%. In this study, arithmetic urban flood vulnerability assessment method using assessment factors that directly affect urban flood was confirmed by accuracy.
Flood Runoff Simulation Using S-RAT Model and Radar Rainfall
Lim, Joo-Ho ; Sung, Jang Hyun ; Hwang, Seok-Hwan ; Kim, Byung-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 307~315
DOI : 10.9798/KOSHAM.2013.13.5.307
This study simulated flood runoff of the Gamcheon Basin on the Nakdong River and Ohsipcheon Basin in Samcheok, Gangwon-do, where they frequently recently suffered from flash flood damages. First, consolidating radar rainfall data to consider time and spacial variabilities and development situations is necessary for an analysis of the flash floods. However, radar rainfall data are not reliable enough that it is difficult to use them as measurements of actual ground rainfall. Hence, this paper compared and analyzed the single polarization S-band data of the Gangneung meteorological radar and dual polarization S-band data of the Mt. Biseul radar to grasp their level of contribution to the runoff simulation. Second, a distributed hydrological model is necessary to effectively use GIS information and radar rainfall data of the grid format. Hence, in this paper, we used the S-RAT model as a distributed hydrologic model. The results of this study showed that the accuracy of peak discharge and time when using the distributed hydrologic model and radar rainfall data were similar to the observed values.
An Experimental Study of Folw Characteristics at the Downstream Depending on Gate Operation of a Sluice Gate
Han, Hyeong Jun ; Kim, Young Kyu ; Choi, Gye Woon ; Lee, Sam Hee ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 317~324
DOI : 10.9798/KOSHAM.2013.13.5.317
The weir is one of the hydraulic structure which is supposed to be used to store water quantity against drought. To solve the disturbance of flood control caused by soil sediment and environment problems from the severance of moving sediment, movable weir is currently set up so as to solve that serious problem. There have been many studies focusing on the weir in specific target area. however, it is not applicable for all kinds of moveable weir. Therefore, In this study, experiments for moveable weir typed sluice gate are performed and hydraulics characteristics are measured depending on gate operation. According to comparison results between apron length calculated by Bligh`s equation and hydraulic jump length by experiments, hydraulic jump length is bigger than apron length by Bligh`s equation where oscillation jump happens. Therefore, it is necessary to set the energy dissipator up for improving stability of hydraulic structure.
Development and Application of an Storm Identification Algorithm that Conceptualizes Storms by Elliptical Shape
Cho, Huidae ; Kim, Dongkyun ; Lee, Kanghee ; Lee, Jinsu ; Lee, Dongryul ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 325~335
DOI : 10.9798/KOSHAM.2013.13.5.325
A storm identification algorithm conceptualizing the storm with an elliptical shape was developed. The developed algorithm identifies the center, major and minor axis, and the inclination angle of the ellipse that contains the maximum volume of rainfall for a given area using the isolated particle swarm optimization algorithm. The developed algorithm was applied to radar precipitation imagery of 10 major storms observed in Korea during the year 2008 and 2012. The algorithm successfully identified the storm shapes for all time steps of all 10 major storms. The following conclusion was drawn from the result of the storm identification: (1) as the size of the ellipse becomes smaller, the diversity of the storm shape increased, and the diversity decreased as the size of the ellipse increases; (2) the temporal variation of the storm center identified by the ellipse is not always continuous; (3) the tracking capability of the algorithm is expected to be improved as the center and the shape of the ellipse at the previous time step is considered in the objective function of the optimization algorithm.
Numerical Experiments of Storm Surge and Coastal Inundation by Unstructured Grid Finite Volume Model FVCOM
Yoon, Jong-Joo ; Shim, Jae-Seo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 337~346
DOI : 10.9798/KOSHAM.2013.13.5.337
The low-lying coastal area of Korea has often been damaged by storm surge and corresponding inundation as the approach of strong typhoons repeated every year. In this study, a systematic investigation of storm surge impact to the coasts of Korea peninsula has been conducted using the unstructured grid model, FVCOM. The model was applied to simulate the storm surge and corresponding inundation. Observations of surge and inland flooding data were used to validate the model with satisfactory results. The results of inundation simulations in this study showed correspondence with not only observed inundation area but also inundation depth to prove its ability as an inundation prediction model. And virtual inundation scenarios with enhanced tidal conditions were simulated to evaluate the possible maximum storm surge and inundation height. The simulation results for these scenarios are approximately 84~134 cm sea levels rising cases compared to typhoon MAEMI(2003)`s observation of surge and inland flooding. The possible inundation height was shown up to 4m in Masan and 1~2 m in Busan, Yeosu. The product of this study could be applied to coastal inundation prediction system and hazard mapping.
