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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
Retrofitting Effects of Seismic Resistance Capacity of Existing RC Wall Type Apartment Slab Structures
Hwang, Jihyun ; Park, Taewon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 1~6
DOI : 10.9798/KOSHAM.2013.13.4.001
A need for seismic design of buildings have been increased dramatically due to the fact that seismic damages have been reported all over the world. In Korea, the seismic design code for buildings was developed in 1988. However, the buildings designed and built before 1988 are expected for serious seismic damages. With this reason, an appropriate seismic retrofitting method is required for such buildings, which needs to be economical and practical. In this study, seismic retrofitting methods by using H-section steel to the slab are developed and introduced applying to the wall-type apartment buildings. As a result, performance of slab test models was improved to satisfy the required retrofitting capacity. Stiffness and energy dissipation capacity of the model were also enhanced.
Evaluation of Vertical Vibration of a High-rise Steel Building Caused by Human Group Rhythmic Activities
Hwang, Ji-Hyun ; Lee, Kyungkoo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 7~13
DOI : 10.9798/KOSHAM.2013.13.4.007
In this study, the effects of human group rhythmic activities on vertical vibration of a high-rise steel building were analytically evaluated. A eigenvalue analysis was first conducted in order to investigate the mode shapes and the vibration characteristics of the building. The requirements for an accurate analysis were drawn based on the comparisons of the measured natural frequencies of the building and the estimated natural frequencies of the building. Then, linear time history analyses were conducted by applying human group rhythmic activities to the slab of the 12th floor of the building model. From the analysis results, the vertical vibration acceleration responses in the upper floors amplified by resonance between building and excitations were evaluated.
Experimental Investigation of the Seismic Performance of RC Column Retrofitted by Ultra-High-Molecular-Weight Polyethylene Fiber Sheet
Kim, Sung Jig ; Chang, Chunho ; Park, Dongbyoung ; Choi, Sunghun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 15~21
DOI : 10.9798/KOSHAM.2013.13.4.015
The paper experimentally investigates the seismic performance of RC columns retrofitted by Ultra-High-Molecular-Weight Polyethylene(UHMWPE) fiber. A total of three specimens with a scale factor of 1/3 was constructed and experimentally investigated through static cyclic tests with a constant axial load in order to assess the structural behavior of the retrofitted RC columns. One specimen was a non-seismically designed column without any retrofitting method, while others were retrofitted with either Carbon fiber or UHMWPE fiber. It is concluded that the UHMWPE retrofitting method increases the strength and ductility of the RC column and can also impact on the failure mode of RC columns.
Experimental Study on the Seismic Performance of Hybrid Buckling-Restrained Braces
Kim, Do Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 23~29
DOI : 10.9798/KOSHAM.2013.13.4.023
Buckling-Restrained Brace(BRB) shows good seismic behaviour. However BRB does not dissipate the energy when it is governed by a minor earthquake or wind. Hybrid Buckling-Restrained Brace(H-BRB) is the new hybrid damper which can improve the wind performance of the BRB system and is composed of the viscoelastic damper and BRB. Also H-BRB has to retain the seismic performance of the BRB in addition to the wind resistance performance. In this paper, BRB specimen and H-BRB specimen with the same steel core are experimentally investigated to make sure the seismic performance of the H-BRB system. It could be concluded that the seismic performance of H-BRBs is more than that of BRBs regardless of viscoelastic damper`s welding fracture.
Evaluation on the Serviceability of Tall Buildings using Hybrid Buckling-Restrained Braces
Kim, Myeong Han ; Kim, Do Hyun ; Ju, Young K. ; Kim, Sang Dae ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 31~37
DOI : 10.9798/KOSHAM.2013.13.4.031
The paper investigates the effect of Hybrid Buckling-Restrained Brace(H-BRB) on the serviceability of a high-rise building under wind loads. While Buckling-Restrained Brace(BRB) has been known as a good energy dissipated device under large events, its performance is rather weak when subjected to minor earthquakes or wind loads. A hybrid damper system, H-BRB which is composed of a Viscoelastic damper and BRBs has been developed to improve the performance of BRBs. In this paper, three 40-story steel buildings with normal steel braces, BRBs and H-BRBs are selected for the analytical investigation and their performances under wind loads are evaluated by using a static analysis and time history analysis. 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 is effective to reduce the story displacement and to improve the serviceability of the building with BRB.
A Study on the Analysis of Characteristics for Safety Depressurization System of Advanced Power Reactor
Lee, HaeChul ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 39~46
DOI : 10.9798/KOSHAM.2013.13.4.039
The purpose of this study analysis is evaluation of Safety Depressurization System function on PWR plant. The Safety Depressurization System is a system which releases steam from the pressurizer of Reactor Coolant System(RCS) and depressurizes RCS. There is a similar system in Boiling Water Reactor(BWR) type plant but the SDS with In-Containment Refueling Water Storage System(IRWST) is a new system to Pressurized Water Reactor(PWR). The current worldwide trend in a new PWR design is to implement a SDS with IRWST because of the advantages in installing IRWST. There have been also trials to install a SDS with IRWST to newly ordered domestic plant was that the domestic technical level for analysis and design of the system was not sufficient to do work.
