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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 Fire Resistance of High Strength Concrete Columns according to Structural Fire Design
Park, Jisun ; Lee, Seahyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 1~6
DOI : 10.9798/KOSHAM.2013.13.6.001
In Korea, in the event of performing fire-proofing work on concrete columns with strength of 50 MPa and above, an assessment of the fire-resistance performance must be carried out in accordance with the Ministry of Land, Transport and Maritime Affairs Notice 2008-334 `Standards for Management of Fire-resistance Performance of High-strength Concrete Columns and Beams`. However, the current standards only prescribe the need to check whether the testing report is submitted during the performance of fire-proofing work. This may pose difficulties in managing the fire-resistance performance in cases where it is impossible to identify whether such work has been done with a naked eye as is the case of the fire mixing method. Thus, in this study, three types of structurally reinforced specimens were fabricated for a fire-resistance performance test in order to propose a structural reinforcement technique that would facilitate the identification of the technique implemented in the field. The structural reinforcement techniques employed in this study were the method of increasing the amount of reinforcement and cross section in accordance with the Euro Code, the metal lath reinforcement method, and the method of increasing the amount of horizontal reinforcement. The strength of concrete used in the experiment was 70 MPa, the standard for design strength.
A study of Satisfaction of under Artificial Ground Metro Depot Working Environment
Kim, Jin-Wook ; Ryu, Kyungshin ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 7~13
DOI : 10.9798/KOSHAM.2013.13.6.007
The artificial grounds which were constructed over the railway land could be praised for maximizing land use efficiency and good way to increase development possibility of old rail way estate. Not only the development of train depots with artificial ground could be an agenda to resolve many problems coming from the congestion of cities by offering space of residence, office and retail but also it has good accessibility to train station. It will help reduce of commuting time and traffics. In this study, we have tried to find problems and offer the improving agendas in terms the necessary environment of under the artificial ground through the survey of railway workers. Through survey for Shinjung Depot, we found several problems issues which were related working environment like temperature, humidity, dust and noise and some psychological problems for rail way workers who are working under artificial ground. As a conclusion, it is recommended to consider the architectural planning in the each facility that workers are inquiring.
Analysis and Evaluation of Net Present Value by means of Monte Carlo Simulation
Chung, Yungbea ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 15~19
DOI : 10.9798/KOSHAM.2013.13.6.015
In order to analyze of feasibility of project, for the construction remodeling and architectural prevention of disasters and so on, it is usually used probabilistic method for supplementation of deterministic assessment, and considered the uncertainty in the future. There is lots of necessity relationship with cost management, and propriety of project. In this study, it was analyzed, and evaluated with Monte Carlo simulation that the assessment of application the Net Present Value (NPV) which includes the main cause of the economic growth rate and inflation for what it was made the probability distribution model optimization. Assessment of the NPV institute the concept of growth rate from probability distribution for reflection of the uncertainty in the future as well as some initial conditions for the feasibility of project the Monte Carlo simulation were carried out. According to the simulation with 3 percentages of the growth rate, the result values of low level and high level for 99 percentages of the confidence level were 3753.86 and 3771.72, respectively. Also the coefficient of variation was obtained 5.58%.
Seismic Behavior of Steel Building considering the Floor Slab
Oh, Myoung Ho ; Kim, Myeong Han ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 21~27
DOI : 10.9798/KOSHAM.2013.13.6.021
This paper was evaluated the reliability of the analytical model compared the experimental with the analytical results using the Fiber Model of PERFORM 3D to find the effect of the floor slab on the steel building. Then the seismic performance of the steel building was analyzed to perform the nonlinear static analysis and nonlinear dynamic time history analysis on the 10-story case study building. The floor slab could be added the seismic response of the steel building if it was modeled by the Fiber Model and it was affected on the seismic performance because of the incremental effect of the initial stiffness and ultimate strength. But the impact of the floor slab was not critical if the beam-column connection was not strong like the domestic steel building. Thus the addition of the floor slab model was not the important impact on the seismic performance of the steel structure building at the moderate seismic zone.
Development of the Risk Index to Inspect the Specific Buildings against Flood
Lee, Youngkyu ; Lee, Chuljoo ; Ahn, Seungil ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 29~37
DOI : 10.9798/KOSHAM.2013.13.6.029
The flood risk index (FRI) is developed to inspect the safety against flooding for the specific buildings, approximately 34,000 buildings, distributed over South Korea. FRI, defined as percentage index of potential flood damage to the possible maximum damage, is evaluated by the risk triangle approach. The flood management map, that includes the flood zones of riverine inundation, storm surge and the flood footprints, is constructed in the study. The exposure and vulnerability for 723 specific buildings is investigated. The vulnerability is assessed by the mean damage ratio curve with respect to the floor water depth and the building property such as the defensive height against flood, first floor height, building structure, wall, interior cost ratio, position of electric transformer vault, and drainage pump. Comparing FRI with the risk zones for the wind and flood induced loss coverage doesn`t show a explicit correlation. Researching FRI with respect to Sido, Korean province, shows that many of the specific buildings located in Seoul and Jeonbuk is distributed lower than the flood level. Considering FRI with the inundation depth doesn`t show an intensive correlation. Comparing the building storey to FRI shows that the ranges of FRI is getting narrow as the storey increases.
A Real Scale Fire Test for the Fire Risk Assessment of Mattress
Yoo, Yong Ho ; Park, Kye Won ; Kim, Sun Myoung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 39~44
DOI : 10.9798/KOSHAM.2013.13.6.039
According to continuous rise of income level and rapid increase of the Western life style, the domestic distribution rates of the bed has reached a very high level, and the damage caused from fire has increased according to this. Mattress has been pointed out as the major cause of flame diffusion in fire. In addition, the mattress, which is consisted of organic details, has acted as a medium of flame diffusion in fire, due to a flash point, which becomes a factor that increases the risk of fire after the toxic gas has been generated not only by ignition of the highly polymer in core materials, but also by flashover to the entire compartment caused by incomplete combustion. In this study, a full-scale experiment for fire has been conducted and the result has been analyzed to evaluate the risk of fire due to this mattress. In case of the general mattress, with the result of the experiment, the entire mattress has been combusted and spread with the laps of 5 minutes, and it has shown a 3MW heat release rates and a rapid growth. This result from the experiment can be used as data for developing the standard test method to evaluate the fire safety of the components in the compartment and designing prevention of fire spread in buildings.
