• Advances in concrete construction
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• 제3권1호
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• pp.1-14
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• 2015

China accounts for nearly half of the global steel production. As a waste material or a by-product in the manufacture process, a large amount of blast furnace slag is generated every year. The majority of recycled blast furnace slag is used as an additive in low-grade blended cement in China (equivalent to the UK CEM II or CEM III depending on the slag content). The cost of using ground granulated blast furnace slag (GGBS) in such low-grade applications may not be entirely reimbursed based on market research. This paper reports an on-going project at Xi'an Jiaotong-Liverpool University (XJTLU) which investigates the feasibility of using GGBS in long-span concrete structures by avoiding/reducing the use of crack control reinforcement. Based on a case study investigation, with up to 50% of CEM I cement replaced with GGBS, a beneficiary effect of reduced thermal contraction is achieved in long-span concrete slabs with no significant detrimental effect on early-age strengths. It is believed that this finding may be transferable from China to other Asian countries with similar climates and economic/environmental concerns.

• Steel and Composite Structures
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• 제19권6호
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• pp.1483-1499
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• 2015

With the improvement of the quality of construction materials and the development of construction technologies, large-scale long-span steel frame buildings have been built recently. The P.E.B system using tapered members is being employed as an economically-efficient long-span structure owing to its advantage of being able to distribute stress appropriately depending on the size of sectional areas of members. However, in December 2005 and in February 2014, P.E.B buildings collapsed due to sudden loads such as snow loads and wind gusts. In this study, the design and construction of the P.E.B system in Korea were analyzed and its structural safety was evaluated using the finite element analysis program to suggest how to improve the P.E.B system in order to promote the efficient and rational application of the system.

• 한국공간구조학회논문집
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• 제10권4호
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• pp.67-74
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• 2010

대공간 구조형식을 갖는 단층 래티스 돔은 역학성, 가능성, 심미성 등을 갖는 구조물로서 그 용도가 점점 확대되고 있다. 단층 래티스 돔의 골조 격자 패턴은 무수히 존재하며, 그 대표적인 패턴에는 삼각형, 사각형, 육각형, 라멜라형, 리브형 등이 있다. 대공간 구조물의 경우, 일반구조물과 달리 재래적인 공법으로 지붕 골조를 시공할 경우 많은 가설재가 소요됨으로 시공비 증가가 예상된다. 따라서 대공간 구조물의 지붕 골조 설치는 특수 Erection 공법에 의하는 것이 일반적이며, 그 중 지상에서 지붕골조를 설치 후 jack-up 서포트에 의해 골조를 인양하는 Step-Up 공법을 적용할 경우 공기와 공비의 대폭적인 절감이 예상된다. 따라서 본 논문의 목적은 Step-Up 공법에 의해 단층라멜라 돔의 지붕골조를 시공할 경우, 인양 중 가설 서포트 개수와 위치에 따른 좌굴특성을 검토하는 것이다. 연구 결과 서포트 개수 및 위치에 따른 단층라멜라 돔의 다양한 좌굴 특성에 관한 실무자를 위한 기초적인 자료를 얻을 수 있었다.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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• pp.75-82
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• 2004

Many researcher's efforts have made a significant advancement of space frame structure with various portion, and it becomes the most outsanding one of space structures. However, with the characteristics of thin and long term of spacing, the unstable behavior of space structure is shown by initial imperfection, erection procedure or joint, especially space frame structure represents more. This kind of unstable problem could not be set up clearly and there is a huge difference between theory and experiment. Moreover, the discrete structure such as space frame has more complex solution, this it is not easy to derive the formulation of design about space structure. In this space frame structure, the character of rise-span ratio or load mode is represented by the instability of space frame structure with initial imperfection, and snap-through or bifurcation might be the main phenomenon. Therefore, in this study, space frame structure which has a lot of aesthetic effect and profitable for large space covering single layer is dealt. And because that the unstable behavior due to variation of inner force resistance in the elastic range is very important collapse mechanism, I would like to investigate unstable character as a nonlinear behavior with a geometric nonlinear. In order to study the instability. I derive tangent stiffness matrix using finite element method and with displacement incremental method perform nonlinear analysis of unit space structure, star dome and 3-ring star dome considering rise-span $ratio(\mu}$ and load $ratio(R_L)$ for analyzing unstable phenomenon.

