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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 14, Issue 6 - Dec 2014
Volume 14, Issue 5 - Oct 2014
Volume 14, Issue 4 - Aug 2014
Volume 14, Issue 3 - Jun 2014
Volume 14, Issue 2 - Apr 2014
Volume 14, Issue 1 - Feb 2014
Selecting the target year
Mechanical, Thermal and Flame Retardant Characteristics for Wood Flour-Polypropylene Composites
Park, Kihun ; Shin, Baegwoo ; Jhee, Kwang-Hwan ; Bang, Daesuk ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 1~6
DOI : 10.9798/KOSHAM.2014.14.2.1
We manufactured wood flour-polypropylene(PP) composites by a modular intermeshing co-rotating twin screw extruder. The limiting oxygen index(LOI) and cone calorimeter experiments were carried out in order to analyze flame retardant characteristics. And mechanical properties were measured by universal testing machine(UTM). The specimens for these tests were prepared by adding four types of flame retardants such as DBDPO(decabromodiphenyl oxide), APP(ammonium polyphosphate), ATH(aluminium trihydroxide) and MP(melamine phosphate). It was found that mechanical properties of the composites with flame retardants showed higher tensile strength and flexural strength than those of control wood flour-PP composites. Also the results of cone calorimeter test indicated that adding flame retardants produced lower heat release rate and mean heat release rate compared to the wood flour-PP composites. Among the four flame retardants, melamine phosphate had the most effective flame retarding characteristics.
A Study on the Prediction of Fire Growth Rate During Initial Fire for Performance Fire Safety Design
Seo, Dong Goo ; Kim, Dong Eun ; Kim, Jeong Hee ; Kim, Dong Jun ; Kwon, Young Jin ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 7~14
DOI : 10.9798/KOSHAM.2014.14.2.7
This study is experimentally examining initial fire behavior important for evacuation safety in order to establish performance-based fire safety design, centering on combustibles. Relation between fire load and heat release rate was examined through an experiment in order to establish a method that could predict initial fire behavior. Besides, initial fire behavior was investigated through comparison with the results derived from real scale fire experiment by using the conventional studied fire growth rate model. As a result, in case fire load was
or over, it was difficult to be derived by using the conventional dynamics equation, but its regression equation could be derived through experimental study. Also, it was verified that a large effect was produced on the initial fire behavior according to the ignition source and arrangement of combustibles.
Evaluation of Structural Performance of Diagrid Node Subjected to Vertical Loads
Jung, In Yong ; Kim, Jin Kyu ; Ju, Young Kyu ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 15~22
DOI : 10.9798/KOSHAM.2014.14.2.15
With various node types in a diagrid structural system, more and more free form buildings have been constructed these days. However, few studies have been carried out on the structural performance of a diagrid node. In this paper, vertical resistance of four different types of a diagrid node, where the shape of a brace member, overlapped length of plates, and welding methods are considered as primal parameters, is experimentally tested and investigated. Under compression tests, all the specimens show strength degradation with out-of-plane deformation. Vertical resistance is identical between each type of diagrid nodes, except for MB type. Also, it is found that the welding method did not affect the performance of MA type specimen.
Seismic Performance Evaluation of H-section Steel Column New Shape Weak-Axis Connection for Constructability
Kim, Sung Bae ; Cho, Han Sol ; Lee, Tae Gyu ; Kim, Sang Seup ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 23~33
DOI : 10.9798/KOSHAM.2014.14.2.23
H-section steel column new shape weak-axis was developed and performed through monotonic loading test regarding basic structural performance evaluation. In this study cyclic loading test was followed up in order to evaluate seismic performance through the full-scale of new shape weak-axis connection for constructabilitiy. 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, three specimens are built for the variables which are overlap length of beam-end and column flange. As the result, New shape of weak-axis connection is appeared special Moment Frame(SMF) and have excellent structural performance and constructablility when the parameter is over 50 mm.
Analytical Study on the Optimum Design of Hybrid Buckling-Restrained Braces
Kim, Myeong Han ; Yoon, Sung-Won ; Ju, Young-Kyu ; Kim, Do-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 35~41
DOI : 10.9798/KOSHAM.2014.14.2.35
Buckling-Restrained Braces (BRBs) are not able to dissipate the energy under minor earthquakes or wind loads. Hybrid Buckling-Restrained Braces (H-BRBs) which are composed of a viscoelastic damper and BRB have been developed to improve the performance of BRBs. In this paper, time history analyses were performed to investigate how the position and range of H-BRBs have an influence on the optimum design of tall buildings. Wind force data (10 year return period) obtained from wind tunnel test was used in the time history analysis. It is concluded that H-BRB applied at the bottom of building is effective to reduce the story displacement and H-BRB applied at the top and bottom of building is able to improve the serviceability of the building. Also it is effective to control serviceability when H-BRBs are installed at the top of the building in the efficiency of H-BRB.
