Öngerme Kablo Düzeninin Aktarma Dönemi Sonrası Kirişin Gerilme ve Kılıflama Parametremeleri Üzerindeki Etkisi
Abstract
Bu çalışmada ön döküm
öngerilmeli beton kirişlerde öngerilme kuvvetinin öngerme kablolarından betona
aktarılmasından sonra öngerme kablo düzeninin gerilme dağılımı ve kılıflama
parametreleri üzerindeki etkisinin belirlenmesi amaçlanmıştır. Öngerme
kablolarının diziliminin belirlenmesi, kablo sayısının belirlenmesi kadar
önemli olmaktadır. Çünkü bu durum gerilme dağılımını ve kılıflama
parametrelerini etkilemektedir. Kılıflama işlemi öngerilmeli kirişin mesnet
bölgelerinde meydana gelen çekme ve basınç gerilmelerini kontrol etmek için
kullanılmaktadır. Bu çalışmada 90 cm yüksekliğe sahip öngerilmeli kiriş örnek
olarak seçilmiştir. Öngerilme düzeninin etkisini belirlemek için, kesit alanı,
efektif hesap açıklığı ve malzeme özellikleri aynı öngerme kablo düzeni
birbirinden farklı dokuz adet kiriş seçilmiştir. Kirişlerin sonlu eleman modeli
SAP 2000 programı kullanılarak oluşturulmuştur. Çalışmanın sonunda sayısal olarak
elde edilen gerilme dağılımı ve hesaplanan kılıflama parametreleri birbiriyle
karşılaştırılmıştır.
References
- [1] Tan, K.H. and Ng, C.K., “Effects of deviators and strand configuration on behavior of externally prestressed beams.” ACI Structural Journal, vol. 94, pp. 13-22, 1997.
- [2] Kannel, J., French, C. and Stolarski, H., “Release methodology of strands to reduce end cracking in pretensioned concrete girders”. PCI Journal, vol. 42 (1), pp. 42-54, 1997.
- [3] Moon, J.H., Shin, K.J., Lim, J.H. and Lee, S.H., “Effects of stressed and unstressed reinforcements on prestressed concrete members with unbonded strands.” KCI Concrete Journal, vol. 12, pp. 131-138, 2000.
- [4] Kang-Su, K., Deuck-Hang, L., Sang-Sik, K., Chang-Hyuk, K. and Jung-Woo, P., “ Study on the efficiency of post-tension slab method by strand lay-out.” Journal of the Architectural Institute of Korea Structure and Construction, vol. 25(9), pp. 59-68, 2009.
- [5] Brice, R., Khaleghi, B. and Seguirant, S. J. “Design optimization for fabrication of pretensioned concrete bridge girders: An example problem.” PCI Journal, vol. 54(4), pp. 73-111, 2009.
- [6] Tadros, M.K., Baddie S.S., and Tuan C.Y., “Evaluation and repair procedures for precast/prestressed concrete girders with longitudinal cracking in the web”. National Cooperative Highway Research Program report 654. Washington, DC: Transportation Research Board, 2010.
- [7] Computers and Structures Inc., SAP 2000 Static and dynamic finite element analysis of structures, Berkeley, CA, USA, 2016
- [8] AASHTO LRFD bridge design specifications, 6th Ed., 2012.
The Effect of Strand Configuration on Stress Distribution and Debonding Parameters of Prestressed Girder After Detensioning
Abstract
The
aim of this paper is to examine the effect of strand configuration on stress
distribution and debonding parameters of precast, pretensioned concrete girders
after prestressing force is transferred from strands to concrete by bond at
their interface. Determination of strand configuration is important as well as
determination of number of strands because it affects stress distribution and
debonding parameters of girders. The debonding of strands is an application in
order to control the tensile and compressive stresses at the support zone of
girder. One of the typical precast girder with 90 cm height is considered in
this study. To determine the effect of strand configuration, nine girders with
the same cross-section, effective span length and material properties but
different strand configuration are selected as an application. Equal
prestressing force is applied all strands simultaneously. Three dimensional
finite element models (FEM) of girder are constituted using SAP 2000 software.
At the end of the study, numerically identified stress distribution and
calculated debonding parameters of girders compared with each other.
References
- [1] Tan, K.H. and Ng, C.K., “Effects of deviators and strand configuration on behavior of externally prestressed beams.” ACI Structural Journal, vol. 94, pp. 13-22, 1997.
- [2] Kannel, J., French, C. and Stolarski, H., “Release methodology of strands to reduce end cracking in pretensioned concrete girders”. PCI Journal, vol. 42 (1), pp. 42-54, 1997.
- [3] Moon, J.H., Shin, K.J., Lim, J.H. and Lee, S.H., “Effects of stressed and unstressed reinforcements on prestressed concrete members with unbonded strands.” KCI Concrete Journal, vol. 12, pp. 131-138, 2000.
- [4] Kang-Su, K., Deuck-Hang, L., Sang-Sik, K., Chang-Hyuk, K. and Jung-Woo, P., “ Study on the efficiency of post-tension slab method by strand lay-out.” Journal of the Architectural Institute of Korea Structure and Construction, vol. 25(9), pp. 59-68, 2009.
- [5] Brice, R., Khaleghi, B. and Seguirant, S. J. “Design optimization for fabrication of pretensioned concrete bridge girders: An example problem.” PCI Journal, vol. 54(4), pp. 73-111, 2009.
- [6] Tadros, M.K., Baddie S.S., and Tuan C.Y., “Evaluation and repair procedures for precast/prestressed concrete girders with longitudinal cracking in the web”. National Cooperative Highway Research Program report 654. Washington, DC: Transportation Research Board, 2010.
- [7] Computers and Structures Inc., SAP 2000 Static and dynamic finite element analysis of structures, Berkeley, CA, USA, 2016
- [8] AASHTO LRFD bridge design specifications, 6th Ed., 2012.
Details
| Primary Language | English |
|---|---|
| Subjects | Engineering |
| Journal Section | Articles |
| Authors | |
| Publication Date | April 6, 2018 |
| Published in Issue | Year 2018 Volume:6 No:2 (2018) (Special Issue: IMCOFE 2017) |