• Title/Summary/Keyword: axial shortening

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A study on the finish work of Reinforced Con'c slab for improving workability in the column shortening compensation. (기둥축소량 보정법에 있어서 시공성 향상을 위한 RC 슬래브 표면마무리에 관한 연구)

  • 소광호;이재옥;양극영
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.147-152
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    • 2003
  • Passage of time axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural element. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening for reinforced concrete structure are introduced. It could be concluded that the survey is a significant factor for the compensation instance of column shortening.

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Evaluation of the influence of creep and shrinkage determinants on column shortening in mid-rise buildings

  • B-Jahromi, Ali;Rotimi, Abdulazeez;Tovi, Shivan;Goodchild, Charles;Rizzuto, Joseph
    • Advances in concrete construction
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    • v.5 no.2
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    • pp.155-171
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    • 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.

A Study on The Compensation Method of Vertical Members for High-rise building (초고층 건축물의 수직부재 보정 방법에 관한 연구)

  • Lee, Jea-Ok;Sho, Kwang-Ho;Yoo, In-Keun;Yang, Keek-Young
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.11a
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    • pp.33-36
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    • 2003
  • Time-dependent axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural clement. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening are introduced. It could be conclued that the survey is a significant factor for the compensation of column shortening.

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A Study on The Compensation Method of Vertical Members for High-rise building (초고층 건축물의 수직부재 보정 방법에 관한 연구)

  • 이재옥;소광호;유인근;양극영
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.33-36
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    • 2003
  • Time-dependent axial shortening in the cores and columns of tall concrete buildings requires special attention to ensure proper behavior for strength of the structure and the nonstructural element. The effects of column shortening, both elastic and inelastic, take on added significance and need special consideration in design and construction with increased height of structures. In this paper, the compensation method of column shortening are introduced. It could be concluded that the survey is a significant factor for the compensation of column shortening.

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Calculation and Measurement of Column Shortening High-Rise RC Structure (초고층 RC구조의 기둥축소량 해석 및 현장계측)

  • 이성원;박현일;김원식;오정근
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.133-138
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    • 2003
  • Axial shortenings of wall and columns were measured on level 2 and precise leveling between wall and columns were surveyed on level 5 at the Galleria Palace structure. Measured and surveyed shortening values were compared with the analysis results at the earlier stage on the process of construction for evaluating the predicted values. Though measured values represent relatively low and scattered values at earlier construction stage, probably they show similar slope curves to predicted ones with the progress of time.

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Scarf Osteotomy for the Treatment of Recurred Hallux Valgus (재발한 무지 외반증의 치료로 시행한 Scarf 절골술)

  • Nam, Il Hyun;Ahn, Gil Yeong;Moon, Gi Hyuk;Lee, Yeong Hyeon;Choi, Seong Pil;Jeong, Taeg Young
    • Journal of Korean Foot and Ankle Society
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    • v.17 no.4
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    • pp.272-276
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    • 2013
  • Purpose: Recurrence is one of the most common complications after primary correction for hallux valgus deformities. The purpose of this study was to evaluate the usefulness of Scarf osteotomy with axial decompression in the treatment of recurrent hallux valgus. Materials and Methods: From April 2006 to April 2011, 14 cases (12 patients) of recurrent hallux valgus were managed with shortening Scarf osteotomy. Preoperative and postoperative radiographs were reviewed for the measurement of the hallux valgus angle (HVA), intermetatarsal angle (IMA), and the amount of the $1^{st}$ metatarsal shortening. Clinical outcomes including the visual analogue scale (VAS), the AOFAS score, and the range of motion [ROM] of the 1st metatarsophalangeal (MTP) joint were evaluated. Results: The mean HVA decreased from 27.9 degrees to 5.2 and the mean IMA decreased from 12.9 to 3.4. The mean VAS improved from 5.3 to 0.3 and the mean AOFAS score improved from 41 to 90. The mean amount of the 1st metatarsal shortening was 3.4 mm (2-5). The mean ROM of the $1^{st}$ MTP joint improved from 22 degrees (15-35) to 68 (55-75). Conclusion: Scarf osteotomy associated with axial decompression can be a useful revision procedure for the treatment of recurrent hallux valgus deformity.

An Evaluation for Vertical Structural Members Compensated during Design Process and These Compensated during Construction of High-rise Building under Seismic Load (설계 및 시공과정에 보정된 고층건물 구조재의 지진하중에 의한 영향 평가)

  • 정은호
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.1
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    • pp.93-102
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    • 1999
  • Increased height of buildings causes severe shortening of vertical structural members due to the accumulated axial load. It not only decreases the serviceability of a structure but also affects significantly the stability of a structure itself due to the secondary stress. The main purpose of estimating the shortening of vertical structural members is to compensate the differential shortening of adjacent members. This paper presents the comparison of stresses between the vertical structural members compensated during construction process and these compensated during design process under the seismic load and represents that the precise compensation of vertical structural members is important.

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Prediction of Time-dependent Lateral Movement Induced by Differential Shortening in Tall Buildings Using Construction Stage Analysis

  • Ha, Taehun;Kim, Sangdae;Lee, Sungho
    • International Journal of High-Rise Buildings
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    • v.6 no.1
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    • pp.11-19
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    • 2017
  • High-rise buildings move during construction due to time-dependent material properties of concrete (creep and shrinkage), construction sequences, and structural shapes. The building movements, including vertical and horizontal displacements, result from the sum of axial and lateral deformation of vertical members at each level. In addition to the vertical shortenings, the lateral movement induced by differential shortening can have adverse effects on the construction tolerance and serviceability of non-structural elements such as elevators and curtain walls. In this study a construction stage analysis method is developed to predict lateral movement induced by shortening, including the effect of creep and shrinkage. The algorithm of construction stage analysis is combined with the FE analysis program. It is then applied to predict lateral movement of a 58-story reinforced concrete building that was constructed in Kuala Lumpur, Malaysia. Gravity induced lateral movement of this building is predicted by the construction stage analysis. A field three-dimensional laser scanning survey is carried out to verify the prediction results, and satisfactory agreement is obtained.