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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
Structural Performance and CO
Reduction Evaluation of the Beam-to-Column Weak Axis Connections for Constructability
Shim, Hyun Ju ; Kim, Sang Seup ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 1~9
DOI : 10.9798/KOSHAM.2013.13.1.001
This paper presents a new beam-to-column connection suitable for the column's weak axis. The proposed system is developed to mainly utilize bolts with the number of welds minimized, thereby avoiding difficulties encountered in in-situ welding. In this system, a wide-flange beam is joined to a wide-flange column by bolted splices at the top flange and without a scallop at the web. The structural performance of the proposed connection was verified through tests of eight specimens, taking into account the effects of the geometry and arrangement of the plate. To evaluate the economy, it estimated the requirements of connection materials and
Evaluation of Shear Strength Equation of Concrete Beams Embedded with GFRP Plates
Choi, Jonghoon ; Kim, Dae Jin ; Kim, Heecheul ; Lee, Young Ha ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 11~16
DOI : 10.9798/KOSHAM.2013.13.1.011
In this paper, we will study the possibility of the design standard applied by modifying the shear strength equation so that we can propose the shear strength equation of reinforced concrete beams strengthened with the new type of GFRP plate. The new GFRP shear reinforcement is manufactured into a plate shape with several openings to ensure perfect integration with concrete. The test was performed on 6 specimens with shear span-to-depth ratio of 2.4. Test variables are the amount of the shear reinforcement and the shape of shear reinforcement. The two types of GFRP plate with different shapes are a rectangle and a parallelogram. A shear strength equation for concrete beams with the proposed GFRP plate was suggested through modifying the existing shear strength equation for concrete beams in CSA A23.3-04 and ACI 318-11. Comparing the test results with the estimations based on the proposed equation, CSA A23.3-04 modified equation predicted the shear strength better than ACI 318-11 modified equation.
A Study on the Proposal of Residual Strength Equation of Reinforced Concrete Columns under Blast Load
Choi, Hosoon ; Shin, Dae Hwan ; Kim, Min-Sook ; Kim, Dae Jin ; Kim, Heecheul ; Lee, Young Hak ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 17~23
DOI : 10.9798/KOSHAM.2013.13.1.017
Damage of structures under blast loading can be classified into local damage and building collapse. The purpose of this study is to propose an residual strength equation being able to predict residual strength of damaged columns. In this study it was carried out 3 different variables, which is aspect ratio, shear span-to-depth ratio and axial force ratio. The equation was proposed by regression analysis based on the analysis results using AUTODYN. The Results indicated the R-square of axial force ratio was the highest value; 0.99. And the presumption equation with all variables has higher accuracy and its R-square was 0.77.
A Study on the Residential Recognition Analysis for Luminous Environments of Apartment Complexes
Kim, Jin-Wook ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 25~30
DOI : 10.9798/KOSHAM.2013.13.1.025
A Residential Apartment Complex is living space for variety mankind and working 24 hours of a day with outdoor area for public. This outdoor spaces are usually safe with lighting facilities to make blight exterior space. Especially, nowaday night time crimes are penetrate to the residential area and it is very important to make proper night light environment for essential elements for urban area. But there is no appropriate national standard for outdoor light environment and research for residence recognition and request elements for safe environment. In this point, inspection for newly developed housing complex block in Seoul were examined. Especially these town were designed for special night scape design for identity of block. Also recognitions of light environment for night time were studied. As a Result, luminance of light for pedestrian area serve with very irregular light condition; values of luminance are from 6.1lx to 120lx. It is not satisfaction value for pedestrian corridor requirement of Korean Industrial Standards. From the survey, residents satisfied about overall light environment, but more than 35% residents did not satisfied intensity of illumination of outdoor space in certain block apartment complex. For conclusion, national standard for outdoor light environment and the administrative procedures would be suggested.
Shear Design of Concrete Belt Walls Reinforced with Post-Tensioning Bars
Eom, Tae-Sung ; Kim, Ju-Yeon ; Kim, Ji-Young ; Kim, Jae-Yo ; Kim, Dae-Young ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 31~39
DOI : 10.9798/KOSHAM.2013.13.1.031
In the present study, shear design methods for concrete belt walls reinforced with pre-stressing steel bars (PS belt walls) were developed. For diagonally reinforced PS belt walls, a strut-and-tie model based on strain-compatibility was proposed to evaluate the shear strength and maximum deformation. For vertically and horizontally reinforced PS belt walls, on the other hand, shear strengths and deformations at concrete cracking and ultimate state were evaluated based on the Compression Field Theory. Design examples for PS belt walls were illustrated and the aspects of the load-transfer and design considerations were discussed. The results showed that diagonally reinforced PS belt walls exhibited brittle shear failure due to concrete crushing before yielding of PS bars. In addition, since the concrete strut rather than PS bars carries significant shear, attention should be paid on the detailing of the nodal zone. On the other hand, vertically and horizontally reinforced PS belt walls failed due to the yielding of PS bars before concrete crushing. However, the number of PS bars for shear design was increased and the reduction in the stiffness after shear cracking was significant.
An Analysis of Life Cycle Cost Using the Fuzzy Reliability Theory of a R.C Structure
Kim, Jong Gil ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 41~49
DOI : 10.9798/KOSHAM.2013.13.1.041
When the fact is taken into consideration that recent collapses, bridge replacement and other many maintenance problems in Korea have caused bridges to be re-constructed or replaced before they reach their expected life for public use, the substantial loss during the life for public use of bridges is estimated. Accordingly, the data obtained from the analysis of the LCC economic feasibility is expected to be used for finding the construction methods and ways for repair and reinforcement necessary in the stage of maintenance and administration, determining the optimum level of performance improvement of existing structures and helping the government decide the priority for investment, and ultimately to help seek the efficient use of cost.