Safety Evaluation of Masonry Buildings for Tsunami
Yang, Wonjik ; Yi, Waonho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 45~49
DOI : 10.9798/KOSHAM.2013.13.6.045
The tsunami that hit Indonesia on December 26, 2004 took the lives of about 300,000 people and caused massive property damage amounting to more than 10 billion dollars. Another earthquake hit the northeastern coast of Japan on March 11, 2011 and triggered a tsunami that battered Japan`s coast, killing 15,800 and causing property damage amounting to 25 trillion yen. Despite this trend, no feasible actions have been taken on the buildings in Korea to reduce tsunami-induced damage. Therefore, this study will present the method of building`s resistance force evaluation and wave force for the building`s safety for the tsunami. Then, according to the inundation depth we examined the safety evaluation of masonry buildings in the shore that occupy more than 80% in Korean buildings.
Damage Pattern Analysis of Buildings by Tsunami
Yang, Wonjik ; Yi, Waonho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 51~56
DOI : 10.9798/KOSHAM.2013.13.6.051
The tsunami that hit Indonesia on December 26, 2004 took the lives of about 300,000 people and caused massive property damage amounting to more than 10 billion dollars. Another earthquake hit the northeastern coast of Japan on March 11, 2011 and triggered a tsunami that battered Japan`s coast, killing 15,800 and causing property damage amounting to 25 trillion yen. Despite this trend, no feasible actions have been taken on the buildings in Korea to reduce tsunami-induced damage. Therefore, we will examine the types of damage on buildings by looking into the previous tsunami-induced damage cases for the purpose of utilizing the study result as basic data to come up with preventive measures against tsunami for buildings.
Shear Tests on Voided Slabs with Board-Type Voiding Material
Lim, Jongjin ; Cho, Seungho ; Paik, Inkwan ; Um, Taesung ; Lee, Inoh ; Han, Juyeon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 57~65
DOI : 10.9798/KOSHAM.2013.13.6.057
Due to less weight (i.e. greater void ratio), voided concrete slabs with board-type voiding materials take advantages of easier fabrication and less transportation cost. However the shear resistance can be decreased due to the greater void ratio(or the poor integrity between concrete plates at the top and bottom of the voiding material). In the present study, the shear resistance and failure mode of the voided slabs with board-type voiding material were investigated. Two-point loading shear tests were performed for 12 slab specimens. Test parameters were the void ratio, the location of the voids, and the presence of reinforcing vertical bar (or dowel bar). Test results showed that premature horizontal cracking developed at the top and bottom of the web concrete, shortly after flexural cracking at the bottom of the slabs. The slab specimens with void ratios greater than 32.5% were ultimately showed the horizontal shear failure of the web concrete, while the specimens with the void ratios less than 28.9% showed the conventional diagonal shear failure. The maximum horizontal shear stresses of concrete at failure, increased 0.26
as the void ratio increased from 32.5 % to 41.4 %. The vertical bars of the web which were perpendicular to the horizontal cracks of the web concrete, enhanced the shear strength of the slabs.
Evaluation of Progressive Collapse-Resisting Capability of RC Structures due to Load Redistribution
Park, Hoon ; Suk, Chul-Gi ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 67~74
DOI : 10.9798/KOSHAM.2013.13.6.067
Progressive collapse indicates the partial or total collapse of structures caused by the local damage of structural members arising from an abnormal load. To induce ideal collapse behavior, the progressive collapse is applied to most explosive demolition design for structures. To apply this progressive collapse phenomenon to the explosive demolition of structures, studies on progressive collapse resisting capacity depending on load redistribution are required. In this study, the progressive collapse analysis of a 10-story RC frame structure was performed by the applied element method for various 1st column removal cases. For each case, the progressive collapse resisting capacity of columns, girder, and slabs was evaluated by the increase rates of the vertical internal force in columns, the normal stress of reinforcing bars in girder, and the tensile stress of slab, respectively.
Analysis of Vertical Behavior of Flat Slab by Disassembling Procedures of Form-Shore System through Field Measurement
Kim, Seonwoong ; Na, Dong Soo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 75~82
DOI : 10.9798/KOSHAM.2013.13.6.075
This study investigated the structural stability of the flat slab through the field measurement for the vertical deflection of the flat slab in accordance with the disassembling procedures of the form-shore system under construction. From the field measurement results, it was found that the biggest affected factors on the vertical deflection of the flat slab in the disassembling procedures of the form-shore system under construction are the concrete placement in the upper floors and disassembling of the shore in the lower floors of the form-shore system. Moreover, if the flat slab stands alone by disassembling of the shore, the vertical displacement of the flat slab can be recovered the total vertical deflection of the flat slab of about 15 percent.
Estimation of Residual Strength and Analysis of Fire Resistant Performance Affecting Elements for Fire Damaged Reinforced Concrete Column
Yeo, In Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 83~89
DOI : 10.9798/KOSHAM.2013.13.6.083
This study aims to estimate the residual strength by experimental and analytic method and analyze the elements affecting fire resistant performance of reinfored concrete column. For predicting strength reduction rate and fire resistant rate of reinforced concrete column
isotherm method of EN 1992-1-2, a simplified calculation method, was used. The residual strength rate of reinforced concrete column, which is exposed to standard fire for 180 minute and assumed to bear the pure axial compressive force, was calculated with inner temperature data achieved from fire resistance test results. Further, the analysis of relations of fire resistance rate affecting elements for reinforced concrete member were performed. The residual strength rate of reinforced concrete column estimated in this study may be used as a significant information for establishing fire load factor and load ratio on performance based fire resistant design.
Evaluation on Fire Resistance of Ultra-High-Strength Concrete Depending on Aggregates and Fibers Types
Lee, Joo Ha ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 91~97
DOI : 10.9798/KOSHAM.2013.13.6.091
In this study, in order to evaluate the fire resistance of ultra-high-strength concrete (UHSC), short columns made of various experimental variables were tested with a standard heating curve of KS F 2257-1 for 3 hours. Especially, the effects of fibers and aggregates on fire resistance of UHSC were studied. The main parameters were the length of the polypropylene fibers, the fiber content ratios of polypropylene, nylon and steel, and aggregate types of conventional natural and electric arc furnace oxidising slag aggregates. The fire resistance performance was evaluated by comprehensively considering the weight loss, the spalling depth and the spalling area. In addition the residual compressive strength, carbonation depth, and microstructure were investigated after fire testing. As a result, hybrid fiber reinforcement of polypropylene, nylon and steel fibers enhanced the fire resistance performance of UHSC.
Fire Tests of Hybrid Fiber Reinforced Ultra-High-Strength Concrete Columns without and with Loading
Lee, Joo Ha ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 99~105
DOI : 10.9798/KOSHAM.2013.13.6.099
In this study, fire tests of ultra-high-strength concrete columns without and with column loading were performed to find out the fire resistance method and to evaluate the behavior under high temperature. Full scale column specimens were constructed with hybrid fiber reinforcement of polypropylene, nylon and steel fibers, and then fire tested with a standard heating curve of ISO 834 for 3 hours. From the fire tests, the residual compressive strength, temperature of steel rebar and concrete, spalling and crack patterns were observed and analysed. In addition, the axial deformation of columns subjected to column load was observed during the fire test. The fire test results without and with column load showed that 3 hours fire resistance of 200 MPa ultra-high-strength concrete columns could be obtained by hybrid fiber reinforcement of 0.2, 0.2 and 0.5 vol.% of polypropylene, nylon and steel fibers, respectively.
