• Title/Summary/Keyword: Ground Level

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Experimental Study for Prediction of Ground Vibration Responses by the Low-Vibration Pile Driving Methods (저진동 파일시공법에 따른 지반진동 응답 예측을 위한 실험적 연구)

  • Park, Sun-Joon;Kang, Sung-Hoo;Jung, Seug-Gyu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2010.10a
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    • pp.201-207
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    • 2010
  • In this study, the SIP (Soil-cement Injected precast Pile) method among the Low-vibration & Low-noise pile driving methods was decided into study compensation. Ground vibrations by the SIP methods step by step divide and were analyzed. Quantitative response values and ground vibration equations with reliability were presented from findings of this study. Also, vibration responses that are occurred by the SIP method of construction were compared as quantitative with vibration responses by general method of construction that are presented in existent study. Ground vibration values by the SIP method correspond to level of 17 ~ 57% of values that are assumed by the Attewell & Famer's equation, respectively, and these result compares in reliability 50% and separated distance 10 ~ 50 m. Also, those values were analyzed that correspond to level of 14 ~ 96% of ground vibration values by the Prof. Park's equation, respectively. Construction limit extents, separation distances from vibration occurs position, were presented that can satisfy domestic criteria for vibration control for the SIP methods. Those presented in this paper were divided newly according to reliability.

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Riverbank Filtration Well Development for a Heat Source/Sink of Ground Water Heat Pumps (시설원예 냉난방을 위한 온도차에너지 열원용 충적대수층 강변여과수 개발)

  • Cho, Yong;Lee, Nam Young;Lee, Song Ee;Moon, Jong-Pil
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.171.1-171.1
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    • 2010
  • Riverbank filtration wells have been developed to supply a heat source/sink of water in the alluvium aquifer to ground water heat pumps for cooling and heating of a green house. In order to look for an appropriate site to carry out the research, two sites of Jinju and Gumi areas were investigated. In the results of the electrical resistivity surveys, Jinju and Gumi areas have the alluvium aquifer in the depth of 6~17 m and 10~20 m under the ground respectively. Two boreholes have been drilled in each site of both areas. The averaged water level at Jinju site is about 3 m under the ground, and 3.5 m and 6.5 m of sandy gravel aquifer layers are existed in each site. While Gumi site has 10 m water level and 2.5 m and 4.6 m of sandy gravel aquifer. Therefore, it is expected that $1,000m^3$/day of water could be withdrawn at Jinju site rather than Gumi site.

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Quality Characteristics of Low-fat Ground Pork Patties Containing Milk Co-precipitate

  • Kumar, Manish;Sharma, B.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.4
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    • pp.588-595
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    • 2003
  • The optimum level of fresh granulated low-calcium (0.2%) skim milk co-precipitate, as fat substitute in low-fat ground pork patties was determined on the basis of physico-chemical, cooking and sensory properties. Low-fat ground pork patties (<10% total fat), formulated with 15 per cent water, 4 per cent added fat, 1.5 per cent salt and 4-10 per cent milk co-precipitate, were evaluated for proximate composition, cooking characteristics and compared with control patties with 15 % added fat. The moisture and protein content of raw and cooked low-fat patties were significantly (p<0.05) higher than control. The incorporation of milk co-precipitate in low-fat patties improved cooking yield, fat and moisture retention and reduced shrinkage. The sensory properties of low-fat patties were comparable with control patties. The overall acceptability of low-fat patties formulated with 7% milk co-precipitate was significantly (p<0.05) higher than patties with 10% level and non-significantly (p<0.05) higher than low-fat patties containing 4% milk co-precipitate and control. Instrumental Texture Profiles of developed low-fat patties and control patties were comparable with slight increases in hardness and gumminess of the low-fat product. The developed low-fat ground pork patties (7% milk co-precipitate) had lower TBA values, better microbiological and sensory refrigerated storage stability than high-fat control patties packaged in air permeable films for 21 days.

