• Composites Research
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• v.25 no.5
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• pp.164-168
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• 2012

The purpose of this experimental research was to evaluate interface shear requirements between UHPC deck and concrete girder with stirrups according to Korean Highway Bridge Design Code and AASHTO LRFD Bridge Design Specifications. The push-out tests are performed to analize the composite behavior in interface of connection. The test results were compared to the values of interface horizontal shear strength predicted by current codes. As the results, it was observed that the test results provided more conservative estimate for horizontal shear strength than the values by current codes equation.

• Magazine of the Korea Concrete Institute
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• v.10 no.1
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• pp.10-19
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• 1998

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.305-312
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• 2014

The current American Concrete Institute(ACI), Canadian Standard Associate(CSA) and CEB-FIP Model Code 2010 provisions on the shear strength of a simply supported deep beam suggest that deep beams should be designed using the strut-and-tie model. Although this is a useful methodology to design members in disturbed regions, the quality of the design is highly dependent on the truss model that designers create. However, Hong et al. derived the shear strength equations of reinforced concrete deep beams. This thesis investigates the validity of the current ACI, CSA and CEB-FIP code provisions on the shear strength of simply supported reinforced concrete deep beams by comparing them with the shear strength equations proposed by Hong et al. The comparison shows that all of these code provisions provide reasonable estimates on the shear strength of concrete deep beam members and the selection of an internal truss model plays an important role on the estimation of shear strength.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.652-654
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• 2007

본 논문에서는 국가의 기간 에너지원인 전력망을 구성하는 구조물인 송전철탑의 설계하중에 가장 큰 요인으로 작용하는 기준풍속 산정을 위한 연구내용을 고찰하고자 한다. 현행의 송전용 지지물 설계 기준은 전기설비기술기준에 고시된 가공전선로 지지물에 관한 기준을 토대로 전력사의 실무적인 설계를 위하여 보다 구체화하여 작성된 한국전력공사 송전설계기준에 근거하고 있다. 이러한 기존 설계기준은 1985년 이전의 기상자료를 토대로 제정되어 본 논문에서는 1980년대 후반부터 약 20년간의 기상청의 풍향, 풍속자료를 추가로 확보하고 이를 분석하여 재현기간을 반영한 지역별 설계기준 풍속 Map을 제시하였다. 이러한 흐름으로 최근의 기상자료를 포함하여 보다 정확한 분석을 도모하고, 사회 환경의 급변함에 따라 우려되는 기상이변 등을 고려한 안전성과 경제성이 향상된 기준풍속 산정과정을 고찰하고, IEC 등 해외 주요국의 풍하중 설계기준에서 반영하고 있는 국부지형을 고려한 설계방법에 대한 국내 기준 적용성 평가를 위한 비교분석 결과를 소개하였다.

• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.19-28
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• 1999

This study deals with developing Critical GaP Model and Merge Probability Model which describe traffic patterns in the microscopic view, for the Purpose of suggesting a proper design criteria within the climbing lane section. Minimum tolerance speeds at the end of the climbing lane are calculated 60km/hr for 2-lane freeway, and 75km/hr for 4-lane freeway. In case of 2-lane freeway, the result is same as existing design criteria. and a new value is 15km/hr higher than existing design criteria for 4-lane freeway. In addition, auxiliary length at the end of the climbing lane is needed about 200m for 4-lane freeway to adjust high minimum tolerance speed. Therefore we propose to increase minimum tolerance speed for 4-lane freeway.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.199-200
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• 2015

도시부 교차로의 설계는 지방부 교차로와 근본적으로 달라야 하나, 현행 도시부 교차로 설계는 지방부 교차로 설계기준을 준용하고 있다. 본 연구는 도시부 및 지방부 교차로의 차이점을 비교 분석하고, 국내외 교차로 종단경사 설계기준을 검토한 후 적정 설계기준(안)을 적용한 후, 이를 통계적 분석기법을 활용하여 검증하여 설계기준을 정립하는 순으로 진행 하였다. 분석결과 정면충돌사고율과 차대차추돌사고율이 종단경사와 상관관계가 있는 것으로 나타났다. 이러한 연구를 통해 적정 교차로 종단경사를 적용한 설계가 이루어져야 함을 확인 할 수 있었다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.3
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• pp.323-335
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• 2020