Flexural Behavior of Concrete Beams Reinforced with High-Strength Steel Bars
Moon, Do Young ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 107~113
DOI : 10.9798/KOSHAM.2013.13.6.107
Reducing the required amount of steel reinforcement is a main issue for saving cost. In this experimental study, high-strength materials were used for reducing amount of steel reinforcement in flexural members. Six beams were cast and tested under flexure. The yield strength of longitudinal steel reinforcement, compressive strength of concrete, and reinforcement ratio are considered to investigate their effect on load carrying capacity, load-displacement behavior, and ductility of the tested beams. Results demonstrated that a beam with concrete strength of 60MPa and with steel reinforcement with yield strength of 600MPa is more profitable compared to other beams in the viewpoint of load carrying capacity as well as ductility. Due to lower reinforcement ratio, the deflection for the beam reinforced with yield strength of 600MPa was greater than that of other beams but was within the amount presented in the KCI specifications for serviceability check. It is found that the equation for effective moment of inertia for calculation of deflection underestimated the actual deflection of the beam with concrete strength of 60MPa. Therefore, it is need to be modified.
A Study on the Temperature and Strength Variation of Steel Plate due to the Local Heating
Kang, Sunghoo ; Kim, Minjung ; Kim, Sunghwan ; Park, Sunjoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 115~121
DOI : 10.9798/KOSHAM.2013.13.6.115
In this study, the retention rate of heat that is generated when steel is locally heated by electrical means was quantitatively evaluated and changes in strength properties of the steel were investigated by experimentation. To do so, the experiment was conducted on specimens with thicknesses of 6 mm, 12 mm and 18 mm. With the limited conditions of this experiment, the steel plate was heated to at most
and the average heat retention rates at 200 mm and 400 mm away from this measurement point were 22.9% and 18.4%, respectively. For the results of the tensile strength test of the locally heated steel, a tensile strength of 400 MPa and yielding strength of 240 MPa that are required from SS400 were all satisfied regardless of the thickness of the steel specimen. In the case of percent elongation, all specimens showed values of 20-30% being within the normal range. The results of the indoor experiment with such restricted conditions showed that the performance of steel is not diminished when locally heated to temperatures of
Seismic Performance Evaluation of Modular-Road System
Roh, Hwasung ; Hwang, Woongik ; Song, Jae-Jun ; Park, Kyung-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 123~129
DOI : 10.9798/KOSHAM.2013.13.6.123
Concrete modular-road system has been proposed to accelerate construction speed and consists of columns, cross-beams, upper slabs, and anchor-bolt connections. In this study, the seismic performance of the single modular system is evaluated through a nonlinear time history analysis. The columns and cross-beams are modeled with inelastic frame elements while the upper slab and anchor-bolt connections are modeled with 3D solid element and three directional-nonlinear spring element, respectively. Also, the soil constraint effects around the embedded columns are considered using layered spring elements. The artificial input ground motions are generated for the operational and collapse prevention levels based on the Korean standard design spectrum classified with seismic level I. From the results, all structural components show an elastic behavior for the operational level and do not reaching their ultimate status for the collapse prevention level. It indicates that the modular-road system considered in this study satisfies the two seismic performance levels.
Joint Performance Evaluation and developement of Modular Road System
Park, Soobong ; Kim, WooSeok ; Song, JaeJoon ; Lee, SangYoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 131~137
DOI : 10.9798/KOSHAM.2013.13.6.131
This study intended to develop vertical joint system of modular roadway system for the use in Korea. Preliminary study was performed to determine appropriate support conditions for the precast concrete slab. Based on the preliminary analysis results, detailed finite element models were developed for a parametric study. Displacements at the top and bottom edges of the slab were checked to determine the required capacity of the horizontal sealing between the slabs, and the anchor bolt responses fixing the slab to crossbeams under the slab were also checked. Based on these results, this study proposed optimized slab sizes and support locations to minimize displacements and anchor bolt responses.
Bond Behavior of Prestressed CFRP Rod for Near Surface Mounted Strengthening
Lee, Woo Sung ; Lee, Hee Young ; Park, Jong Sup ; Kang, Jae Yoon ; Jung, Woo Tai ; Chung, Won Seok ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 139~144
DOI : 10.9798/KOSHAM.2013.13.6.139
The most common form of prestressed tendon is made of steel which is vulnerable to corrosion in aggressive environment. Recently, the NSM (Near Surface Mounted) strengthening using prestressed CFRP rod has been studied for improving the life of aging concrete bridges. Since prestressed CFRP rod has different material characteristics with respected to steel tendons, the bond characteristics between the CFRP rod and filler mortar in the sleeve must be thoroughly investigated. In this study, strength and additive of filler mortar was adopted as test parameters. Total 25 specimens were fabricated and pull-out tests were conducted. Bond behavior including bond strength and failure mode was analyzed and discussed. The strength of filler mortar was proposed to ensure the intended failure mode in the NSM sleeve.
Development of IDF Curves Based on RCP4.5 Scenario for 30-Reservoirs in South Korea
Park, Jihoon ; Kang, Moon Seong ; Song, Inhong ; Hwang, Soon Ho ; Song, Jung-Hun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 145~159
DOI : 10.9798/KOSHAM.2013.13.6.145
The main objective of this study is to evaluate the impact of climate change on Intensity-Duration-Frequency (IDF) curves for the selected 30-Reservoirs in South Korea. A bias inherent in future precipitation data based on Representative Concentration Pathways (RCP) scenario was corrected by a quantile mapping method. The trends in future precipitation changes were analyzed for the three different time periods (correspond to 2025s: 2011~2040, 2055s: 2041~2070, and 2085s: 2071~2100). Gumbel distribution was selected as the probability distribution and parameters were estimated by probability weighted moment method. Rainfall intensity of Han, Geum and Yeongsan river watersheds was greatly increased in 2085s period than 1990s period. Rainfall intensity of Nakdong river watershed appeared to increase sharply in 2025s period than 1990s period. The newly developed IDF curve might enhance the stability of agricultural reservoirs through considering climate change impact into structure design process.
