한국방재학회:학술대회논문집
Korean Society of Hazard Mitigation (KOSHAM)
- 기타
Domain
- Earth Science(Earth/Atmosphere/Marine/Astronomy) > Nature Disaster Analysis/Forecast
2007.02a
-
Kim, Hak-Sun;Lee, Sung-Su;Nam, Kwang-Hyun;Kim, Yong-Dal;Hong, Chang-Moon;Shim, Kyu-Cheoul;Kim, Eung-Chul 29
Damages induced typhoons have been increased and super-typhoons have occurred frequently. In our study, we propose a storm risk assessment technique based on CFD for the industrial structures and equipment located in the coastal regions. Inflow wind speeds are obtained through the information of geography and meteorology in considering regions before pressures of wind-environment and structures corresponding to different winds are calculated with wind speed multiplier and pressure coefficient. The results are applicable to evaluate a warning wind speed or regions vulnerable to debris in a considering region and to examine the safety of structures and their exteriors. -
This study shows the basic data for setting up a response modification factor of unreinforcement masonry structure by considering and analyzing the experiment results of the domestic walls. If the result of this study compare with the value R of KBC-2005, 1.5, the average value, 1.2, is the low value. However, the maximum value, 2.57, is more than 70% bigger than the standard value. The standard value of overstrength factor, 2.5 is judged to have relatively bigger value than this study.
-
Although masonry buildings fell into disfavour in the 1990's because of factors such ac bricklayers' high labor costs, bad reputation of poorly constructed masonry, masonry face wall is still preferred in korea as well as in other countries for its decorative value. Recently may problems with masonry face wall with opening have been reported, including cracks, deflection, swelling and even wall collapse in old masonry buildings, that mainly induced from the corrosion of connecting materials. So, it is necessary to develop the effective and uncorrosion connector. Therefore, this study aims to investigate the structural performance of masonry face walls with opening constructed by new connectors, spiral stainless anchors and to provide basic data for the field application of this method. The specimen reinforced bed joint has maximum load and displacement any other specimens.
-
In repairing and reinforcing modem architecture, altering the features must be minimized. We concluded that inserting CFRP(Carbon Fiber Reinforcement Polymer) plate method is the most appropriate reinforcing method that minimize altering the features. This study focuses on the effect of reinforcement by inserting CFRP plate in the timber beam of the modem architecture's roof truss. We concluded that inserting CFRP plate method is highly influenced by its parent material, however, it is obvious that materials had reinforced by this method in general. We guess that this method is applicable to reinforcement in the modern architecture's roof truss in various ways.
-
The aim of this study is to estimate the compressive force of steel member using a system identification technique with vibration measurements. To date, several methods have been presented to estimate the compressive force using static and/or dynamic responses of the steel member. However, each and every one of these methods has its disadvantages as well as advantages in its procedures, level of accuracy, and equipment requirements. The paper reports a qualitative investigation of vibration under monoharmonic excitation. The methodology utilizes the relationship between the natural frequencies, the structural parameters, and the compressive force of the member. In this paper, experimental results are presented with a steel beam subjecting to several compressive forces and the proposed method is validated using both numerical and experimental data.
-
Terrestrial Laser Scanning(TLS) was developed at the mid-to-late 1990s. This technique enables to perform reconnaissance surveying of regions or structures hard to access. Besides, TLS has been extended its application gradually such as preservation of historical remains, underground surveys, slopes, glaciers monitoring and so on. However, though the technique has a lot of advantages, an application for structural health and safety monitoring is a beginning stage and it need much research. Therefore in this study, as a groundwork, the estimation model on stress of structures using TLS and Finite Element Method(FEM) applied by the Digital Elevation Model(DEM) technique of geoinformatics is proposed. For the verification of this model, experiments were performed with a continuous steel beam subjected to point loads and outputs were compared with those of electrical strain sensors.
-
It was previously introduced a new displacement measuring technique using terrestrial laser scanning (TLS) that remotely samples the surface of an object using laser pulses and generates the three-dimensional (3D) coordinates of numerous points on the surface. In this paper, for an assessment of the capabilities of the measuring technique about existing structures, the field tests for vertical displacement measurement of an existing long span steel box-girder are experimentally carried out. The performance of the technique is evaluated by comparing the displacements obtained from TLS system and displacements directly measured from linear variable displacement transducer (LVDT).
-
The hollow RC(Reinforced concrete) pier has decrease of weight and reduced of materials compared to solid RC pier. However, the hollow RC pier shows a low ductile behavior due to brittle failure of inside concrete. To overcome this problem, the internally confined hollow reinforced concrete column has been developed. In this study, the behavior of internally confined hollow RC piers were evaluated with safety ratio, ductility, total material cost, the total weight of the pier, etc. The chosen parameters for the study are hollow ratio, thickness of internal steel tube, intervals between vertical re-bars, numbers of horizontal re-bars, and strength of concrete.
-
In recent years, the concrete cracks in most construction field have been widely presented and developed. Also it is well known the repair cost of the concrete cracks have been rapidly increased in Korea. So the concrete crack expert system was developed to minimize the repair cost and to support the field engineer. The feature of this web based system for diagnosing the causes of concrete cracks is comprised of comfortable user application.
-
A methodology to evaluate fatigue vulnerability of steel bridge members affected by corrosion and truck traffic variation is proposed. A fatigue limit state function including corrosion and traffic variation effects is established to make the criterion whether the steel bridge member is damaged by fatigue. Corrosion effects are expressed as increase of the average corrosion depth, and the traffic variation effects are modeled as the accumulated number of stress cycles. Reliability analysis is carried out by Monte-Carlo simulation method for the fatigue limit state function. The methodology Proposed is verified by comparing reference study and applying for the steel bridge in service.
-
Thin-walled multicell box girders subjected to an eccentric load can be produced the three global behaviors of flexure, torsion, and distortion. But it is very difficult to evaluate each influences of major behaviors numerically. If we can decompose an eccentric load P into flexural, torsional, and distortional forces, we can execute quantitative analysis each influences of major behaviors. Decomposition of Applied Load for Thin-walled Rectangular multi-cell box girders is researched by Park, Nam-Hoi(Development of a multicell Box Beam Element Including Distortional Degrees of Freedom, 2003). But researches about thin-walled trapezoidal multi-cell section is insufficient. So, this paper deals with decomposition process and independent analysis method of multi-cell box girders include trapezoidal section.
-
The structural methodology in designing a transmission tower have been performed to assume a simple truss behavior. But there're quite differences between a simple truss behavior and a real one. A suitable explanation for a structural stability can be expressed as a semi-rigid connection instead of the assumed hinged connection. This study proposes an alternative structural analysis modelling strategy for the transmission tower design. Proposed element models are truss element model, beam element model, and combined beam-truss element model. The static finite element analysis shows that there's a moment distribution between a mainpost member and the other bracing member.
-
Data for occurrence of hail over Korean Peninsula for the period 1961-2005 are obtained from the Korea Meteorological Administration (KMA). According to the average occurrences during each season in Korea Peninsular, hail days are almost distributed uniformly in the spring, fall and winter, except the summer and have averages of 5 days for each season. Analysis of regional occurrence of hail shows that inland of Korea Peninsular is vulnerable to hail in the spring and summer and the islands of Ullung, Baegryeong and Cheju and the coastal regions vulnerable in the fall and winter. It can be postulated that these seasonal patterns of hail is affected by the Monsoon effect.
-
Data of the typhoon affecting Korean peninsula from 1951 to 2005 are obtained from the RSMC best track and six climatological characteristics of the typhoons are examined. Local wind speeds are obtained by the physical model for wind fields. Typhoons are generated by the Monte Carlo simulation and their wind speeds are distributed using Weibull CDF. Simulated typhoon wind speeds are used to obtain different wind speeds corresponding their mean recurrence intervals.
-
The rainy season started in July, 2006 and the rainfall occurred much damage from July 26 to 28 for three days. Injae and Yangyang which many damage generated by rainfall was made applicable to research. Research of a study has grasped the damage aspect and present condition of Kangwondo. The cause of damage and the measure were concluded in consideration of the collapse characteristic.
-
This study aims to find the characteristics of damage and states of natural disasters at Gimhae, Gyeongsangnam-do from 1985 to 2004. Using the data of Statistical yearbook of calamities issued by the National Emergency Management Agency and Annual Climatological Report issued by the Korea Meteorological Administration. we have analyzed the cause, elements, and vulnerable regions for natural disasters. Major causes of natural disaster at Gimhae are four, such as a heavy rain, heavy rain typhoon, typhoon, storm snow, and storm. The cause of disaster recorded the most amount of damage is typhoon. The areas of Hallim-myeon, Sangdong-myeon, and Saengnim-myeon are classified the vulnerable region for the natural disasters in Gimhae. Therefore, it seems necessary to build natural disaster mitigation plan each cause of disaster to control water resources and to reduce damage for these areas.
-
There is no overall understanding about the road marking situation in Korean national highway nowadays. In addition road marking increases risk in traffic accidents especially while it's raining at night because of diffused reflection. So administrator has a lot of problems to maintain and make a decision about the road marking. In this paper, literature review and field investigation about the road marking are carried out from the viewpoint of road safe and the propriety in retroreflective performance of the road marking is grasped. Also, improvement methods about retroreflective performance of the road marking are proposed on the basis of the result in field investigation.
