• 콘크리트학회논문집
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• 제15권6호
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• pp.848-855
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• 2003

콘크리트 타설중, 콘크리트 타설경로로 인한 부분재하는 동바리의 연결부에 횡력을 발생시킨다. 이러한 횡력을 구속하기 위해 동바리의 상$.$하부 접합부가 못으로 긴결되어야 한다. 그러나 시공성과 동바리 철거의 편의성을 위해 작업자들은 못을 거의 사용하지 않는다. 이러한 경우 동바리의 접합부는 전단력과 회전에 저항할 수 없다. 그리고 이러한 상황은 거푸집-동바리 시스템의 붕괴를 유발시킬 것이다. 그러므로 시공현장의 상황을 고려한다면 거푸집-동바리 시스템의 접합부 해석을 위해 접촉모델 및 스프링모델이 요구된다. 이에 따라 동바리에서의 접합부의 몇가지 유형에 따른 전단강성과 회전강성의 효과를 이해할 필요가 있다. 본 논문은 못의 길이, 개수, 위치의 변수에 따라 동바리의 연결부의 회전강성값과 전단강성값을 실험을 통해 평가하고자 하며 동바리의 지지단에 따른 결과를 보여준다. 그리고 이러한 결과는 실제 상황과 유사한 스프링모델 설정 및 좌굴하중 평가에 사용될 수 있다.

• 한국산업보건학회지
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• 제26권3호
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• pp.267-276
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• 2016

Objectives: This study, aims to examine the distribution characteristics of asbestos-containing building materials; risk assessment and area of distribution of asbestos-containing building materials depending on year of construction; building materials; types of building materials; and usage in public buildings in order to create fundamental data for safe management of public buildings. Methods: The asbestos investigation was conducted by an asbestos research institution from March to May 2014, targeting 41 public buildings which were subject to asbestos investigation in South Chungcheong-do Province. With respect to 381 presumed asbestos-containing materials, an investigation was conducted into whether they contained asbestos, asbestos type, content, year of construction, and use in the building were examined, and a risk assessment was performed. Results: Asbestos-containing building materials were used in 35 buildings(85.4%). Among them, 31(88.6%) were public buildings. Asbestos was detected in 73% of 381 suspected asbestos-containing materials, which were mostly ceiling materials (85.2%). The older the buildings, the more they showed a tendency to have a significantly higher risk assessment score. The ratio of average area with asbestos-containing building materials to total floor area was 57.6%, 44.1%, and 17.8% for buildings built in the 1980s, 1990s, and 2000s, respectively. This showed a tendency to be significantly higher with the age of the building. Conclusions: From the results above, it can be concluded that with the age of the buildings, the risk assessment score and the ratio of average area with asbestos-containing building materials to total floor area became significantly higher. Given the concern about the exposure to asbestos of residents and civil petitioners, safety management of older public buildings and measures for dismantling and removal of asbestos-containing building materials should therefore be urgently established.

• 한국안전학회지
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• 제35권5호
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• pp.49-58
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• 2020

In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

• 한국건설순환자원학회논문집
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• 제6권4호
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• pp.324-330
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• 2018

2007년 산업안전 보건법의 개정에 따라 우리나라도 유럽 및 일본과 같이 석면의 수입, 유통, 제조를 완전히 금지하였다. 이에 따라 현재의 석면의 문제는 기존에 시공된 석면 건축자재의 안전한 유지관리 및 친환경 해체, 그리고 폐기된 석면 건축자재의 안정적인 최종처리에 있다고 할 수 있다. 과거 우리나라는 매년 10만 톤의 석면을 사용하였으며, 이를 사용한 건축자재는 년간 100만 톤을 초과하였다. 이러한 석면 건축자재가 2006년까지 지속적으로 사용되었고, 이러한 자재는 향후 2044년까지 계속 유지될 것으로 환경부에서 예측한 바 있다. 석면 폐기물의 무해화 처리를 위한 사전 전처리 단계로 설치되어 있는 석면 건축자재에 침투성 경화제를 도포 하고, 해체 철거를 실시하면, 해체단계에서 석면의 비산을 억제하고, 무해화 단계에서 알칼리 공급 작용을 하여 무해화 처리 조건이 개선될 수 있다. 따라서 석면 건축자재에 침투성 경화제가 안정적으로 침투될 수 있어야 한다. 본 연구에서는 sodium silicate를 주성분으로 하는 침투성 경화제와 증류수의 희석 비율에 따른 침투 효과를 비교하고자 하였다. 시험결과 K성분의 침투에 따른 침투 깊이 평가가 가능할 것으로 판단되었으며, 증류수 희석 비율이 높을수록 침투효과는 커지는 것으로 나타났다. 본 연구를 통하여 중밀도 수준의 폐석면 건축자재의 무해화를 위한 사전 전처리 방법의 제시가 가능할 것으로 사료되며, 향후 화학적 무해화를 위한 사전 전처리를 효율적으로 하기 위해서는 침투성 경화제와 중류수의 혼합비율의 최적화가 가장 중요한 요소인 것으로 나타났다.