Analysis of Landslide Characteristic During Joseon Dynasty through Historical Literature Survey
Lee, Changwoo ; Seo, Junpyo ; Kang, Youngho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 161~165
DOI : 10.9798/KOSHAM.2013.13.6.161
In this study, the characteristic and occurrence on landslide of Joseon Dynasty were analyzed in order to compare with those of the present. Using the historical records on the Annals of Joseon Dynasty(朝鮮王朝實錄). The daily records of royal secretariat of Joseon Dynasty(承政院日記) and Bibyeonsadeungnok(備邊司謄錄), the record of landslide, debris flow and rockfall of Joseon Dynasty was investigated. The major cause of landslide of Joseon Dynasty was rainfall that was occupied by 81%, the ratio of landslide occurrence per 50 years was similar to frequency of torrential rain for same period. The ratio of landslide damage by month was the highest in August(30.7%) and the next was the July(22.9%) and September(18.8%) in order. And the ratio of landslide damage by region was the highest in Kangwon province(16.3%) and the next was the Seoul city(14.4%), Gyeonggi(13.4%), Gyeongbuk(11.4%), Gyeongnam(10.9%) province in order. The result show that causes, occurrence period and the damage ratio by regional on landslide of Joseon Dynasty were similar to those of the present, but there was a little difference in the city area. These results will be helpful to predict landslide trend in the future and set up policy countermeasures for landslide.
Economic and Logistic Regression Analysis for Verifying of Validity of the Regeneration Project Policy for the Zones Vulnerable to Natural Disaster
Lee, Kyung Su ; Kim, Tae Hyeong ; Jung, Jae Kwang ; Ahn, Sang Jin ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 167~178
DOI : 10.9798/KOSHAM.2013.13.6.167
There are 1,210 Zones vulnerable to Natural Disaster in Korea until 2012. If it is designated as `the Zones Vulnerable to Natural Disaster` some budgets are assigned to repair and restoration. But it is difficult to predict the natural disaster, so the overall correspond strategies of the natural disasters are needed as aver. We tried to have expedient B/C analysis in different 20 districts and analyzed the difference of qualitative analysis effects". And we try to confirm the key points that need to manage the related works. To know these facts we analyzed how the qualitative elements effect to The B/C score using logistic regression analysis. According to this analysis, the average B/C score was 2.77 and it means there are average 2.77 B/C ratio. We analyzed the effects of the results based on the B/C 3.0. Related to the policy parts, the districts that have above 3.0 B/C score, overcome mental shocks easily, and they supported the policy more than any other districts, and the results was much better. According to the logistic regression analysis when the policy rationality increased, the probability of the B/C 3.0 score was more than 154%. The policy appropriateness was 52%, policy support was 66% and the mental shock overcome was 50% increased. Therefore the B/C results were related to the policy parts more than policy results.
Analysis of Slope Hazard-Triggering Rainfall and Geological Characteristics in 2011 and 2012
Hwang, Hyungun ; Lee, Seung Woo ; Kim, Gihong ; Choi, ByoungKoo ; Yune, Chan-Young ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 179~189
DOI : 10.9798/KOSHAM.2013.13.6.179
There has been many slope hazards due to heavy rainfall and typhoon in Korea. Recently, typhoon `Meari`, `Muifa` and heavy rainfall events in 2011, and typhoon `Sanba` in 2012 caused many slope disasters throught Korea, respectively. In this study, field investigation was conducted for the sites where the exact time and location of slope disaster were confirmed in 2011 and 2012 throughout Korea. Rainfall and geologic data for a total of 134 sites were collected as database and analyzed in various aspects. Analysis result showed that debris flow was the majority in numbers compared to the other types of slope hazard such as natural slope failure and artificial slope failure. Many slope hazards were occurred below the warning criteria of hourly rainfall. In addition the rainfall characteristics both in short term and long term period were critical for occurring the slope hazard. Result also confirm that metamorphic rocks were vulnerable to slope hazard.
Improvement of Technique for Analyzing Sheet Pile under Vibration
Lee, Seunghyun ; Kwon, Ohsoon ; Han, Jintae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 191~197
DOI : 10.9798/KOSHAM.2013.13.6.191
Improvement of existing analysis technique for analyzing sheet pile under vibration and analyses results were compared with existing field test results. Vertical displacement of the pile obtained from the improved technique showed that penetration rate decrease with increasing of penetration depth and displacement amplitudes were greater than the displacement for condition of idling of vibrator. It can be seen that load transfer curves obtained from the improved technique reflect the trends of variation of vertical displacement of pile with penetration depth and the maximum value of load transfer reasonably reflect the N value of the test ground. Comparing the penetration rates of the pile, penetration rates predicted by the improved technique were closer to the measured ones than those predicted by the existing technique.
Development and Evaluation of Analysis Technique for Piles Driven by Vibratory Pile Driver
Lee, Seung Hyun ; Jang, In Sung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 199~205
DOI : 10.9798/KOSHAM.2013.13.6.199
Technique for analyzing a pile installed by vibratory pile driver was developed and analyses were performed with varying system variables in order to evaluate reliability of the developed technique. Negative skin friction which defines dynamic skin load transfer curve seems to be obtained by trial and error method for the situation without static vertical load. Vertical displacment of the pile was proportional to the static vertical load. It can be seen acceleration of the pile was dependent on excitation force regardless of the negative skin friction and the static vertical load. Comparing the shapes of skin load transfer curves with static vertical load, amplitudes of the curves were nearly the same but it can be seen that the curves shift to upward. Maximum values of the toe load transfer curves were constant regardless of the negative skin friction and the static vertical load.
A Study on Stress Analysis of Epoxy Asphalt Pavement on Orthotropic Steel Bridge Deck
Jo, Shin Heang ; Kim, Nakseok ; Wee, Kwang Hwan ; Jung, Yoon Soo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 207~213
DOI : 10.9798/KOSHAM.2013.13.6.207
Epoxy asphalt is an excellent material for overlay of long-span bridges with orthotropic steel deck. The superior characteristics of epoxy asphalt allow epoxy asphalt overlay to be applied with a thickness of 5.0-5.5 cm, which can significantly reduce dead load and benefit the structural efficiency. With limited experience in the domestic market however, concerns still exists regarding higher risk of steel deck damage due to the thinner application of the overlay. In this study, structural analysis of an orthotropic steel deck with epoxy asphalt overlay is carried out to evaluate a field application example. Analysis results showed that deformation and tensile stress were very small, and shear stress between layers was smaller than bond strength. According to the analysis of study results, the epoxy asphalt pavement can provide sufficient stability and performance life as thin-overlay on orthotropic steel bridge deck.
Construction of FMD Investigation Mobile System for Real-Time Collection of Disease Spatial DB
Park, YeJin ; Yom, Jae-Hong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 215~221
DOI : 10.9798/KOSHAM.2013.13.6.215
The end of November 2010, foot-and-mouth disease(FMD) is damage occurred nationwide due to delay of preventive measures. It was analyzed that the spread range raised delayed propagation medium. It was regionally distributed a variety of information about FMD propagation medium and appeared limit of rapid making-decision and measure establish because it was` t collected farm`s visit information about quarantine measures. Therefore it is necessary to real-time analysis and collect distributed information considering the elements of the spatial. The study was designed spatial DB optimized scenario of FMD occurrence based location and constructed FMD investigation mobile webapp system of real-time DB of information of farm`s visitor using moility, accessibility, portability benefits of smart phone. This system understand immediately farm`s visit information and can be improved rapid making-decision and quarantine measures.