-
아스팔트포장의 수명 및 공용성 확보를 위한 품질관리 대책의 하나로 아스팔트포장 포설면의 온도 불균형(Thermal Segregation) 현상 최소화를 위하여 균질한 다짐밀도를 확보하기 위한 연구가 미국에서 수행되고 있다. 특히, 적외선 카메라(Infrared Camera)를 이용하여 포설 또는 다짐작업 중인 아스팔트포장 표면의 온도분포를 파악하여 품질관리 기준으로 활용하고 있다. 국내에서도 온도분포 파악을 통한 아스팔트포장의 효율적인 다짐관리 방안이 필요하고 이에 대한 연구가 현재 수행되고 있다.
-
To determine design or remaining life of flexible pavement, tensile strain at the bottom of asphalt concrete course and vertical strain on top of subgrade should be estimated. Various computer programs can be used for determining the strain at the critical position in pavement. However, these are conducted under the assumptions of full bonded or unbound state of layer interface conditions. This study compares the output of finite element analysis and multi-layer elastic analysis as vertical load was applied to the surface of flexible pavement. It is noted that the pavement performance is significantly affected depending upon the interface conditions.
-
본 연구는 폐유리 미분말의 아스콘용 채움재로써의 성능을 평가하기위해서 수행되었으며, 상대적인 특성을 평가하고자 현재 국내에서 아스콘용 채움재로 많이 사용되고 있는 석회석분과 제강 더스트 혼합물의 물리적 성능을 비교 평가하였다. 실내 공용성은 마샬 안정도, 간접인장강도, 회복탄성계수, 휠트랙킹 시험을 수행하였고 수분에 대한 저항성은 마샬 잔류안정도와 수분민감도 시험을 통해서 평가하였다. 이상의 실내 실험을 통해서 폐유리 미분말을 채움재로 첨가한 혼합물은 기존의 제품인 석회석분, 제강 더스트 혼합물과 동등한 성능을 발휘하는 것을 확인하였고, 수분 민감도의 경우에는 폐유리 미분말 혼합물이 가장 높은 저항성을 나타내고 있는 것을 확인하였다.
-
The main purpose of this paper is to introduce the early traffic opening-capable continuous multi-layer asphalt pavement maintenance method using electric arc furnace slag aggregate and emulsified asphalt to the actual construction sites. As well known, the previous surface treatment method of emulsified asphalt mixture have various shortcomings such as long work-time, traffic congestions, plastic deformation and poor evenness. Thus, the proposed method has enabled tile early traffic opening by utilizing the optimized emulsified asphalt after consideration of the climate and road conditions in Korea. The application of the electric furnace slag with
$6\;{\sim}\;18\;mm$ thickness is helpful to become a environment-friendly construction method. And also, it has been improved enough to accommodate night-time works of mechanized construction activities for wearing course and control course. -
지하 주차장 바닥 마감재로 칼라 아스팔트 콘크리트의 적용을 위해 기존 마감재의 장,단점을 조사하고 지하 주차장에 사용되기에 적합한 칼라 아스팔트 콘크리트의 배합설계를 수행하였다. 칼라 아스팔트 콘크리트를 주차장 바닥 마감재로 사용할 경우 미끄럼 저항성의 향상과 소음감소에 효과가 있을 것으로 판단된다.
-
In this paper, a PMS(Pavement Management System) application is presented to control the LCC(Life Cycle Cost) of road pavement. The aim of this paper is to provide the decision makers with the planning information regarding maintenance strategies for efficient road pavement management. The validity of PMS application presented in this paper is investigated through case studies for conducted for 22 national highway road sections in Korea.
-
한반도의 단주기 표면파의 특성을 연구하기 위하여 기상청 지진관측망에서 관측된 지진자료에 잡음의 상호상관기법(Campillo and Paul, 2003; Shapiro et al., 2005)을 적용하였다. 다론 시간에 관측된 지진자료의 에너지를 평준화시키기 위해 1 비트 샘플링 방법이 아닌 화이트닝 기법을 사용한 것을 제외하고 일반적인 상호상관기법이 그대로 적용되었다. 잡음상호상관기법으로 얻어진 그린함수에서 다중필터기법으로 군속도를 계산하였다. 군속도를 역산하여 0.5 - 20 초 주기에서 표면파 분산의 공간적인 변화를 이미지화하였다. 사용된 토모그래피 역산기법은 각 주기의 공간적인 이미지 뿐만 아니라 주기함수인 분산 곡선을 동시에 구하기 위하여 모든 주기의 군 속도자료를 역산하였다. 역산결과, 한반도 남동부 지역인 경상분지에서 낮은 군속도를 확인할 수 있었다.
-
한반도의 지각에 대한 지진파의 파형들을 피킹하기 위하여 한반도의 남동부지역에서 시행된 폭파로부터 각 관측소에서 관측된 지진자료를 2 차원 수치 순산모델링으로 계산된 이론적인 신호와 비교하였다. 실제 지진자료와 같은 완전한 파형을 얻기 위해서는 실체파뿐만 아니라 표면파를 포함한 모든 파형을 이론적으로 생성하여야 한다. 또한, 각 파형의 Q 값을 고려하여 그 감쇄 정도를 파악하여야 실제 파형과 똑 같은 이론적인 파형을 만들 수 있다. 본 연구에서는 FEM(Finite Element Method)과 FDM(Finite Difference Method) 같은 전형적인 수치 모델링 기법 대신에 수도스펙트럼기법(pseudo-spectral method)을 사용하여 이론적인 파형을 계산하였다. Q 값을 고려하지 않았기 때문에 완전한 파형을 얻기에는 어려움이 있었다. 그러나 각 관측소에 도달하는 실체파의 초기 파형들의 주시를 실제 파형과 맞추었다는 데에 그 성과가 있다고 할 수 있다. 본 연구의 궁극적인 목표는 수치 모델링을 통하여 지진원의 위치와 종류를 밝혀 내는데 그 정확성을 높이는 것이다.
-
An Approximation Expression of Wave Velocity of Viscous Boundary for Infinitely tong Elevated BridgeA continuing elevated bridge is replaced with mass-spring system model, and a part of the bridge is cut out as an analytical area. A viscous boundary is installed at both ends, and dynamic analyses are carried out changing the wave velocity of the viscous boundary, The result is compared with a result of a very long model corresponding to the solution with infinite length. A wave velocity is chosen so that the good performance of a viscous boundary is exhibited. The parametric analyses are carried out changing the model of various structural properties, and an approximation expression is suggested to obtain the wave velocity easily for setting a viscous boundary.
-
Internally Confined Hollow-Concrete Filled Tube(ICH-CFT) column which has two tubes on both side of concrete, inner tube and outer tube perform great seismic abilities, ductility and absorption of energy, by the tubes and the hollow part. So this study does qualitative analysis about seismic capacities depending on parameters - diameter of column, hollow ratio, thickness of tubes - by moment-curvature analysis.
-
The Korea Meteorological Administration has been operating a tsunami warning system which is based on tsunami scenario database for the East Sea. Recently, the tsunami scenario database for the Yellow sea and the East China sea is also generated so that the tsunami warning system is extended to the whole Korean seas. Tsunami scenario database includes tsunami arrival times and heights generated by performing huge numbers of tsunami propagation simulations. A leap-frog method for shallow water equation is used for the simulation. The simulation code is parallellized via Message Passing Interface and has run on Cray X1E.
-
Efficiency and limitations of HAZUS-MH, a GIS based systematic and informative system developed by FEMA and NIBS for natural hazard loss estimations, are discussed by means of a pilot study in the Korean Peninsular. Gyeongsang-do has been selected for the test after careful reviews of previous studies including historical and modern seismicity in the peninsular. A ShakeMap for the selected scenario earthquake with magnitude 6.7 in Gyeongju area is prepared. Then, any losses due to the scenario event have been estimated using HAZUS. Results of the pilot test show that the study area may experience significant physical, economic and social damages. Detailed study in the future will provide efficient and crucial information to the decision makers and emergency agents to mitigate any disaster posed by natural hazards.
-
The numerical efforts are presented for investigation of irregular waves passing a slit cassion and a warock block breakwater. In the numerical model, the Reynolds equations are solved by a finite difference method and
$k-\varepsilon$ model is employed for the turbulence analysis. To track the free surface displacement, the volume of fluid method(VOF) is employed. Numerical predictions of reflection and transmission coefficients are compared with those of the warock block breakwater with the slit caisson. Energy dissipation and seawater exchange rates of the slit caisson are better than those of the warock block breakwater. -
For numerical analysis of a tidal flow, a two-dimensional hydrodynamic model is developed by solving the nonlinear shallow-water equations. The governing equations are discretized explicitly with a finite difference leap-frog scheme and a first-order upwind scheme on adaptive hierarchical quadtree grids. The developed model is verified by applying to prediction of tidal behaviors. The calculated tidal levels are compared to available field measurements. A very reasonable agreement is observed.
-
The stability of a typical rubble mound breakwater defenced by a submerged structure is investigated using hydraulic experiments. Incident irregular waves are obtained from the Bretschneider-Mistuyasu spectrum. Experiments are carried out for different spacings between two breakwaters (X/d=2-3) and for different relative widths (B/h=0.7-3.0) of the submerged structure. It is observed that a submerged structure of (B/h) of 0.7-3.0 constructed at a seaward distance (X/d) of 2-3 breaks all the incident waves and dissipates energy and breakwater.