An Experimental Study on the Bending Characteristics of Graphite/Epoxy Composite Material
Kim, Doo-Hwan ; Choi, Chong-Hyuk ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 47~53
DOI : 10.9798/KOSHAM.2013.13.4.047
Currently, composite materials technology developed rapidly and many industries frequently utilize the technology. But construction parts remains to the traditional construction materials yet. Because of composite material`s theory is so complicated that it couldn`t application of construction structural engineering easily. For making an application in construction parts of the composite material`s complicated theory needs to accumulation of data by the help of study and experiment(demonstrate). From this study, bending test are carried out to investigate the bending characteristics of Graphite/Epoxy composite material. The results of the analysis are shown in variable sections properties, so it would be useful to whom have not many experiences and knowledges. Solving the problem will enable us to build the composite material structure of variable section where installing construction field is regarded impossible.
Applicability of Double-Skinned Composite Tubular Member for Offshore Wind Turbine Tower
Han, Taek Hee ; Won, Deokhee ; Kim, Seungjun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 55~65
DOI : 10.9798/KOSHAM.2013.13.4.055
A double-skinned composite tubular(DSCT) offshore wind power tower was suggested and an automatic section design software was developed. The DSCT offshore wind tower has two types. One has steel tubes and the other has fiber reinforced polymer(FRP) tubes. The developed software adopted the nonlinear material model and the nonlinear column model which was proposed by Han et al.(2010, 2013). If an outer diameter, material properties and requested capacities are given for the DSCT wind power tower, the developed software performs axial force-bending moment interaction analyses for hundreds of sections of the tower and suggests ten optimized section designs. By using the developed software, example design processes were performed for a 5.0 MW turbine and a 3.6 MW turbine. The steel and FRP were considered as the material of inner and outer tubes. The designed section and analysis results showed that the developed suggested rational and satisfactory section designs. And they showed the possibility which a DSCT tower can be used as a offshore wind power tower.
Dynamic Analysis for Low Depth Track System Under Train and Car Moving Loads
Kim, Ja-Yeon ; Sagong, Myung ; Cho, Kook-Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 67~75
DOI : 10.9798/KOSHAM.2013.13.4.067
As a low depth light rail system is getting issued recently, It is important to understand dynamic effects from train and car moving loads. In this study, Numerical analyses were performed to evaluate ground surface vibrations from train and car operations on low depth track system using LUSAS which is finite-element analysis program. The dynamic serviceability of a building is evaluated using analysis results. The evaluated vibratory acceleration under the moving loads of car and train at the depth of 1.0 m is 0.0042 g, 3.0 m is 0.0037 g and the value of 0.00048 g at the depth of 5.0 m. The research results show that low depth train system can be used with low vibration effect by comparing with the maximum allowable criteria of 0.102 g.
Estimation the Porosity of Pervious Concretes based on X-Ray CT and Submerged Weight
Ahn, Jaehun ; Lee, Younseok ; Vaidya, Susurut ; Kim, Jeong-Ho ; Lee, Seong-Woo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 77~81
DOI : 10.9798/KOSHAM.2013.13.4.077
Recently due to climate change and urbanization, and following changes in rain fall pattern, the stormwater management is becoming a major issue for research in civil and urban engineering. The use of pervious pavement is one of promising tools to control runoff and water quality along with several other benefits, and therefore the pervious pavement is widely adopted for sidewalks, parking lots, and bike roads where the loads are not heavy. The porosity of the pervious pavement is the most important property of the pavement regarding current hydrologic design in practice. In this article, the porosity of a pervious concrete sample cored from the road for bikes and pedestrians are evaluated by two approaches: measuring dry and submerged weights and X-Ray image analysis, and the test procedure is proposed. The porosities estimated by two approaches were both around 30%, and they gave consistent results.
Dynamic Behaviors of a Curved Steel Tunnel Lining with Various Curvatures under Wind Loads due to Consecutive Passing Vehicles
Mha, Ho-Seong ; Cho, Kwang Il ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 83~90
DOI : 10.9798/KOSHAM.2013.13.4.083
Dynamic behaviors of the steel lining of curved tunnels with various curvatures are throughly examined to see the effect of wind loads due to consecutively passing vehicles. The wind pressure upon the lining is simplified into the pressure and suction while the vehicles are passing the specific positions. Results from cases of sole driving and consecutive driving conditions for both curved and straight tunnels are compared. It is found that the maximum displacements occur at middle location of the tunnel, and that the responses from consecutive passing vehicles increase compared to those from the single vehicle conditions for all tunnels. It is also found that the responses increase at the higher speed of passing vehicles while the responses decrease as the curvatures increase. In the case when the consecutive vehicles go at the high speeds, the increments of the responses become hardly noticeable compared to those from single passing vehicle conditions since the safety distance are getting long enough to eliminate the effect of wind load from the following vehicles.
Evaluation of Suitability of Caliche as Backfill of MSE Wall Considering Its Compaction and Strength Characteristics
Moon, Joon-Shik ; Chang, Buhm-Soo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 91~96
DOI : 10.9798/KOSHAM.2013.13.4.091
This paper presents laboratory test results analyzing the compaction and strength characteristics of Caliche (also known as calcrete or gatch) which is commonly used for road construction in arid or semi-arid region including Middle East area. Caliche material is easily ripped and crushed with excavating equipments at the borrow pit conforming the grain-size distribution specification, but the particles can be additionally broken down to finer particles due to slaking and compaction, and consequently bearing capacity would be dropped. The compaction and strength characteristics were investigated by performing grain-size analysis, compaction tests, and CBR tests. The compacted samples were soaked for as long as 400 days and tested in the lab in order to investigate the long-term behavior of Caliche material.
Examination on Seismic Behavior of Interface of a Concrete-rockfill Composite Dam Using Centrifuge Model Test
Lim, Jeong-Yeul ; Ha, Ik-Soo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 97~106
DOI : 10.9798/KOSHAM.2013.13.4.097
The objective of this study is to examine the characteristics of the acceleration amplification and the deformation of the interface of a concrete-rockfill composite dam subjected to earthquakes. In this study, dynamic centrifuge tests on the dam interface model, which was prepared for an existing composite dam, were carried out. From the analysis of the accelerations measured at the dam base and at the crest of the concrete, the joint, and the rockfill model around the interface, the acceleration amplification characteristics of the interface was examined. From the analysis of the displacements measured at the crest around the interface, the characteristics of the horizontal and vertical deformation of the interface was investigated. From the test results, it is found that the acceleration amplification characteristics of the joint is similar to that of the concrete model, and, on the contrary, the horizontal deformation characteristics of the joint is similar to that of the rockfill model. On all the test conditions of this study, the rockfill of the concrete-rockfill interface heaved over the concrete part during excitations.
A Study on Mechanical Vibrational Properties of Vibro-hammer
Lee, Seunghyun ; Yoon, Kiyong ; Kim, Eungseok ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 107~111
DOI : 10.9798/KOSHAM.2013.13.4.107
Vibrational properties of vibro-hammer were studied and the influences of eccentric moment, frequency, vibratory mass and spring constant to the amplitude, acceleration, spring force and theoretical power were analyzed. Existing approach of determining input of pile head force which is necessary for analyzing a pile constructed by vibro-hammer were reviewed and rational one was suggested. In addition, existing governing equation shown in the literature, which simulates the vibrating system of vibrator/pile was modified through rational evaluation.
Reliability Assessment of Lane Divider for Jaywalking Ban
Kim, Jong Gil ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 113~120
DOI : 10.9798/KOSHAM.2013.13.4.113
The Government has recently selected and is implementing the safety measures for ensuring the safety of pedestrians in living zone in order to reduce the number of traffic casualties by half. This study has carried out researches on the analysis of pedestrian accidents, the criteria for performance evaluation of jaywalking ban facilities, and the performance evaluation of jaywalking ban facilities lane divider. As a result, we have analyzed the failure mechanisms of material damages, support bar bending, the bar fracture, anchor-pullout, lower fixed shear fracture, reflection performance degradation of the reflective sheet, etc. due to vehicle crashes, which are the factors in the failure of the lane divider for jaywalking ban, a road safety facility. We have also developed a reliability evaluation method which is able to reproduce those failures. As a result of evaluating the reliability of the jaywalking ban facilities lane divider product, we have been able to assess the criteria for reliability evaluation which is an important measure to durability, and to provide a guide for the reliability of reasonable level of the product quality.
Development and Application of Pressure Driven Analysis Model based on EPANET
Lee, Ho Min ; Yoo, Do Guen ; Kim, Dong Young ; Kim, Joong Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 121~129
DOI : 10.9798/KOSHAM.2013.13.4.121
Hydraulic analysis of water distribution systems (WDS) is divided into two types, one is Demand Driven Analysis (DDA) which applies to a steady state condition and other is Pressure Driven Analysis (PDA) which applies to an abnormal condition. In DDA, it is assumed that available discharge in demand nodes is always equal to the required discharge, and the assumption is suitable for a steady state condition. However, in abnormal conditions such as pipe failure or excess of demand, DDA model may produce unrealistic outputs such as negative pressure, so application of PDA model is required. The Gradient Algorithm used for DDA in EPANET was improved to develop a PDA model based on the Global Gradient Algorithm. Additionally, the developed model was applied to evaluate the emergency water supply plan of a large block system in Yeong Wol. The results showed to 66~100% of the total network demand was available in the emergency scenarios of failure in each reservoir. The developed PDA model is capable to solve negative pressure problem shown in existing DDA model and to analyse evaluation of emergency water supply plan with high reliability.
