半圓頂型屋蓋結構表面平均風壓係數設計值之探討

Design Values of Mean Pressure Coefficients for Domed Roofs

羅元隆(Yuan-Lung Lo) ； 孫濤(Tao Sun) ； 李家豪(Chia-Hao Lee) ； 鄭啟明(Chii-Ming Cheng)

《結構工程》 30卷1期 (2015/03) Pp. 93-111

https://doi.org/10.6849/SE.201503_30(1).0005

摘要

大跨徑屋蓋結構為現今社會常見的結構型態之一，具有大空間且多功能的特性。依照我國建築物耐風設計規範中定義，此類結構物高寬比多偏小，應可歸類為低矮建物。然而由於跨度大且材質輕的特性，屋蓋表面受風壓分佈影響甚鉅，一般不建議以簡易計算方式給定設計風力載重，而另行於規範中表列其表面風壓係數設計值提供給工程師參考。本研究進行以探討各國規範於大跨徑屋蓋結構中，半圓頂型屋蓋結構表面平均風壓係數的設計值為主，輔以風洞實驗結果，進而探討目前國內規範應對於此類結構型態之表面風壓係數設計值作何修正或建議，並提出本研究於未來規範修訂之建議方案。由初步的風洞實驗結果與各國規範設計值之比較可看出，除了表面風壓特性應具有分區概念（Zoning concept）以外，屋蓋結構的高跨比（f/D）與底座高跨比（h/D）對於分區之影響亦應列入規範修訂考量。

關鍵字

半圓頂型屋蓋結構 ； 表面風壓係數 ； 高跨比 ； 分區

並列摘要

Large span roof structures are one of the most welcomed structural types for its spatial feature and multi-functional performance. Most of them are categorized as low-rise buildings; however, its light-weight and long span characteristics make wind pressures dominate the subsequent structural response and make the wind load evaluation a difficult task. The simplified methodology of design wind loads may not be adoptable. In this research, systematic wind tunnel tests and several codes were compared and discussed on the domed roof structures, which is one category of large span roof structures. It was demonstrated that the design values in several codes may cause over conservative or unfavorable unsafe design in certain local area of the roof surface. Based on wind tunnel data, this research proposed a suggestive flowchart to evaluate the mean wind pressure coefficients in terms of span height ratio (f/D) and wall height ratio (h/D).

並列關鍵字

Domed roof ； External pressure coefficient ； Height-span ratio ； Zoning