• 한국공간구조학회논문집
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• 제4권1호
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• pp.49-59
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• 2004

이전 논문에서 미 중부 및 동남부 지역의 전형적인 다경간 단순효와 다경간 강거더 연속교의 지진 응답을 연구하였으며, 이런 교량에서 덱 사이의 충돌과 큰 연성이 요구되는 기둥은 취약하여 손상을 입을 수 있다는 것을 보여주었다. 더구나, 고정 및 가동 교조장치는 강한 지진운동에 쉽게 피해를 입을 수 있다. 이 논문에서는 몇 개의 개선된 고무 베어링, 납-고무 베어링 그리고 제지선을 사용하여 전형적인 다경간 단순교와 다경간 강거더 연속교의 지진 응답을 평가하였다. 납-고무 베어링은 지진에 취약한 전형적인 교량의 응답을 개선하는데 효과적인 방법으로 평가되었다. 고무 베어링은 기둥의 요구량을 줄이지만, 다경간 단순교 강거더 교량에서 덱 사이의 강한 충돌을 유발시킨다. 제지선은 일반적으로 사용되지만 다경간 단순교와 다경간 연속교의 지진에 대한 손상을 절감하는데 중간정도의 효과를 보여주었다.

• 한국강구조학회 논문집
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• 제22권4호
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• pp.345-354
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• 2010

기존의 빔과 거더로 이루어진 장스팬 구조물의 경우 기둥 사이의 거리가 길기 때문에 부재의 크기와 수직 처짐이 증가하게 된다. 효과적인 장스팬 구조물의 실현을 위하여 구조물 하부에 스트럿과 케이블로 구성된 언더텐션시스템을 적용하였다. 이는 거더의 휨모멘트를 효과적으로 분산시키기 때문에 부재의 크기를 줄이고 경제적인 효과를 기대할 수 있다. 또한 급속시공을 위한 폐단면 신형상의 모듈화 PF500단면을 사용하여 성능을 검증하고자 하였다. 언더텐션 시스템의 성능검증을 위하여 가로 10m, 세로 2.4m의 실험체 두개를 대상으로 가력실험을 실시하였고 언더텐션 시스템 유무와 케이블 장력변화에 따른 거동을 확인하였다. 실험으로부터 케이블 장력이 증가함에 따라 실험체의 거동이 작아졌으며 언더텐션 시스템이 하중분배 역할을 수행하는 것으로 나타났고 PF500단면의 성능이 우수함을 나타내었다.

• 한국공간구조학회논문집
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• 제18권1호
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• pp.67-75
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• 2018

Steel roof construction is on the most important and critical factors in the large spatial construction and necessary to be prepared under a radical planning. Therefore, the major management factors of steel roofing structure assembly must be critically reviewed during planning. Through the review process, it is necessary to reduce the construction cost, to prevent delays in the construction schedule, and to minimize construction errors. However, domestically due to the lack experience in large spatial constructions, a planning of roof construction is limited to have a radical planning. Especially due to unclear organization of the management factors in hierarchy, using them in reality for construction planning is difficult and reliability is low. Therefore, in this study, the goal is to conduct the major management factors in the large spatial construction. To achieve this, we have reviewed and analyzed the numbers of construction plans and construction reports and conducted a total 68 of the management factors. Based on the conducted factors, we have interviewed 16 experts with experience in large spatial construction. From the interview result, we have deduced the factors scored above 4.20 of 10 for critical factors. The results of this study will be used as a guidance for planning steel roofing structure assembly in large spatial construction. The critical factors will be provided to the site mangers for the quality management of large spatial constructions in practice.