An Exploratory Development of a Mathematical Programming Model for Planning of Restricted Water Supply
Kim, Jaehee ; Jun, Hwandon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 131~136
DOI : 10.9798/KOSHAM.2013.13.4.131
In order to reduce the damages of water shortages, it is important to allocate water resources efficiently. Therefore, we present a prototype of the mathematical model for optimal allocation of water resources among blocks in a water supply network for situations where restricted water supply planning is inevitable. The model is a goal programming model that does not minimize the total amount of water shortages but the total weighted penalties considering the importance of water demands partitioned into smaller blocks according to their importances. With the model, we can meet the demands with higher priorities and mitigate the severity of water shortages by minimizing the maximum of water shortages of each block.
Study on The Optimal Grid-size and Station-density for Water Resources Applications
Hwang, Seok Hwan ; Ham, Dae Heon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 137~148
DOI : 10.9798/KOSHAM.2013.13.4.137
In a purpose to manage precipitation monitoring network more safely and economically and to efficiently use spatial precipitation data in the water resources, we conducted a trade off study on density of Korea Meteorological Administration (KMA) stations and analysis on optimal grid size when estimating accurate spatial precipitation. For the analysis, we compared areal precipitation and spatial accuracy of estimated grid precipitation by station densities and grid sizes for Seoul region where Automatic Weather System (AWS) stations were most dense. Based on 29 stations near in Seoul, we estimated grid precipitation by station densities, grid sizes using daily precipitation data of KMA`s AWS and Automatic Synoptic Observation System (ASOS) during 2001-2010. To find a optimal station density, we specified the case of 29 stations (average distance about 5km between stations), 20 stations (average distance about 6 km between stations) and 7 stations (average distance about 10km between stations). Then, we also calculated grid precipitation of 10 km, 5 km, 1 km size by each station density to find a optimal grid size. From the results of a accuracy tests on the estimated grid precipitation by station density and grid size, we found that station density acted as the most crucial factor to improve space accuracy. In addition, for an accurate spatial precipitation estimation, the appropriate station density and grid size should be sub-5 km and sub-1km respectively in South Korea.
Evaluation of Spatial Downscaling Methods for Enhancement of Spatial Precipitation Estimation
Hwang, Seok Hwan ; Ham, Dae Heon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 149~163
DOI : 10.9798/KOSHAM.2013.13.4.149
In order to estimate a reliable spatial precipitation which has high resolution sub-measuring scale, a systematical research for spatial interpolation methods and evaluation of characteristics of them are required. This will be able to reduce disputes on selection of methodologies and estimate uncertainties of downscaled data. Therefore, we assessed the spatial interpolation methods using automatic weather system (AWS)`s daily data of Korea Meteorological Administration (KMA) during past 10 years (2001-2010), so as to reduce arbitrary interpretations of the result by selecting particular regions or storm events. In addition, we adopted inverse distance weighted method (IDW), ordinary kriging method (KRG) and multi-quadric interpolation method (MQI) to produce
grid precipitation. For quantitative evaluations of each interpolation method, thiessen polygon method (TSN) was used as a comparison method. When comparing the gridded daily precipitation for the past 10 years (2001-2010) by middle scale basins, differences of whole average for each methods were not significant when using KMA`s AWS network. However, in case of regions where stations were sparse and each storm event, significant differences were founded caused by interpolation methods or characteristics of regions.
A Research of Component Analysis for Wetting Agent
Kim, Sung Soo ; Rie, Dong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 165~169
DOI : 10.9798/KOSHAM.2013.13.4.165
Wetting agent was used for extinguish at the porosity and stacked substance fire. It makes lower surface tension for upgrade permeation performance. Most common extinguish technique, water-based fire extinguishing has advantage of being faster cooling effect. Because of water has big evaporative latent heat. When wooden building, porosity and stacked substance were being burned, it is prone to deep seated fire. And deep seated fire is hard to extinguish because water can`t permeate into where a fire source were located. For it overcome difficulty to extinguish, wetting agent were mixed to water for upgrade permeation performance. Recently, standard of wetting agent is needed. Surfactant was mixed to wetting agent for lower surface tension. But, it is unknown that wetting agent was included which kinds of surfactant. Component analysis is needed for assessment a common performance and characteristic by products. In this study, component of wetting agent was studied common and characteristic component by basic research. So, result of this study was used making fingerprint region. It is proper application for post management technique of certificated products.
Effect of Wearing Fire Leather Boot For Physical Balance
Huh, Yu-Sub ; Bang, Chang-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 171~175
DOI : 10.9798/KOSHAM.2013.13.4.171
The aim of study intends to investigate effect of weight of fire leather boot for physical balance and to provide the base data for the safety of firefighter. The results of the study are as follows. Static balance tests with closed-eyes foot balance, opened-eyes foot balance on cushion and dynamic balance tests with beam walking, closed-eyes walking at 10 m, barefoot group and fire leather boot group is not statistically significant. For balance comparisons between firefighting and rescue & EMS was not statistically significant between barefoot and fire leather boot. For balance checks about career, closed-eyes foot balance is appeared statistically significant between career groups and the rest of the test results are not statistically significant.