Assessment of Estimated Damage Area by CCTV Images: Case Study of Gumi Hydrofluoric Acid Gas Leakage
Lee, Mi-Ran ; Koo, Seul ; Shim, Jae-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 223~229
DOI : 10.9798/KOSHAM.2013.13.6.223
In this study, a new methodology is proposed to estimate the diffusion range and the damaged area by analysing the CCTV(Closed Circuit Television) image and aerial photograph for the Hydrofluoric Acid Gas leakage event in 2012. The CCTV images and the aerial photograph were used to estimate the diffusion direction of the gas and the damaged area respectively, which was verified by comparing with AWS(Automatic Weather System) observations around the scene of accidents. As the results, it was found that the damage area estimated by the new methodology could be within a 1km radius from the leakage point, which could not be found out through the coarse ground observations and the atmospheric dispersion modeling.
A Study on Demanded Competency of Emergency Manager in Korea
Bang, Ki-Sung ; Lee, Young-Jai ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 231~238
DOI : 10.9798/KOSHAM.2013.13.6.231
The research presented in this paper analyzes risk-related tasks of emergency managers and their employees in public organizations, and identifies competencies required to successfully perform risk management. The emergency management tasks performed in South Korea are summarized in 24 subsections under the categories of planning, situation management, resources management, and maintenance management. This is based on the emergency management standard; thirteen types of universal roles and competencies for emergency managers are drawn from international literature research. A survey of emergency management experts in South Korea gauges the level of competency required, using 13 competency factors and 24 task subsections. Results based on the data analysis demonstrated that the 13 competency variables can be condensed into 10 competency factors in Korea in terms of the awareness of managers. In addition, 3 core competencies (communication, public policy, and community engagement) are the most attributed (regardless of class) in the order based on competency demands. A great discrepancy between management and operation is also identified in the recognition of competency demands. This paper utilizes the performed analysis as a reference point for creating a competency development education program that adapts to differing levels of emergency managers.
A Study on the Methods to Analyze Climate Change Driven Urban Disaster Vulnerability for Disaster Preventive Urban Planning
Sim, Ou Bae ; Lee, Byoung Jae ; Lee, Chan Hee ; Kim, Jae Ho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 239~247
DOI : 10.9798/KOSHAM.2013.13.6.239
Because of climate change, urban disaster is gradually becoming larger and diversified. In order to create a safe city against disaster, urban planning including land use, infrastructure, buildings planning should consider disaster vulnerable areas in the city. On December 15th, 2011, Ministry of Land, Infrastructure and Transport revised urban planning guideline and started the disaster vulnerability analysis institution. Since July 1st, 2012, newly established urban planning should conduct the disaster vulnerability analysis and reflect it`s results. Therefore, in this study, domestic and foreign examples of climate change disaster vulnerability analysis were examined and the indicators for the disaster vulnerability analysis were established. For the practical analysis, the disaster vulnerability analysis indicators about current and future vulnerability for heavy rain, heat wave, heavy snow, drought, strong winds, sea level rise were drawn. Urban comprehensive disaster vulnerability can be analyzed by overlapping the current and future disaster vulnerability analysis results.
The Study for School Bullying Mitigation
Ryu, Junhyuk ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 249~256
DOI : 10.9798/KOSHAM.2013.13.6.249
The purpose of this study is examining risk factors that influence the possibility of school bullying victim. Especially, this study explored the relations between different types of bullying victims and risk factors including a large number of other characteristics that may affect bullying victimization. Research uses the data from Korea Child Youth Panel Study 2011. This study has shown that the range of characteristics related to bullying victim is wide and complex. In addition, this study has shown that students with some kinds of characteristics are more likely to be victims of specific types of bully. One consequence of these results is an increased awareness of the kinds of student who are at greatest risk of being bullies in middle school today. At last, this will suggest several study limitations and future research direction.
Estimation of Sediment Yield in a Disaster Area by a Fired Forest
Choo, Tai Ho ; Yoon, Hyeon Cheol ; Noh, Hyun Suk ; Ko, Hyun Soo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 257~263
DOI : 10.9798/KOSHAM.2013.13.6.257
As exposure of soil surface arises from completely burned vegetation caused by forest fire, the secondary damage is likely to happen due to sediment runoff during heavy rains. In order to mitigate sediment disaster the various methods have been conducted such as erosion control, forestation project and so on. However, the dangerousness is generally ignored because sediment yield can not be estimated by quantitative analysis in forest fire region as well as neighborhood. In the current study, therefore, the sediment yield and soil loss amount were estimated by using the RUSLE(Revised universal soil loss equation) based on GIS in study area. Also, the potential areas of soil disaster were visually proposed by estimating the soil loss amount each rainfall frequency to apply and implement erosion control project.
Study on the Development of CO-hybrid Single Station Detector
Jong, Jong-Jin ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 265~270
DOI : 10.9798/KOSHAM.2013.13.6.265
In this work, a CO-hybrid single station detector was developed that can detect not only the heat or smoke of a fire but also the incomplete combustion gas by adding a CO gas detector. This detector can be used for AC/DC, and it is a long-life(10 years) type to avoid frequent replacements of the battery. In addition, the tests were carried out in the certified laboratory in order to verify a reliability of the detector. As a results, it was verified that current consumption of the developed detector is less than those of domestic or foreign detectors.
A Study on the Knuckle Crane Truck Fire Caused by a Short during Expressway Driving
Lee, Euipyeong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 271~281
DOI : 10.9798/KOSHAM.2013.13.6.271
1,003 automotive fires broke out in the expressway in 2012 in Korea. Although truck fires accounted for 43.8%(489), there are few researches on the truck fires in the expressway. This study analyzed the cause of the knuckle crane truck fire breaking out during expressway driving. The truck was purchased 50 days ago and its mileage was 6,000 km. The results of analysis suggested that the fire was caused by a short made by a conductor touching an iron support because of damaged coating of wire harness wiring from the penetration of the body frame on the right of an engine room to the driver room.
A Study on the Characteristics of Smoke Control Using Lower Part Pressurization with an Opening in a Large Scale Space
Ju, Hyeon-Don ; Ahn, Dae-Young ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 283~291
DOI : 10.9798/KOSHAM.2013.13.6.283
Smoke control systems of an atrium keep occupants safe from smoke generated during unwanted fires. The two-zone layer interface of the atrium is clearer than small room or corridor. Smoke control in large spaces are achieved using pressurization of the lower layer by mechanical ventilation. The objective of this study are to calculate the inflow and outflow mass rates through the upper and lower opening of the atrium, to study the lower part pressurization with or without the lower opening of the atrium, and to predict the steady-state smoke layer height which the mass outflow rate through the upper opening is more or less equal to the mass rate of fire plume. The smoke layer height are analyzed by FDS developed by the National Institute of Standard and Technology, USA. The part of analyzed results by FDS are compared with the experimental results performed by Yamana and Tanaka. It is known that the lower part pressurization smoke control for the mass flow of the lower opening directing into the atrium from outside were superior to the smoke control directing into the outside from the atrium.