Evaluation on Structural Performance of Hybrid Friction Damper Components I: One-nodal Rotary Frictional Component
Kim, Do-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 43~50
DOI : 10.9798/KOSHAM.2014.14.2.43
As tall buildings have increased in Korea, various dampers have been applied. In order to minimize the space, cost and construction process, the new hybrid friction damper which can be installed at a coupled beam was developed. This damper, which is composed of two one-nodal rotary frictional components and a slotted bolted frictional component, is able to operate at various displacements of building. In this study, dependency tests were carried out to evaluate on the structural performance of one-nodal rotary frictional component. Test results show that one-nodal rotary frictional component does not depend on a displacement, a frequency and a long term loading. However friction coefficient is reducing as a clamping force is increasing.
Second Order Temporal Finite Element Methods in Linear Elasticity through the Extended Framework of Hamilton's Principle
Kim, Jinkyu ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 51~58
DOI : 10.9798/KOSHAM.2014.14.2.51
The extended framework of Hamilton's principle provides new rigorous weak variational formalism for a broad range of initial boundary value problems in mathematical physics and mechanics. In this paper, its potential in the development of numerical methods for transient problems in various dynamical systems, when adopting temporally second order approximation is investigated. For this, linear elastic single-degree-of-freedom systems are primarily considered to investigate computational characteristics of the developed numerical algorithms. For the undamped system, all the algorithms are symplectic and unconditionally stable with respect to the time step. For the damped system, they are shown to be accurate with good convergence characteristics.
Study of Soil-Structure-Structure Interaction on Earthquake Response with Different Foundation Arrangement
Kim, Dong Woo ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 59~66
DOI : 10.9798/KOSHAM.2014.14.2.59
The aim of this paper is to study the interaction between adjacent buildings with different foundation levels under earthquake loading conditions. Buildings and soil are represented by three different models. In the first and second cases the building itself is modeled with standard frame and equivalent bar element, whereas the soil behavior is stimulated by a special grid model. In the third case, the building and soil are represented by plane stress or plane strain elements. The modulus of elasticity of the ground is varied. Just like the modification of the modulus of elasticity the varying relations of inertia have a strong influence on the section forces within the buildings. The analysis is carried out using numerical program which has developed based on the axisymmetric fine element method in corporation of rough element for soil region and wave input technique transit boundary condition. Interaction of the proposed method is demonstrated in numerical examples.
Study of Deterioration Prediction Model of Water Distribution System Using the Development of Method of the Amend Indirect Condition Assessment
Park, MiYun ; Sho, ByungChoon ; Park, JaeHak ; Kim, KwangHo ; Sim, JaeHo ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 67~76
DOI : 10.9798/KOSHAM.2014.14.2.67
Korea's rapid ubanization development has changed the country, water and waste water facilities also has been continuously increased. Especially in the 80's and 90's, a lot of Pipe had been installed and Pipe network has rapidly extented, and those are over 40~50 years old. The concurrent increase of the replacement arrival period makes a large of national financial burden on government and society. For this reason, to build the appropriate and reasonable budget investment strategy, the determination of introduction of asset management system about water treatment and wastewater facilities is desperately needed. Thus, in this study, a pilot area for a particular technology to assess the current state of the diagnostic evaluation and safety inspection of the facility safety analysis to compare the result to derive the correlation between the two diagnostics, environmental characteristics, and tend to apply the aging of Water Distribution System the aging of the proposed prediction model. To assess the level of the facilities at the present time, and it's based on the long-term national plan for infrastructure asset management is a very important part seems to be able to be utilized.
Prediction of Chloride Penetration into Concrete Pavement under Deicing Chemicals
Na, Okpin ; Lee, Jaesung ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 77~83
DOI : 10.9798/KOSHAM.2014.14.2.77
Deicing chemicals have been used to prevent the freezing of concrete pavement during winter season and the usage amount of the chemicals is increasing every year. Deicing chemicals gradually penetrate into concrete and exacerbate the concrete damage originating from freezing and thawing. The purpose of this study is to carry out the chloride penetration analysis with Nernst-plank equation and numerical model. In this study, the transport phenomenon of various deicing chemicals such as Nacl,
into concrete was expressed with electro-neutrality condition and electric potential. Nernst-plank equation was substituted into fick's second law and material model was considered with curing, water-cement ratio, temperature, moisture, and free chloride and so on. This mathematical model can be solved with finite element method, one of the numerical methods. As the results, this model was well agreed with experimental results and the diffusion analysis of other chemical ions into concrete can be predicted as well.
