周遭建築物對屋頂風壓影響之實驗研究｜國立中央大學博碩士論文系統

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研究生：	葉鑫 Hsin Yeh
論文名稱：	周遭建築物對屋頂風壓影響之實驗研究 Influence of Adjacent Buildings on the Roof Pressures of Downwind Buildings
指導教授：	朱佳仁 Chia-Ren Chu
口試委員:
學位類別：	碩士 Master
系所名稱：	工學院 - 土木工程學系 Department of Civil Engineering
論文出版年：	2019
畢業學年度：	107
語文別：	英文
論文頁數：	107
中文關鍵詞：	風壓係數、風洞實驗、建築物間距、極值風壓、甘保機率分布
外文關鍵詞：	Wind tunnel experiment, Pressure coefficient, Building spacing, Peak pressure, Gumbel distribution
相關次數：	點閱：7 下載：0
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本研究使用風洞模型實驗探討低矮建築物前棟對後棟建築物表面風壓的影響，在不同風向角、不同間距下，量測建築外牆與屋頂的風壓分佈以計算其所受風力。實驗結果顯示：當風向角22.5o時，會因為屋頂角偶處渦流，使得屋頂發生最大的時間平均風壓係數 -1.46。本研究並使用獨立峰值法以及分段法取樣分析極值風壓的發生機率，分別計算其甘保機率函數以及通用型極值機率函數，比較結果顯示分段法計算得之極值風壓高於獨立峰值法的結果。此外，本研究建議一個尖峰因子g來推算極值風壓，計算結果與建築物耐風設計規範(2015)建議之極值風壓比較，發現建築物耐風規範低估屋頂的極值風壓，利用準穩態假設計算之極值風壓較安全。最後，再利用實驗量測之風壓計算對後棟建築物時間平均風壓和極值風壓的干擾係數，干擾係數會隨著間距增加而增加。當間距為6倍建築物高度且風向0o時，時間平均風壓的干擾係數會趨近於0.90；當風向於22.5o以及67.5o，干擾係數會趨近於1.0，亦即不再受前棟建築物的影響。

This study uses wind tunnel experiments to investigate the effect of upwind cubic building on the surface pressures of a downwind building. The surface pressures of the cubic building were measured under different wind directions and spacing between the buildings. The experimental results revealed that the maximum negative pressure occurred when the wind direction is 22.5o, due to the conical vortices at the building roof. The independent peaks method and segment method were used to determine the extreme values of surface pressures. The Gumbel distribution and the General Extreme Value (GEV) distribution were used to describe the probability of extreme pressures. The comparison results show that the peak pressures calculated by the segment method were larger than that by the independent peaks method. Based on the measured pressures, a gust pressure factor g was suggested to compute the peak pressures, and compared with the peak pressure coefficients recommended by the wind code of Taiwan (2015). This method can be used to predict the extreme wind pressure on the building walls. Furthermore, an interference factor is used to quantify the interference effect of upwind buildings to the surface pressures of downwind building. It was found that the surface pressure of the downwind building is no longer affected by the upwind building when the spacing is larger than 6 times of building height and the wind direction is 22.5o and 67.5o.