The Optimization of Hyperbolic Settlement Prediction Method with the Field Data for Preloading on the Soft Ground (쌍곡선법을 이용한 계측 기반 연약지반 침하 거동 예측의 최적화 방안)

  • Choo, Yoon-Sik;Kim, June-Hyoun;Hwang, Se-Hwan;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.457-467
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    • 2010
  • The settlement prediction is very important to preloading method for a construction site on a soft ground. At the design stage, however, it is hard to predict the settlement exactly due to limitations of the site survey. Most of the settlement prediction is performed by a regression settlement curve based on the field data during a construction. In Korea, hyperbolic method has been most commonly used to align the settlement curve with the field data, because of its simplicity and many application cases. The results from hyperbolic method, however, may be differed by data selections or data fitting methods. In this study, the analyses using hyperbolic method were performed about the field data of $\bigcirc\bigcirc$ site in Pusan. Two data fitting methods, using an axis transformation or an alternative method, were applied with the various data group. If data was used only after the ground water level being stabilized, fitting results using both methods were in good agreement with the measured data. Without the information about the ground water level, the alternative method gives better results with the field data than the method using an axis transformation.

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Effects of Clear-cutting on Forest Arthropod Communities at Two Different Vertical Levels (Crown and Ground Surface) (산림 벌채가 산림의 수관 및 지표 절지동물 군집에 미치는 영향)

  • Park, Young-Seuk;Park, Young Kyu;Yang, Hee Moon
    • Korean Journal of Ecology and Environment
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    • v.49 no.4
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    • pp.271-278
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    • 2016
  • Forest clear-cutting operations influence biodiversity through habitat changes and food resource availability for inhabitant species. This study examined the effects of clear-cutting on forest arthropod communities. Arthropods were collected from two different forest treatment areas (clear-cut and control) in summer and autumn. In each treatment area, arthropods were sampled from both crown and ground surfaces using sweeping and pitfall trap methods, respectively. Then, the taxonomic order of the collected arthropod specimens was easily identified. Results indicate that arthropod abundance and number of taxa present were higher at ground surface than at crown levels in both clear-cut and control areas. At crown level, more homopteran species were present in clear-cut areas than in control areas in summer. At ground surface, populations of Isopoda and Opiliones were higher in control areas than in clear-cut areas, whereas numbers of Araneae, Orthoptera, and Hymenoptera were greater in clear-cut areas. Cluster analysis and principal component analysis showed distinct differences between clear-cut and control communities at crown level in summer and at ground surface in autumn. Thus, our results indicate that clear-cutting significantly influences arthropod communities, and higher taxa are valuable for conducting rapid biological assessments of ecosystem disturbances.

Seismic failure analysis and safety assessment of an extremely long-span transmission tower-line system

  • Tian, Li;Pan, Haiyang;Ma, Ruisheng;Dong, Xu
    • Structural Engineering and Mechanics
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    • v.71 no.3
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    • pp.305-315
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    • 2019
  • Extremely long-span transmission tower-line system is an indispensable portion of an electricity transmission system, and its failures or collapse can impact on the entire electricity grid, affect the modern life, and cause great economic losses. It is therefore imperative to investigate the failure and safety of the transmission tower subjected to ground motions. In the present study, a detailed finite element (FE) model of a representative extremely long-span transmission tower-line system is established. A segmental damage indicator (SDI) is proposed to quantitatively assess the damage level of each segment of the transmission tower under earthquakes. Additionally, parametric studies are conducted to investigate the influence of different ground motions and incident angles on the ultimate capacity and weakest segment of the transmission tower. Finally, the collapse fragility curve in terms of the maximum SDI value and PGA is plotted for the exampled transmission tower. The results show that the proposed SDI can quantitatively assess the damage level of the segments, and thus determine the ultimate capacity and weakest segment of the transmission tower. Moreover, the different ground motions and incident angles have a significant influence on the SDI values of the transmission tower, and the collapse fragility curve is utilized to evaluate the collapse resistant capacity of the transmission tower subjected to ground motions.