An Experimental Study on the Effective Using of Fire Department Connection in High-rise Building
Kim, Eung-Jin ; Kim, Hyung-Yel ; Kim, Hak-Joong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 293~297
DOI : 10.9798/KOSHAM.2013.13.6.293
Recently, the building has been higher and more complicated. High-rise buildings are more dangerous when fire occurs because of fast fire spreading through vertical space. This makes difficulty for fire fighter`s moving when they suppress fire. The pump impeller will be obstacle when fire water is supplied from fire department connection, if the power is failure or the pump is breakdown. This study identifies the defect of fire department connection system and compensates that. It is verified the difference of flow rate and pressure in the case through pump impeller and in the case through bypass piping by test. Based on the result of this study, it suggest that the installation of bypass piping at the discharge side of pressurization pump have to be prepared in case of pressurization pump stopping.
Establishment Scheme of Seismic Performance Objectives of Facilities for Naional Earthquake-Risk Management
Kim, Ickhyun ; Sun, Changho ; Park, Kwangsoon ; Seo, Hyeongyeol ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 299~304
DOI : 10.9798/KOSHAM.2013.13.6.299
Generally, seismic performance objective of facilities is to minimize casualties by preventing collapse. Thanks to this performance the casualties in the past earthquakes were minimized in the advanced seismic engineering countries. However, they suffered from a great effort of recovering a social function because of heavy economical damage, which led a new seismic design paradigm to expand the current No-Collapse performance into Damage-controlled one. Because the seismic performance of our facilities is similar a severe damage will be led in earthquakes, which should be an obstacle in a rapid recovery of social system. The damage level should be restricted under a controlling level for a national earthquake-risk management and the performance of facilities should be assigned to meet this purpose. In this study the establishment scheme of seismic performance of facilities has been proposed to satisfy national seismic performance objective established in advance.
Seismic Hazard Assessment of Architectural Heritage: Buyeo Historic City
Hwang, Hea Jin ; Kim, Dong Soo ; Park, Hyung Choon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 305~314
DOI : 10.9798/KOSHAM.2013.13.6.305
Architectural heritage should be safely conserved as historic assets. Recently, frequency and magnitude of earthquake has dramatically increased. Accordingly, disaster prevention for heritage conservation is required. This study is a geotechnical perspective for heritage conservation. It assess the seismic risk of architectural heritage and the historic city. The hazard occuring in structure such as architectural heritage arise from earthquake ground motion is largely influenced by the local site condition. Therefore, seimsmic hazard to heritage can be indirectly assessed through the assessment on the ground motion. In this study, seismic hazard of Buyeo historic city where is located a lot of heritage is assessed by site investigation and site-specific ground analysis.
The Re-evaluation of the Potential Seismic Hazard in Relation to Nuclear Power Plants of Korea
Kim, So Gu ; Lee, Seoungkyu ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 315~325
DOI : 10.9798/KOSHAM.2013.13.6.315
The seismic hazard of the southeastern part of the Korean peninsula is re-evaluated in relation to safety of nuclear power plants. We take into account two main factors such as seismic hazard with active faults and tsunami occurrences. Major seismic hazard re-evaluation is performed by mechanism of earthquakes and relocation of active faults including tsunami phenomena. The basic relationship between an earthquake strong motion in terms of gravity (g) and magnitude is clearly demonstrated for an earthquake resistant design in nuclear power plants. At present we are operating 23 nuclear power plants and we will increase more nuclear power plants in the next decade. Nevertheless the nuclear power plants in the southeastern part of Korea are not free from seismic hazard in the light of recent seismicity - Pohang Earthquake on April 15, 1981 (M
A Comparison Study of the Dynamic Amplification Characteristics of the Major Domestic Seismic Observation Sites using Background Noise and S-wave Energy of Ground Motions from 15 Fukuoka Earthquakes Series
Kim, Jun Kyoung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 327~334
DOI : 10.9798/KOSHAM.2013.13.6.327
Observed ground motions are mainly composed of 3 main factors such as seismic source, seismic wave attenuation and site amplification. Among them, site amplification is also important factor and should be considered to estimate soil-structure dynamic interaction with more reliability. Though various estimation methods are suggested, this study used the method by Castro et al. (1997) for estimating site amplification. This method has been extended to background noise, coda waves and S waves recently for estimating site amplification. This study applied the Castro et al. (1997)`s method to the background noise. This study analysed more than 298 background noises from 15 macro earthquakes including main Fukuoka earthquake (2005/03/20, M
Behavior of Geogrid-Sandy Soil Interface due to Cyclic Load
Yoo, Ji Hyeung ; Park, Inn Joon ; Kim, Dae Sung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 335~342
DOI : 10.9798/KOSHAM.2013.13.6.335
This study is to apply and complement disturbed function(D), deviatoric plastic strain trajectory(
) using multi-purpose interface apparatus(M-PIA) developed to analyze the features of the shear stress and the relative displacement on geosynthetic-soil interface of reinforced earth retaining wall when the cyclic dynamic load is pressed. In addition, the feature of shear failure of geogrid- sandy soil interface of reinforced earth retaining wall by cyclic dynamic load was drawn and the parameter disturbed state concept(DSC) constitutive model was calculated by presenting the regression line of the Disturbed functional formula modified from laboratory test data. On the other hand, the program has been designed using FISH language in order to connect these values to FLAC, numerical analysis program and the simulation test was done by using numerical analysis model so that dynamic correlation system method of geogrid-sandy soil was verified in reinforced earth retaining wall.
Development of Design Flood Estimation System for Mountainous River Basin Using Fuzzy Regression Method
Yi, Jaeeung ; Lee, Taegeun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 343~350
DOI : 10.9798/KOSHAM.2013.13.6.343
Recently, enormous human and property damages have occurred frequently by flood and debris-flow in mountainous river basin. In order to minimize these damages, the reliable estimation of flood runoff is required. However, when analyzing flood runoff in small streams in mountainous river basin, this process is difficult to perform properly due to the complication of the process and data requirement. Besides, for floods occurring in mountainous river basin, it is difficult to calculate accurate flood runoff since flow velocity is fast and concentration time is short. In order to resolve these difficulties, the method which can estimate flood runoff at arbitrary point in the mountainous river is developed with relatively high accuracy by using fuzzy regression analysis techniques with the basin area and the channel slope as input data. In this study, the previously developed methods are improved to reduce uncertainty and to estimate flood runoff with enhanced accuracy by adding a new variable that represents hydrologic characteristics at a arbitrary point in a basin in addition to both basin area and channel slope. Accuracy analysis result showed improved accuracy than conventional method and uncertainty was reduced to approximately 1/2~1/3. The a flood estimation program is developed for mountainous river so that general users can easily estimate flood runoff in practice.