Contents
Abstract ············································································ 
Contents ············································································ II
Notation ············································································ IV
Figure Caption····································································· VI
Table Caption······································································ X
1. Introduction ···································································· 1
2. Experimental setup ···························································· 5
3. Results and discussion ························································ 9
3.1 Time-averaged Pressure ················································ 9
3.1.1 Single building ····················································· 9
3.1.2 Target building ····················································· 11
3.2 Probability of pressure fluctuation ···································· 13
3.2.1 Sampling method ·················································· 13
3.2.2 Comparison of non-exceedance probability ···················· 14
3.2.3 Comparison of different calculation method ··················· 14
3.2.4 Comparison of GEV and Gumbel distribution ················· 15
3.3 Peak Pressure ····························································· 15
3.3.1 Single building ····················································· 15
3.3.2 Target building ····················································· 16
3.4 Model to calculate peak ················································· 17
3.5 Interference factor ·······················································19
4. Conclusions ···································································· 21
References ········································································· 23
Figures ·············································································· 29
Figure captions:
Figure 1 Photograph of the cubic building models (H = 0.2 m) in wind tunnel. .................. 29
Figure 2. Schematic diagram of the experimental setup in the wind tunnel. ........................ 30
Figure 3. Vertical profiles of the approaching flow. ............................................................. 31
Figure 4. Comparison of time-averaged surface pressures along the centerlines of a single
building by different studies. ......................................................................................... 33
Figure 5. Time-averaged pressure coefficient Cp on the centerline of the single buildings
under different wind direction. ...................................................................................... 34
Figure 6. Time-averaged pressure coefficient Cp on the centerlines of building external walls
under different wind direction. ...................................................................................... 37
Figure 7. Root-mean-square pressure coefficient Cprms on the centerline of the single
buildings under different wind direction. ...................................................................... 38
Figure 8. Time-averaged wind pressure coefficient on the roof of the single building. ....... 40
Figure 9. Root-mean-square wind pressure coefficient on the roof of the single building. .. 42
Figure 10. Time-averaged pressure on the centerline of the downwind buildings under wind
direction  = 0o with different spacing between the buildings. ..................................... 43
Figure 11. Time-averaged pressure coefficients on the centerlines of building external walls
under  =0o. (a) windward façade; (b) leeward façade.................................................. 44
Figure 12 . Time-averaged wind pressure coefficient of the roof of the downwind building
under wind direction  = 0o. .......................................................................................... 47
Figure 13 . Root mean square wind pressure coefficient on the roof of the downwind
building under wind direction  = 0o.. ........................................................................... 50
Figure 14. Time-averaged pressure coefficient on the centerline of the building under wind
direction  = 22.5o. ........................................................................................................ 51
Figure 15. Time-averaged pressure coefficients on the centerlines of building external walls
under  = 22.5o. ............................................................................................................. 52
Figure 16. Time-averaged pressure coefficients on the roof of downwind buildings under 
= 22.5o. .......................................................................................................................... 55
Figure 17 . Root-mean-square wind pressure coefficient on the roof of the downwind
building under wind direction  = 22.5o. ....................................................................... 58
Figure 18. Time-averaged pressure coefficient on the centerline of the building under wind
direction  = 45o. ........................................................................................................... 59
Figure 19. Time-averaged pressure coefficients on the centerlines of building external walls
under  = 45o. ................................................................................................................ 60
Figure 20. Time-averaged pressure coefficients on the roof of the building under wind
direction  = 45o. ........................................................................................................... 63
Figure 21 . Root-mean-square wind pressure coefficient on the roof of the downwind
building under wind direction  = 45o. .......................................................................... 66
Figure 22. Time-averaged pressure coefficient on the centerline of the building under wind
direction  = 67.5. ........................................................................................................ 67
Figure 23. Time-averaged pressure coefficients on the centerlines of building external walls
under  = 67.5o. ............................................................................................................. 68
Figure 24. Time-averaged pressure coefficients on the roof of the building under wind
direction  = 67.5o. ........................................................................................................ 71
Figure 25 . Root-mean-square wind pressure coefficient on the roof of the downwind
building under wind direction  = 67.5o.. ...................................................................... 74
Figure 26. Measured pressure coefficient Cp under different wind direction. ...................... 75
Figure 27. Pressure variation at the centerline. ..................................................................... 76
Figure 28. Probability cumulative function of roof pressure at location x/H = 0.1, y/H = 0.4
under wind direction  = 45o. ........................................................................................ 77
Figure 29. Probability cumulative function of roof pressure (at location x/H = 0.1, y/H = 0.4)
under wind direction  = 45o by different sampling methods (a) in linear coordinate
without moving average; (b) in non-linear coordinate without moving average; (c) inlinear coordinate with moving average; (d) in non-linear coordinate with moving
average. .......................................................................................................................... 79
Figure30. Peak pressure coefficient under wind direction  = 45o by segment method at (a)
Windward facade; (b) Leeward facade; (c) Roof of building (x/H = 0.1). ................... 81
Figure 31. Cumulative density function of roof pressure at location x/H = 0.1, y/H = 0.4
under wind direction  = 45o by using segment method without moving average (a) in
linear coordinate; (b) in non-linear coordinate. ............................................................. 82
Figure 32. Cumulative density function of roof pressure at location x/H = 0.1, y/H = 0.4
under wind direction  = 45o by using independent peaks method without moving
average(a) in linear coordinate; (b) in non-linear coordinate. ....................................... 83
Figure 33. Time-averaged pressure coefficient Cp on the centerlines of building external
walls under different wind direction.(a) Windward façade; (b) Leeward façade; (c)
Roof ( x/H = 0.1); (d) Roof ( x/y = 1.0); (e) Roof ( y/H = 0.1). .................................... 86
Figure 34. Peak pressure coefficients on the centerlines of windward walls under wind
direction. ........................................................................................................................ 88
Figure 35. Variation of the peak pressure factor of under different wind directions. (a) peak
pressure factor of windward g78 = 4.48; (b) peak pressure factor of roof g78 = 4.95. ... 89
Figure 36. Comparison of measured and predicted peak pressure coefficients Cpeak on the
windward wall (a) Peak factor g = 4.48 with measured Cprms to predict Cpeak; (b) Gust
response factor Gp = 2.92 with measured Cp to predict Cpeak. ...................................... 90
Figure 37. Comparison of measured and predicted peak pressure coefficients Cpeak on the
windward (a) The peak pressure factor g = 4.95 and measured Cprms were used to
predict Cpeak. (b) The gust response factor Gp = 3.12 and measured Cp were used to
predict Cpeak. .................................................................................................................. 91
Figure 38. Interference factors of the time-averaged pressure at different angles (a)
Windward façade (b) Leeward façade (c) Roof. ........................................................... 93
Figure 39. Interference effect factor for peak pressure under different wind directions. (a)
Windward façade; (b) Leeward façade; (c) Roof. ......................................................... 95
Figure 40. Flow chart for the calculation of peak pressure. .................................................. 96
Table captions:
Table 1. Comparison of peak pressure coefficients by different thresholds. ......................... 25
Table 2. Roof pressure of single building at location (x/H = 0.1, y/H = 0.4) ........................ 26
Table 3. Comparison of different sampling methods to calculated peak coefficients. .......... 26
Table 4. Pressure coefficients recommended by the Wind Resistance Code of Taiwan (2015)
for low-rise buildings ................................................................................................ 27
Table 5. Comparison of measured and predicted pressures by the Wind Code. ................... 28
Table 6. Comparison of measured and predicted pressure coefficients by the Wind Code .. 28