Validation of Multi-satellite Precipitation Products for Assessing their Potential Utility of Hydrological Application Over South Korea
Kim, Jong Pil ; Park, Kyung-Won ; Jung, Il-Won ; Kim, Gwangseob ; Yoon, Sun-Kwon ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 85~96
DOI : 10.9798/KOSHAM.2014.14.2.85
Multi-satellite precipitation products can provide possible opportunity for diverse hydrological applications in Korea. This study investigated the potential utility of three multi-satellite precipitation estimates, including TRMM(Tropical Rainfall Measuring Mission) 3B42v6, CMORPH(Climate Prediction Center Morphing), and GSMaP(Global Satellite Mapping of Precipitation)-MVK(Moving Vector with Kalman filter), from 2002 to 2009 by comparing with ground-gauged precipitation data over four major river basins of South Korea. The results showed that the frequency and amount of TRMM 3B42v6 estimates agreed well with observations at daily scale. However, CMORPH and GSMaP-MVK exhibited relatively poor performance than TRMM 3B42v6 with significantly underestimated precipitation. Overall, our results were consistent across four major river basins.
Snow Disaster Risk Index in the Ulsan Metropolitan City
Park, Hee-Seong ; Lee, Seung Joon ; Yu, Insang ; Jeong, Sangman ; Chung, Gunhui ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 97~106
DOI : 10.9798/KOSHAM.2014.14.2.97
In this study, Snow Disaster Risk Index(SDRI) is proposed using PSR analysis to prepare heavy snowfall and distinguish snow disaster vulnerable area. Proxy variables to calculate Pressure Index(PI), State Index(SI), and Response Index(RI) are selected in the Ulsan metropolitan city. The weights of the proxy variables are determined using AHP method which uses a pairwise comparison survey and Entropy theory based on variation of the data. PI, SI, and RI were calculated using those weights and SDRI is provided. As a result, SDRI is higher with respect to the aspect and slope of the region. The weights calculated using entropy theory have relatively equivalent values, thus, AHP method provides bigger discrepancy than entropy theory on the final SDRI. Both methods proposed that the Ulsan metropolitan city has low snow disaster risk, and the results could be used as the basic information for snow disaster risk mitigation policy.
Investigation of Behavior of Suction Caisson Anchors based on Single-Wall and Double-Wall Model Caissons
Kim, Yusuk ; Teodosio, Bertrand ; Ahn, Jaehun ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 107~113
DOI : 10.9798/KOSHAM.2014.14.2.107
Wind power presently reflects a very promising source of renewable energy. The optimal type of foundations for offshore wind turbines, in very deep water, is the floating type; the research on floating wind turbines is very active worldwide. It is essential to develop anchoring system for floating structures, and the suction caisson anchor is one of most widerly used in deep oceans. This paper addresses the anchor holding capacity of suction caisson anchors under vertical pull-out, and friction and reverse end bearing coefficients based on mode tests. The values of friction and reverse end bearing coefficients put in similar ranges with literature values, but are still lower than those suggested in design guides. It is, therefore, suggested the current model tests may predict qualitative trends of suction caission anchors' behaviors. As subsequential works, based on current results, it is planned to conduct cyclic tests to estimate the permanent behavior of anchors under oceanic environments.
Analysis of Landslide Triggering Rainfall Threshold for Prediction of Landslide Occurrence
Oh, Jeongrim ; Park, Hyuck Jin ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 115~129
DOI : 10.9798/KOSHAM.2014.14.2.115
Landslide occurs mostly during rainy seasons in Korea, and rainfall is the largest factor causing landslides. This study is intended to establish the rainfall standard to predict the risk of landslides, taking into account of regional/geological characteristics. To that end, historical data of landslides and rainfall data were investigated and analyzed. To predict the landslide risk using rainfall data, rainfall data which were related to causing landslide previously, was selected and analyzed to establish the rainfall standards and real-time rainfall approach was applied to establish the rainfall standards and determine the potential risk. Reliability in predicting the landslide risk using rainfall data, is heavily dependent on the spatial density of rainfall observatory stations and in this study the risk analysis using rainfall data focuses on predicting the time of landslide occurrences. In this study, rainfall standards by region are proposed using 250 landslide historic data and past rainfall data. Reliability of established rainfall standards was verified and rainfall standards would lead to reliable prediction of landslide occurrence time.
Analysis of Measured Data obtained from Vertically Vibrating Pile
Lee, Seunghyun ; Yoon, Kiyong ; Kim, Eungseok ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 131~137
DOI : 10.9798/KOSHAM.2014.14.2.131
In order to analyze the behavior of a pile installed by vibrohammer, single accelerometer which is put on the pile head and strain gauges which are put on both head and toe of the pile and depth measuring drum are likely to be the minimum sufficient measuring instruments. Dealing with the data obtained from the depth measuring drum, number of the data which is equal to 10 times of the data acquisition frequency seems to be sufficient for calculating penetration rate of the pile. Details of obtaining displacement history through minimizing zero offset of the measured acceleration and fine tuning the zero offset is presented in the paper and the resulted displacement history shows smooth and repetitive shape. The shapes of the obtained dynamic load transfer curves are similar to those of the past researcher. Results obtained from analyzing the measured data show that analyzed results rationally reflect the distribution of the N value with depth.