A Study on the Fatigue Performance Evaluation of Deck Plate Composite Material
Kim, Doo-Hwan ; Park, Jun-Seok ; Kim, Seong-Pil ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 51~56
DOI : 10.9798/KOSHAM.2013.13.1.051
Recently the compound material has been interested in using the structural material as the bridge member assembly. It is the lighter material against existing construction material and has excellent durability and economy. The existing floor of bridge has its short period to repair and replace compared to other parts of the bridge with the pavement and the shoe. These deteriorations of usage and safety by aging and corrosion are needed frequent maintenance. The use of compound material as a structural member suggests solve these problems. It is determined that if the bridge member is to reflect maximum the strong points of compound new material to solve the expected problems, the compound material can improve remarkably the life and durability of bridge floor plate bringing the least maintenance and be possible to use the structural material to reduce its life cycle cost in the long term. So this thesis evaluates the static and the fatigue performance for whether there are fiber lamination direction of FRP floor plate, the compound material.
Numerical Model for Cyclic Compressive Behavior of Concrete Confined by Steel Plates Using External Pressure
Choi, Eunsoo ; Song, Segeun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 57~61
DOI : 10.9798/KOSHAM.2013.13.1.057
This study provides a model for cyclic compressive behavior of concrete confined by steel wrapping jackets without grouting. This study uses concrete specimens of
) with steel jackets of the thickness of 1.0 mm and 1.5 mm. The peak strength of concrete increases by 32.1% and 45.6% with applying the steel jacket of 1.0 mm and 1.5 mm, respectively. This study adopts the Sakai and Kawashima model for cyclic compressive behavior of confined concrete, and it is found that the experimental results correspond well to the adopted model.
Experimental Study on Tensile Strength of Steel Fiber-Reinforced Concrete Subjected to High Temperature
Moon, Do Young ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 63~71
DOI : 10.9798/KOSHAM.2013.13.1.063
Tensile strength of steel fiber-reinforced concrete was investigated with experimental program. For the investigation, Double Punch Test, which is known as a test method with low validity, was used. Fiber type(hooked and twisted fiber), mix ratios by volume ranged from 0.25% to 1.0%, aspect ratio were used as variables for the tests. The specimens were exposed to the elevated temperatures(
) for 2 hours and placed at ambient temperatures for 12 hours before testing. Results demonstrated that residual tensile strength increases as mix ratio and aspect ratio increase. The effect of fiber type was insignificant. Based on the test results, the linear equation for prediction of DPT residual tensile strength was proposed in terms of mix ratio and aspect ratio.
Experimental Study on the Evaluation of the Human Stability due to Overtopping Waves in the Breakwater
Bae, Hyun Ung ; Choi, Hong Soo ; Yi, Gyu Sei ; Lim, Nam Hyoung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 73~79
DOI : 10.9798/KOSHAM.2013.13.1.073
Major loss of life can occur in the breakwater when people are toppled by overtopping waves. Over the last four decades, a number of numerical(analytical) and experimental studies to define the limit criteria of the loss of human stability in flood flows have been conducted. However, the analytical or experimental study to investigate the loss of human stability in overtopping waves has not been performed up to now. In this paper, the experimental investigation of the human stability in overtopping waves is conducted using two-dimensional large scale multipurpose wave flume for wave-current-tide. These new experimental results show that the toppling of human can be expected in lower depth/lower velocity compared to that of ordinary flood flows based on previous experimental study. Also the criteria for the stability of people subject to overtopping waves are proposed.
Local Buckling Strength of Modular Hexagon-section Shell Wind-Turbine Towers
Choi, Byung Ho ; Park, Seong Mi ; Hwang, Min-Oh ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 81~87
DOI : 10.9798/KOSHAM.2013.13.1.081
Since dimensions and height of wind-turbine towers keep growing, new modular construction methods using polygonal-section shell columns are strongly required in order to enhance the economical construction during fabrication, transportation and erection of those. This study examines the local buckling strength of newly proposed 3-module type and 6-module type hexagon-section shell towers by using the finite element method. Initial imperfections due to newly proposed fabrication processes were considered for numerical evaluation of local buckling strenngth of hexagonal section modular towers. The strength equations suggested by AASHTO LRFD, DIN codes and previous research results were compared with the analytically evaluated strengths from this study. From the comparative study, it could be identified that design equations show statistically better correlation with the analysis results. Experimental studies to verify initial imperfections existed in the modular hexagonal-section shell towers are required for future study.
Development of Seismic Fragility Functions of LNG Storage Tanks by an Analytical Method
Lee, Tae-Hyung ; Kwon, Soonhwan ; Park, Hyo-Sang ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 89~95
DOI : 10.9798/KOSHAM.2013.13.1.089
When a Liquified Natural Gas (LNG) receiving terminal is damaged by an earthquake, the socio-economic impact of it's damage might be huge. Therefore, it is important to understand the seismic resistant capacity of such facilities, specially LNG storage tanks, in order for minimizing the earthquake hazard. Even though seismic design criteria are so strict that LNG storage tanks rarely suffer from earthquakes, we still need to know what to happen when a larger earthquake than a design earthquake occurs. A seismic fragility function is frequently used to express the seismic performance of structures. In this study, the seismic fragility functions of LNG storage tanks that are under operation in Korea are developed. A so-called 'tuning-fork model' is used to evaluate the dynamic response of the LNG tank based on a series of time history analyses. The fragility functions are developed based on the performance limit states that are defined in HAZUS, a popular seismic performance evaluation program. Finally, the analytical fragility function is updated by combined by pre-defined empirical fragility functions. According to the fragility functions, the probabilities of having minor cracks and moderate cracks on the tank wall are 1.0% and 0.0%, respectively, for the design-level earthquake with the peak ground acceleration (PGA) 0.2 g. For PGA 0.4 g, the corresponding probabilities are 27.0% and 10.0%, respectively.
