• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
• /
• pp.142-147
• /
• 1993

In the reinforced concrete structure, as the height of building structure increases, the accurate estimation of differential column shortening is important factor in the structural design. In this study, the analysis of column shortening is applied to 36-story building structure to be built in time. As a result, it may found that, as the difference of compressive stress become larger, differential shortening effect due to creep and shrinkage are more signicant factor to structural designer.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2003년도 학술.기술논문발표회
• /
• pp.143-146
• /
• 2003

Tall Buildings have been popular in recent years. Tall buildings require special consideration to design and construction due to their structural features. Column shortening is one of the important technologies to be considered in. The long-term deformations of concrete cause vertical shortening on cores and columns, trigger deformations on cladding, partitions and finishes, and damage their serviceability. This also affects structural stability by inducing unexpected stress to the structural members such as outrigger. The main objective of this paper is to re-evaluate column shortening according to revised field information and to compare the analysis results with the actual field measurement. Mok-Dong Hyperion, a 69-story apartment building which is currently under construction, was chosen for the case study.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
• /
• pp.67-70
• /
• 2011

The effect of column shortening is a major consideration in design and construction of tall buildings, especially in concrete and composite structural systems. To avoid unexpected demage in structural and nonstructural elements, differential shortening between vertical members resulting from differing stress levels, loading histories, volume-to-surface ratios and other factors in a high-rise building must be properly considered in the design process. This paper represents analyzed and measured shortening results of RC cores and columns at the 72 story Haeundae I'Park. It shows that WACS program based on ACI and PCA material model is effective for the prediction of column shortening.

• 국제초고층학회논문집
• /
• 제6권1호
• /
• pp.91-99
• /
• 2017

Special consideration should be given to differential column shortening during the design and construction of a tall building to mitigate the adverse effects caused by such shortening. The effects of the outrigger - which is conventionally used to increase the lateral stiffness of a tall building - on the differential shortening are investigated in this study. Three analysis models, a constant-section, constant-stress, and general model, are prepared, and the differential shortenings of these models with and without the outrigger are compared. The effects of connection time, sectional area, and location of the outrigger on the differential shortening are studied. The sectional area of the outrigger shows a non-linear relation in reducing the maximum differential shortening. The optimum locations of the single and dual outriggers are investigated by an exhaustive search method, and it is confirmed that a global optimum location exists. This study shows that the outrigger can be utilized to reduce the differential shortening between the interior core wall and the perimeter columns as well as to reduce the lateral displacements due to wind or earthquake loads.

• 국제초고층학회논문집
• /
• 제6권1호
• /
• pp.73-82
• /
• 2017

Vertical shortening in tall buildings would be of little concern if all vertical elements shortened evenly. However, vertical elements such as walls and columns may shorten different amounts due to different service axial stress levels. With height, the differential shortening may become significant and impact the strength design and serviceability of the building. Sometimes column transfers or other vertical structural irregularities may cause differential shortening. If differential shortening is not addressed properly, it can impact the serviceability of the building. This paper takes the perspective of a structural engineer in planning the design, predicting the shortening and its effects, and communicating the information to the contractor.

• 한국전산구조공학회논문집
• /
• 제35권2호
• /
• pp.119-129
• /
• 2022

초고층 건물에서 수평변위 제어와 수직부재에서 발생하는 부등축소에 대한 검토가 필수적이다. 이러한 부등축소는 비구조요소의 사용성과 구조요소의 안전성에 대해 문제를 야기할 수 있다. 따라서 이 연구에서는 120층 규모의 철근콘크리트 주거용 초고층 건물에 대해 시공단계해석을 수행하여 각 수직부재의 부등축소량을 비교하고 콘크리트의 장기거동의 영향을 분석하였다. 이를 위해 영향요인에 따라 축소량을 탄성축소량, 크리프축소량, 건조수축축소량으로 구분하여 검토하였으며 최대 절대축소량에 대한 지배적 요인을 분석하였다. 또한, 입주완료 후 30년에서 발생한 부등축소량에 대해 사용성 검토를 진행하였으며, 구조요소에 대해 설계단계와 시공단계의 부재력을 비교하여 분석하였다.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.490-495
• /
• 2006