Prediction of the Landslide and Effect on Heritage Located in Mountain induced Earthquake
Jeon, Seongkon ; Kim, Derkmoon ; Choi, Wonil ; Choi, Eunhwa ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 139~148
DOI : 10.9798/KOSHAM.2014.14.2.139
It was selected as the study area where heritage are located on the Mountain in Seoul. The variation of landslide risk induced earthquake by using the Newmark displacement model and the prediction of debris flow pattern due to landslides were performed. And these effects on heritage distributed in the study area were investigated. As a result, it was analyzed that heritage on landslide risk areas induced earthquake does not be placed, however the further research for Sajikdan on the predicted moving path of debris flow would be recommendable.
The Model for Sensing of Disaster Signs Based on Big Data
Choi, Seon Hwa ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 149~157
DOI : 10.9798/KOSHAM.2014.14.2.149
In recent years, social media has become ubiquitous and important for social networking and content sharing. Especially, in the disaster area, social media supports backchannel communications, allowing for wide-scale interaction that can be collectively resourceful, self-policing, and generative of information that is otherwise hard to obtain. At the time of great Japan and Haiti earthquake, social media channels actively were utilizing to grasp the damage, to warn, and to exchange information. This paper is to introduce the model for sensing the signs of inundation and detecting inundation risk areas by analyzing big data related to disasters. This model is comprised of three steps: a sign sensing step through monitoring and analyzing unstructured data such as social media, a risk detecting step through comparing and analyzing structured data such as precipitation, inundation hazard maps, and so forth, and a disaster status dissemination step to disaster related organizations, local governments, and the public. By applying our model to Gangnam inundation damage, 2011, in Korea, we substantiated that there is the potential for utilization on our model.
Priority Assignment for Emergency Medical Service Provision in Disaster by Considering Resource Limitation
Shin, Kyohong ; Lee, Taesik ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 159~168
DOI : 10.9798/KOSHAM.2014.14.2.159
EMS resources management is one of the determinants to maximize the number of survivors effective first response in the aftermath of mass casualties. This paper concerns a problem of patient prioritization for EMS provision by constructing a Markov Decision Processes( MDP) model. While prior research tends to focus solely on transport resources (i.e., ambulance), we show that factors on the involved hospitals (i.e., capacity and capability) in the disaster response affect optimal response policies. Experiments on hypothetical scenarios are conducted to compare the proposed model with the existing algorithms from the literature, including the standard triage practice known as START(Simple Triage And Rapid Treatment). We show that considering hospital factors can save more patients than the other algorithms in most scenarios. The results of the study suggest that capacity and capability of the hospitals participating in the response should be factored into decision makings in the EMS response to maximize the life savings.
On the Effect of Wind in the Extinguishing System for Wild Forest Fire
Gim, Gyun-Ho ; Shin, Jong-Hyeon ; Chang, Se-Myong ; Seo, Younggwang ; Lee, Byungdoo ; Nam, Songhee ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 169~176
DOI : 10.9798/KOSHAM.2014.14.2.169
In this study, experimental and computational methods are applied for the appropriate positioning of the extinguishing system for wild forest fire, and we especially focussed on the effect of wind as an environmental condition. The fire extinguishing system is generally installed for the protection of wooden cultural properties as well as the resource of forest. Setting the experimental model around the wind farm in Bieungdo-dong, Gunsan-shi, Jeonbuk, the characteristics of three conventional nozzles are investigated, and a set of experimental correlation for the effect of wind field has been induced so far. Additionally, the numerical analysis model using a commercial code ANSYS-CFX has been made to compare with the experimental result and to extend the data for strong wind field.
The Assessment for Leakage Rate of Pressurizer Manway Bolting
Cho, Nam Jin ; Sin, Pyung Sik ; Kim, Woo Chang ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 177~183
DOI : 10.9798/KOSHAM.2014.14.2.177
In nuclear power plant, defected bolts used in pressurizer manway could have bad effect on the safety of the plant. Thus, the bolts should maintain their integrity while used in the plant. However, damaged bolts, such as corroded or cracked bolts, have been reported; thus, well-organized monitoring is required. This study evaluates safety of bolts currently used in a nuclear plant using the leakage rate. Using ANSYS program, the opening of a manway due to damaged bolts is estimated and corresponding leakage rate was estimated by SQUIRT code. The results exhibit that even in the case of 3 damaged bolts the leakage rate satisfies the allowable level, 1 gpm. However, continuous in-service inspection is still required to ensure the safety of bolts as considering the development of leakage rate.
Analysis of the Truck Fire Breaking Out During Expressway Driving
Kim, Youn Hoi ; Lee, Eui Pyeong ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 185~194
DOI : 10.9798/KOSHAM.2014.14.2.185
In this paper, leakage of fuel and oil, overheating of engine and exhaust pipe, foreign material on exhaust pipe and turbocharger, short-circuit on electrical wires, defect of turbocharger and starter, arson and smoking material and so on were analyzed in detail to investigate the cause of the new 3.5-ton truck fire which broke out during expressway driving. The compressor fan axis of turbocharger turned normally but the blade part was lost and its root part was split in three pieces. It indicated that the truck fire was caused by turbocharger defect(compressor blade damage or oil leakage). The fire liability rested with a manufacturer because the truck fire was caused by manufacturing defect of turbocharger. And strengthening of quality management of truck maker was suggested to prevent truck fire because the truck fire broke out within term of warranty.