• 보존과학연구
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• 통권35호
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• pp.73-86
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• 2014

서산 용현리 마애여래삼존상(국보 제 84호)이 새겨진 암체는 층암절벽에 수직수평 방향으로 구조선이 매우 발달한 암체이다. 2007년 보호각 해체 후 상부 암체로부터 유입되는 낙수로 인하여 본존불 좌측에 생물학적 풍화가 진행되고 우측 보살상 상부에는 백화가 관찰되고 있다. 마애불상의 풍화를 저감시키고 훼손으로부터 미연에 방지하기 위한 조치로 건 습식세척으로 부재에 손상이 가지 않도록 오염물을 제거하고, 암체 상부에 L-30을 사용하여 물길을 설치하여 상부로부터 유입되는 낙수로 마애불상 표면이 오염되지 않도록 차단하였다. 또한, 마애불상 주변의 수목을 제거하고 정면부에 자생하는 잡목을 벌목하여 마애불상의 일조량을 증가시키고 통풍을 원활하게 하였다.

• 화약ㆍ발파
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• 제36권1호
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• pp.20-33
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• 2018

국부손상 구조물은 내 외부에서 발생하는 비정상 하중에 의해 구조물 일부가 구조적 기능을 상실하여 재사용이 불가능한 구조물이다. 비정상 하중의 발생 원인으로는 자연재해와 인공재해로 대별되며 이러한 비정상 하중에 의해 발생한 국부손상 구조물은 추가적인 2차 붕괴의 위험요소들을 내재하고 있어 신속한 전면해체가 요구된다. 본 시공사례는 건설실패 및 태풍으로 피해를 입은 필리핀의 철골 트러스 구조의 교량에 대해 발파해체를 적용한 사례이다. 발파해체를 위해 성형폭약의 사용이 필요하나 현지에서 수급이 불가하여 장약용기를 제작한 후 용기 속에 에멀전계열 폭약을 충전하여 발파해체에 적용하였다. 발파해체 결과 교량의 중앙부가 수직 자유낙하하고, 교량 끝단이 지지부를 중심으로 회전하면서 자유낙하 하였다. 교각 및 주변에 피해가 발생하지 않았으며, 발파 후 철거대상부의 파쇄 상태는 매우 양호하였다.

• 한국실내디자인학회논문집
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• 제13호
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• pp.181-186
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• 1997

If you compare recent works in small commercial places along with the terms such as Post-Modernism, Late-Modernism, and Dismantling, to those of 60's and 70's, you will discover for sure that recent works try to model individually with 'surface'. Expressing the responses to the multilateral cultural desires is available through the organization of surface, so are the re-presentationsof classic notions by adding decorations to the vertical walls, which are different from modern constructions that have persisted on only space itself as a main point. These trends are various organizing techniques with forms, decorations, materials, color etc. and made the surface modeling develop. What a 'surface element' means as a concrete notion in a design process in a commercial place is enormous. So, it implies lots of notions and logic, and can be a strong message-conveying means as well as an expressional language. At this point of view, the research was limited to Facade, which is treated as a creational object to a designer all the time in order to study what kind of system the surface organization has in a small commercial place. This is to find out what kind of system the designer uses to make the spatial images, orders and forms through surface, but ultimately it is to discover the designer's basic tecniques that he or she uses when planning. To sum up, we have studied the meanings of the composition and the changes of the organization of Facade to analyze the organizing techniques in Pasad in a small commercial construction which designers planned as material. We have also investigated the organizing techniques of surface by examining and analyzing the elements of Facade organizing techniques, i.e. its form, decoration, material, pattern and color.