Bending Behavior of Thick-Walled Press-Braked Z-Section Beams with Inside Bend Radii
Choi, Su Young ; Choi, Byung Ho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 97~103
DOI : 10.9798/KOSHAM.2013.13.1.097
Press-braked cross-section beams might be easily fabricated as economic plate structures due to the reduction of cutting and welding process. However, there is not sufficient a proper guide or relevant researches on press-braking fabrication of thick plates. Current fabrication guides and manuals speculate limitation of inside bend radii to thickness ratio (
) for cold-bending for relatively thin plates. Press-braked beams have to be verified as to a sufficient structural ductility. Thus, the main objective of this study is to provide a relative evaluation of effect of
on the moment-plastic rotation capacity of press-braked Z-shape beams which are fabricated by using SM490 24mm thick steel plates. Comparative studies are conducted for the press-braked beams with
values of 5 and 15. Through the finite element analyses, it is found that the press-braked beam model with
of 5 could attain the plastic moment strength suggested by the AASHTO LRFD and also show the rotational capacity exceeding 4, which means it has a sufficient structural ductility. More experimental studies are required for calibration of the analytical method for practical use.
A WRF Sensitivity Study in Precipitation Amount over Yeongdong Province to the Choice of Nesting Methods: Case Study
Lee, Jae Gyoo ; Sung, Hyun Min ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 105~119
DOI : 10.9798/KOSHAM.2013.13.1.105
WRF (the Weather Research and Forecasting) model was run with one-way grid nesting or two-way grid nesting, respectively for Yeongdong province's two typical precipitation cases of the coastal precipitation case (event A) and the mountain precipitation case (event B) which were synoptically under the influence of the northeasterly to examine whether the choice of nesting method can have a significant impact on the precipitation distribution. For the coastal precipitation case (event A), the average accumulated-precipitation from simulation using two-way nesting was approximately 7.78 mm bigger than that using one-way nesting in the Yeongdong coast area. However, that from simulation using two-way nesting was approximately 4.23 mm smaller than that using one-way nesting in the mountain area. Similarly, for the mountain precipitation case (event B), the average accumulated-precipitation from simulation using two-way nesting was approximately 1.56 mm bigger than that using one-way nesting in the Yeongdong coast area. In addition, that from simulation using two-way nesting was approximately 4.91 mm smaller than that using one-way nesting in the mountain area. That is, for both the coastal precipitation case (event A) and the mountain precipitation case (event B), the average accumulated-precipitation from simulation using two-way nesting was bigger than that using one-way nesting in the coast area, but in the mountain area that was the reverse.
Extreme Storm Estimation by Climate Change Using Precipitable Water
Park, Minkyu ; Park, Moojong ; Kim, Sangdan ; Joo, Jingul ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 121~127
DOI : 10.9798/KOSHAM.2013.13.1.121
In this study, probable maximum precipitation change was predicted using RCP 8.5 IPCC climate change scenario as extreme storm change. The modelling results based on average have the restriction on extreme rainfall value representation and future behavior prediction. To overcome these problems, this study uses air temperature change and precipitable water relationship in order to calculate the magnitude of probable maximum precipitation. The results showed about 40% increase in probable maximum precipitation. These were expected to use as reference of extreme storm increase such as IDF changes.
Assessment of Inundation Risk Degree for Urban Areas
Joo, Jin Gul ; Yang, Jea Mo ; Kim, Joong Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 129~136
DOI : 10.9798/KOSHAM.2013.13.1.129
The flood damage is increasing at urban area by poor interior drainage systems. It is important to assess the degree of the inundation risk for the establishment of consistent disaster management policy. In this study, regression curves were estimated including four parameters (mean elevation, mean slope, impervious area, drainage system index) to assess degree of the inundation risk at urban areas. The regression equations were applied in Seoul, Korea, and the results revealed that the equations closely reflected inundation area during last 6 years. The results of this study are expected to utilize to flood management to at urban areas.
Evaluation of Influential Area of High Pressure Injection Method for Ground Remediation
Yune, Chan-Young ; Jung, Woo Young ; Lee, Seung-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 137~144
DOI : 10.9798/KOSHAM.2013.13.1.137
In this research, influential area of the high pressure injection method was evaluated by laboratory test and numerical analysis according to various conditions. To simulate the high pressure injection in the ground, testing device was developed. Test results showed that the increase of injection time and injection pressure increased the extent of injection area, but the increase of overburden pressure decreased the injection area. In addition, the effect of injection time and pressure is greater in weathered soil even though the influential area of sand was greater than weathered soil. High negative stresses were observed at the end of crack by numerical analysis. And it could be inferred that the crack would propagate because the soil can not resist the tensile stress.