Standardizing Acceleration Test Methods for Assessing the Durability of the Sprayed Fire Resistive Materials
Kim, Dae-Hoi ; Choi, Dong-Ho ; Lee, Gun-Chul ; Lee, Sae-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 195~201
DOI : 10.9798/KOSHAM.2014.14.2.195
The buildings constructed with steel structure is coated with certified Sprayed Fire Resistive Material(SFRM) to resist from fire. All the building materials lose their initial performances as time passes, so they need durability. This study covers standardization of the methods for assessing the durability of SFRM. In Korea, more than 90 percent of SFRM are used indoors. So their fire performance were tested under indoor conditions before and after accelerate wet/dry cycling and temperature cycling to standardize the methods for assessing their durability.
Effects of Repetitive Firefighting on Human Body
Bang, Chang-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 203~208
DOI : 10.9798/KOSHAM.2014.14.2.203
The aim of study intends to investigate the effects of repetitive firefighting on human body and to provide the basic data for the safety of firefighter. The results of the study are as follows; On two separate occasions under ambient temperature WBGT
, dry bulb temperature of
, relative humidity 26.7%), nine firefighting majoring students(n=9; age
) completed two 15 min treadmill walking(Ex1, Ex2) 9 METs(6 km/h, 10%) separated by a 15 min recovery period(Rest), during which students were either wearing firefighting protective equipment or wearing shorts(control). After experiments, mean skin temperature change(214.0%), tympanic temperature change(175%), heart rate(20.5%), respiration rate(14.2%), RPE(50.0%), thermal Sensation(12.0%), weight loss(60.0%) are statistically significantly higher in the case of wearing firefighting protective equipment. It is concluded that physiological responses of human body varied considerably and reflected by repetitive fire fighting.
An Analysis on the Main Causes of Explosion in Industrial Settings and a Study on its Prevention
Choi, Minseok ; Sin, Pyungsic ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 209~215
DOI : 10.9798/KOSHAM.2014.14.2.209
Explosion occurring in industrial settings happens when materials handled or fuel used are mixed abnormally or leak, and they are in an unsafe condition. The unsafe condition which can be developed to explosion has many cases by carelessness in use rather than equipment defects such as obsolescence of equipment, system failures, etc, to prevent accidents by carelessness, despite the efforts of strengthening safety training and relevant regulations and modernizing emergency equipment, the reason large and small explosion occurs continuously is that the cause of accidents which is an act of the operator, that is 'carelessness' is treated as a personal matter. Since accidents caused by carelessness are originated from complex problems which can be generated in facilities, systems, working processes as well as individual work situations, specific safety rules throughout the working process as well as personal duty of care should be provided to prevent accidents by carelessness.
A Study on Limited Area Ratio of the Non-insulated Glazed Window in Fire
Park, Soo Young ; Seo, Hee Won ; Wang, Nam Woong ; Kim, Dae Hoi ; Yeo, In Hwan ; Choi, Dong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 217~225
DOI : 10.9798/KOSHAM.2014.14.2.217
In foreign countries, a non-insulated fire glazed window is permitted in fire compartment restricting the use and size, but on the domestic side, not permitted. So, there is a need to confirm the fire resistance of the domestic non-insulated fire glazed window and to evaluate the fire safety of that. In this study, the fire resistance tests of 4 types of windows were conducted depending on window area, and the measured radiant heat fluxes and temperatures were evaluated in fire safety. As a result, we suggested the window/wall area ratio secured the fire safety.
Performance Evaluation of Seismic Reinforced Column of Buildings
Lee, Youngkyo ; Park, Yoen-Jun ; Park, Inn-Joon ; Park, Seunghee ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 227~232
DOI : 10.9798/KOSHAM.2014.14.2.227
It have been increasing societal and economic demands on seismic design and retrofit because of recently frequent occurrence of earthquake in Korea. Structural collapse due to the earthquake results from the failure of columns and hence the columns have to be reinforced to improve the seismic performance of the structures. In this study, new seismic retrofit method for columns of buildings was proposed so that the bottom part and the base of the columns could be reinforced with steel plates and fire-proof rubber pads. Statical loading tests were performed with the columns to evaluate the seismic performance of the proposed retrofit method. The failure mode and the strain variation of the reinforced column were analyzed according to the static loading and the results were compared to those from the unreinforced column. As a result, the seismic performance of the reinforced column was significantly improved.