Impact of adjacent excavation on the response of cantilever sheet pile walls embedded in cohesionless soil

  • Singh, Akshay Pratap;Chatterjee, Kaustav
    • Geomechanics and Engineering
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    • v.30 no.3
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    • pp.293-312
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    • 2022
  • Cantilever sheet pile walls having section thinner than masonry walls are generally adopted to retain moderate height of excavation. In practice, a surcharge in the form of strip load of finite width is generally present on the backfill. So, in the present study, influence of strip load on cantilever sheet pile walls is analyzed by varying the width of the strip load and distance from the cantilever sheet pile walls using finite difference based computer program in cohesionless soil modelled as Mohr-Coulomb model. The results of bending moment, earth pressure, deflection and settlement are presented in non-dimensional terms. A parametric study has been conducted for different friction angle of soil, embedded depth of sheet pile walls, different magnitudes and width of the strip load acting on the ground surface and at a depth below ground level. The result of present study is also validated with the available literature. From the results presented in this study, it can be inferred that optimum behavior of cantilever sheet pile walls is observed for strip load having width 2 m to 3 m on the ground surface. Further as the depth of strip load below the ground surface increases below the ground level to 0.75 times excavation height, the bending moment, settlement, net earth pressure and deflection decreases and then remains constant.

A Failure of disturbed natural-slope ground caused by cutting slope (절토에 의한 상부자연지반의 붕괴 특성 연구)

  • Nah, Kwang-Hee;Chang, Buhm-Soo;Shin, Chang-Gun;Kim, Yong-Soo;Choi, Yong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.629-634
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    • 2004
  • When it was a localized torrential downpour last year, a natural-slope fell down above a cut-slope. They were caused that stress was opened by cutting slope, ground water level rose quickly and a ground mass strength fell etc. So volume of ground mass increase because of that reasons, finally the disturbed ground was collapse. Therefore I suggest that safety of a natural-slope is a consideration, when a cut-slope is made by cutting ground.

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Enhanced dissolution rates of piroxicam from the ground mixtures with chitin or chitosan

  • Koh, Ik-Bae;Shin, Sang-Chul;Lee, Yong-Bok
    • Archives of Pharmacal Research
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    • v.9 no.1
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    • pp.55-61
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    • 1986
  • To increase the dissolution rate of piroxicam, chitin and chitosan which are widely occurring biodegradable natural materials were used as drug carriers. The ground mixtures of piroxicam with chitin or chitosan were prepared by grinding in a ball mill. The dissolution rates of piroxicam from the ground mixtures were enhanced markedly than that from the physical mixtures or from intact piroxicam. The X-ray diffraction peaks disappeared in the ground mixture indicating the production of the amorphous form. The comparison of infrared spectra of the physical mixture and the ground minture showed an interaction such as association between the functional groups of piroxicam and chitin or chitosan in the molecular level. The weight losses in TGA curves shoed all the same patterns. However, in the ground mixture by DTA curve, the undothermic peak due to the fusion of piroxicam was disappeared indicating the different thermal property.

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Comparative Measurement of Touch and Step Voltages in Ground Systems (접지시스템에서 접촉전압과 보폭전압의 비교측정)

  • Kim, Hwang-Kuk;Moon, Byung-Doo;Park, Dae-Won;Kil, Gyung-Suk;Han, Ju-Seop
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.311-315
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    • 2008
  • Ground systems set the reference voltage level of circuit and system, and suppress Ground Potential Rise (GPR) by flowing fault currents to ground safely. There are several parameters which evaluate the performance of ground systems as ground resistance, touch voltage and step voltage. The touch and step voltages are especially important to ensure safety of human body. In this paper, we measured the touch and step voltages by injection of power frequency and surge current. Also correlation between touch and step voltages is compared and analyzed for the same ground systems.

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