• Title/Summary/Keyword: 510(k)

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Analysis of Moment Effect of Bridge Design Live Load KL-510 by Statistical Analysis of WIM Data of Expressway (고속도로 WIM 데이터의 통계분석을 통한 교량 설계활하중 KL-510의 모멘트 효과 분석)

  • Paik, Inyeol;Jeong, Kilhwan
    • Journal of Korean Society of Steel Construction
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    • v.29 no.6
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    • pp.467-477
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    • 2017
  • The live load effect of KL-510 of the current Korean bridge design code is examined by comparing with that of the multiple trucks of which the weights are statistically estimated from measured traffic data as well as with those of the related live load models. The truck weight data measured on the expressway before and after overweight enforcement are used to obtain the truck weights following the same procedures in deciding the live load model of the design codes and the results are compared with the load effect of KL-510. KL-510 yields a very uniform loading effect compared with the multiple truck effects when the weights are estimated from the data which contains some of the heavy trucks over the operational weight limit. KL-510 yields consistent results with the live load of AASHTO LRFD and shows less variation than the past load model DB-24 over the span lengths considered in this study. As a result of this research, the actual truck combinations equivalent to the notional KL-510 load model are constructed and it can be applied to the evaluation of the existing bridge and the calibration of the load factor of the permit vehicle.

Design Bending Moment of Cantilever Slab for Long Span decks with KL-510 Load (KL-510 하중을 적용한 장지간 바닥판의 캔틸레버부 설계휨모멘트)

  • Chung, Chulhun;Joo, Sanghoon;Lee, Hanjoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.4
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    • pp.595-604
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    • 2016
  • This paper proposed the design bending moments of cantilever slabs with KL-510 load according to span length of long span decks. Their span length range is from 6.0 to 12.0 meter, and length of cantilever slabs is from 30 to 50 percent of their span length. The effects of orthotropic concrete decks, stiffness of steel girders and multiple lane loading factors (MLLF) were reflected in the design bending moments. The proposed design bending moments of cantilever slabs were compared to the design bending moments with DB-24 load.

Minimum Thickness of Long Span RC Deck Slabs for Composite 2-girder Bridges Designed by KL-510 Load Model (KL-510 하중모형을 적용한 강합성 2거더교 RC 장지간 바닥판의 최소두께)

  • Park, Woo-Jin;Hwang, Hoon-Hee
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.72-78
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    • 2014
  • The minimum thickness of long-span deck slab is proposed by checking the limit state according to the Korean highway bridge design code(limit state design). Both minimizing thickness and ensuring safety of deck slab are important design factors to increase a competitive price of the long span deck slabs. The required thicknesses for satisfying flexural capacity, preventing punching shear failure and limiting deflection were calculated by considering KL-510 load model which has increased total load compared to DB 24 from 432 kN to 510 kN. The results of the required thickness for various limit states were compared to propose the minimum thickness as a function of span length of deck slabs. The proposed minimum thickness is influenced by satisfying flexural capacity and limiting deflection. It turns out to be similar compared to the results of the previous study by ultimate strength design method even if the live load model was increased in total weights.

A Study on the Design Bending Moments of Long Span Decks with KL-510 Load (KL-510 하중을 적용한 장지간 바닥판의 설계휨모멘트에 관한 연구)

  • Chung, Chulhun;Lee, Hanjoo;Joo, Sanghoon;An, Hohyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.3
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    • pp.375-384
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    • 2016
  • In the current Korea highway bridge design code (KHBDC), the criteria of concrete bridge decks are mainly based on short span decks of steel plate girder bridge, there are very little the specific criteria of long span decks in the twin steel plate girder bridge. Therefore, to put more rational and practical design criteria of the long span decks on the code, the complements of the related criteria are required in the current design code. This paper proposed the design bending moments of decks with 6.0~12.0m span for KL-510 load in direction to bridge (longitudinal direction) and perpendicular direction to bridge (transverse direction). The effects of orthotropic concrete decks, stiffness of steel girders and multiple lane loading factors (MLLF) were reflected in the design bending moments. The proposed design bending moments were compared to the design bending moments with DB-24 load.

Characterization of Unrecorded Yeasts Isolated from Leaves of Trees of Oknyeobong Peak and Yeonjasan Mountain in Daejeon, Korea (대전광역시 옥녀봉과 연자산 나뭇잎으로부터 야생효모의 분리 및 국내 미기록 효모의 특성)

  • Han, Sang-Min;Lee, Jong-Soo
    • The Korean Journal of Mycology
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    • v.45 no.1
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    • pp.23-30
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    • 2017
  • Twenty-two yeast strains of 15 species were isolated from the leaves of 20 trees on Oknyeobong Peak, and 24 yeast strains of 12 species were isolated from the leaves of 20 trees on Yeonjasan Mountain in Daejeon city, Korea. Cryptococcus bestiolae (5 strains) and Aureobasidium pullulans (8 strains) were the predominant isolates from Oknyeobong Peak and Yeonjasan Mountain, respectively. Of a total of 46 yeast strains, Cryptococcus kuetzingii JSL508, Cryptococcus vishniacii JSL509, and Dioszegia takashimae JSL510 from Okyeobong Peak, and Plowrightia periclymeni JSL514, Erythrobasidium hasegawanium JSL0193, and Rhodotorula nothofagi JSL0196 from Yeonjasan Mountain were determined to be yeast strains that were yet unrecorded in Korea. Morphological and cultural characteristics of these unrecorded yeasts were investigated. Erythrobasidium hasegawanium JSL0193 and Rhodotorula nothofagi JSL0196 did not form ascospores and pseudomycelia. All the strains, except Dioszegia takashimae JSL510, were halotolerant or halophilic, and Cryptococcus kuetzingii JSL508 and Dioszegia takashimae JSL510 were thermophilic, growing at $37^{\circ}C$.

Biosynthesis of polyhydroxybutyrate and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by bacillus thuringiensis R-510

  • Park, Sang-Kyu;Lee, Kang-Tae;Kim, Young-Baek;Rhee, Young-Ha
    • Journal of Microbiology
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    • v.35 no.2
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    • pp.127-133
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    • 1997
  • Biosynthesis of polyhydroxybutyrate and copolymer consisting of 3-hydroxybutyrate and 3-hydroxyvalerate [poly(3HB-co-3HV)] by Bacillus thuringiensis R-510 grown with glucose or with mixtures of glucose and propionate was investigated. n-Alkanoic acids other than propionate were not precursors of 3HV units. The fraction of 3HV unit in the copolymer increased from 0 to 84 mol% of 3HV. Polymer yield decreased as the fraction of propionate was increased but the molecular weight distribution was not affected by the composition of carbon substrate. The minimum melting temperature (around 65.deg.C) of poly (3HB-co-3HV) copolymers was observed for the polymer bearing approximately 35 mol% of 3HV. Polyhydroxyalkanoates production by this organism was not dependent on nutritional limitation, but remarkably influenced by dissolved oxygen concentration in the culture medium. Low level of dissolved oxygen concentration prevented spore formation in the cells and stimulated the synthesis of polyhydroxyalkanoate. The composition of poly (3HB-co-3HV) produced by B. thuringiensis R-510 lyhydroxyalkanoate. The composition of poly(3HB-co-3HV) propduced by B. thuringiensis R-510 varied according to the growth time. However, there was no evidence that polymers isolated from cells were mixtures of immiscible polymers.

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