Collapse Capacities of Steel Intermediate Moment-Resisting Frames I
Park, Jin-Young ; Yi, Waon-Ho ; Kim, Hyung-Joon ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 233~243
DOI : 10.9798/KOSHAM.2014.14.2.233
Domestic structural design code, KBC2009 specify the criteria for satisfying life safety level in design earthquake. But criteria for satisfying collapse prevention level in maximum considered earthquake are stated allusively. This study designed and modeled three prototype structure of steel intermediate moment resisting frame classified with the number of story. Through nonlinear time history analysis, adequacy of life safety level in design earthquake and collapse prevention level in maximum considered earthquake are evaluated in this study. global and local dynamic response of prototype structures were observed changing the plastic deformation capacity which is one of the most important factor in collapse capacity to achieve two seismic capacity goals; life safety level in design earthquake and collapse prevention level in maximum considered earthquake.
Collapse Capacities of Steel Intermediate Moment-Resisting Frames II
Park, Jin-Young ; Yi, Waon-Ho ; Kim, Hyung-Joon ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 245~254
DOI : 10.9798/KOSHAM.2014.14.2.245
The first paper of continuing two papers observed that the one of most important factor of determining collapse capacity is plastic deformation capacity of column. This study investigated the plastic deformation capacity satisfying collapse prevention level in maximum considered earthquake. For this purpose, incremental dynamic analysis was performed with the prototype structure introduced in former paper using 40 ground motion records. The Collapse capacity was evaluated with confidence factor method of FEMA355F and methodology of FEMA-P695.
Analysis of Discharge Capacity for Intake Structure at Deep Underground Storm Water Tunnel Using Fluent Model
Kim, So Young ; Kim, Jung Soo ; Yoon, Sei Eui ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 255~265
DOI : 10.9798/KOSHAM.2014.14.2.255
Recently, the deep underground storm water tunnel for inundation reduction has been designed and constructed in urban areas. However, practical studies considering characteristics of domestic urban areas are insufficient. Especially, flow pattern and drainage capacity of intake structures are influenced by intake types of a drop shaft. Therefore, it is necessary to analyse flow characteristics and discharge capacity of the intake structure with change of intake types. The computational fluid dynamics (CFD) model, Fluent 6.3, was applied to investigate the flow characteristics of the drop shaft structure for various of intake types (scroll, spiral, and tangential). The Fluent model was carefully assessed by comparing simulated results with the experiment, and there was good agreement between them. The numerical simulation was carried out according to change in intake types and inlet slopes. The simulated results were showed that spiral and tangential-inlet were stably drained the rate of inflow into the drop shaft. However, the tangential-inlet was showed steady discharge capacity at intake regardless of variation of inlet slopes compared with the spiral-inlet. Therefore, the tangential-inlet was appropriate as inlet of the deep underground storm water tunnel that be able to install on narrowish underground space of urban areas.
Analysis of Urban Inundation Reduction Effect by Early Operation of Drainage Pumping Station
Song, Yang Ho ; Park, Moo Jong ; Lee, Jung Ho ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 267~276
DOI : 10.9798/KOSHAM.2014.14.2.267
In low-lying districts of urban areas, drainage pumping stations were built to protect urban inundation by the heavy rain and, in the station, the pump operation is performed by only reservoir depth. But the effect of pump operation can be improved by various pumping rules. This study would like to analysis the reduction effects of urban inundation by early operation of pumps. The various design rainfall events were applied to Gasan 1 pumping station in Seoul and then, the most effective period of early operation was 10 minutes. Also, the maximum water levels of reservoir simulated by early pump operation were 10~70 cm lower than results by the existing operation rule and the overflow volumes in upstream sewer network were reduece by about 50%. Therefore, in urban areas, the flood control stability can be improved by efficient operation of the existing pumping station.
An Experimental Study on Hydraulic Characteristics at Bangudae Petroglyphs by Changing Management Water Level of Sa-yeon Dam
Chegal, Sun Dong ; Cho, Hong-Je ; Kang, Ho Seon ; Lee, Seung Oh ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 277~287
DOI : 10.9798/KOSHAM.2014.14.2.277
If water level control will be executed in order to prevent the inundation for preservation of Bangudae petroglyphs, the assessment of hydraulic characteristic on rock sides was carried out with hydraulic model experiments. Hydraulic model was constructed by 1:50 scale to be applicable to flow characteristic of both stream and reservoir. Furthermore, this study was conducted to numerical simulation and pressure measurement on the surface of petroglyphs model at the same time. As results from this study, inundation time was clearly reduced but inundation prevention was barely occurred. Maximum mean velocity at the front of Bangudae petroglyphs was measured from 10 years to 80 years frequency flood event and not proportional to the frequency. Increasement of mean velocity was about 425% for 200 year frequency flood and about 666% for 2 year frequency flood compared to current condition. If water level control would be adjusted, potential damages of Bangudae petroglyphs would be likely to increase in flooding seasons, which should be requested for alternative prevention plan.