A Study on Evaluating the Economic Value of Urban Facilities for Damage Prevention Using CVM -In the Case Gyeong-do Fire Station-
Ryu, Tae-Chang ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 177~184
DOI : 10.9798/KOSHAM.2013.13.4.177
As people have more and more interest in service benefits provided in urban facilities for damage prevention(fire stations) and the occurrences of all sorts of disasters increase, the value of fire stations is increasing as well. However, most of the research is still limited to measuring the value of certain services based on fragmented knowledge about measuring methods. Thereupon, this study aims to evaluate the value with the public measurement model for all kinds of public goods since there is no theory related with public measurement on facilities for damage prevention (fire stations). As the study method, the paper adopts the Contingent Valuation Method(CVM), and to secure reliability and acquire base line data for the research, it conducts the survey twice.
The Assessment for Coupling of Steam Generator Support Bolting in Nuclear Power Plants
Cho, Nam Jin ; Im, Seok Been ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 185~190
DOI : 10.9798/KOSHAM.2013.13.4.185
In nuclear power plant, anchor bolts for steam generator supports are sufficiently used in terms of safety reason, but field inspections have reported that some bolts exceed the limit of their allowable hardness. Because the high level of hardness may lead to failures due to the stress corrosion or fracture toughness, a regular inspection is required for the bolts in nuclear power plant. Thus, this research measures the hardness of bolts currently used in steam generator supports and then estimates maximum allowable stresses preventing failures by stress corrosion and fracture toughness. Using the ANSYS program, the stresses of the bolts in the regular condition and accidental condition have been calculated, and the possible maximum stress has been compared with the estimated allowable stresses. From the results, the stresses of bolts in the accidental condition satisfy the allowable safety stress from the stress corrosion failure.
Determination of Optimized Blasting Pressure through Critical Volumetric Strain Monitoring
Lee, Won-Sup ; Jung, Seung-Won ; Park, Yang-Hoo ; Cho, Kook-Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 191~197
DOI : 10.9798/KOSHAM.2013.13.4.191
The more increase of construction of railways and roads, the more increase of tunneling in Korea. NATM(New Austrian Tunneling Method) is used for most tunneling construction, and excavations by blasting are usually adopted. The most important consideration in blasting excavation is how to minimize damages and overbreaks in the rock, which is brought up interests from many researchers. The damages and overbreaks in the rock directly influence on the stability of the tunnel during construction as well as on maintenance after construction. The dynamic properties of the rock are measured by strain gauges during trial blasting from two different sites. A procedure to evaluate the critical volumetric strain of the rock using measured values during blasting is proposed. Rock damage zone analyses are performed using a FEM analysis program called ABAQUS/Explicit by adopting the evaluated critical volumetric strain. The technique to determine optimum blasting pressure is also proposed using numerical analysis results.
Flood Inundation Scenario Development and Analysis Using HEC-HMS/RAS and HEC-GeoRAS Models
Kim, Seon Jeong ; Kim, Geon Tea ; Jeong, Jong Hyeok ; Han, Sang Ok ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 199~205
DOI : 10.9798/KOSHAM.2013.13.4.199
Damages by hurricanes and regional torrential rains due to anomaly climate changes take up the most of recent meteorological disasters in Korea. To reduce these damages, producing flood hazard maps and disaster maps is essential, and accordingly, the interpretation of flood inundation by scenario accounts for an important part. This study established a flood inundation scenario at Sacheon River in Gangneung-si and carried out an analysis using the HEC-GeoRAS model. The rainfall data at the Gangneung General Observation Post from 1961 to 2010(50 years) were used for probable rainfall, and the scenario was analyzed by assuming the case of Typhoon Rusa with 100-year and 200-year frequencies and Probable Maximum Flood (PMF). As a result, flood inundation is predicted if it exceeded the 100-year frequency rainfall while for the 200-year frequency and PMF frequency, flooded areas were simulated at 64.3 ha and 135.9 ha, respectively and maximum flooded depths in 4.1 m and 5.7 m, respectively. It is expected that these results will help predict flood inundation area with rainfall in the duration using the synthetic data of the real-time weather data and the model numerical analysis.
Analysis of the Disaster Environmental Change Considering Climate Change : 1. Analysis of Flood Elevation
Kim, Eung Seok ; Lee, Jae Hyuk ; Park, Moo Jong ; Chung, Gunhui ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 207~217
DOI : 10.9798/KOSHAM.2013.13.4.207
Recently, the increase of the abnormal flood events mainly due to the climate change led the severe casualty and property damages particularly in the small and medium size of watersheds. Therefore, in this study, the water level changes cased by climate change in the mainstream and tributaries of the Nakdong river basin were analyzed. As results, 0.35~0.74 m of the water levels in the mainstream were changed and 0.47~0.72 m of alteration in the tributaries. To evaluate the effect of climate change, the expected differences on the relationship between return period and flood level in the tributaries were evaluated using the existing data in the basin plan report for the Nakdong river basin. Also, the effected areas by the climate change were analyzed using the water level alterations caused by climate change and the resulted flooding area in the Nakdong river basin was increased 6.45% in maximum with the consideration of climate change. It is therefore expected that the proposed method to estimate the effected area by climate change might provide the basic information on developing natural disaster mitigation strategies.