Statistical Frequency Analysis of Earthquake Data at East Sea Using Mixed Distribution Functions
Shin, Ji Yae ; Kim, Tae-Woong ; Kim, Seok Cheon ; Yoon, Sung Bum ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 347~354
DOI : 10.9798/KOSHAM.2013.13.5.347
In Korea, the occurrence frequency of earthquakes has recently increased compared to the past. In neighboring countries such as Japan and China, damage from major earthquakes has also increased leading to high earthquake risk. This study quantitatively estimated the occurrence probability and frequency of huge earthquake using statistical frequency analysis on instrumental earthquake data at East sea in order to cope with earthquake damage. After adapting Various distribution functions such as Gumbel, Lognormal, Gamma, and Weibull for earthquake data, we applied mixed distributions to reflect the characteristics of the occurrence of earthquakes. The results show that the mixed models estimated earthquake magnitude larger than the Gutenberg-Richter (G-R) equation, and the mixed Gumbel distribution estimated most closed values with the G-R equation. It was found that the G-R equation is very limited to estimate a huge earthquake since there is no observed data over magnitude 8.0 and the frequency analysis is also limited to be applied in practice because the lack of data induces high uncertainty on the estimates of 1,000 year-earthquake. However, this study has an experiential significance in that the statistical frequency analysis was applied to instrumental earthquake data at East sea as an alternative.
A Study on an Environmental-Load Analysis for Airport Pavement
Min, Sung-Gyu ; Kim, Sung-Keun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 355~363
DOI : 10.9798/KOSHAM.2013.13.5.355
In this study, the LCA analysis technique, which quantitatively calculates the environmental load from the entire life cycle, is used to assess the environmental load of the airport pavement and the method to reduce the environmental load is suggested. The LCA analysis is conducted for the entire life cycle of the airport pavement to quantitatively determine the environmental load in six categories of the Environmental Product Declaration. The LCA analysis results show that 98.4% of the total environmental load of the airport pavement is generated from the global warming category.
accounts for 88.24% of the total emission: 38.03% in the initial construction stage, 61.96% in the maintenance stage, and 0.01% in the demolition stage. To reduce the
emission level of the wide parallel pavement method that is mostly used in these days, the warm mix asphalt is applied to some sections in airport pavements, and the capacity of dump trucks is changed. The suggested reduction plan is also applied to actual cases, and its reduction effect is verified via the LCA analysis.
Real-Time Drought Index for Determining Drought Conditions in Natural Water Supply System Communities
Sim, Hyun-Jun ; Ryu, Jung Su ; Ahn, Jaehyun ; Kim, Jeongsuk ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 365~373
DOI : 10.9798/KOSHAM.2013.13.5.365
Drought occurs more frequently in non-urban area where artificial water supply systems are not well equipped than in urban area where artificial water supply systems are well equipped, and occurs the first in such non-urban communities. In this study a drought index which can be applied to determine actual drought conditions on a daily basis at a region where artificial water supply systems are not well equipped is proposed. The proposed drought index is calculated on a basic local government basis using the standard precipitation index, the real-time available amount of water supply and water demand. It is applied at 164 basic local government regions during the period from 1980 to 2012. As a result, it is shown that the index can reproduce well major historical drought events. Hence, the drought index proposed in this study is expected to be well applied for determining real-time drought conditions in communities where artificial water supply systems are not well equipped.
Characteristics of Pollutants by Rare Earth Mine Decomposition/Purification Process, and of Treatment Technology
Kang, Kyounglim ; Kim, Dukmin ; Kim, Seoungsup ; Khim, Jeehyeong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 5, 2013, Pages 375~385
DOI : 10.9798/KOSHAM.2013.13.5.375
In this study, it was observed that the characteristics of pollutants produced during the processes of ore dressing and purification depends on the properties of rare earth and deposits from natural resources. The commercially important rare earth minerals discerned in this study were ion adsorption deposit, carbonate bastnasite and phosphate monazite. The ore dressing process for ion adsorption deposit elution was done by use of ammonium sulfate and calcination, while the process for bastnasite and monazite was smashing/grinding, gravity/magnetic separation and flotation. The process of decomposition/separation is mainly adopted for the purification process of rare-earth oxide by acid/alkali, P507 (
) and carbonation and calcination. At the ore dressing process, dominant water pollutants were heavy metals, fluoride, sulphate, arsenic, and radioactive compounds, while purification process generally produced harmful gases (HF,
, CO), radioactive tailings and wastewater with heavy metals, fluoride, ammonium, radioactive materials (Th, U), and organic pollutants. Harmful gases were specifically generated from acid/alkali decomposition process while organic pollutants were originated from separation/purification process. To treat wastewater, chemical precipitation could be applied to remove heavy metal, fluoride and radioactive compounds, and stripping and struvite precipitation treated ammonium ions, while oxidation treated organic compounds.