The Determination of External Pressure Coeffcients on The Silo Surface According to Different Standards

Year 2017, Volume: 7 Issue: 2, 107 - 114, 30.06.2017

Hakan Kibar

Abstract

In this study, wind external pressure coeffcient (C
p
) values were investigated according to different
height/diameter (h/dc) and different wind arrival angles (θw) to the silo surface in a steel cylindrical silo with 14
m height and 6 m diameter. Eurocode (EN), Australian standard (AS) and British standard (BS) were used for the
external pressure coeffcients in the study. In the study, coeffcient values were obtained calculating according to
EN and AS standards and compared with the table values given for the BS standard. Depending on the EN and AS
standards, positive C
p
coeffcients were obtained at different h/dc ratios up to a 20° wind arrival angle to the silo
surface. Negative C
p
coeffcients were determined at higher values of the 20° wind arrival angle to the silo surface.
Statistically signifcant differences (P<0.05) were found among the EN, AS and BS standards. As a result, design
must be made considering the C
p
coeffcients which can vary depending on the wind speed and the topographic
conditions of the area in the calculation of the wind load which is one of the important environmental load groups
in the silo design.

Keywords

Australian standard, external pressure coeffcient, Eurocode, British standard, silo

Farklı Standartlara Göre Silo Yüzeyindeki Dış Basınç Katsayılarının Belirlenmesi

Abstract

Bu çalışmada 14 m yüksekliğinde ve 6 m çapa sahip çelik silindirik bir siloda farklı yükseklik/çap
(h/dc) ve silo yüzeyine farklı rüzgar geliş açılarına (θw) göre rüzgar dış basınç katsayı (Cp) değerleri araştırılmıştır.
Araştırmada dış basınç katsayıları için Eurocode (EN), Avustralya standardı (AS) ve İngiliz standardı (BS)
kullanılmıştır. Araştırmada EN ve AS standartlarına göre hesaplamalar yapılarak katsayı değerleri elde edilmiş
olup BS standardı için verilen çizelge değerleri ile karşılaştırmalar yapılmıştır. EN ve AS standartlarına bağlı olarak
farklı h/d
c oranlarında silo yüzeyine 20°’ lik rüzgar geliş açısına kadar pozitif Cp katsayıları elde edilmiştir. Silo
yüzeyine 20°’ lik rüzgar geliş açısından sonraki açı değerlerinde ise negatif C
p
katsayıları belirlenmiştir. İstatistik
analiz sonucunda EN, AS ve BS standartları arasında istatiksel olarak P<0.05 düzeyinde önemli farklılıklar tespit
edilmiştir. Sonuç olarak silo tasarımında önemli bir çevresel yük grubundan olan rüzgar yükünün hesaplanmasında
rüzgar hızı, ve yörenin topoğrafk koşullarına bağlı olarak değişim gösterebilen C
p
katsayılarının dikkate alınarak
tasarım yapılması gerekmektedir

Keywords

Avustralya standardı, dış basınç katsayısı, Eurocode, İngiliz standardı, silo

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