-
In this study, the numerical model for simulation of tsunamis is constructed by using the dispersion-correction scheme, 2nd upwind scheme, dynamic linking method, and so forth. The composed numerical model is used to simulate a hitorical tsunami event. The target tsunami event is the 1983 Central East Sea Tsunami. And, the predicted run-up heights of the tsunami at Imwon port are very reasonable compared to available observed data.
-
Numerical simulations on the suspended load in the Do jang fish port are carried out. Suspended load is analysed by using the two-dimensional advection-diffusion equation. To describe behaviors of a pollutant in costal zone, a split-operator method is applied to the numerical model. The advection part is first solved by SOWMAC and then the diffusion part is solved by a three-level locally implicit scheme.
-
A free-surface correction(FSC) method is presented to solve the 3-D shallow water equations. Using the mode splitting process, FSC method can simulate shallow water flows under the hydrostatic assumption. For the hydrostatic pressure calculation, the momentum equations are firstly discretized using a semi-implicit scheme over the vertical direction leading to the tri-diagonal matrix systems. A semi-implicit scheme has been adopted to reduce the numerical instability caused by relatively small vertical length scale compare to horizontal one. and, as the free surface correction step the final horizontal velocity fields are corrected after the final surface elevations are obtained. Finally, the vertical final velocity fields can be calculated from the continuity equation. The numerical model is applied to the calculation of the simulation of flow fields in a rectangular open channel with the tidal influence. The comparisons with the analytical solutions show overall good agreements between the numerical results and analytical solutions.
-
Kirpich formula was selected as the proper formula for calculating the concentration time at island streams. Kirpich formula can be applied for the expanded range from surface area of
$0.453km^2$ and channel bed slope of$3{\sim}5%$ to surface area of$2.0km^2$ and channel bed slope of 1.5%. -
The type, the length, and the install space of the grate inlets in main street were designed with the consideration of discharge calculated with street surface rainfall. However, the discharge that was not intercepted at transverse grate inlets in steep local roads increases inundation areas around main street Therefore, it is necessary to analyze the flow characteristics and interception capacity at transverse grate inlets in steep local roads. Hydraulic experimental apparatus which can be changed the longitudinal slopes(
$2{\sim}10%$ ) of street, the size ($20{\sim}50cm$ ) and the types(TYPE I, II) of grate inlet was installed for this study. The range of the experimental discharges were from$2{\ell}/sec$ to$24{\ell}/sec$ . The interception discharges of transverse grate inlets per unit width changing the longitudinal slope of steep local road were calculated by the hydraulic experimental results. The design method of transverse grate inlets was developed by the interception discharges per unit width. This design method was applied to decide the space and size of transverse grate inlets. -
In storm sewer networks a lot of manholes are installed to maintain and connect a sewer of urban area. There are some shapes of manhole such as circular type, square type, and so on. Square shape manholes are installed to connect the large diameter drainage pipes in general and have lager head losses than circular one. Consequently, it is important to analyze the head losses in square manhole because the head losses in square manhole are much bigger than the friction losses in pipes. Hydraulic experimental apparatus which can be changed the inside shape in square manhole was installed for this study. The experimental discharge was
$16{\ell}/sec$ . The head loss coefficients in the manhole were calculated by the experimental results. The range of head loss coefficients in the general square manhole were from 0.33 to 0.48 and the range of head loss coefficients in the square manhole changed inside shape were from 0.23 to 0.28. -
도시 침수모형에 있어서 도로, 빌딩, 그리고 제방과 같은 구조물은 홍수전파에 큰 영향을 주므로 모형구성상 고려되어야 한다. 건물 밀집지역에 대한 침수모형은 현재 주요한 연구과제이지만 불충분한 자료로 인하여 큰 진전을 이루지 못하고 있다. 본 연구는 건물 추출, 격자 크기 등을 고려한 도시 침수모형을 구축하여 그 영향을 검토한다.
-
The accurate estimation of the area of individual landuse in each subbasin is crutial. However, because of the complication in landuse of an urban watershed, it is almost impossible to estimate the area of individual landuse in each subbasin by manual ways. For this reason, in this study, a systematic methodology is suggested to estimate individual landuse area of each subbasin using GIS. To construct data for applying GIS, CAD data including sewer layout and landuse are collected and converted into the GIS data such as shape files. An urban watershed, then, is divided into subbasins with respect to sewer layout and landuse. For each subbasin, the area of individual landuse including road areas are estimated by applying several GeoProcessing functions. The proposed methodology is applied to the Goon-Ja watershed in Seoul to demonstrate its applicability and it is concluded that the proposed methodology can estimate individual landuse properties efficiently and accurately.
-
The purpose of this study was to establish the basic information for natural drainage capacity assessment in urban area. We sorted midium watershed of Han river and Nak-dong river, and selected 30 rainfall events during 1995 to 2000 according to high level of damage. The inundated area showed high watershed slope about 25% and it indicated the greatest damage around the watershed located in 200-300m of altitude. Besides, the great damage by inundation was occurred in the mountainous agriculture region, where the forest scale was high and the urbanization was being progressed gradually. However, inundated area was small in case of grassland, water tone such as riparian area, bare ground and wetland. Moreover, the inundated area was different according to river shape and characteristics of river distribution such as the density of the stream order, conservation constant of the river system, and the number of undulations in the watershed. Therefore, it showed that land use, river shape and distribution characteristics of stream influence on inundation.
-
Since 1973, we attain a successful achievement of nation-wide afforestation such as a thick forest and heaped-up leaves. However, the higher of the formation density in forest, the more dangerous to be a large-scale forest fire whenever fire occurs. According to the type of forest in the country, 42% of the forest is occupied by conifer forest that are highly flammable, and the distribution of forest age is in a transition period from immature forest to mature one. And the structure is too weak to the forest fire for the occurrence and spread because there are too many scrub and shrub trees in the forest. As a matter of course, it is on the increase of the thinning-forest that can shift the forest structure from a weak on forest fire to a strong one nowaday. In other words, thinning-forest has primary purposes such as the promotion of producing forest trees, production of excellent timbers, and build-up of public forest area. Furthermore, in some reports, the reduction of ladder fuel by eliminating the vertical/horizontal fuel in a forest and ensuring spaces in the forest can decrease the occurrence of forest fire and the risk of spread of burning as by-effect. Therefore, this study is designed to clarify the relation with the risk of forest fire by an on-spat-investigation of the characteristics of forest composition on the thinning and the non-thinning area.
-
Nowaday, for the promotion of producing forest trees, production of excellent timbers, and build-up of public forest area, it is on the increase of the thinning-forest for artificial forest, natural forest, eco-friendly forest, and the forest for development and improvement of forest resources nationwide. Even though the thinning-forest is applied around 180,000ha every year, the quantity of collected/used products is only 18,000ha
$(240,000m^3)$ which is 10% of the whole thinning-forest area. Meanwhile, some reports represent that the left products after thinning-forest might increase the severity of forest fire and the waste of resources. Therefore, this study focused on the analysis of correlation between the accumulated products after thinning-forest and forest fire, and providing a preparation plan for the forest fire. -
To monitor process of vegetation rehabilitation at the damaged area after large-fire is required a lot of manpowers and budgets. However the analysis of vegetation recovery using satellite imagery can be obtaining rapid and objective result remotely in the large damaged area. Space and airbone sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. Burn severity incorporates both short- and long-term post-fire effects on the local and regional environment. Burn severity is defined by the degree to which an ecosystem has changed owing to the fire. To classify fire damaged area and analyze burn severity of Samcheok fire area occurred in 2000, Cheongyang fire 2002, and Yangyang fire 2005 was utilized Landsat TM and ETM+ imagery. Therefore the objective of the present paper is to quantitatively classify fire damaged area and analyze burn severity using normalized burn index(NBR) of pre- and post-fire's Landsat satellite imagery.
-
The forest seemed apparently to die on the forest fire area in Honjima, Kagawa Prefecture, Japan. However, the soil that became growing basic of vegetation hardly suffered damage, and the forest recovery was started by the sprout, etc. in the next year. For restoration of forest fire area, the fascine mulching works and log barrier works using the damaged trees were used for the upper-stream, and chack dam and erosion control dam were set up in the downstream. Also, the forest restoration was tried with the plants and the microorganism that inhabit in Honjima to preserve a peculiar forest ecosystem.
-
초고층건물의 주된 피난경로인 계단실에 발생하는 연돌효과는 계단실 차압분포에 큰 영향을 주고 피난에 장애가 될 수도 있으므로 적정 범위 내에서 억제되어야한다. 고층건물의 연돌효과를 해소하는 방법을 찾기 위해 몇 가지 경우에 대해 시뮬레이션을 하고 계단실 상하부의 fan으로 가압과 감압을 적절히 병용한 결과 연돌효과에 의한 차압불균형을 해소할 수 있었다.
-
This paper discusses the standards for disaster prevention and safety management of rail tunnel. The purpose is to establish safety management standards and methods of disaster prevention for each underground traffic spaces, after the full revision of the cause of accidents and its effects, the function and selection of safety equipment, and the efficiency and convenience of maintenance, standards based on prevention and reduction is proposed to reaction to disaster.