Analysis of the Disaster Environmental Change Considering Climate Change : 2. Flood Risk Area Assessment
Kim, Eung Seok ; Yoo, Ji Young ; Chung, Gunhui ; Park, Moo Jong ; Choi, Hyun Il ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 219~226
DOI : 10.9798/KOSHAM.2013.13.4.219
The climate change has clearly affected most parts and systems in the globe. Particularly, the recent global warming is presumed as the main reason of the increasing severe flood frequency, resulting a significant damages on the human life and property. This increasing trend on the occurrence of severe flood is very remarkable in the Korean Peninsula as well. Therefore, the appropriate flood prevention and mitigation methods are required. In this study, to assess the climate change effects on flooding risk areas in the Nakdong river basin, the flood and river acts from Korea and other countries were investigated and the current situation and problems were analyzed. The flood risk considering climate change were also assessed for the flood risk areas among the natural disaster risk areas proposed in 2010 to suggest the future management strategy against the future severe flood damage. The proposed flood risk assessment results for the flood risk areas might be used as a basic information to develop climate change adaptation strategy.
Estimation of deposition from Namgang Dam Discharge in Sacheon Bay
Lee, Taesam ; Shin, Ju-Young ; Kim, Jinkyung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 227~233
DOI : 10.9798/KOSHAM.2013.13.4.227
During a flood in the Nam River basin, tremendous amount of water is discharged to the Sacheon Bay and large amount of deposition and organics are delivered to this region. At the time of the flowing tide, the water is stagnated in this bay. In the current study, we estimate the amount of deposition that has been accumulated in the Sacheon Bay by the discharge from the Nam River dam after the construction of the dam with Kriging and Theissen method. The results showed that around 1.67meter of deposition has been accumulated. We conclude that the consideration of the flow from tributaries to the Sachenon Bay for the deposition estimation is required. Furthermore, the efforts to recover the oceanic ecosystem such as the discharge reduction or dredging must be followed.
Analysis on Hydraulic Characteristics at Bangudae Petroglyph by Water Level Declination of Sa-yeon Dam
Kim, Hayong ; Kim, Yongtae ; Park, Moojong ; Jeong, Sangman ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 235~243
DOI : 10.9798/KOSHAM.2013.13.4.235
Assesment of hydraulic Characteristics has been carried out of Daegokcheon because Sa-yeon dam water level decline operation for proper due to world cultural heritage edged Bangudae petroglyphs. Analyses on the Dae-gok stream were conducted by changing the water level of the Sa-yeon Dam by using the 1D HEC-RAS numerical model for the inundation of height variations and 2D RMA-2 model for the flow characteristics. As a result of the modeling, if the water elevation on the Sa-yeon Dam is higher than EL.52.5 m, the Bangudae Petroglyphs starts to be flooded. The Bangudae Petroglyphs starts submerging from EL.60.0 m to EL.56.5 m on Sa-yeon Dam. The Bangudae Petroglyphs water level increased by 2.7 m for 20year and 3.47 m for 200year flood frequencies, 73% and 93.8% of the inundation occurs, respectively. As a result of the change on the water level of the Sa-yeon Dam, from EL.52.5 m to EL.60.0 m, the flood flow characterization on the Bangudae Petroglyphs showed that the velocity multiplied by 2.5 times the normal flow. The maximum velocity directly approches the Bangudae Petroglyphs thus, causing damaged.
Assessment of Flood Damage Vulnerability Considering Regional Flood Damage Characteristics in South Korea
Lee, Min Woo ; Kim, Tae-Woong ; Moon, Geon Woo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 245~256
DOI : 10.9798/KOSHAM.2013.13.4.245
In this study, flood damage characteristics were classified by analyzing relationships of different types of flood damage with extreme rainfall. The Flood Damage Vulnerability Index (FDVI) was proposed considering regional flood damage characteristics in South Korea. The FDVI was calculated by averaging Flood Damage Vulnerability Rating (FDVr). The FDVr was determined based on the classification flood damage characteristics through introducing the sensitivity and adaptation capacity over the flood damage. The sensitivity is a hydrometeorological indicator which represents the scale of influence over the flood damage, whereas the adaptation capacity is an indicator of geographical, social and economic ability which represents the scale of defensive ability over flood damage. Using the FDVI, this study evaluated the flood damage vulnerability for 228 administrative districts in South Korea. In order to analyze the variability of flood damage vulnerability, the data period were divided into 1970s, 1980s, 1990s and 2000s. The temporal and spatial variation of flood damage vulnerability were also analyzed by constructing the FDVI map. The results show that the flood damage vulnerability was changed regionally from the past to the present. The recent highest flood damage vulnerability area was Gangwon-do. The FDVI would be utilized as a basic data for planning more rational countermeasures of preparation, response and restoration of flood damage.