Study on Problems Related to Slope Stability Analysis Under Dry Condition and Proposed Alternative
Kim, Jinhwan ; Baek, Yong ; Kwon, O-Il ; Park, Jae-Woo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 145~151
DOI : 10.9798/KOSHAM.2013.13.1.145
Safety factors used in slope design is divided into wet and dry condition. In general, a safety factor of 1.5 is used for the dry condition and 1.2~1.3 is used for the wet condition. Unfortunately the application of safety factor for the wet and dry condition for the same slope has some problems. Slope stability analysis programs were used to determine problems in the slope design conditions. Stability analysis were performed and reinforcements to calculate safety factor for the wet and dry condition of arbitrary slope. Slope designed conditions used in Korea and other countries were analyzed and compared. When slope stability analysis for the wet and dry condition is performed separately, it was determined from the result of the study that the safety factor for the dry condition is always satisfied when the safety factor for the wet condition is satisfied. This shows that there is a problem in the condition of stability analysis that is currently used and modifications must be made except the dry conditions analysis.
Holding Capacity of Shallow Suction Caisson Anchor based on Finite Element Analysis
Ahn, Jaehun ; Lee, Hanmin ; Kim, Yun-Tae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 153~159
DOI : 10.9798/KOSHAM.2013.13.1.153
Foundations of offshore structures have been actively studied to provide design guides for oil platforms in the past. Presently, this asset from oil industry now finds its application in the design of the foundations for offshore wind turbines. The analytical solutions for the hold capacity of suction anchors have been developed based on limit equilibrium and limit analysis theorems and often compared to the results of novel approaches such as finite element (FE) analysis. However, some solutions show discrepancy with the FE analysis results under specific conditions, say under certain value of the ratio of length to diameter. The main scope of this paper is to analyze the failure envelope of suction caisson anchors, especially with an aspect ratio of 2 based on FE analysis. The results will provide a basis to enhance the existing plasticity solutions for anchor hold capacity. The effect of soil disturbance and location of optimal loading point are also investigated.
Slope Stability Analysis based on Probabilistic Characteristics of Unsaturated Soil Properties of Weathered Granite Soil
Jeon, Kyung Han ; Lee, Seung Rae ; Yoon, Suk ; Kim, Yun Tae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 161~168
DOI : 10.9798/KOSHAM.2013.13.1.161
The unsaturated soil properties such as soil-water characteristic curve, unsaturated permeability and unsaturated shear strength, always involve uncertainties associated, making it hard to obtain a representative value in analyzing the stability of slopes. Because a deterministic approach use a representative value, soil properties with severe variance sometimes lead to misestimate and hence the consequence also varies from person to person. To address this problem, a probabilistic approach to the analysis of slope stability has been adopted. Even though the probabilistic characteristics of soil are essential for probabilistic approach, it has not been established. Therefore, in this paper, the probabilistic characteristics of the unsaturated soil properties were defined. A simple procedure for the probabilistic approach was proposed to obtain the unsaturated soil properties for the slope stability analysis. Finally, the probabilistic analysis of unsaturated slope stability using monte-carlo simulation method was conducted for the Korean weathered granite soil.
Yield Stress and Viscosity Characteristics of Soils with Liquidity Index
Kang, Hyo-Sub ; Kim, Yun Tae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 169~175
DOI : 10.9798/KOSHAM.2013.13.1.169
Rheological properties such as yield stress and viscosity is the main parameters to determine the fluidity of the debris flow. To evaluate the effects of liquidity index(water content) on the rheological properties of fine-grained soils, several series of rheometer tests were performed on soil specimens with various liquidity indices. The general shape of the flow curve for fine-grained soil is a shear thinning fluid, whereas some soils with high liquidity index are close to a pseudoplasticity-like fluid. The yield stress and viscosity gradually decreased as the liquidity index(water content) increased. Also, the yield stress and viscosity tend to increase with increasing concentration by volume(
) of the fluid matrix. The values of the four empirical coefficients
and were obtained by regression analysis for each fine-grained soil.
A Study of the Dynamic Amplification Characteristics of the Major Domestic Seismic Observation Sites using Ground Motions from 12 Fukuoka Earthquakes Series
Kim, Jun Kyoung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 177~185
DOI : 10.9798/KOSHAM.2013.13.1.177
For protecting effectively structures from seismic hazard through more reliable estimation of soil-structure interaction, site amplification characteristics should be considered. Among various estimation methods, this study used the Nakamura's method (1989) for estimating site amplification. This method was originally applied to background noise. However, recently this method has been extended and applied to the S wave and Coda wave energy successfully. This study applied the Nakamura's method to the S wave. We used more than 255 observed ground motions from 12 macro earthquakes including main Fukuoka earthquake (2005/03/20, M=6.5) and then analysed site amplification characteristics for 8 major seismic stations. Each station showed characteristics of site amplification property in low-, high- and specific resonance frequency ranges. Comparison of this study to other studies can give us much information about dynamic amplification of domestic sites characteristics and site classification.
Parametric Study on Lateral Behavior of Nonhomogeneous Pile Installed in Sand
Lee, Seunghyun ; Lee, Suhyung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 187~190
DOI : 10.9798/KOSHAM.2013.13.1.187
Parametric studies on nonhomogeneous pile and homogeneous pile were performed to investigate the effects of considered factors on the lateral pile behaviors. According to the results of parametric studies on the homogeneous piles, values of the parameters of the pile with larger flexural rigidity along the depths of embedment were greater than those of the pile with smaller one. Parameters for the case of the nonhomogeneous pile were converged to the same ones of the homogeneous pile as nodal point moves away from point of material boundary. Results of the parametric studies would be helpful for determining the adequate upper pile length of the nonhomogeneous pile which could be resulted in similar load bearing behavior with the homogeneous pile.