-
The purpose of this research is focussed on the numerical predictions of the heat and smoke propagations for a passenger train fire in an underground subway tunnel for different air supply and extraction flowrates. The analysis is performed for one of the stations on subway line #5 in Seoul under the emergency operation mode for different air supply and extraction flowrates. Five different the air supply and extraction flowrates are considered for the numerical analyses. The numerical results show that the air supply and extraction flowrates affect the smoke control performance significantly by improving the smoke removal performance for the balanced control of air supply and smoke extraction and for the unbalanced control with lager smoke extraction than air supply.
-
In our country it develop damage reduction and prediction technology for prevention the danger of the rockfall and landslide which is repeated yearly. And it constructs integrated and efficient the misfortune management system it will be able to manage. So we will accomplish aims that is the rockfall and landslide damage occurrence reduction.
-
In this paper, analysis results on the failure of slope behind a Plant Complex of Gimhae due to typhoon Rusa in 2002 are introduced. The left side of the slope was reinforced by soil nails and the right side of the slope was going to construct slope reinforcement works. In the slope failure, the damage area is about
$34,000m^2$ , the lower width of slope failure is about 230m, the upper width of slope failure is about 50m, and the height of slope failure is about 120m. The elevation of a bedrock in the right side of the slope was lower than the left side of the slope. Due to the depth of weathered soils and weathered rocks in right side of the slope was thick, it will be expected that the effects of pore-water pressure during the rainfalls are large. For the analysis of the failure mechanism, 3-dimensional numerical analysis was carried out by FLAC-3D. -
토석류를 동반한 수해 피해를 줄이기 위해서는 구조적인 대책뿐만 아니라 비구조적인 대책수립을 포함한 종합적인 수해 대응대책이 중요하다. 본 연구에서는 비구조적인 대응대책 중 인명보호의 차원에서 중요한 피난활동을 중심으로 실제 피난행동을 하기까지의 영향요인을 설문조사를 토대로 분석하였다. 토석류모의 실험을 통하여 그의 특징을 분석하여 향후 토석류 발생에 따른 피해를 줄이는데 기본 자료를 제공하고자 한다.
-
Lately, there are actively proceeding in making a plan for subway construction, a high-speed railway construction and a expansion of road and also all kinds of large-scaled construction in Korea. Construction works were delayed from noises and vibrations occurred by usage of a large-sized construction equipments and driven and also blast or there were often stopped from them under construction. Therefore, this study was modeling operation of the cyclic loading and conforming effects from grasping displacement-changing method through a variable analysis.
-
필 댐의 내진해석은 간극수압을 고려하지 않을 경우에는 지진에 의한 동수압을 고려할 수 없기 때문에 지진력을 과소평가할 수 있다 그러나 현재까지도 필 댐의 내진해석에서 주요 변수에 따른 동수압의 변화는 연구 실적이 많지 않다. 따라서 본 연구에서는 지진하중과 간극수압을 모두 고려하는 경우에 대해 다양한 변수분석을 수행하여 지진과 간극수압의 상호작용을 알아보았다.
-
When ground disturbance takes place due to vertical drain construction through mandrel penetration, that affects excess pore water pressure dissipation time because of soft clay coefficient of permeability decreasing. Eventually, consolidation time is influenced. In this research, we measure process of excess pore water pressure dissipation before and after each other different shape's mandrel penetration through model test, and calculates range of smear zone, coefficient of permeability and horizontal coefficient of consolidation after model test. Using of test result, we grasp a degree of drainage ability drop resulting from vertical drain construction.
-
지반을 보강 또는 지하수를 차단하기 위해 실시되는 그라우팅과 같은 공법이 제대로 효과를 발휘하기 위해서는 bulging 또는 sheet 형태의 그라우트체 형상의 조절이 필수적이다. 본 논문에서는 이러한 그라우트체 형상에 영향을 끼치는 인자를 찾기 위해 포화된 사질토지반에서의 그라우트 실험을 다수 실시하였다. 그라우트의 주입속도와 점성의 크기, 사질토의 상대밀도와 입도크기의 인자를 사용하여 실험을 사용한 결과, 비교적 느린 주입속도와 작은 상대밀도, 그라우트의 점성과 입자가 클수록 bulging 형상의 그라우트체가 형성이 되었다. 이와는 반대로 빠른 주입속도와 높은 상대밀도, 그리고 그라우트의 점성과 흙 입자가 작을수록 sheet 형상의 그라우트체가 형성이 됨을 확인하였다.
-
Stress concentration have a effect on commission of structures and sometimes it cause the fracture of structures. Stress concentration is appeared where have a sudden section change like pipe connections. So stress concentration is a potent influence at pipe connentions. This paper make a study of pipe connections to alleviate stress concentration, and propose the stress concentration alleviation method that will make better efficient pipe system and will have a good effect on economic, social aspect.
-
This study investigated the out-of-plane elastic buckling load and effective length factor of X-bracing system. The members of X-bracing system which are studied in this paper are rigidly attached to the structure at their end connections, and are pinned or rigidly connected at their point of intersection. The effective length factors are derived for the general case where the tension and compression brace have different material and geometrical properties.
-
최근에 빠른 발전을 이루고 있기는 하나, 하중 저항 계수나 미관효과 면에서 박스 거더를 고속도로 분야에 폭넓게 사용하고 있는 실정이다. 최근의 박스 거더 설계를 기반으로 살펴보면 뒤틀림 하중은 그다지 고려되지 않았다. 특히 직선교에서는 뒤틀림 하중의 효과가 작지만 곡선에서는 어떻게 작용하는지 조차 알려진 것이 없었다. 그러한 이유에서 이 연구는 뒤틀림 거동에 미치는 주요한 변수들에 대해 다루었다. 그리고 유한요소법을 사용하는 Dabrowski formula를 바탕으로 하여 다양한 변수의 교량에 대해 연구하였다. 이 연구에서는 다음과 같은 변수들이 사용된다. : 지간장, 곡률반경, 단면높이, 단면폭, 그리고 내부단면각(internal section angle) 연구된 결과로부터 적당한 초기 기하형상에 대한 변수들을 구할 수 있을 것이다.
-
CWR(Continuous Welded Rail) and bridge interaction produce rail force, bridge displacement and rail/bridge relative displacement. Each of these has limitation by many codes. In this paper, analysis of interaction has been carried out by using foreign codes(UIC 774-3 R code of Europe etc.) because there is no code about interaction between rail and bridge in Korea. Recently, railway bridges with CWR has been constructed for structural and economical reasons. When designer plans railway bridges, design a bridge model first and then investigate railway forces and displacement by interaction analysis. If these results go out bounds from limitation, designer plans railway bridges again and again. In this paper, using the parametric study on CWR and railway bridge interaction, railway bridge parameters such as length of bridge span, area of bridge, moment of inertia, stiffness of pier, etc. are presented. It helps preliminary design of railway bridges.
-
In the case of the railway bridges, uplift forces were occurred at the edge of the segments when vehicular loads were applied. These forces made the compressive and tensile forces occur in the fastening system. Therefore, the structural analysis was performed to investigate the safety of fastening system which was modeled as one directional spring element. In this case, the stiffness of the spring element was obtained from experimental study which was conducted by compressive load. For that reason, to perform rational and exact structural analysis, the translational stiffness of the fastening system obtained from the experimental study applied the tensile load and the rotational stiffness should be considered because it was occurred the tensile force as well as the compressive force in fastening system. In this study, an elastic and inelastic experimental study was performed for six specimens. The translational stiffness along the vertical axis of rail and the rotational stiffness along the strong axis of rail were investigated. Also structural behavior of the fastening system was analyzed.
-
In order to reduce the amount of damage from natural disasters, we needs prevention meteorological database classified into the cause of disaster, damage elements etc. For this, we have analyzed four data, such as Statistical yearbook of calamities issued by the National Emergency Management Agency and Annual Climatological Report issued by the Korea Meteorological Administration and Recently 10 years for natural disaster damage and Statistics Yearbook from the Ministry of Government Administration and Human affairs. Through the analysis of disaster data, we have selected input variables, such as causes and elements, occurrence frequencies, vulnerable areas of natural disaster, etc. In order to reduce damage from natural disaster, the prevention activities and forecasting based on meteorological parameters and damage datas are required. In addition, it is necessary to process meteorological information for disaster prevention activities. Through these procedure, we have established the foundation of database about natural disasters. This database will be used to assess the natural disasters and build risk model and natural disasters mitigation plan.
-
This study aims to find the characteristics of damage and states of natural disasters at the Korean Peninsula from 1985 to 2004. Using the data of Statistical yearbook of calamities issued by the National Emergency Management Agency and Annual Climatological Report issued by the Korea Meteorological Administration. we have analyzed the cause, elements, and vulnerable regions for natural disasters. Major causes of natural disaster at Korean Peninsula are four, such as a heavy rain, heavy rain typhoon, typhoon, storm snow, and storm. The frequency of natural disaster is the highest from June to September. The period from December to March also shows high frequency. The total amount of damage is high during the summer season(Jul.-Sept). The period from January to March shows relatively high amount of damage due to storm and storm snow The areas of Gangwon-do, Gyeongsangnam-do and Gyeongsangbuk-do are classified the vulnerable region for the natural disasters. By establishing mitigation plans which fit the type and characteristics of disaster for each region, damage from disaster can be reduced with efficient prevention activities.
-
Recently, occurrence frequency of natural disasters decrease but scale of damage increase remarkably by the Climate change due to global warming. Especially, extreme heat become more critical weather problem in the Korean Peninsula. But, we don't have exact threshold about extreme heat. Extreme heat does not classify into natural disaster. Therefore, we have compared death count of the natural disaster with the one of extreme heat at Seoul, Korea. As a result, the number of death by extreme heat don't smaller than one by the natural disasters and we knew extreme heat have also to consider as natural disaster.
-
Cha, Eun-Jeong;Lee, Kyung-Hi;Park, Yun-Ho;Park, Jong-Suk;Shim, Jae-Kwan;In, Hee-Jin;Yoo, Hee-Dong;Choi, Young-Jean 327
23 tropical cyclones of tropical storm(TS) intensity or higher formed in the western North Pacific and the South China Sea in 2006. The total number is less than the 30-year$(1971{\sim}2000)$ average frequency of 26.7, Out of 23, 15 cyclones reached typhoon(TY) intensity, three severe tropical storm(STS) intensity, and five TS intensity. The tropical cyclone season in 2006 began in May with the formation of CHANCHU(0601). While convective activity was slightly inactive around the Philippines from late June to early August. In addition, subtropical high was more enhanced than normal over the south of Japan from May to early August. Consequently, most tropical cyclones formed over the sea east of the Philippines after late June, and many of them moved westwards to China. CHANCHU(0601), BILIS(0604), KAEMI(0605), PRAPIROON(0606) and SAOMI(0608) brought damage to China, the Philippines, and Vietnam. On the other hand, EWINIAR(0603) moved northwards and hit the Republic of Korea, causing damage to the country From late August to early September, convective activity was temporarily inactive over the sea east of the Philippines. However, it turned active again after late September. Subtropical high was weak over the south of Japan after late August. Therefore, most tropical cyclones formed over the sea east of the Philippines and moved northwards. WUKONG(0610) and SHANSHAN(0613) hit Japan to bring damage to the country. On the other hand, XANGSANE(0615) and CIMARON(0619) moved westwards in the South China Sea, causing damage to the Philippines, Thailand, and Vietnam. In addition, IOKE(0612) was the first namded cyclone formed in the central North Pacific and moved westwards across longitude 180 degrees east after HUKO(0224). -
줄눈콘크리트 슬래브의 초기 재령특성 분석을 위하여 인천국제공항 건설 현장에 설치된 슬래브에 온도와 습도를 측정 후 해석하였다. 성숙도 방법을 이용하여 결정한 콘크리트 슬래브의 초기경화시간은 콘크리트 타설 후부터 약 2시간 40분이었다. 콘크리트 슬래브 변형률의 변화는 초기경화 시간 이후부터 시작되었고, 이는 센서가 설치된 각 위치와 깊이에서 서로 다른 값을 나타냈다.
-
콘크리트포장의 줄눈의 초기균열발생과 움직임에 영향을 주는 중요한 인자는 콘크리트 내부의 초기온도이므로 이를 측정하고 분석하는 것은 매우 중요하다. 이를 연구하기 위해 인천국제공항 포장공사 지역에 써머커플과 습도센서, 진동형스트레인게이지, 디멕디스크 등을 설치하였다. 초기균열 거동은 디멕게이지를 이용하여 측정하였고, 초기균열 및 줄눈분 균열은 육안으로 확인 하였다. 분석결과, 콘크리트포장의 온도는 줄눈거동에 크게 영향을 주는 것으로 나타났다. 줄눈에 발생한 균열의 폭은 콘크리트슬래브의 열팽창의 영향으로 온도가 하강하는 야간이나 새벽에 증가하고, 온도가 상승하는 주간에는 줄어드는 것을 확인할 수 있었다. 균열이 발생하지 않은 줄눈의 거동은 이와는 반대의 경향을 나타내었다.
-
본 연구는 단지계획에 있어 상용화하여 사용되고 있는 DAS S/W(단지설계프로그램)와 GIS 분석기법(셀[cell]-베이스[base] 분석기법)을 이용하여 각각 토공량을 산정하고, 좀 더 정밀한 토공량을 산정할 수 있는 분석 방법을 제시하고자 하였다. 또한 토공량 산정 자료를 이용하여 DAS S/W에 GIS 기법을 적용하여 향상된 토공이동 모델을 제안하고자 한다. 본 분석기법의 적용으로 토공량 산정기법의 정확성과 토공모델의 효율성을 높일 수 있을 것으로 기대된다.
-
Asphalt overlay resurfacing techniques have been widely utilized in maintaining asphalt concrete in Korea, causing severe traffic congestions while being in construction and difference in level due to the repeated overlay. Besides on these technical difficulties, there have been financial disadvantages associated with technique, mainly because overlay method has been executed for pavements with intact foundations, which is contrary to the norm. This study is aiming to increase the expected life length of the asphalt pavement up to the endurance period, to raise the efficiency of the pavement by maximizing the social benefit and to enhance public character of the street through combining ceramics with epoxy resins, which has advantages in compatibility with the existing pavement materials, durability to abrasion and endurance. It has been expected that the adoption of new method and pavement materials to the actual work sites will develop the performance of the pavements, and to lengthen the durability of the existing materials. The other advantages of the 'thin surfacing' method could be the improved adhesiveness, waterproof, corrosion-proof and bending strength.
-
공항에 신규 활주로 및 유도로를 시공하기 위하여 공용중인 공항의 아스팔트 포장부를 모니터링한 결과, 종방향 균열이 관찰되었다. 종방향 균열의 원인은 아스팔트 포장 시공시 발생되는 종방향 시공조인트부의 낮은 밀도와 비행기의 높은 하중으로 판단되었다. 이에 따라 종방향 균열의 최소화 시공을 위해 공항의 연성 포장 구간에 12m폭의 스크리드를 가진 아스팔트 피니셔를 이용하여 편대포장을 실시하였다. 편대포장을 사용하면 첫 번째 차선의 비구속 단면부가 두 번째 차선과 같이 다짐되므로, 종방향 조인트부가 개선된다. 결과적으로 편대 포장 시공법을 사용하여 종방향 조인트부의 밀도와 인근의 일반 포장부의 밀도를 같게 하는 결과를 얻을 수 있었다.
-
Water retaining pavement is a pavement to lower the surface temperature by using evaporation of the water that the pavement contains when the pavement is heated by the sun in the daytime. The objective of this study is to develop water retaining materials. In this study we evaluated the practical application of a sepiolite and a charcoal as a water retaining material. We produced dense grade asphalt pavement, porous asphalt pavement, semi-rigid Pavement, semi-rigid pavement included a charcoal and semi-rigid pavement included a sepiolite, and then tested surface temperature characteristics. The test result says that water retaining pavements using a sepiolite and a charcoal lower surface temperature more than
$10^{\circ}C$ compared to dense grade asphalt pavement. We confirm the practical application of a sepiolite and a charcoal as a water retaining material according to the test results. -
The characteristics of every organization is going to be under investigation should be previously analyzed and reviewed in details for senior disaster management organization In this research, disaster management organizations above mentioned are investigated and arranged respectively. And the guidelines for evaluation is suggested and the results offers foundations for the development of evaluation index.
-
In recent, the utilization of underground in urban area is increased as subway, store, and others but we have done a few studies for the inundation of underground due to flooding. So, we investigate the examples of underground inundation and the causes of inundation for flood events. And the relationship between flood characteristics and underground inundation is analyzed through the frequency of rainfall which is made by annual multi maximum series. As a result, most of underground is inundated by high frequency of rainfall. And there are some cases that the underground is inundated by low frequency of rainfall because of poor drainage system and characteristics of location.
-
Due to the benefit of QRA(Quantitative Risk Analysis) method, we can evaluate the risk, and it helps us to make our safe. We also depend to some of correlation equations to assess the jet fire at high pressurized transmission line. However, we can evaluate the risk within limitations. After comparing the current model to investigation report of natural gas transmission line accident at EL-Paso in U.S., this study concludes that more research and study are required because currently developed model cannot expect factors of the fire risk such as flame configuration.
-
In recent years, the natural damage associated with flood disaster has been dramatically increased. However, there is no rational method which reflects urban characteristics to estimate the regional safety assessment for flood disaster. The purpose of this study is to develop the regional safety assesment model for urban flood. Flood risk and reduction assesment were estimated by using the linear sum of the Z score of the assessment factors and the weight value of each factor from the expert survey data. And then the regional safety assessment was estimated by subtracting reduction factor value from risk factor value. GIS tool was used to estimate the factor assesment and integrated regional safety. This study can be used to determine the priority of flood protection project, execute the flood insurance and establish the urban plans and the flood mitigate plan.
-
The present study aims to document the run-up height, losses of human lives and property damage due to the tsunami occurred on December 26, 2004 in Andaman and Nicobar Islands, India. These Islands were severely devastated by the tsunami. Approximately 1,925 people were lost their lives and 5,555 people were reported missing. A field survey carried out at 26 locations indicates that the passenger jetty of Little Andaman area recorded the highest run-up height of 17.3m and the Chidiyatopu area had the greatest inundation of 500m from the coastline.
-
The mixing characteristics of heated water discharged from different types of effluents are simulated using a commercial software, Flow-3D model. In order to verify the model, the comparison of numerical results with the experimental data are conducted for each type of effluent, the submerged and surface overfall. It is observed that the numerical results show a reasonable agreement with the experimental data. Based on this study the application to the heated water discharge problem in the field can be expected as a further study and it can be the fundamental data when determining the type of effluent in a powerplant.
-
The field survey of a tsunami damage is carried out to collect and obtain real data. There data can be used to make the countermeasures against possible tsunami attackings. In the survey, many data collecting techniques such as interviewing with local people, taking pictures of the inundated field, recording the location by the GPS, measuring the level and distance of the maximum flood level can be used for practical and effective survey.
-
In this study, new dispersion-correction terms are added to leap-frog finite difference scheme for the linear shallow-water equations with the purpose of considering the dispersion effects of the linear Boussinesq equations for the propagation of tsunamis. The new model is applied to near Gadeok island in Pusan about The Central East Sea Tsunami in 1983 and The Hokkaldo Nansei Oki Earthquake Tsunami in 1993 one simulated in the study.
-
This project is the 1st. stage for the foreshore reclamation at Jang-Hang area and its scope is to construct a seawall as outer facilities, road adjacent to the seawall and drainage gate. for the safe protections of the facilities at the reclaimed land hereafter, we adopted the mild slope rubble mound type for the seawall structure which was excellent in interrupting the wave overtopping, as a result of numerical & hydraulic model test about alternative 4 sections. For the flooding prevention of the reclaimed land, we planned the drainage system that could make the flood water level lower than the reclaimed land level. Also, we planned the eco-friendly waterfront area with 8 nature themes through the whole seawall sections.
-
This paper focused on the way of prevention of disaster in the accident of explosion when the fire broke out in the boiler room where installed the basement of the building, and showed the effective ways for sustaining people and property safely in the view of problems and improvement of the law and safety awareness of people.
-
수자원시스템은 매우 복잡한 시스템이고 또한 물리학, 생물화학, 생태학, 사회학, 추계학 및 정책 등의 내부 독립적인 복잡한 시스템의 영향을 받는다. 의사결정지원시스템의 발전은 내부 관련된 시스템과 의사결정자와 결함하여 종합적으로 구조와 비구조적 조치를 고려하고 시스템분석방법 및 컴퓨터기술을 이용하여 수자원시스템의 문제를 들거나 해결한다. 컴퓨터의 의사결정시스템을 수자원시스템 관리에 응용한 역사는 벌써 20년이 된다. 본 연구에서는 종합수자원관리 및 의사결정시스템이 종합수자원관리에 대한 응용과 발전에 대하여 검토한다.
-
A methodology for XML documentation of the structural calculation document is presented to support manipulation of the design information on the internet. The text file format is chosen as a neutral format because it can be easily translated from office documents generated from engineering practice. The first word of each line is compared with the reserved numbering groups, and relative levels among the lines are defined to generate the hierarchically structured XML document of the text file. The demonstration subjected to sample general documents and structural calculation documents shows that the prototype application module based on the developed methodology can be adopted to build the database of design information which supports the safety management of infrastructures.
-
Application이나 3D 모델로 구현된 맵 관련 위성영상, UAV 영상을 통해 현장감 있는 정보를 정확하게 얻는 것은 중요하다. 방재관련 업계에서는 3D 모델링에 근거한 재해지역 주변의 정확한 3차원 지형공간정보 취득의 필요성을 인식하고 있다. 본 논문에서는 GIS 기술을 활용하여 3D 모형을 생성하고, 각종 영상들을 로딩하고 처리하는 부분에 있어서의 방법을 제시하였다. 그리고 대상지역의 수치고도모형과 지형지물을 위해 수치 지형도를 사용하였다. 결과는 3D 모델링 기반의 간단한 application의 구현이다. 제시한 방법은 방재 관련업계의 종사자들에게 더 나은 방법을 제시하기에 활용 가능하다.
-
In order to measure corrosion level of reinforcement rebar which is inside reinforced concrete structure, infrared thermographic technique was employed. Experimental test parameters were ambient temperatures, various levels of corrosion states. After analysis of temperature distributions of concrete surface, the amount of heat flux from the concrete surface is directly proportional to the corrosion level which is inside of concrete.
-
For smart structure technologies, the interests in wireless sensor networks for structural health monitoring are growing. The wireless sensor networks reduce the installation of the wire embedded in the whole structure and save the costs. But the wireless sensor networks have lots of limits and there are lots of researches and developments of wireless sensor and the network for data process. Most of the researches of wireless sensor network is applying to the civil engineering structure and the researches for the highrise building are required. And strain-based SHM gives the local damage information of the structures which acceleration-based SHM can not. In this paper, concept of wireless sensor network for structural health monitoring of highrise building is suggested. And verifying the feasibility of the strain-based SHM a strain sensor board has developed and tested by experiments.
-
We analyzed the sloped ground safety factor, which is not presented in the design specification, using a computational analysis program L-Pile Plus 13.8. To achieve this we chose a required parameter set and a level ground safety factor presented in the design specification, and then determined its values comparing with the change of the safety factor according to the parameter. Using these parameters, we estimated the sloped ground safety factor for the slope of 35 degrees considering the improvement value of the slope presented in the design specification. As a result of this analysis, we obtained the smaller safety factor by about 0.7 times than the case of the level ground and verified that a number of concrete poles fail to assure 1 degree of the safety factor. We, therefore, concluded that an adjustment of the embedment depth is required in the case of the sloped ground.
-
Design equations for calculating the lateral-torsional buckling moment resistances of I-section beams with continuous lateral top-flange bracing subjected to several loading conditions are investigated based on elastic finite-element analyses. The equations presented in this study are compared with current moment gradient modifiers presented by other researchers and specifications. The equation suggested in the SSRC Guides(1998) has a good agreement with the results of finite-element analyses. The moment gradient correction factors proposed in the SSRC Guides(1998) should be easily used to calculate the lateral-torsional buckling moment resistance of I-beams with continuous lateral top-flange bracing.
-
Surge tank generally are used near the downstream end of tunnels of penstocks to reduce change in pressure caused by waterhammer resulting from load changes on the turbines. In this paper, the surge tank with chamber is selected to analyze water surface oscillation. the governing equation are derived using the law of conservation of mass and momentum. the water surface oscillation in the surge tank are computed using governing equation. In the case of upsurging, water surface oscillation is damped gradually and in the case of downsurging, it is damped rapidly.
-
교량의 플러터 발생풍속을 예측할 경우에는 주로 주형의 2차원 단면실험을 통하여 추정하고, 전체교량의 3차원 모형실험을 통하여 확인하게 된다. 주형단면의 2차원 단면모형 실험에서는 교량거더의 수직방향과 비틀림 방향의 2자유도계로 간략화하여 구조물의 거동을 살펴보게 된다. 전산풍공학적 방법에 의하여 구조물의 공기력을 산정하는 방법은 기존에 주로 사용되던 풍동실험을 대치하는 방법으로 개발되고 있으며, 교량의 플리터 발생풍속 예측을 위한 산정기법 역시 다양하다. 본 논문에서는 유사한 형상비를 가지는
$\pi$ 형 단면 거더의 플러터 발생풍속을 비교하였으며, 교량단면의 2차원 단면실험을 통하여 그 결과값을 비교, 검토하였다. -
After over a century of effort by researchers and engineers, the problem of bluff body flow, in particular vortex shedding frequency, remains almost entirely in the empirical, descriptive realm of knowledge. Computational methods have been systematically applied for vortex-induced vibrations of the cable-stayed bridge with steel composite deck by unsteady wind loadings due to vortex-shedding. The focus of this paper is to predict the vortex-induced vibration of the cable-stayed bridge with steel composite deck based computational fluid dynamics(CFD).
-
이 논문은 도로의 침수를 방지하기위하여 집주정 스틸 그레이팅의 설계 방안을 검토하였다. 현재 사용되고 잇는 스틸 그레이팅은 단지 모양만을 고려하여 사용하고 있으며, 차량 하중 등에 대한 고려를 하지 않고 있다. 따라서, 도로설계시 반드시 하중에 대한 검토와 도로표준시방서 등의 검토해야 한다.
-
이 논문은 2006년 집중호우로 인하여 발생한 강원지역의 도로시설물 피해 원인 및 대책에 대하여 기술하였다. 최근 집중호우로 인하여 산악지형에 위치한 도로는 계곡하천의 급류와 계곡 상류지역에서 발생한 토석류 등에 의하여 유실 및 붕괴가 발생하고 있다. 피해의 주요 원인은 계곡부의 산지하천의 급류에 의한 만곡부 및 수충부의 침식과 토석류 및 부유목 등에 의한 횡단배수암거의 통수능 부족 등이다. 따라서, 산악지형의 도로시설물에 대하여 주요 원인에 대하여 도로 배수시설물의 확대 및 토석류 대책 등이 필요하다.
-
Recently, in Korea vehicle market, the proportion of SUV is increasing. However Korea SINCAP(Side Impact New Car Assessment Program) doesn't reflect this circumstance. This paper focused on improvement of Korea SINCAP by comparing IIHS(Insurance Institute of Highway Safety) side impact test protocol with Korea SINCAP.
-
Korea's road traffic has been the important role of social and economic development, and it'll be a much more important in the future. But we require a far more efficient road traffic system to solve the problem of vehicle increases. So this paper is analyzed and researched both road traffic systems and road traffic safety, and hypothesized a solution to the problem by using small town's road traffic system demands as a good example. The road traffic system should harmonize around the structure of the town, and be related to the safety, By analyzing road traffic system, we can understand how importantly the traffic system is related with safety, efficiency and overall benefits for our community.
-
The major distresses in asphalt concrete pavement are rutting and fatigue cracking. Once the distresses are observed on pavement surface, an appropriate rehabilitation method should be found. Usually, asphalt patching or overlay methods are used to improve the pavement performance. The research presents the fundamental study on effective longitudinal rehabilitation methods for asphalt concrete pavements. The rehabilitation method will be applied to rutting that is occurred asphalt Pavement surface course and longitudinal cracking or fatigue cracking with light to moderate distress levels.
-
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). Thus, this study is conducted research and analysis about the Influence of repeated loading cycles on Strength Ratio of the high quality material which is Carbon/Epoxy Composite Laminates through the test of tensile and fatigue Characteristics, based on it, construction engineers will can apply composite materials to construction technical without difficulty.
-
The present study is an exploratory research concerned with evaluation of three types of high performance concrete for bridge deck applications. These include A-Type (silica fume 6%), B-Type (silica fume 6% plus fly ash 20%), C-Type (silica fume 6% plus blast-furnace slag 40%). Test results compare with Latex modified concrete (LMC) and Ordinary portland cement concrete (OPC). The results indicates that high performance concrete for bridge deck overlay shows the excellent mechanical and durability performance for LMC and OPC in case of static loading test. Analytical results are similar with experimental results. However there are relative errors of
$1{\sim}4mm$ for deflection and maximum 12% for strain. -
Recently, rainfall induced hazard has been increased gradually, for example, typhoon Rusa in 2002 and Maemi in 2003. In addition, localized heavy rainfall has been also caused tremendous damage to railroad systems. Measured data from the Meteorological Adminstration sometimes, However, are not in accordance with those of rain gauges in local area, because of its good distance. This study develop automatic alarming software to estimate and prevent these kind of rainfall induced hazards in railroad system with online transportation.
-
This paper focused on "the information management for the disaster prevention", which is based on If, which copes with partial or whole national disaster effectively and which helps to reduce the damage by natural or artificial disasters promptly.
-
Data structure was designed not only to estimate LCC but also to analyze time-variant reliability index of plate girder bridges. Information model for data structure was categorized into cost information, cost variable information, user cost information, and reliability analysis information according to the characteristic of data. EXPRESS language of STEP was adopted to describe the data structure for the electronic representation of LCC information. The suitability of the developed data structure was verified by estimating LCC and analyzing time-variant reliability index of a plate girder bridge considering corrosion on the basis of the constructed test database.
-
Slope-related disasters have occurred in the rainy season. It can be assumed that one of the most important factor slope-related disasters is rainfall intensity. Slope-related disasters occurred in relatively short time and had characteristics that lead to huge damage. Therefore, if rainfall characteristics were applied to estimate slope stability effectively, slope-related disasters could be predicted and prepared in advance. In this study, the SEEP/W program was used and the frequency rainfall estimated by using precipitation data(
$1961{\sim}2005$ ) in Seoul was applied to analyze the change of groundwater level according to rainfall intensity. -
Usually, cut-slope is the term that call rock slope. Therefore, the cause of instability of cut-slope is influenced generally in lithological and structure geological qualities including weathering disintegration. Through the several case studies, we could confirm that stabilization countermeasure also should be based in geological properties.
-
Yeom, Kyu-Jin;Chun, Kun-Woo;Cha, Doo-Song;Lee, Si-Young;Lee, Hyun-Kyu;Lee, Myung-Woog;Kim, Youn-Jin;Lee, Jin-Ho;Kim, Suk-Woo;Tsugio, Ezaki 509
The fire area need management to prevent enlargement of collapes and sinkage. and it need that repair Vegetation sack work, Soil arresting structure, Terrace-sodding works, Direct seeding works in greening works and Water cushion in erosion control dam. The whole of the Concrete stream grade stabilization structures were broken, it need to be repair. As pass the time, a lot of structures were abandoned. Therefore, it need to reorganize erosion control structures and the method of construction in the fire area -
This study is to establish the appliance model for the automatic fire alarm system in clean room within the framework of the performance based design. Because of the environmental and dimensional characters of clean room, this space is exposed to fire and toxic damage, so it is very important to notify the occupants of these dangerous situations.
-
The paper is to show the methodology that they have a new understanding of a fire extinguisher's function and utilization through a deeper look. This new approach method will help to extinguish a accidental fire practically
-
This study is for reduce the damage of human life and property occurred by a fire in the normal house and market according to increase rate of a fire. this is focused on the present domestic code about prevent a fire and sprinkler system in residential occupancies.
-
Storm and flood damage management systems in national disaster management system(NDMS) were organized into three operation systems. They are prevention, preparation, response, and recovery systems. Disaster resources in each system must be promptly and exactly applied to minimize casualties and loss of properties. However, the disaster resources in current management system can not be immediately used in calamity situation due to the lack of efficiency in statistical data. In this study, the classification system of the disaster resources in storm and flood damage systems was examined to develop the a standard technology in disaster resources management. Problems and reformation points of the classification system were also presented to improve the classification technique and to construct the data base.
-
Our country occurs yearly damage, because of every year in the summer season characteristic localized torrential downpour. Therefor, we will research damage instance and natural calamity reduction effective plan through research against a landslide relation Debris Barrier, And the Debris Barrier decide suitability of Mountains among the Kangwon.
-
The soil nailing was generally using method in practical business, in application of the soil nailing, the analysis was primarily used to Beam-Colum Method, Finite Element Method and Limit Equilibrium Method. Beam-Colum Method and Finite Element Method were able to examine transformation but widely using Limit Equilibrium Method wasn't able to examine transformation and displacement Therefore, this study was focused on presenting stability in comparison with former study-results about horizontal displacement of the soil nailing retaining-walls satisfing a criterion safety factor of Limit Equilibrium. There were performing comparison field measurements and former study-results in first step.
-
본 연구에서는 복합 AAM 영구 앵커를 소개하고, 앵커의 설계시 인발력(
$P_a$ )에 의해 앵커에 작용하는 힘의 관계 검토, 지압파괴에 대한 검토, 앵커사이 지반에서의 인장파괴 유발하중 검토 등을 통하여 복합 AAM 영구 앵커의 설계법을 소개하였다. 그리고 복합 AAM 영구 앵커의 거동특성을 알아보기 위하여 설계법의 의한 예측결과와 현장인발시험 결과를 비교 검토하였다. -
The vertical drain method generate the disturbed zone, because the drainage should be penetrated into the in-situ ground. The characteristics of the smear zone generated cause the problems that the coefficient of permeability decreases and the consolidation time anticipated in the design is not properly shortened. In this study, in order to understand such influence, the laboratory test were carried out so as to reasonably determine the coefficient of consolidation in silt. For that procedure, mandrel of a diversity were penetrated into the soil tube with silt, and then the variation of pore water pressure was measured with the pore pressure meter, Then, the range of smear effect on silt was estimated with monitoring data through the laboratory test, and also analyzed with inputting the coefficient of consolidation into the theoretical equation.
-
High excess pore water pressure may develop when loose saturated sand is subjected to earthquake excitation, resulting in reduction in the shear strength and stiffness, and ultimately can result in liquefaction. It is very important to accurately assess the level of the pore pressure generation for seismic design and to perform effective stress analysis. A simple numerical 모형 is developed for estimating the development of pore water pressure due to seismic loading. The method only uses two parameters and the length of the accumulated shear strain. The accuracy of the proposed 모형 is verified through a series of laboratory test data. Comparisons show that the modified 모형 is an improvement over existing 모형s.
-
본 연구의 목적은 현재 지반지진공학에서 가장 큰 문제점 중 하나로 대두한 동하중의 주파수에 비례하는 흙의 거동이 지반진동에 미치는 영향을 규명 하는데 있다. 이를 위해 주파수의 영향을 고려하여 지반거동을 모사할 수 있는 지반진동해석 프로그램을 제시하고자 한다. 이 프로그램은 주파수에 비례하는 흙의 전단탄성계수 및 감쇠비를 모두 고려할 수 있는 새로운 해석기법이 될 것이다. 이를 이용하여 주파수에 비례하는 흙의 거동이 지반진동에 미치는 영향을 심도 있게 연구하고자 한다.
-
This paper focused on the ways of disater prevention and risk analysis of the passengers setting up the hypothesis when urban rapid transit broke out fire in subway tunnel which is PSD(Platform Screen Door) installed environment. compared the flud dynamic changes and evacuation specifications whether PSD being installed or not, tried to search the effective ways for sustaining passengers safety.
-
This case was successfully constructed as a leakage prevention case of primary 2-arch tunnel located in Anyang, Gyungkido. The leakage of primary 2-arch tunnel was observed at middle wall of tunnel and girder of tunnel. Such a leakage of primary 2-arch tunnel generally occurred due to the damage of the waterproof membrane constructed on the middle wall during the blasting works of right and left tunnel after construction of the middle wall. As the leakage, icicles hanged from girder of tunnel in the winter. In such phenomenon, the risk of the traffic accident in the tunnel was high. In this case, leakage prevention works were successfully constructed using the heat insulated drainage.
-
The explosionproof apparatus is a devices that is enclosed in a case capable of withstanding an explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within, and that operates at such an external temperature that a surrounding flammable atmosphere will not be ignited thereby This kind of exeplosionfproof devices should be installed suitable for the characteristics of the space or process condition that should be protected to prevent explosion or fire. But, due to the lack of information and techniques on the explosionproof technology, some dangerous area is not properly protected from an explosion or it cost too much to implement the explosionproof devices. In this report, the basic guidelines and several case studies of explosionproof devices installation will be introduced to be of help to field safety engineer.
-
The purpose of this research is to analyze sensitivities on hydraulic characteristic factors of bridge and culvert causing flood water level rising. With HEC-RAS and RMA2 models, analysis of backwater due to bridge and culvert in an ideal stream was carried out. The results of hydraulic modeling and sensitivity analysis indicated that the opening ratio and the Froude number were the most sensitive factors and other factors were not quite sensitive to flood water level rising.
-
The objective of this study is to analyze the regionalization of point rainfall by statistical methods for regional frequency analysis of the rainfall. The rainfall data used in this study are annual maximum rainfall at 57 stations during the period of more than 30 years for 12 durations(10min, 1, 2, 3, 4, 5, 6, 8, 10, 12, 18, 24hr) in Korea. The Mann-Whitney U test, Kruskal-Wallis one-way analysis of variance of nonparametric test the principal component and the cluster analysis have been performed to analyze the regionalization of rainfall. The results of this study are as follows; (1) The region which hydrological homogeneous is accepted does not exist for whole duration in Korea. (2) The result of nonpametric test shows that hydrological homogeneous regions of point rainfall are divided by 5 regions. (3) In case of cluster analysis hydrological homogeneous regions of point rainfall are divided by 6 regions and 4 other areas.
-
In this paper, the inundation simulations were carried out by using GIS tools for the analysis of detention efficiency based on the results of runoff analysis according to location and scale of regional detention facilities. The inundation maps could be drawn by the inundation simulations, and the locations and magnitude of inundation areas could be estimated through the inundation maps. The inundation simulations with GIS tools are approved to be the one of the useful method in designing optimized location and scale of regional detention facilities.
-
본 논문에서는 삼수원신안강모형(三水源新安江模型)으로 한국 위천유역에 대하여 홍수예보를 모의하였다. 결과 신안강모형(新安江模型)은 위천유역의 홍수를 비교적 정확하게 모의하였고 평균 모형 효율성 계수는 0.93이나 되었으므로 홍수예보를 적용하는데 적합하다. 신안강모형(新安江模型)은 습윤 반습윤지구의 축만유출(蓄滿流出)의 모형으로서 초기 토양함수량이 풍부한 흥수에 대해서는 정확도가 매우 높다. 그러므로 홍수예보를 하는데 있어서 신안강모형(新安江模型)이 광범한 실용가치가 있다고 예상된다.
-
한계자기회귀모형(TAR)을 응용하여 동시에 해조와 홍수의 영향을 받을 때 삽교천 감조구간의 삽교호수위관측소의 월 최고수위를 예측하는 모형을 구축하였으며, 모형구축과정에서 유전알고리즘으로 한계값과 자기회귀계수의 매개변수를 최적화한다. 계산결과 한계자기회귀모형은 감조하천의 비선형성특성을 모의 할 수 있으며, 예측의 정확도와 예측성능의 안정성을 확보할 수 있다. 연구결과 유전한계자귀회귀모형으로 감조하천구간의 월 최고수위를 예측하는 것이 가능하며, 또한 감조하천구간에서 기타 수문요소의 비선형성 서열예측 중에서도 광범한 실용가치가 있다고 본다.
-
The purpose of this study is to estimate the critical flood discharge and flash flood trigger rainfall for alarm system providing for a flash flood in mountainous. This study was effectively estimated a topographic characteristic factor of basin using the GIS. Especially, decided stream order using GIS at stream order decision that is important for input variable of GCIUH. Result that calculate threshold discharge to use GCIUH, at the Mureung valley basin, flash flood trigger rainfall was 16.34mm in the first 20 minutes when the threshold discharge was
$14.54\;m^3/sec$ . -
Urban storm water collection and conveyance systems are critical components of the urban infrastructures. During a storm event, street grate inlets are usually loaded with debris by the first-flush runoff volume. Grate inlets are subject to clogging effects. Effective interception area of grate inlets was decreased by clogging. It also decreased the interception capacity of grate inlets and increased the inundation area in street. Therefore, it is necessary to analyze the clogging characteristics and interception capacity change by clogging for appropriate design and management of grate inlets. In this study, field survey was executed to investigate debris and clogging pattern of grate inlet in 9 areas. The clogging factor with consideration of urban area characteristics was estimated with the field survey results.
-
Flood damage has been increased due to abnormal climate and extreme rainfall. Especially, the increase of impervious areas and the decrease of flow travel times due to the urbanization have been caused heavy division of flood with the recent rainfall characteristics. In this study, hydrodynamics flow analysis has been needed two dimensional numerical analysis for correct stream flow interpretations on bridges as hydraulic structures in rivers. Therefore, comparative analysis has been accomplished by using HEC-RAS model and SMS-RMA2 model for one and two dimensional flow. Also, flood characteristics have been analyzed in urban stream basin.
-
Recently, the frequency of unexpecting heavy rains has been increased due to abnormal climate and extreme rainfall. There was a limit to analyze one dimension or two dimension stream flow of domestic rivers that was applied simple momentum equation and fixed energy conservation. Therefore, hydrodynamics flow analysis in rivers has been needed three dimensional numerical analysis for correct stream flow interpolation. In this study, CFD model on FLOW-3D was applied to stream flow analysis, which solves three dimension RANS(Reynolds Averaged Navier-Stokes Equation) control equation to find out physical behavior and the effect of hydraulic structures. Numerical simulation accomplished those results was compared by using turbulence models such as
$k-{\backepsilon}$ , RNG$k-{\backepsilon}$ and LES. Those numerical analysis results have been illustrated to bends and junctions by the turbulence energy effects, velocity of flow distributions, water level pressure distributions and eddy flows. -
-
The environmental damage caused by river-improvement and slope of incision cliff can dest habitations of animate nature and it takes long time for restoration. River system constructed with stability of flood control, fine biotope, harmony with surroundings should be need to protect and restore nature. Therefore, in this study, conduct comparative experiment in various methods which are stable hydraulically and develop vegetation on revetment of bank, stream bed protection and disaster prevention aspect.
-
Recently, flood damage has been increased annually by severe rain storm and Typhoon. In this case, it needs to the effective flood management using not only hydrologic data but also numerical map, DEM(Digital Elevation Model), satellite image and so on. At this point in time, therefore, applying mobile GIS technology is expected to increase efficiency about the management of hydraulic structures and can promote LBS(Location Based Service) service for residents. In this study, the flood management technology using mobile GIS is suggested by standing on the basis of a super-highway information network.
-
The purpose of this study is developing a disaster prevention information system using Internet GIS to manage disaster information more efficiently and timely. This system has good potential with environment of Internet which has appropriate characteristics of rapidity, wide reach, generality, cost effectivity for disaster management. With this system, general user can easily retrieve disaster information with visuality such as maps. graphs, and texts just by using web browsers. Hence the need of developing Internet GIS system for disaster prevention is growing in these days.
-
There are many channel confluences existing in natural river systems, where the hydraulics are very complex because of the interactive between tributary and main river The RMA-2 model Is applied in this paper to model the confluence between Uksu Chun subriver and Nam Chun main river. Based on three types of assumed confluence forms, the model resuits present the hydraulics at channel confluence can be divided into several zones including a zone of separation immediately downstream of the junction branch channel, a maximum and minimum velocity region at upstream and downstream in the confluent channel, and a shear plane developed between the two combing flows at downstream of confluent channel. And the different types of confluent forms performs a very high effect on drainability of tributary, so it is very necessary to design a reasonable confluent forms.
-
One of the structural measures for the peak flow reduction is infiltration facilities. There are many types in infiltration facilities - infiltration basin, trench, bed, porous pavement, percolated subdrain, dry well. In this study runoff reduction effect of infiltration trench is analyzed by WinSLAMM. Runoff reduction effect is investigated by each design rainfall and temporal pattern of rainfall particularly. The biggest reduction is shown in Yen and Chow's temporal pattern of design rainfall and the smallest reduction is shown in Huff's first quartile pattern. Runoff reduction rate is presented about 6 to 14 percentage, and the larger return period, the smaller runoff reduction rate.
-
Detention pond has an important role in peak flow reduction to mitigate flood damage. Design of detention pond is accomplished through the preliminary stage, planning stage, and design stage in general. New development projects produce increased peak flow and flow amounts. In this case it is necessary to design the detention pond easily and simply. The simple procedure of detention pond design is proposed in this study. The relevant variables are peak flow ratio (
$\alpha$ ) for the before and after development, and storage ratio which is ratio of storage volume to flow amounts. Simplified method for the detention pond design with runoff reduction is easily used for practical purposes. -
The frequently flooded area has been known as very vulnerable area. This area has nature disasters such as typhoon, storm and flood almost every year. The purpose of this study is to develop a management system for frequently flooded area by Web based. So this system is possible to disaster management which irrespective of time and place. Through this system, general user can easily retrieve status information and obtain that in visual way such as maps. graph, and texts if they have only certain web browsers.
-
The purpose of the present research is to provide a plan for an effective evacuation of residents and people who's in need of evacuation (such as children, the handicapped, and the old) and for the situation when staircase is not available for evacuation, by means of analyzing the evacuation behavioral characteristics of the residents or the evacuators and suggesting an evacuation plan using an emergency elevator in order to minimize casualties in case when fire broke out in a skyscraper.