In this study, a series of site measurement of particulate and gases pollutants at five tunnels were carried out along with case studies to review the suitability of the current road tunnel ventilation design standards. Previous studies by other researchers have shown that the ratios of the level of measurement to the standard were 27.9%, 1.6% and 3.4% for TSP, CO and NOx, respectively. Those measured in this site study shows even lower ratios; the ratios were 2.6%, 0.8% and 0.3%, for TSP, CO and NOx, respectively. The particle size analysis of TSP for the five tunnels shows that PM10 including tire wear and re-suspended road dust exceeded 20.4%. This implies that non-exhaust particulate matter must be taken into account, since the current design standards for the particulate matter (visibility) include only the engine emission. Based on the recent research results, for vehicle emission rate and slope-speed correction factors, revision of ventilation design standards for pollutants is required. WRA (PIARC) also emphasizes the necessity of the ventilation design standards for pollutants. In addition, enactment of a new road tunnel ventilation system operation standard or guideline is strongly recommended when considering the low operating rate of the ventilation system with jet-fans.

• 월간 기계설비
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• s.143
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• pp.60-74
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• 2002

건축물의 에너지 이용을 효율화하기 위하여 단열기준 등을 기존보다 20% 이상 강화하는 것을 골자로 하는 건축물의 에너지절약 설계기준(건설교통부 고시 제2001-118호)이 지난해 6월 1일부터 시행되고 있다. 개정 기준의 가장 큰 특징은 단열기준의 적용 부위를 외기에 직접 면한 부위와 간접 면한 부위로 구분하고, 지역을 중부와 남부, 제주도로 구분$\cdot$설정하여 부하조건과 에너지 소비특성에 따라 건축물의 단열기준을 세분화한 것이다. 특히, 종래에는 최하층 바닥에만 적용하였던 거실 바닥(온돌)의 단열기준을 중간층까지 확대$\cdot$적용하였고, 여기에 온돌시스템의 열적 특성을 고려하여 단열기준의 적용 부위를 보다 구체적으로 설정하고 있다. 따라서 종래의 온돌시스템에서 채움층으로 일반적으로 사용하고 있는 현장 타설식 경량기포콘크리트의 열전도율이 0.13W/mK 내외임을 고려한다면 현행 습식온돌시스템의 열관류율은 $1.0W/m^{2}K$ 이상이 될 것으로 예상됨으로서 앞으로 온돌시스템의 배관층 하부에 $1.0m^{2}K/W$ 이상의 열전도저항을 지닌 단열층이 구성되어야만 개정기준에서 정하는 열관류율 $0.81W/m^{2}K$(기준층 기준)의 성능과 배관하부의 열전도저항값 적용비율을 만족할 수 있을 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6C
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• pp.251-258
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• 2009

In this study, the optimum design conditions for embankment construction on soft clay layer improved by soil compaction pile (SCP) are discussed by comparing the practical design method to the reliability design which is based on the loss function and advanced first order second moment (AFOSM) method. The results are summarized as follows; 1) the relationship between safety factor and failure probability becomes heavy exponentially, failure probability decreases rapidly till 1% approximately until safety factor is smaller than 1.2 and after then, failure probability decrease gradually along the increase of the safety factor. The design safety factor of 1.2 may be the critical value that has been established on considering both relationships appropriately, 2) the safety factor of 1.15 at the minimum expected total cost is a little smaller than the design safety factor of 1.2 and the failure probability is about 1%, 3) the sensitivities of the ratio of stress share and the internal friction angle of sand is larger than the variables related the undrained shear strength of soft layer. This result means that the distribution characteristic of n and ${\phi}$ influences on the stability analysis considerably and they should be considered necessarily on stability analysis of embankment on soft layer improved by SCP, 4) new failure points of the input variables at the design safety factor of 1.2(below failure probability of 0.1~0.3%) is far 1~2 times of standard deviation from the initial design values of themselves.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.76-83
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• 2021

This study examines the bending behavior of lap-spliced ultra-high-strength fiber-reinforced concrete members and evaluates the safety of the design codes for ultra-high-strength fiber-reinforced concrete structures. An experiment on a total of six beams was performed. The main variables were the fiber-inclusion and the lap-spliced length at the center of the beams. The steel fibers in a volume fraction of 2% were used, and the lap-splice lengths were determined to be 8db and 16db. As a result of the test, the specimens not reinforced with fiber lost abrupt load-bearing capacity at the lap region and did not experience yielding of the reinforcing bar. In the case of fiber-reinforced concrete, if a lap-splice length of 16db is secured, the yielding of the main reinforcing bar can be experienced, and appropriate flexural strength can be expressed. Based on the experimental results of this study, as a result of reviewing the lap-splice length calculation formulas of the current design standards and the ultra-high-strength concrete structural design recommendations, it was found that all of them were evaluated conservatively.