Embankment Protection Method Against Overflow by Flood in Reservoir
Chang, Dong Su ; Kim, Yong Seong ; Choo, Yun Wook ; Im, Eun Sang ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 191~198
DOI : 10.9798/KOSHAM.2013.13.1.191
In this study, the failure behavior of a levee under overflow conditions was investigated by conducting centrifuge tests on a small scale model for the Janghyun levee in Kangrung, Kangwon-do, and based on the test results a levee protection method using waterproof mat was proposed. The model levees were constructed by scaling down the prototype levee to 1:50, where LVDT and pore-pressure sensors were installed to monitor the behavior of the levees during overflow. Overflow tests were carried out in three different conditions depending on where the waterproof mat was installed; 1) no waterproof mat, 2) installed in upper slope and crest of the levee, 3) installed in the entire levee. The centrifuge test results indicated that the application of the waterproof mat reduced erosion and soil loss in the levee. Especially, it was found that under overflow, the levee breach could be avoided with the waterproof mat installed in upper slope and crest only, although soil loss occurred in downstream slope inevitably. It is expected that levee failures occurred frequently in rainy season may be effectively prevented by using waterproof mat if overflow of levee due to heavy rains is well predicted in advance.
Strength and Microstructure Properties of Volcanic ash-Cement Soil Mixtures
Lee, Chung-Won ; Chang, Dong-Su ; Onoue, Kozo ; Kim, Yong-Seong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 199~206
DOI : 10.9798/KOSHAM.2013.13.1.199
The aim of this study is to investigate the engineering characteristics of volcanic ash-cement mixtures using unconfined compression test, flexural strength test, SEM and XRD analysis. The specimens were prepared with volcanic ash from Mt. Baekdusan and Mt. Hallasan, and cement as the ratios of 3.5:1, 4.0:1, 4.5:1, 5.0:1 with and without metakaolin. From the test results, both compressive strength and flexural strength degraded with increasing of the amount of volcanic ash, and increased with addition of metakaolin as a binder. Also, ettringite generated by cement hydration was detected by SEM and XRD, and that possibly contributes to the strength of volcanic ash-cement mixtures.
Evaluation of Permeability of Hot Mix Asphalt
Lee, Kwan-Ho ; Kim, Seong-Kyum ; Kim, Jeong-Ku ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 207~214
DOI : 10.9798/KOSHAM.2013.13.1.207
In recent, lots of multi-functional hot mix asphalt, including permeable pavements, quiet pavement, SMA, etc, have been developed. The performance and permeability of each pavement highly depend on the void characteristic of hot mix asphalt. Couple of different mixtures, including permeable asphalt pavement, SMA and dense-graded asphalt mixture, were used for void analysis. In case of PA-13 permeable asphalt pavement and SMA 10 mm, the effective void, total void and the ratio of connection between void increase as the level of compaction decreases. In case of permeability, the dense graded HMA showed little permeable. The permeability of permeable pavement were 0.18 to 0.41 cm/s. The modified Hazen model and Kozeny-Carman model were used to predict the permeability of each pavement. The
of modified Hazen model and
of KC model were recommended for permeable pavement.
Use of Structural Condition Index for Pavement Structural Evaluation Tool
Oh, Jeongho ; Gharaibeh, Nasir ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 215~220
DOI : 10.9798/KOSHAM.2013.13.1.215
In this study, an effort was made to evaluate pavement condition using the pavement structural condition index (SCI), which is based on falling weigh deflectometer (FWD) deflection basin and structural numbers that incorporated various levels of traffic and subgrade resilient modulus. Extensive field validations were conducted to assess the effectiveness of SCI along with comparison of pavement distress and condition score restored in the Pavement Management Information System (PMIS). The analysis results revealed that the SCI appears to realistically capture the existing pavement condition compared to the pavement scores and field survey results. Based on this finding, probabilistic and deterministic models were developed to estimate SCI when FWD data is not available. These models are deemed most useful for network-level analysis purposes to aid establish pavement maintenance and rehabilitation plans.
Study on Impact Analysis of Reducing Temperature in Central Business Area by Installation of Tree Box Using ENVI-met
Yang, Inchul ; Hwang, Hwan-Chul ; Lee, Yuhwa ; Lim, Ji-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 221~228
DOI : 10.9798/KOSHAM.2013.13.1.221
A tree box provides an efficient water circulation environment, and stores more soil moisture content than typical trees along sidewalks due to its special-design concept. It is expected that the tree box has more reducing temperature effect since evaporation process consumes latent heat to reduce air temperature around. In this regard, a three dimensional micro-climate model, ENVI-met, was employed to run a scenario-based simulation to evaluate the effect of reducing temperature of the tree box. The outcomes showed that the tree box has a positive effect on mitigation of the heat island effects in urban area by reducing air temperature. It also turns out that comfort index improves when the tree boxes are installed despite a relative humidity increase.
The Effect of Sunlight on the Legibility of VMS
Lee, Suk Ki ; Lee, Ho Jun ; Kim, Chul Yong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 229~234
DOI : 10.9798/KOSHAM.2013.13.1.229
It would be impossible for drivers to recognize messages and symbols displayed on VMS due to the light of the sun, and this phenomenon is called as Sun-Phantom. Sun-Phantom has to be considered in designing highway facilities related to sight distance. This study described problems of legibility due to Sun-Phantom and developed a LED module with a ventilation system to minimize the phenomenon. The study shows that the developed LED module appeared to have less of an effect on the sun, compared to existing LED modules.