                                

References
[1] 朱佳仁，林坦誼，楊智凱，劉明怡半圓柱形溫室風壓係數之實驗研究，農業工程學報，第62卷第3期，2016年9月，63-73頁，2016 年。
[2] 羅元隆，低矮建物屋頂表面極值風壓之特性分布探討，第六屆全國風工程研討會，2016 年。
[3] 林坦誼，半圓柱形溫室表面風壓之實驗研究，中央大學土木工程研究所碩士論文，2016 年。
[4] 曾育凡，干擾效應下的極值分布特性，私立淡江大學土木工程研究所碩士論文，2017 年。
[5] Banks, D.B., 2013. The role of corner vortices in dictating wind loads on tilted flat solar panels mounted on large flat roofs. J. Wind Eng. Ind. Aerodyn. 123, 192-201.
[6] Cook, N.J., Mayne, J.R. 1980. A Refined working approach to the assessment of wind loads for equivalent static design, J. Wind Eng. Ind. Aerodyn. 6, 125-137.
[7] Gough, H., King, M.-F., Nathan, P., Grimmond, C.S.B., Robins, A., Noakes, C.J., Luo, Z., Barlow, J.F., 2019. Influence of neighboring structures on building façade pressures: Comparison between full-scale, wind-tunnel, CFD and practitioner guidelines. J. Wind Eng. Ind. Aerodyn. 189, 22-33.
[8] Hui, Y., Tamura, Y., Yoshida, A., 2012. Mutual interference effects between two high-rise building models with different shapes on local peak pressure coefficients. J. Wind Eng. Ind. Aerodyn. 104-106, 98-108.
[9] Kasperski, M., 1996. Design wind loads for low-rise buildings: A critical review of wind load specifications for industrial buildings. J. Wind Eng. Ind. Aerodyn. 61, 169-179.
[10] Kim, W., Tamura, Y., Yoshida, A., 2011. Interference effects on local peak pressures between two buildings. J. Wind Eng. Ind. Aerodyn. 99, 584-600.
[11] Lo, Y.L., Tseng, Y.F., 2017. Interference effects on tail characteristics of extreme pressure value distributions. J. Wind Eng. Ind. Aerodyn. 170, 28-45.
[12] Pearce, W., Sykes, D.M., 1999. Wind tunnel measurements of cavity pressure dynamics in a low-rise flexible roofed building. J. Wind Eng. Ind. Aerodyn. 82, 27-48.
[13] Peterka, J.A., 1983. Selection of local peak pressure coefficients for wind tunnel studies of buildings. J. Wind Eng. Ind. Aerodyn. 13, 477-488.
[14] Pearce, W., Sykes, D.M., 1999. Wind tunnel measurements of cavity pressure dynamics in a low-rise flexible roofed building. J. Wind Eng. Ind. Aerodyn. 82, 27-48.
[15] Richards, P.J., Hoxey, R.P., 2012. Pressures on a cubic building—Part 1: Full-scale results. J. Wind Eng. Ind. Aerodyn. 102, 72–86.
[16] Richards, P.J., Hoxey, R.P., 2012. Pressures on a cubic building—Part 2: Quasi-steady and other processes. J. Wind Eng. Ind. Aerodyn. 102, 87-96.
[17] Richards, P., Norris, S., 2015. LES modelling of unsteady flow around the Silsoe cube. J. Wind Eng. Ind. Aerodyn. 144, 70-78.
[18] Richards, P.J., Hoxey, R.P., Connell, B.D., Lander, D.P., 2007. Wind-tunnel modelling of the Silsoe cube. J. Wind Eng. Ind. Aerodyn. 95, 1384-1399.
[19] Richards, P.J., Hoxey, R.P., 1996. The folly of using extreme-value methods in full-scale experiments. J. Wind Eng. Ind. Aerodyn. 60, 109-122.
[20] Richards, P.J., Hoxey, R.P., 2004. Quasi-steady theory and point pressures on a cubic building. J. Wind Eng. Ind. Aerodyn. 92, 1173-1190.
[21] Suaris, W., Irwin P., 2010. Effect of roof-edge parapets on mitigating extreme roof suctions. J. Wind Eng. Ind. Aerodyn. 98, 483-491.
[22] Tamura, Y., Kikuchi, H., Hibi, K., 2001. