• Title/Summary/Keyword: Environmental impact test

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Laboratory Tests for the Applicability of Various Testing Devices for Measuring Degree of Compaction (여러가지 다짐 평가장비의 적용성을 위한 실내시험)

  • Yoo, Wan-Kyu;Lim, Nam-Gyu;Kim, Byoung-Il;Kim, Ju-Hyong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1178-1187
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    • 2008
  • Quality assurance for embankment compaction is one of very important procedures to guarantee high quality construction. However, only sand replacement method (KS F2312) and static plate load test (KS F2310) which are conventional and tiresome methods are used to evaluate degree of compaction at construction fields. Recently, new types of devices such as the geogauge and the light falling weight deflectometer (LFWD), the soil impact hammer (CASPFOL) and dynamic cone penetration test etc. which are able to substitute for the conventional methods are begun to use to evaluate soil stiffness. In this study, a laboratory model test was performed to evaluate correlations among test results obtained from the new devices and to assess the potential use of them. All test results have correlations with relative density and water content. Especially, the coefficients of correlation between $E_G$ from the geogauge and $K_{30'}$ from the soil impact hammer and between $E_G$ from the geogauge and $E_{LFWD}$ from LFWD are more than 0.7 but those between the results from DCP and others are less than those between $E_{G{\cdot}}$ and $K_{30'}$ and $E_G$ and $E_{LFWD}$.

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A Pilot Study on Nondestructive Assessment of Compressive Strength Using Impact Force Response Signal (충격력 응답신호를 이용한 비파괴 압축강도 산정에 관한 기초연구)

  • Son, Moorak;Choi, Yoonseo
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.4
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    • pp.5-9
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    • 2019
  • This paper is to provide the results of a pilot study of the usability and possibility of impact force response signal induced from impacting an object for the assessment of compressive strength of various materials (rock, concrete, wood, etc.) nondestructively. For this study, a device was devised for impacting an object and measuring the impact force. The impact was carried out by an initial rotating free falling impact and following repetitive impacts from the rebound action which eventually disappears. Wood and rock test specimens for different strengths were tested and an impact force response signal was measured for each test specimen. The total impact force signal energy which is assessed from integrating the impact force response signal was compared with the directly measured compressive strength for each specimen. The comparison showed that the total impact force signal energy has a direct relationship with the directly measured compressive strength and the results clearly indicated that the compressive strength of construction materials can be assessed nondestructively using total impact force signal energy which is assessed from integrating the impact force response signal induced from impacting an object.

A Study on the Characteristics of the Tube-to-Support Dynamic Impact Force Measurement Facility (튜브와 지지대 사이의 동적상호 충격력 측정장치 특성규명에 관한 연구)

  • 김일곤;박진무
    • Journal of KSNVE
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    • v.5 no.1
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    • pp.95-106
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    • 1995
  • Flow-induced vibration in heat exchanger (or fuel rod) in nuclar power plant can cause dynamic interactions between tubes and tube supports resulting in fretting-wear. To increase the reliability and design life of heat exchanger components, design criteria that establish acceptable limits of vibration and minimize fretting wear are necessary. The fretting-wear rate is dependent upon material combination, contact configuration, environmental conditions and tube-to tube support dynamic interaction. It is demostrated that the fretting -wear rate correlates well with tube-to-support contact force or work rate. The tube-to-support dynamic interaction, which consists of dynamic contact forces and tube motion, is used to relate single-span wear data to real heat exchanger configurations consisting of multi-span tube bundles. This paper describes the test facility to measure tube-to-support dynamic impact force and reports its dynamic characteristics through the four impact tests - a force transduces independent and external impact tests, central ring inside impact test and additional cylinder impact test. Through the tests the impact parameter change dependent upon the material difference of impacting ball is studied, and the impact parameters of Force Transducer Assembly components are measured. And also the dynamic behavior of Force Transducer Assembly is analyzed. The force measurement technique herein is shown to provide a reasonable measure of dynamic contact forces.

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Effects of Tool Plunge Position on Mechanical Properties of Friction-stir-weleded Region in A6061-T6/AZ31 Dissimilar Metals (A6061-T6/AZ31 이종금속 마찰교반접합부의 기계적 특성에 미치는 툴 삽입 위치의 영향)

  • Lee, Kwang-Jin;Kim, Sang-Hyuk
    • Journal of Welding and Joining
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    • v.30 no.5
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    • pp.22-26
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    • 2012
  • Butt-joints of A6061-T6 and AZ31 plates were successfully manufactured by using a friction stir welding method. Off-set free joints and off-set joints were fabricated to investigate the effect of the tool plunge position on the mechanical properties of the joints. Hardness test, tensile test and charpy impact test was performed to evaluate the mechanical properties of the joints. Off-set condition resulted in increase of mechanical properties of the joints. The variation of the hardness distribution in the SZ was also stabilized in the off-set condition. Tensile strength of the off-set joint was about 85% against to that of the AZ31 base metal. Impact absorption energy by Charpy-Impact-Test of the off-set joint also increased by almost 2 times against to that of the AZ31 base metal.

Impact Assessment Model of Bird Species for Land Developments (개발사업에 따른 조류종 영향평가모형 개발 및 적용)

  • Lee, Dong-Kun;Kim, Eun-Young;Lee, Eun-Jae;Song, Won-Kyong
    • Journal of Environmental Impact Assessment
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    • v.19 no.3
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    • pp.347-356
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    • 2010
  • Forests are being seriously fragmented as a result of land development. Land development with disregard to its subsequent environmental impacts is a primary threat to biodiversity by incurring massive habitat losses and changes in structure and composition of forests. The purpose of this study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest species to determine degree of impact from land development. The edge effect of forest fragmentation on the number of bird species, population size, and bird diversity was obvious. In particular, the bird diversity sharply declines around the forest edge where intensive land development projects take place. To assess the disturbance of forest species, the factors selected were the bird diversity and the rate of edge species. The impact assessment model about bird diversity was explained by type of forest fragmentation and type of vegetation ($R^2$=0.23, p<0.005). The other model about edge species explained by a distance, type of forest fragmentation, type of vegetation, and width of road ($R^2$=0.34, p<0.001). In order to test the applicability of the model developed in this study, the models was applied to the Samsong housing development in Goyang-si, Gyunggi-do. The impacts of land development on the bird species were reasonably quantified to suggest effective mitigation measure. The impact assessment model developed in this study is useful to assess the magnitude of disturbance of bird species. Particularly, the model could be applied to the current Environmental Impact Assessment practices to predict and quantify the impacts of land developments projects on forest bird species.

Study on the Factors Affecting the Richness Index of Bird Species in Environmental Impact Assessment (환경영향평가에서 조류 종풍부도 변화에 미치는 요인 고찰 연구)

  • Hyunbin Moon;Eunsub Kim;Dongkun Lee
    • Journal of Environmental Impact Assessment
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    • v.33 no.2
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    • pp.64-73
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    • 2024
  • As the seriousness of habitat destruction caused by development projects emerges, the importance of environmental impact assessment (EIA) is increasing to preserve biodiversity. In previous studies, research is being conducted to quantitatively evaluate the biodiversity impact of development factors and surrounding environmental factors on the landscape scale, but research on the factors affecting the reduction of biodiversity based on development projects is insufficient. This study examined whether independent variables (size of development project, type of the development, DEM, ecosystem and nature map, distance from the green land, distance from the protected area), which have been proven to effect biodiversity through the previous researches, have a significant effect on the change of richness index (RI) through multi-class logistic regression analysis, T-test, and analysis of the development type. As a result, only the size of development project and the first richness index in EIA showed p-value less than 0.05. And it was confirmed that the reduction in biodiversity was significantly changed in the following construction types: installation of sports facilities, energy development, and development of industrial location and industrial complex. Since the results of this study confirmed that the impact of the variables may be inconsistent depending on the analysis scale, additional study of necessary indicators at the development project is needed to analyze biodiversity changes in EIA accurately.

Effect of Slag Dumping on Heavy Metals in the Neighbour Sea and Direction of Recycling on Slag (제철 슬래그(Slag) 매립으로 인한 인근 해역의 중금속 오염도 변화 및 재활용 방향에 대한 연구)

  • Chung, Yong;Kim, Yong-Bum;Kwan, Yong-Sik;Lee, Sun-Hi
    • Journal of Environmental Impact Assessment
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    • v.5 no.2
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    • pp.21-31
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    • 1996
  • To assess the impact resulted from the slag dumping, we studied that the changes in the concentration of heavy metal were researched through the statistic analysis at 4 stations in Yongil bay, Korea from 1988 to 1995. And in order to clarify resulting from the changes in heavy metal concentration due to be leaked out from dumped slag, it was fulfilled experiments of the slag extraction. In the extracting experiment, Pb and As were only leaked out from slag aged during 10 days but all of heavy metals were not from it aged during 90 or 180 days. It was found that the concentrations of heavy metals in sea water of vincinity of slag dumping area were still remained in similar, comparing with it of control site(site 4) when they were by analysed statistic method, anova test and Mann-Whitney test. The slag recycling ratio of our country is lower than foreign country. While we need to apply a new process for phosphate treatment, foreign country already apply a slag to phosphorous removal. We suggest that slag dumping cannot putatively affected the changes in the concentration of heavy metal. And we thought that impact of heavy metal induced by slag dumping was not severe. So, it is necessary to utilize this process in phosphorous removal, like a foreign country.

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Application of Three-Dimensional Model to Evaluate Stream Discharge Capacity due to Vegetation (식생분포에 따른 하도의 통수능 검토를 위한 3차원 모형의 적용)

  • Noh, Joon Woo;Lee, Jin Young;Ahn, Ki Hong
    • Journal of Environmental Impact Assessment
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    • v.20 no.1
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    • pp.37-48
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    • 2011
  • Recently, the social and environmental functions of nature river are important due to the increase of expectation for river restoration. So it should be considered the effect of vegetation affecting the conveyance capacity and hydraulic resistance. However, it has not yet proposed a objective standard and modeling method to estimate the effect of conveyance capacity according to vegetaion distribution in the watercourse such as water level or velocity. Therefore, this study simulates the variations of water level and velocity using 3-dimensional hydrodynamic model, EFDC, to consider a conveyance capacity in downstream of the Soyang Reservoir. The simulation results were validated using statistical index such as F-test and T-test. As results, the water level rises about 0.01 to 0.47m and velocity difference are about -0.95m/s to 0.23m/s.

Impact of Pro-environmental Behavior on Dysmenorrhea (친환경행위가 월경곤란증에 미치는 영향)

  • Kim, Hyun-Kyoung
    • Journal of Korean Academy of Nursing
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    • v.41 no.2
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    • pp.236-244
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    • 2011
  • Purpose: In this study the impact of pro-environmental behavior, well-being oriented behavior, and use of cloth menstrual pads on dysmenorrhea in Korean female adults was examined according to the theory of reasoned action. Methods: A cross-sectional study was conducted with 195 Korean female adults. Data were collected from June to August, 2010 using self-report questionnaires. Data were analyzed using t-test, one-way ANOVA, Pearson correlation coefficients, multiple regression, and logit regression with STATA 10.0. Results: Pro-environmental behavior explained 48% of well-being oriented behavior. Well-being oriented behavior explained 10% of cloth pad use. Use of cloth pad explained 4% of dysmenorrhea and 5% of menstrual pain. The path through well-being oriented behavior had a significant effect from pro-environmental behavior to cloth pad use. Conclusion: Use of cloth pad was significantly related with well-being oriented behavior, pro-environmental behavior, social influence, dysmenorrhea, and menstrual pain. The results of this study suggest that pro-environmental strategies can help health care providers diminish clients' menstrual symptoms. Nursing intervention can support pro-environmental behavioral strategies.

Investigation of toxic organic solvent exposure in work places (작업장에서의 유해 유기용제 폭로에 관한 연구)

  • Jo, Young Min;Kang, Sang Wan;Oh, Jong Min
    • Journal of Environmental Impact Assessment
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    • v.9 no.1
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    • pp.75-86
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    • 2000
  • The purpose of this work was to document the conditions regarding organic solvent exposure to the workers in paint industry. Air concentrations of organic solvents were measured by passive personal samplers and analyzed by a gas chromatography. Urine samples for hippuric test were also taken from 330 workers who have worked at seven domestic factories for more than two years. Amongst 25 organic elements detected in the indoor environment of working places, toluene was the most common element, and methanol showed the highest mean concentration(18.2ppm). A few elements including methylethyl ketone and toluene partially exceeded the Korean Permissible Exposure Limit. A lack of environmental facilities such as exhaust ventilation, automatic cleaning system, and personal safety devices at present work plaus brings about various occupational diseases.

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