Flood Forecasting Estimation Methodology of Standard Rainfall for Urban Mid and Small Rivers considering Upper- and Down-stream Water Levels
Song, Yang Ho ; Song, Young Seok ; Park, Moo Jong ; Lee, Jung Ho ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 289~298
DOI : 10.9798/KOSHAM.2014.14.2.289
The flood forecast and warning system means the system which can watch and predict flood disaster in advance and is one of the representing unstructured measures to mitigate flood disaster damage. Recently if we regard the characteristic of the history of torrential rain as rapid rise of water level of river due to regional heavy rain, in the flood forecast and warning system, securing preceding prediction time necessary for evacuation time and decision making is very important element. Especially, for urban stream basin because of the characteristics of short reaching time the effective method of flood forecast and warning is essential for securing preceding time. This study suggested the analysis method and standard in order to secure preceding time for flood warning in urban stream. This method predicts the water level change in the stream when rainfall event is predicted and then upper- and down-stream water levels are considered to analysis the water level change according to the predicted rainfall depth. Uper- and down-stream water levels are respectively the water level at warning point and the backwater level at joined river point. In this study, the suggested method was applied to Soyang stream which is urban mide and samll river. For the conference for the water level conditions which are various, we composed the rainfall scenario as the standard for flood warning which considers both cumulative precipitation and rainfall duration.
Evaluation of Inherent Flood Vulnerability in Seoul Administrative Districts Using Flood Protection Capacity and Damage Matrix
Kim, Eung Seok ; Choi, Yu Jin ; Choi, Hyun Il ; Chung, Gunhui ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 299~307
DOI : 10.9798/KOSHAM.2014.14.2.299
Due to the rapid urbanization rate and extreme rainfall as a form of the abnormal climate, the urban flood frequency has been increased. Therefore, it is very important for the policy makers to evaluate the urban flood vulnerability and propose the corresponding flood mitigation policies. Since the interests on the urban flood mitigation is increased, many structural flood measures has been constructed. If a city has many structural flood measures, the city is considered as the flood safe city. In this study, inherent flood vulnerability is proposed using Flood Protection Capacity and Damage(PCD) matrix with the flood damage cost and constructed structural flood mitigation measures. The proposed inherent flood vulnerability method was applied in Seoul. The results are categorized by four areas such as relatively flood safe area, flood risk area, inherent flood vulnerable area, and the area where more structural flood measures are needed. Calculated inherent flood vulnerabilities were compared to the conventional flood vulnerability-resilience indices. The proposed inherent flood vulnerability showed more reasonable results. For example, Songpa and Mapo were considered as the flood safe districts because of its high financial independence rate and many constructed flood mitigation measures. However, their inherent flood vulnerability is relatively high. There results could show the comprehensive aspect on the flood mitigation policies.
Study on Stormwater Runoff Reduction Effects by LID Application Areas
Kim, Eung Seok ; Yeon, Jong Sang ; Shin, Hyun Suk ; Lee, Jong Seok ; Choi, Hyun Il ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 309~316
DOI : 10.9798/KOSHAM.2014.14.2.309
LID(Low Impact Development) techniques, the distributed facilities, have been recently planed and implemented for stormwater runoff reduction tools, because the centralized facilities for flood controls were limited in reducing urban stormwater runoff amount. Thus, this study has analyzed the stormwater runoff reduction effects by application areas of the representative LID element techniques such as the green roof(GR) and the permeable pavement(PP). Three selected LID features, GR, PP, and both of them(GR+PP), were respectively applied with the four installation area ratios(0, 25, 50, 75, and 100%) to the actual areas of roofs and roads available in a frequently inundated basin under study utilizing SWMM(Storm Water Management Model) LID Controls. The SWMM-LID simulation results represent that the increase of installation areas of the three LID features can reduce the stormwater runoff in both peak discharges and runoff volumes. It is also observed that the GR application with 25% area ratio, the PP application with 75% area ratio, and the GR+PP application with 50% area ratio are most effective, respectively for the stormwater runoff reduction by LID installation areas.
Lake Environmental Risk Index using PSR Framework
Kim, Eung Seok ; Sim, Kuy Bum ; Chung, Gunhui ; Nam, Young Kyu ; Choi, Hyun Il ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 317~326
DOI : 10.9798/KOSHAM.2014.14.2.317
This study has proposed the LERI(Lake Environmental Risk Index) based on the PSR(Pressure-State-Response) framework for the environmental risk assessment in lakes due to water pollution in an integrated aspect of lake watersheds. The total 11 assessment factors were selected and constructed for the spatial resolution of the 17 lake basins in the Geum River Watershed to calculate PI(Pressure Index), SI(State Index), and RI(Response Index) in the PSR classification system. The weight coefficients for assessment factors were also calculated by the Entropy method in order to reduce subjective judgement on the effect of weight coefficients. The lake environmental risk rank results with/without the weight coefficients of assessment factors ware compared to examine the practical application of the proposed lake environmental risk assessment method. The LERI results regardless of weight coefficients indicated that the Sapgyo Lake and the Geum River Estuary are at higher risk of water pollution induced by the industrial development and land reclamation projects. The lake environmental risk rank results estimated in this study can be used for the long-term water quality analysis and management in lakes.