Developing Incident Response Manuals Standardized for Transporting Hazardous Materials
Kim, Si Gon ; Chung, Sung Bong ; Lim, Kwang Kyun ; Park, Min Jun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 235~241
DOI : 10.9798/KOSHAM.2013.13.1.235
The incidents related to transporting hazardous materials may cause serious impacts on neighborhood and surrounding areas. It is essential to have a consistent incident command system and the corresponding response procedures. Currently, the command system is not integrated into one channel, which makes it difficult to control an incident over in a voice. Another problem is that the event status is not appropriately shared among authorities having responsibilities taking down the incidents. This paper investigates previous studies covering the emergency response manuals prepared for hazard material transports and suggests an integrated command system that helps communicate effectively and promptly between authorities on site. Additionally, we classify types of incident happened while transporting the hazardous materials and develop incident response manuals according to the classifications for prompt reactions.
A Study on the Evaluation of Vulnerability of Urban Commercial Areas Using a Modified Scoring Model -In the Case Traditional Markets Gyangsngnamdo-
Ryu, Tae-Chang ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 243~252
DOI : 10.9798/KOSHAM.2013.13.1.243
This study was aimed to deduce objective and scientific values obtained by using quantitative data such as a modified scoring model combined with weighted grades (a scoring method and entropy) related to existing fire in the traditional markets of primary commercial areas in Gyeongsangnam-do and to obtain the values of spatial distribution summary using Arc Gis. The values obtained through the evaluation method of vulnerability were given to local self-governing bodies, thus letting them get prepared for what they would need for supporting the policies of improving safety and vulnerable areas (traditional markets) corresponding to the regional conditions, and these were provided for the grounds for enhancing the effectiveness of data, safety and fire prevention that could suggest more effective methods in executing the budgets and establishing the policies.
Study on the Survival Kit Configuration through the Overseas Cases
Kim, Tae Hwan ; Park, Nam Hee ; Yeo, Wook Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 253~258
DOI : 10.9798/KOSHAM.2013.13.1.253
Ensure safety of life measures in the event of a disaster situation are very important points. So alternatives arrangement is urgent. One of alternatives is to development of survival kit for Korean situations. Before the developments which studied case of survival kit for foreign countries, analyse the list of foreign survival kit and current event, the result of analysis that used to established survival kit list for Korean.
An Experimental Study on Water-Screen Protection Systems Formed by Water-Splash Nozzles for Preventing the National Archive Facilities in the Mountain from Neighboring Forest Fires
Lee, Young-Jae ; Park, Hyung-Joo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 259~267
DOI : 10.9798/KOSHAM.2013.13.1.259
Most of Korea National Archives among the mountain exposed to forest fire environments, therefore, people has worried about their burn-out from neighbouring forest fires. It is necessarily protected from both flame radiant and flying fire-flakes. It has investigated that special water-screen protection system become one of the alternatives for preventing them from neighbouring forest fires due to limitation on extinguishing ability of fire regional fire departments. This study has focused on a development and assessment of various water-screen protection system formed by drencher nozzles for prevention the Nara national archive facility from igniting flame radiant and fire-flakes. Because a water-screen protection system using water-splash nozzles installed on surrounding roof-top line only has proved very effective, we could accept the effect of binding capacity of splash water droplets in terms of screening films's quality.
Downward Smoldering Fire Characteristics of Wood Chips and Wood Flour
Kim, Jin Su ; Rie, Dong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 269~274
DOI : 10.9798/KOSHAM.2013.13.1.269
Deep-seated fire that flameless combustion is one of the smoldering fires. It continues when fuel condensed state for heated by temperature. Deep-seated fire is toxic compounds many more than flame combustion. When that is no in case of heat source that is vulnerable, will serve as a middle step to generate a flame. However, causing deep-seated fire progress is not consistent. Also it is difficult to reproduce the experiment. The study is basic experiment for reproduce the deep-seated fire according to the density of the wood, deep as the basis for the experiment to analyze the burning rate of the fire. It is analyze that characteristics of the wood-flour and wood chips in the fire. Experimental container made of quartz was used in order to observe the eyes, the fire, the rate of progress in the vessel equipped with a thermocouple, to be able to measure the internal temperature. In addition, by using an infrared thermal imaging camera on the outside surface temperature was measured. Weight by measuring the reduction of deep-seated fire burning rate and calorific value of the correlation was derived.
Analysis of Forest Fire Based on Statistics Over the Past 50 Years in Korea
Kim, Seung-Soo ; Lee, Myung-Woog ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 275~280
DOI : 10.9798/KOSHAM.2013.13.1.275
Over the past 50 years, the causes of forest fire were mainly broken out by accidential fire of mountain goers regardless of the era. In 1960s and 1970s, forest fires occurred in the following order; carelessness of visitors to their ancestral tombs, children's playing with fire, burnings on the ridges between fields or rice paddles, incineration of garbage, and incompletely extinguished cigarette butts stand in order for the highly causes of the fire. However, after 80s, the order was changed to burnings on the ridges between fields or rice paddles, incompletely extinguished cigarette butts, incineration of garbage, carelessness of gravesites, and children's playing with fire. The fire occurrences by gravesites and children's playing with fire were largely decreased except the fire which was broken out mistakenly by mountain-goers, but the one by burnings on the ridges between fields or rice paddles, incineration of garbage, and incompletely extinguished cigarette butts showed a continuously increase. The occurrences by the ridges between fields or rice paddles and incineration of garbage have been increased after the enforcement of volume-rate disposal system since 1990s. The cases by children's playing with fire was decreased with the rapid declination of the number of children in farmland and mountainside country. The cases by carelessness of gravesites have been also decreased since 1970, and it was shown that the case of forest fire was decreased by changing with the funeral culture.
A Study of Improving Way about the Fire Door Performance Criteria in Buildings
Choi, Dong Ho ; Seo, Hee Won ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 281~287
DOI : 10.9798/KOSHAM.2013.13.1.281
The openings for fire doors and fire shutters are installed on fire compartment to stem fire spreading and evacuation passage in building. Fire spreading tend to grow through these openings, so it is important to organize the standard related to opening protectives. In case of the fire door in Korea, its criteria is only integrity 1 hour regardless of fire resistance of a building member, therefore it is difficult to protect the fire spreading effectively. In this study, foreign performance criterion of the fire door were reviewed and the base data for improving way about the fire door performance criteria were suggested.
A Study of Improving Way about the Elevator Door and the Fire-protection-rated Glazing Performance Criteria in Buildings
Choi, Dong Ho ; Kim, Dae Hoi ; Seo, Hee Won ; Park, Soo Young ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 289~295
DOI : 10.9798/KOSHAM.2013.13.1.289
The openings for fire doors and elevator doors are installed on fire compartment to stem fire spreading, evacuation passage and elevator hoistway in building. Fire spreading tend to grow through these openings, so it is important to organize the standard related to opening protectives. Unlike in the past, due to being tall and large, the elevator for evacuation is being more important. For this reason, it is required for elevator door to be safe in fire and it is necessary for the glazing installed on fire doors to be reviewed with respect to fire spreading. In this study, foreign performance criterion of the fire elevator door and the fire-protection-rated glazing were reviewed and the base data for improving way about the fire performance criteria were suggested.
A Study on the Actual Conditions of Fire Protection Control for Apartment
Park, Jae Sung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 297~301
DOI : 10.9798/KOSHAM.2013.13.1.297
Apartment occupies more than half of the nation's residential forms, so the fire in apartment and the resulting casualties are the national importance. In order to improve the fire safety of apartment, fire protection awareness and strengthening of response capacity of fire wardens who are primarily responsible for overall facility management including fire safety management are more important than what will be. If fire wardens of apartment understand the fire safety, especially fire-fighting facilities and prepare the ability to operate those, secondary damage by not being able to operate those or not proper operation of those will be much lessened. This study analyzed the characteristics and problems of Fire protection control of apartment through fire statistics, laws and regulations and the survey to fire wardens. It also analyzed that the professional and systematic training to enhance fire wardens' duty capacity, improvement of related system and the education and promotion for residents are to be accompanied.
Estimation of Effective Rainfall Guidance Considering Infiltration Capacity-Rainfall Intensity
Kang, Young Bok ; Kim, Bong Jin ; Park, Soo Jin ; Choi, Han Kuy ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 303~308
DOI : 10.9798/KOSHAM.2013.13.1.303
This study investigated the effect of the lag time on the concentration time and the change in effective rainfall depending on the infiltration capacity and rainfall intensity by the status of land use to research the relevance of infiltration capacity-rainfall intensity and the effective rainfall by land categories according to the characteristics of the drainage basin. As a result of analysis, deviation in the lag time is significantly occurring from two hours to nineteen hours and fifty-five minutes depending on the rainfall intensity and the form of the flood hydrograph rising limb is being determined by this. It has been analyzed that the forest land is divided into the region where runoff does not occur even with the rainfall of more than 500 mm/hr and the region where runoff occurs 100% with the rainfall of more than 80 mm/hr and there is an upland field area where runoff does not occur even with the rainfall of more than 120 mm/hr and the area where runoff occurs 100% if the rainfall of more than 20 mm/hr occurs while runoff may occur 100% in the land and rice paddy with the rainfall of 20 mm/hr. As the infiltration capacity varies according to the soil series and status of land use, the objective application of the runoff coefficient of rational method and runoff curve number is needed.
Water Resources Infrastructure: Sustainability and Resilience
Kang, Doosun ; Kim, Tae-Woong ; Ahn, Jae-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 309~315
DOI : 10.9798/KOSHAM.2013.13.1.309
This paper sets forth key concepts and advances working definitions for sustainable and resilient infrastructures (S&R-Infra), specifically for water systems. Three water infrastructure scales, such as large, medium, and small scales are considered, each of which is represented by water resource system, regional water and wastewater infrastructure, and local water distribution system, respectively. All three scales are interconnected each other since water travels from sources to end users and returns the other way. This study is beneficial by suggesting indicators to evaluate system sustainability and resilience against outer disturbances. After S&R definitions and potential indicators are provided, application examples are examined to demonstrate the applications of the proposed indicators. Application results show that the proposed indices are useful for quantifying water system performance. While the approach is refined and applied to synthetic cases, it may be considered applicable to real-world systems as system performance indicators and/or system planning and design goals within an optimization framework.
Regional Independent Storm Occurrence Characteristics Using Storm Event Analysis
Park, Minkyu ; Park, Moojong ; Song, Youngseok ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 317~325
DOI : 10.9798/KOSHAM.2013.13.1.317
In this study, occurrence characteristics of storm event throughout Korea were analyzed as essential information on designing storage facilities or LID for climate change adaptation measures. The comprehensive storm characteristics such as storm event duration, storm event volume, IETD(interevent time definition) for independent storm separation etc., are more important for designing storage facilities or LID than traditional Intensity-Duration-Frequency relationship. The harmonic average characteristics on typical storm events said storm event duration 24 hours and storm event volume 140 mm as a national average. In this analysis, IETD was considered as 10 hours. These results will be helpful to set up baseline of climate change analysis for disaster mitigation.
A Monitoring of Reduction of Peak Runoff, Ecological and Environmental Effectiveness of Dispersal Detention System in Apartment Complex
Byeon, Chan-Woo ; Park, Hyun-Joo ; Lee, Hee-Chang ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 327~336
DOI : 10.9798/KOSHAM.2013.13.1.327
This study is the evaluation and analysis on monitoring for reduction of peak runoff, ecological and environmental effectiveness of the dispersal detention system in the apartment complex that was made in the country for the first time. After ecological and environmental restorative construction the hydrological monitoring results showed the flood peak discharge of the ten-year period in Seoul area is reduced by 12% and show the lagged effect of 20 minutes. For ecological environmental waterway that was most concerned from the hydraulic point view, ecological wooden crib and natural stone work showed stability in order. For florae as ecological restoration effect, 11 families 15 species of Korean persicary, bulrush, Iris pseudoacorus L., reed, Phragmites japonica Steud. were dominant for flora species within the dispersal detention system and for faunas 3 families 4 species of endangered narrow-mouthed toad, Rana nigromaculata, Rana amuriensis coreana were found. BOD of inflow water purification effect was inflow concentration of 1.2 mg/l, outflow concentration of 0.7~0.8 mg/l, SS showed inflow concentration of 6.3 mg/l, outflow concentration of 5.0 mg/l as a results very clear water was monitored.
Prediction of Tsunami Hazard Area based on Probable Maximum Flooding Probability
Kim, Yong Cheol ; Park, Jin Won ; Cho, Yong-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 337~345
DOI : 10.9798/KOSHAM.2013.13.1.337
The mitigation against tsunami hazard is increasingly significant due to huge casualty of human beings and property damage. However, available researches on tsunami mitigation are mainly focused on prediction of run-up height through numerical simulations with some numerical models. In this study, a hazard area due to unexpected tsunami attacking is predicted by employing a probabilistic concept. To predict a hazard area, a probability distribution type of flooding data is first determined, and the probability of flood exceeding a criterion height is then estimated by the cumulative distribution function. The probability of flood exceeding a prescribed criterion height is calculated for 83 cases. Finally, the tsunami hazard area is predicted by employing the probable maximum flooding probability.
Run-up Heights of Solitary with a Hydrodynamic Pressure Model
Lee, Jin Woo ; Cho, Yong-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 347~352
DOI : 10.9798/KOSHAM.2013.13.1.347
A three-dimensional hydrodynamic pressure model is newly developed in this study. The velocity components, the free surface elevations and the hydrodynamic pressures are calculated with two steps in the model. In the first step, the momentum equations are solved using the previously calculated hydrodynamic pressure and free surface elevation within a staggered grid system. In the second step, the velocity fields and free surface elevations are obtained. The developed model is applied to propagation and sub-sequent run-up process of nearshore solitary waves attacking a circular island. The obtained run-up heights are compared with laboratory measurements done by the Coastal Engineering Research Center(CERC), US Army Corps of Engineers. A very reasonable agreement is observed.
Analysis of the Wave Energy Reduction Effect by Varying Coastal Slopes and Artificial Riprap Arrangements
Kim, Hayong ; Jung, Taehwa ; Jeong, Sangman ; Kim, Keedong ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 353~360
DOI : 10.9798/KOSHAM.2013.13.1.353
The occurrence of beach erosion has been considered as a significant problem in many countries, which poses a great threat and should be addressed accordingly to avoid further complications. Existing revetment structures for coastal protection are insignificant in reducing the wave energy in coastal areas, in addition, generate collapsing of the revetment structures by bed scouring, and form gravel layers with beach erosion by reflected waves. Various types of pervious structures are used to reduce wave energy, but studies on the influence of both the friction area and void fraction of riprap arrangements on the reduction of wave energy are insufficient. Therefore, this study analyzed the wave energy reduction effects of varying coastal slopes and artificial riprap arrangements. It was observed that the artificial riprap arrangements yield to the increase of varying friction area and void fraction. The results of this study showed that the coastal slope is inversely proportional to the wave energy reduction effect. Furthermore, the riprap arrangement portrays a significant role to reduce the wave energy.
Sustainable Flood Mitigation through Land Use Planning and Management
Jung, Juchul ; Lee, Dalbyul ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 361~369
DOI : 10.9798/KOSHAM.2013.13.1.361
This research examines the relationship between natural hazard damage (like flood damages) and urban development in environmentally sensitive areas (like floodplain). Current structural approaches such as dams and levees to reduce hazard damages are criticized because of their threats to environmental sustainability. Through literature review and empirical case studies, this research proposes an environmentally sustainable approach, that is, 'hazard mitigation policy.' The hazard mitigation policy through land use planning and management is a long term policy that aims at sustainable development by both removing sprawls in environmentally sensitive areas and preserving the environmentally sensitive areas such as parks and open spaces.
Climate Exposure Assessment Mapping for Nak-dong River Area
Jo, Deok Jun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 1, 2013, Pages 371~377
DOI : 10.9798/KOSHAM.2013.13.1.371
Climate change has been done since a long time ago, a special response from various fields are required. Occurrence of various weather elements, especially in the complex due to climate change, climate exposure for improving an adaptable alternative to raise is the most basic items that should be considered. The study of meteorological party affected by the occurrence of multiple exposure to assess climate Nakdong River Basin is located in the meteorological data of 15 stations were investigated. In addition, analysis of each meteorological station using the Thiessen method subarea for exposure in the climate after the conversion to compare the relative has a mapping for each subarea. Climate exposure results in the Nakdong River area mapped quantitative analysis of exposure in the climate was much easier to compare. In addition, downstream of the Nakdong River basin, the climate exposure, especially in areas near the coast have been estimated significantly.