• 건축역사연구
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• 제19권4호
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• pp.71-90
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• 2010

The names of Seokgatab and Dabotab are almost generalized among the people along with Bulguksa the most well-known temple in Korea. But, despite this generalized situation, the names of Seokgatab and Dabotab have not secured the clear standpoint till now. It is because the names of Seokgatab and Dabotab can be found only in the 18C documents like and . More complicatedly, in the record of the Goryeo sarira case found during the dismantling of Seokgatab, the name of Seokgatab was 'Mugujeonggwangtab' or 'Seoseoktab'. This paper is to secure the nominal validity of Seokgatab and Dabotab to remove the confusion due to their names and to raise the efficiency of studies related with Bulguksa in the future. First, their names and the problems related with them were summarized in Chapter 2. Based on this critical consciousness, Chapter 3 deals with the tragedy of Asadal related with the creation of the stone pagodas and its symbolic re-interpretation. In this process, we can see that there could be a viewpoint of the great comprehension in them through the completion of 'the Buddhist Nation'. Then, the architectural features of Seokgatab and Dabotab were analyzed in the ritual view point of . Finally, in Chapter 4, on the basis that the viewpoint of one specific sect can not be predominantly applied in the construction of Buddhist land, it is held that Avatamsaka Idea and Saddharma-pundarika Idea can coexist without any conflict. It is shown in the fact that Seokgatab and Dabotab can make harmony together in the Avatamsaka Idea while keeping their names. With these efforts, we can clearly see that the peculiar titles of Seokgatab and Dabotab can be said to secure sufficient validity.

• 대한토목학회논문집
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• 제31권6C호
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• pp.221-229
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• 2011

필댐의 코어죤은 차수 기능을 담당하는 댐의 중요한 요소이다. 따라서 코어죤의 물성 및 거동 특성은 댐의 안정성 해석에 있어서 아주 중요한 요소이나, 지금까지 실제 댐 코어의 물성에 대한 연구는 아주 드물었다. 댐 코어의 물성은 표면파 탐사 또는 경험식과 같은 간접적인 방법에 의해 획득되거나 추정되어 왔다. 본 연구에서는 기존 댐의 해체 과정에서 수행된 현장 및 실내시험 결과의 분석을 통하여, 댐 건설 후 코어죤 물성의 시간적 변화와 깊이별 특성에 대해 직접적으로 조사를 수행하였다. 실제 댐 코어의 전단파 속도와 전단탄성계수가 측정되었고, 기존의 경험식과 비교하였다. 아울러, 일련의 실내실험을 통하여 동적물성의 에이징 특성도 연구하였다.

• 건축역사연구
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• 제23권1호
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• pp.7-19
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• 2014

This study considers the proper repair techniques by examining the most representative repair cases of the Korean arch bridges and proposes the constructional manual which can apply similar occasions. The cases are Seonamsa Seungseongyo and Songgwangsa Geukrockgyo where this researcher had taken part in the repair works. This Study proposes the maintenance construction manual about the performance degradation drew by performance degradation of the both Korean arch bridges in the maintenance process. First, arch bridge maintenance should be carried out in the dry season, when water is impermeable in the bottom surface of the bridge. Moreover, risk factors of the maintenance should be excluded to secure the water vally flow, the bypass and the temporary bridge. Second, prior to repair, it has to precede (1)3D shooting (2)formal examination (3)structure safety test (4)geological and lithic surveys (5)arch curvature establishment and makeshift frame settlement before transformation (6)relationship expert comments. Third, if the baduk and the foundation stones are inevitable to replace due to performance degradation on the foundation, it should use the high quality stones and secure greater stress by extending the standard range. The foundation on irregular rock needs to be flattened and underside on the replaced materials require Grengyijil to deliver the equal loads. Fourth, In the process of dismantling the stones of the arched bridge, it could make heavy weathering degree and not reuse the materials. Charge should converge the expert advices to choose the reuseable, the conservate and the alternative materials, and increase the reutilization of the raw materials by preservation and reinforcement treatments. Fifth, the side wall should be repaired by the rubble work technique which is not able to pile compost satiety, so it must use long depth of masonary stones for reinforcement. It is considered to reinforce the stone wall in shore as much as possible and protect the abutment and the side wall on the upstream for the arch bridge maintenance works.