Study for Management of Non-point Source in Sooyeong River Watershed Using SWMM
Lee, Jeonghoon ; Kang, Dookee ; Park, Moojong ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 327~336
DOI : 10.9798/KOSHAM.2014.14.2.327
In Sooyeong River watershed, non-point sources and CSOs(Combined Sewer Overflows) from urban-residential area are the most common causes of water pollution. This paper suggests an installation plan for non-point source facility and a priority management basin in order to promote effective prevention of non-point sources for Sooyeong River watershed using SWMM(Storm Water Management Model). Futhermore, the efficiency for suggested installation plan were analyzed.
Improvement of the Empirical Formula for Estimating Stormwater Capture Ratio of WQF Treatment BMPs
Choi, Daegyu ; Park, Moojong ; Kang, Minji ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 337~343
DOI : 10.9798/KOSHAM.2014.14.2.337
Reduction loads of treatment BMPs can be calculated by using rainfall capture ratio which means the ratio between treated rainfall by BMPs and total annual rainfall in Korean TMDL. In this paper, Rainfall capture ratio and related terms was changed, and it is suggested the improved empirical formula of stormwater capture ratio which can consider the runoff characteristics because treatment BMPs collect not rainfall but stormwater with contaminants. We calculated the real stormwater capture ratio which can be altered by runoff coefficients by using long-term (43years, 1970-2012) rainfall data in seven rainfall stations (Busan, Daegu, Daejeon, Gangreung, Gwangju, Jeju and Seoul), and then, the empirical formula of stormwater capture ratio for WQF treatment BMPs is derived from the real stormwater capture ratio.
Parameter Estimation Methods of Rainwater Harvesting System Reliability Model for Improving the Applicability to Korea: Application to Busan, Korea
Keem, Munsung ; Kang, Dookee ; Park, Moojong ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 345~354
DOI : 10.9798/KOSHAM.2014.14.2.345
Rainwater harvesting(RWH) system reliability model provides useful information on the RWH design since the model can generate the quantitative result, the reliability, of whether RWH system meets water utility amount of a certain region. The reliability is influenced by rainfall, water demand, and residence characteristics of the region, which can be considered as the model parameters. However, in Korea, appropriate data for estimating the parameters have not been established, so it is difficult to apply the reliability model to Korea. Therefore, in this paper, we propose the methodology to estimate the model parameters based on available data in Korea and try to improve the applicability of the model to Korea by applying the methodology to Busan, Korea. Especially, in order to consider the seasonal variability of the reliability, we generate water demand on a monthly basis that is one of the most important parameters. As a result, we observed that parameter estimations using the methodology proposed in this paper can represent the seasonal characteristics of rainfall and water demand more efficiently, and these results can help improve the model accuracy.
Review of Some Advanced Stream Environmental Assessment Systems
Chun, Seung Hoon ; Park, Sang Gil ; Chae, Soo Kwon ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 355~362
DOI : 10.9798/KOSHAM.2014.14.2.355
This study was carried out to suggest principles & guidelines necessary for setting up of the assessment system applied in Korean stream. The work was based on the review and discussion of advanced stream assessment techniques and its adjustment for Korean stream condition and management status. The results obtained from this study were summarized as follows: Firstly, stream assessment system has been developed from the fact that geomorphological structures and chemical qualities forming stream system in the hierarchy, were closely correlated to the biological diversity through temporal and spatial scales. Therefore, Korean stream assessment system must be developed with a sufficient consideration on the characteristics of stream conditions as well as actual status of stream management. The other side, those advanced and standardized assessment system, which has been originated from a long experienced lessons on stream management, interdisciplinary knowledge and techniques, represented much logic consistence in view of basic components such as aims for assessment, establishment of assesment indicators and criteria, selection of reference conditions. Accordingly, our assessment system must be also progressed towards scientifically oriented and integrated system which reflects our real stream surroundings and also includes some principles and process and techniques reviewed in advanced system.
Development and Application of Annual Evapotranspiration Estimation Model Considering Vegetation Effect
Park, Yoonkyung ; Cho, Seonju ; Park, Moo Jong ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 14, issue 2, 2014, Pages 363~372
DOI : 10.9798/KOSHAM.2014.14.2.363
The hydrologic response of watershed determined by complex process about climate-soil-vegetation. Evapotranspiration is very important component of hydrological cycle to connect climate, soil and vegetation. The research of annual evapotranspiration the watershed is primary topic for understanding hydrological cycle in watershed. A suitable model for South Korea which relates annual evapotranspiration to precipitation, potential evapotranspiration, and ratio of forest considering vegetation effect, is proposed in this study. Result of the proposed model is not high quality about estimating evapotranspiration but it is better than previous model which relates annual evapotranspiration. This study is able to suggest research direction about dynamic analysis of climate-soil-vegetation.