Determining Optimal Volume and Quantifying Runoff Reduction Effects of On-site Stormwater Detention Facilities
Park, Changyeol ; Yoo, Chulsang ; Shin, Sang Young ; Son, Eun Jung ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 257~266
DOI : 10.9798/KOSHAM.2013.13.4.257
The purpose of this study is to quantify the runoff reduction effects of on-site stormwater detention facilities in urban area, and to determine the optimal size of storage capacity. The modified rational equation was used to calculate the hydrograph into detention facilities. The storage effect by the facilities was estimated with respect to rainfall characteristics, land cover type, and facility sizes. Also, the optimal storage volume and the condition of location of on-site stormwater detention facilities analyzed through field survey in a case study area. This study results could be helpful to easily understand the flood reduction effect, and to determine the optimal capacity when designing on-site stormwater detention facilities in built-up areas.
The Regional Steric Sea Level Rise due to Global Warming in the Northwestern Pacific
Lim, Chaewook ; Kim, Dong-Hoon ; Woo, Seung-Bhum ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 267~272
DOI : 10.9798/KOSHAM.2013.13.4.267
In order to consider the effect of steric sea level change directly, we developed the regional version ocean circulation model (ReMOM) using the GFDL MOM version 4 which does not use the Boussinesq approximation. The GFDL CM2.1`s SRES A1B and B1 results from IPCC were used for the initial and boundary conditions in the northwestern Pacific. The sea surface temperature and sea surface height were increased by about
and 30cm for SRES A1B, and about
and 22 cm for SRES B1 after 100 years, respectively. East Sea was affected by steric effect more than Yellow Sea. It caused by the warmer Tsushima current passing the Korea strait due to global warming. The sea level rises by the direct steric effect were higher than by the indirect steric effect.
Experiments for Wave Transformation of Regular and Uni-directional Irregular Waves over a Submerged Shoal
Lee, Jong-In ; Kim, Young-Taek ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 273~278
DOI : 10.9798/KOSHAM.2013.13.4.273
Laboratory experiments are conducted to study transformation of water waves propagating over a submerged elliptic shoal in a basin. Incident waves are both regular and uni-directional irregular waves. For non-breaking wave conditions over the center of the shoal, a focusing of waves is observed at the rear side of the shoal. The measured relative heights of regular waves are greater than those of uni-directional irregular waves. Under breaking condition, the relative wave heights are small at the center of the shoal, while they are large relatively at laterals. Around the center of the shoal, the measured wave heights of uni-directional irregular waves are larger than those of regular waves because of the small wave height components of the irregular waves.
Computation of Armor Block Weight and Erosion of Damaged Breakwater
Yoo, Dong Hoon ; Lim, Hak Soo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 279~286
DOI : 10.9798/KOSHAM.2013.13.4.279
Compared are the equations of Hudson, van der Meer-de Jong and Yoo for the estimation of armor block weight and in addition the equation of critical wave height for erosion at the front bottom has been developed. All empirical equations have been reformed according to Hudson equation, which has been widely employed for engineering design, and additional incremental factor has been added to each reformed empirical equation. The additional incremental factor reflects the characteristics of each empirical equation. The wave action slope, introduced by Yoo(2003), employs wave celerity as well as wave height, and both parameters are taken at the place of interest. The wave celerity has been calculated by using Stokes 4th order wave theory which is valid for deep water or by modified solitary wave theory, which is valid for a wide range of water depth. In the present study modified solitary wave theory is found generally valid for a wide range of application. On the other hand several places are found inadequate for erosion of sea bottom in front of breakwater. The equation of critical wave height for erosion has been developed and employed to test the sea bottom stability, and with this inclusion the credibility of the over-check has been increased up to 87.7%.
Sedimentation Characteristics and Prediction of Riverbed Variation of the Lower Naeseong Stream Considered SS Concentration
Jo, Chang Dae ; Yoon, Jong Su ; Lee, Jae Woon ; Cheon, Se Uk ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 287~293
DOI : 10.9798/KOSHAM.2013.13.4.287
This study was conducted with the national river, Naeseong stream which is typical alluvial river. In this paper, various sediment transport equations were used to predict and estimate long-term riverbed variation for downstream in Naeseong stream. Statistical variables such as RMSE(Root Mean Square error) and RMAE(Relative Mean Absolute Error) were used to evaluate reliability of HEC-RAS model. Also calculations of time-series of 91 river stations were reviewed. To confirm flow of suspended load of the Naeseong stream, We examined SS concentrations. As a results, SS flow was retained by maintaining over the certain concentration in dry season.