• 한국공간구조학회논문집
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• 제12권4호
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• pp.109-118
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• 2012

The large-space single-layer lattice dome is relatively simpler in terms of the arrangement of the various framework members and of the design of the junction than the multi-layered lattice dome, can reduce the numbers and quantity of the framework members, and has the merit of exposing the beauty of the framework as it stands. The single-layer lattice dome, however, requires a stability investigation of the whole structure itself, along with an analysis of the stress of the framework members, because an unstable phenomenon called "buckling" occurs when its weight reaches critical levels. Many researchers have systematically conducted researches on the stability evaluation of the single-layer lattice dome. No construction case of a single-layer lattice dome with a 300-m-long span, however, has yet been reported anywhere in the world. The large-space dome structure is difficult to erect due to the gigantic span and higher ceiling compared with other common buildings, and its construction cost is generally huge. The method of erecting a structure causes major differences in the construction cost and period. Therefore, many researchers have been conducting various researches on the method of erecting such structure. The step-up method developed by these authors can reduce the construction cost and period to a great extent compared with the other general methods, but the application of this method inevitably requires the development of system supports in the center section as well as pre-existing supports in the boundary sections. In this research, the safety during the construction of a single-layer lattice dome with 300-m-long span using pre-existing materials was examined in the aspect of structural strength, and the basic data required for manufacturing the supports in the application of the step-up method developed by these authors during the erection of the roof structure were obtained.

• 한국공간구조학회논문집
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• 제6권1호
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• pp.83-90
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• 2006

Gust Factor법은 구조물의 등가정적 풍하중을 평가하는 일반적인 방법으로 구조물의 최대 응답시의 풍하중의 분포가 평균풍하중의 분포와 동일한 형상을 가진다는 가정하에 적용한다. 그러나 대스팬 구조물의 경우 평균 풍하중의 형상과 변동 풍하중의 형상이 다를 수 있어 1차모드뿐 아니라 고차모드의 영향을 고려하여 구조물의 풍응답과 풍하중을 산정하여야 한다. 본 논문에서는 등가정적 풍하중을 산정하기 위하여 현재 사용되고 있는 Gust Factor 법 (GF법), Load-response-correlation법 (LRC법)에 대해 고찰하고, Advanced Conditional Sampling 법 (ACS법)을 제안하였다. ACS법은 최대하중효과를 나타내는 순간에 선택된 풍압분포와 구조물의 동적거동에 의해 발생한 관성력을 합성하여 등가정적풍하중을 산정하는 방법이다. 최대하중 효과는 풍동실험에서 얻어진 풍압데이터를 이용하여 시간이력해석으로 평가한다. 제안된 ACS법과 기존의 GF법 및 LRC법을 지붕 구조물에 적용하여 등가정적 풍하중을 산출하고 이를 상호 비교 분석함으로써 ACS법의 유효성을 검증하고자 한다.

• Structural Engineering and Mechanics
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• 제33권2호
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• pp.239-255
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• 2009

In the companion paper, a simple but effective analysis procedure termed an Improved Modal Pushover Analysis (IMPA) is proposed to estimate the seismic capacities of multi-span continuous bridge structures on the basis of the modal pushover analysis, which considers all the dynamic modes of a structure. In contrast to previous studies, the IMPA maintains the simplicity of the capacity-demand curve method and gives a better estimation of the maximum dynamic response in a bridge structure. Nevertheless, to verify its applicability, additional parametric studies for multi-span continuous bridges with large differences in the length of adjacent piers are required. This paper, accordingly, concentrates on a parametric study to review the efficiency and limitation in the application of IMPA to bridge structures through a correlation study between various analytical models including the equivalent single-degree-of-freedom method (ESDOF) and modal pushover analysis (MPA) that are usually used in the seismic design of bridge structures. Based on the obtained numerical results, this paper offers practical guidance and/or limitations when using IMPA to predict the seismic response of a bridge effectively.