The analysis method proposed by PCA is widely used in calculating the column shortening of reinforced and composite columns of a tall building. However, residual creep factor which relates creep strain of reinforced concrete to creep strain of plain concrete is based on Rate of Creep Method (RCM) which has theoretical defects and is considered obsolete. In this paper, a new equation for the residual creep factor based on Age-adjusted Effective Modulus Method (AEMM) which is considered exact and better than RCM is proposed. The residual creep factor by RCM is found to be higher than one by AEMM, which means current PCA method overestimates the shortening of a reinforced concrete column. By using the residual creep factor by AEMM, more exact column shortening of a tall building can be obtainable with a simple modification to PCA method.

• Advances in concrete construction
• /
• 제5권2호
• /
• pp.155-171
• /
• 2017

The phenomenon of concrete column shortening has been widely acknowledged since it first became apparent in the 1960s. Axial column shortening is due to the combined effect of elastic and inelastic deformations, shrinkage and creep. This study aims to investigate the effects of ambient temperature, relative humidity, cement hardening speed and aggregate type on concrete column shortening. The investigation was conducted using a column shortening prediction model which is underpinned by the Eurocode 2. Critical analysis and evaluation of the results showed that the concrete aggregate types used in the concrete have significant impact on column shortening. Generally, aggregates with higher moduli of elasticity hold the best results in terms of shortening. Cement type used is another significant factor, as using slow hardening cement gives better results compared to rapid hardening cement. This study also showed that environmental factors, namely, ambient temperature and relative humidity have less impact on column shortening.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
• /
• pp.173-174
• /
• 2009

본 연구는 최근 초고층 건축물의 등장으로 인하여 기존의 토목 구조물에서만 사용되었던 축소량에 대하여 검토가 시작되었다. 이러한 수직부재에 대한 축소량의 검토는 기본적으로 콘크리트가 받는 하중, 재료특성 등으로 발생되는 변형을 기본으로 하고 있다. 하지만 이러한 콘크리트가 받는 작용 인자나 특성을 가지고 계수 산정을 통한 축소량 해석을 하고 있지만, 각각의 재료시험적인 측면에서의 분석을 다소 미미하게 되고 있다. 따라서 본 연구에서는 수직부재 즉 기둥축소량 보정을 위한 기본적인 재료시험항목에 대하여 각각을 분석하여 축소량 보정을 위한 계수산정전 재료시험의 신뢰성을 파악하고 이에 대한 성능적인 검토를 하고자 하는데 목적이 있다.

• 대한물리치료과학회지
• /
• 제18권1호
• /
• pp.51-60
• /
• 2011

Purpose: The purpose of this study was to investigate hamstring length during static uprighting position using weight distribution ratio. Methods: Ninety-six volunteers(56 males) were participated. The active knee extension test(AKE) was measured 3 times on both legs. The mean score of AKE was obtained. Then, the measurement of weight distribution ratio was observed 3 times on both legs, and its mean value was also calculated. Subjects were divided four groups based on their hamstring length measurement; both hamstring shortening group, left hamstring shortening group, right hamstring shortening group and normal hamstring length group. One-way ANOVA was employed to analyse collected data. Pearson's correlation was also hired to see any relationship between the hamstring length and the weight distribution. Results: In anterior/left area and posterior/right area, both hamstring shortening group left hamstring shortening group were superior to right hamstring shortening group and normal hamstring length group. Significant difference was existed statistically(p<.05) between groups. The correlation analysis between hamstring length and weight distribution ratio has not been shown any significant findings(Pant/post=0.733, Plt/rt=0.135). Conclusion: The results of the study may be applied to therapeutic management in posture and movement skill in musculoskeletal physical therapy.