Determination of Optimal Locations of Urban Subsurface Storage considering SWMM Parameter Sensitivity
Lee, Jung Ho ; Song, Yang Ho ; Jo, Deok Jun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 295~301
DOI : 10.9798/KOSHAM.2013.13.4.295
Recently, the danger of flooding has increased due to the result of extreme climate change and urbanization around the metropolitan areas. To prevent this kind of problems, installing underground retaining facility around the metropolitan basin has been discussed. Even though the several researches related to the underground retaining facility are on progress, the general consideration of the capacity and the location is unsatisfying. Therefore, this research has developed an optimal model which would help to decide an adequate capacity and location according to the numbers of the facilities that need to be installed. For this optimal technique, Harmony Search (HS) is utilized, and SWMM (Storm Water Management Model) 5.0 DLL is constructed accordingly for the better interpretation of hydraulic, hydrological. And the sensitivity analysis was performed for SWMM parameters such as manning`s roughness coefficient and manhole loss coefficient which affect overflow in the sewer network. And this sensitivity analysis was considered to determine the optimal positions of storages. The developed optimal model has been simulated in BEXCO district in Busan, and it has determined the positions according to the different numbers of the facilities which need to be installed.
An Analysis of Runoff Mitigation Effect Using SWMM-LID Model for Frequently Inundated Basin
Shin, Dong Soo ; Park, Jae Beom ; Kang, Doo Kee ; Jo, Deok Jun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 303~309
DOI : 10.9798/KOSHAM.2013.13.4.303
Recently meteorological phenomena caused by climate change have brought localized heavy rainfalls, flash-floods causing severe damage for human-life and property. They also increase the occurrence of record-breaking rainfall. Development in urban area decreases the portion of open spaces, landscapes, leading to significant diminution of storage and detention function of the basin. The expansion of impervious areas increases the extent of peak-runoff and runoff volume, especially the shorter time of concentraion due to development makes the basin have different hydrological characteristics compared to pre-development. In addition, urbanization worsen the requirement of site for residence and public facility so that even floodplain and inundated district are urbanized threatening safety for flood control. In this study, applicable LID techniques are analyzed and implemented using LID modules of SWMM, which is the model for urban stormwater-runoff management in the project area. Effects of implementing LID practices are also assessed and reviewed. The result shows that scenario B and C ruduced 288.52ton(15.62%), 240.26ton(13.01%) each in runoff simulations compared to scenario A.
Effects on Transmission Loss of Soundproof Panel Depending on Material and Thickness of Air Layer
Lee, Juhaeng ; Kim, Ilho ; Park, Jongbin ; Ahn, Hosang ; Kim, Kwang soo ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 311~315
DOI : 10.9798/KOSHAM.2013.13.4.311
Shortage of site suitable for housing caused by rapid urban development has led to a construction of the high-rise apartment complex along the roadside. This gave rise to the increasing number of population exposed to the traffic noise. Nowadays, transparent noise barriers are used to replace the conventional noise barriers to solve the problems such as maintenance and urban landscape. However, transparent noise barriers have also several problems such as discoloration, stains and scratching to lose initial advantages. In this study, it was focused to compare the soundproofing performance according to the type of polymer materials and panel structure to development of eco noise barrier. As a result, it was observed that PE and PP showed similar a soundproof performance with PC. And in case of soundproofing panel with double layer, sound insulation performance is improved about 17% compare to soundproofing panel with single layer.
A Study on the Ground Reinforcement Method in Soft Ground Tunneling
Jeong, Dong-Uk ; Im, Jong-Chul ; Joo, In-Gon ; Hwang, Seong-Pil ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 317~322
DOI : 10.9798/KOSHAM.2013.13.4.317
There are many problems about safety of many ground or underground structures, when we excavate tunnels in downtown area. Therefore, it is necessary to rise the stability considering the special condition. This paper uses micro pile that has eco-friendly, low noise and low vibration to slove the above problems. The paper analyzes settlements of earth surface, displacements of piles and crown settlements that is measured 321 section in the tunnel of Busan subway line 3 In order to examine the effect of micro piles. And this paper compares the measured data and numerical analysis to examine the effect on the angle and length of micro piles.
A Study on a Carbon emission and Reduction Plan for the Construction Phase of a Natural Gas Plant
Choi, Dae Young ; Kim, Sung-Keun ;
Journal of Korean Society of Hazard Mitigation, volume 13, issue 4, 2013, Pages 323~331
DOI : 10.9798/KOSHAM.2013.13.4.323
The estimation of carbon emission from a natural gas plant is performed with the recently ordered project of the plant in South Korea. The carbon emission coefficients suggested in the guideline by the Ministry of Land, Transport and Maritime Affairs in 2011, are used to calculate the carbon emission from all construction materials and the fuel consumption of construction machinery in the construction phase. To present a method for reducing the carbon emission, it is assumed that some portion of construction materials is replaced by industrial byproducts and construction waste recycling materials, and the amount of carbon reduction for the natural gas plant is analyzed. Also, the amount of carbon emission for producing recycled aggregate is analyzed through the data collected from 3 recycling companies. For the given natural plant, it is found that the major elements that generate most
are construction materials and pipelines. And the recycling of industrial byproducts and construction waste recycling materials reduces carbon emission by 11%.