Optimal Design of Agricultural Irrigation Systems Considering System Reliability
Lee, Young Jin ; Kim, Kyung Wan ; Kang, Doosun ; Kim, Young Hwa ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 351~358
DOI : 10.9798/KOSHAM.2013.13.6.351
Agricultural irrigation system is required to be designed economically and should be reliable with minimal suspension in water supply. This study suggests a multi-criteria design approach for irrigation pipe network systems. A system reliability is suggested as a second objective, which is defined as annual non-supplied volume of water by considering pipe failure. The non-supplied water is quantified based on the expected number of pipe failure and pipe repair time. A hydraulic simulator(EPANET) is linked with a heuristic-search optimization algorithm(Genetic Algorithm, GA) for least-cost system design. Once the least-cost design is determined, the system reliability is calculated for the obtained optimal design. In order to evaluate the relation between system cost and water-supply reliability, three layouts(two branch- and a looped-networks) were suggested for least-cost design and reliability estimation. The application results showed that the multi-criteria design approach is superior than single-objective design scheme by providing decision makers with additional information to determine optimal designs.
Improved Approach for Optimal Design of Agricultural Irrigation System
Kim, Kyungwan ; Lee, Youngjin ; Kang, Doosun ; Kim, Younghwa ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 359~365
DOI : 10.9798/KOSHAM.2013.13.6.359
Traditionally, open channel flow systems have been mainly utilized for agricultural irrigation water supply. To date, a pipe network system is gaining spotlight as an alternative in this field for reliable and efficient water supply. Optimization techniques are beneficial for least-cost design of large-scale irrigation systems. Previous optimization techniques, however, had drawback in terms of computational efficiency when applied to a large scale system with lots of decision variables, and often provided solutions not applicable to real network design. In this study, an improved approach for determining optimal diameter of agricultural pipe systems are proposed. The model consists of a heuristic search approach, Genetic Algorithm (GA), and a hydraulic simulator, EPANET. Instead of using random initial population for GA, a strategic initial population was constructed and provided from a pre-processing based on iterative hydraulic analyses. The proposed approach enabled the optimal design to be found and improved computational efficiency of GA. The developed model was applied to a large-scale irrigation network and optimal designs were obtained with lower economic cost yet better hydraulic performances. This paper describes the proposed approach utilizing the strategic initial population and the application procedures and results are discussed.
A Methodology for Flood Forecasting and Warning Based on the Characteristic of Observed Water Levels Between Upstream and Downstream
Jun, Hwandon ; Lee, Jiho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 367~374
DOI : 10.9798/KOSHAM.2013.13.6.367
For flood forecasting and warning in rivers, it may be a better way to use observed water levels between upstream and downstream, instead of using the rainfall-runoff models such as the storage function method, to minimize the error involved in flood forecasting. In addition, the advanced time should be acquired to prepare the disaster mitigation action to minimize flood damages. For this purpose, in this study, we suggest a flood forecasting and warning methodology which is able to predict downstream water levels at the point of flood forecasting in short time period, based on the currently observed upstream water levels. Applying the Artificial Neural Network to the currently observed upstream water levels, we can predict water levels at a flood forecasting region which may occur within 30 minutes. After the suggested method is applied to the upstream Nam-gang watershed in the Nakdong-River basin, it is concluded that the method can predict downstream water levels in certain accuracy and will be used as a flood forecasting and warning system in the region.
Hydraulic Model Test on Scour Protection with Scale Effect
Kim, Changsung ; Kim, Jongtae ; Kang, Joongu ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 375~379
DOI : 10.9798/KOSHAM.2013.13.6.375
The objective of this paper is to figure out critical velocity of SPF(Scouring Protection Form) method that is installed to prevent dam and weir of scour. Through hydraulic experiments, critical flow of SPF was evaluated by making scale model of bed protection. The destruction flow velocity analyzed 5.57 m/s, 4.08 m/s in actuality rivers manufacturing 1/10 miniature. In case of 1/20 scale, the destruction flow velocity was 5.55 m/s, 4.32 m/s and 5.00 m/s, 4.31 m/s as a scale of 1/30 and 4.09 m/s, 4.65 m/s as a scale of 1/50 respectively. Scale model ratio is directly proportional to critical tractive force and scale model size is inversely proportional to critical tractive force. As a result, the hydraulic test showed to need the hydraulic model experiment over 1/20 scale when evaluating structures such as SPF mat that have to be able to withstand strong turbulence.
Development of Comprehensive Flood Forecasting Models for Main Tributaries in the Han River and Parameter Optimization
Park, Hee-Seong ; Chung, Gunhui ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 381~391
DOI : 10.9798/KOSHAM.2013.13.6.381
In this study, comprehensive flood forecasting model for main tributaries in the Han river was developed using the model structures of comprehensive 4 rivers flood forecasting model newly coded in 2012. The main tributaries in the Han river is Joong-Rang Cheon, Wang-Seok Cheon, Tan Cheon, and An-Yang Cheon. The optimized parameters in the tributaries were proposed as well. In the tributaries, because of the short forecasting time, the model parameters tend to be determined in each basin. Therefore, the optimized parameters in the newly developed flood forecasting model were proposed. Storage function method is also utilized in the comprehensive flood forecasting model with the combination of the subsurface flow model which is for calculating infiltration, percolation, and groundwater flow. Therefore, the newly developed flood forecasting is applicable in the long-term river flow forecasting. The 2-stage optimization was proposed. In the first stage, parameters in the subsurface flow model were optimized using a long-term rainfall-runoff data, and the parameters for the storage function method were optimized in the second stage using the rainfall events. A range of the optimized parameters was presented, from which the sensitivities and the parameters could be estimated. However, the understandable interpretation about the ranged parameters was not possible. Therefore, the representative parameters were proposed using weighted average, middle value, and representative rainfall events. As a result, the parameter value which provide the smallest error was selected as the final proposed parameter. It could improve the efficiency of the runoff forecasting in the practical application.
Numerical Simulation for Run-up of Solitary Wave on Slopes
Jung, Wooyoung ; Wang, Taekwon ; Cho, Yong-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 393~399
DOI : 10.9798/KOSHAM.2013.13.6.393
An accurate analysis of incident waves around coastal structures is directly indispensable to the safety of those structures. Thus, a three-dimensional numerical model is strongly recommended to analyze wave transformation instead of a two-dimensional model. In this study, a numerical model solves the space-filtered averaged Navier-Stokes equations. The LES approach is adopted to model the turbulence effect by using the Smagorinsky SGS model. The solitary waves are probably most suitable incident waves representing behaviors of tsunamis and they can propagate a long distance without transformation. The maximum run-up heights of solitary waves attacking on slopes are investigated and the accuracy of the numerical model is checked by comparing the laboratory measurements related to maximum run-up heights of solitary waves.
Evaluation of Ultrasonic Oxidation of Diethyl Phthalate Using Box-Behnken Design with Response Surface Methodology
Cui, Mingcan ; Jang, Min ; Kang, Kyounglim ; Kim, Duk Min ; Kim, Seoungsup ; Khim, Jeehyeong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 401~409
DOI : 10.9798/KOSHAM.2013.13.6.401
The kinetic constant of diethyl phthalate (DEP) oxidized by ultrasound was measured as a function of ultrasound power density,
concentration and solution temperature. The ultrasonic oxidation kinetic of DEP could be described by the pseudo-first-order reaction d[DEP]/dt
EMC Analysis by Land Use Types based on Long-term Monitoring of Nonpoint Source Pollution in Geum River Basin
Lee, Jung Ho ; Song, Yang Ho ; Kim, Dongho ; Park, Suyoung ; Kim, Jiyeon ; Park, Moo Jong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 411~422
DOI : 10.9798/KOSHAM.2013.13.6.411
During the dry periods, many types of pollutants are being accumulated on the land surface and the accumulated various pollutants are inflowing in th the near watershed areas for the rainfall periods. Then, the monitoring study needs to analysis of the pollutant loads and an establishment of a management plan for nonpoint source. The aims of this study are the characterization of discharge from nonpoint source, the analysis of the pollutant loads and an establishment of a management plan for nonpoint source of Geum river basin. For this purpose, 7 monitoring points was selected to the investigated. During the period from April, 2008 to August, 2013, the water automatic sampler system has been installed in each monitoring points. Event Mean Concentration(EMC) of
, SS was calculated based on the monitoring data of 318 rainfall events at 7 monitoring points. The land use of the studied basins were divided into forested land and grassland. As the results, a significant relationship was observed from the correlation between EMCs and rainfall characteristics. The present study is achieved to provide the correlation between rainfall events and nonpoint source pollutants. And the data which were build up in this study will contribute to establish the management policy for the nonpoint source pollutants.
The Effect Analysis of Climate and Watershed Characteristics on Precipitation Partitioning in Nakdong River Basin
Park, Yoonkyung ; Choi, Daegyu ; Kim, Jeongsook ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 423~428
DOI : 10.9798/KOSHAM.2013.13.6.423
First, precipitation is infiltrated into subsurface or is discharged through surface. Infiltration water is discharged into groundwater or is evaporated. This is called precipitation partitioning. This phenomenon can be quantified by the Horton index. This study analyzed effect of climate and watershed characteristics on precipitation partitioning using the Horton index. In the Nakdong river basin, the Horton index is primarily affected by precipitation of climate factors. Considering precipitation and landscape characteristics of watershed, predictability of the Horton index is improved. Especially, average slope of watershed is significant indicator among landscape characteristics.
Temporal and Spatial Analysis of Water Quality Data Observed in Lower Watershed of Nam River Dam
Kim, Gyeong-Hoon ; Jung, Kang-Young ; Yoon, Jong-Su ; Cheon, Se-Uk ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 429~437
DOI : 10.9798/KOSHAM.2013.13.6.429
Despite the Implementation of TMDL, the water quality in lower watershed of Nam river dam has worsened continuously since 2005. Multifarious pollution sources such as cities and industrial districts are scattered around it. Nam river downstream bed slope is very gentle towards the downstream water flow of slows it down even more, depending on the water quality deterioration is accelerated eutrophication occurs. In this study, Nam River targets the mainstream by observation station looking at the status of water quality, water quality temporal and spatial characteristics of each analyzed station by station. The chemical and physical water quality in phytoplankton(Chl-a) to assess the impact on growth correlation analysis and multivariate analysis was performed. This section focused on the Nam River mainstream considering the temporal and spatial characteristics attributable to analyze water quality target for water quality management to help achieve the aims.
Analysis and Prediction on Water Quality Improvements by Aquatic Plants in a Storage
Kim, Eung Seok ; Sim, Kuy Bum ; Chung, Gunhui ; Choi, Hyun Il ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 439~446
DOI : 10.9798/KOSHAM.2013.13.6.439
The different types of influent pollutants due to the urbanization has exceeded the self-purification capacity in storage, and the water quality degradation and ecosystem destruction have been the main concerns in the urban area. Since the selected Garakbawi storage was the leisure area of the local residents, located in Asan-si Tangjung-Myeon where is the newly urbanized area, this study has analyzed the degree of water quality improvement by using eco-friendly aquatic plants. For the qualitative analysis on the water quality improvement abilities of the aquatic plants, the required water surface area was estimated by literatures on the pollutant load removal efficiency with respect to the water quality scenarios such as 10%, 25%, and 30% improvements of TN and TP, which are known as the main reason of eutrophication. This study has also implemented WASP7 model under the above water quality improvement scenarios to predict water pollutant concentrations on the inlet and outlet points of the storage in 2013. The WASP7 simulation results show that the water quality concentrations were improved at the outlet of the storage as about 13.4% of TN and 14.81% of TP under the 10% water quality improvement scenario, as about 22% of both TN and TP under the 25% water quality improvement scenario, and as about 25% of both TN and TP under the 30% water quality improvement scenario, respectively. It would be concluded that the construction of an artificial floating island in Garakbawi storage is not only a good ecofriendly approach for water quality improvements but also the most efficient restoration method.
Evaluation of Water Quality Monitoring Network in Geum River System Using Entropy Theory
Lee, Jung Ho ; Song, Yang Ho ; Hong, Seonhwa ; Kim, Dongho ; Lee, Soohyung ; Park, Moo Jong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 6, 2013, Pages 447~453
DOI : 10.9798/KOSHAM.2013.13.6.447
Entropy theory was applied to generate standards for the assessment of the optimal water quality monitoring network. The entropy theory considers the trans-information among both locations where water quality monitoring facilities are installed and locations without such facilities. Therefore, the theory can support the establishment of the water quality monitoring network by reducing the uncertainty on the basis of information produced by the network. This study has been applied to Geum river system to evaluate if the current network for each water quality item is in proper level. In the results, The order of significant sites is different for each water quality item. It is because each water quality item has different influence factors. The pattern of information increase from an additional site is different from each water quality items. For some items (BOD, pH, T-N) the total information stagnates after a certain number of sites, however, for others (COD, SS, T-P) it still increases almost linearly as a new site is added. This means that the current monitoring network has insufficient number of sites for some water quality items.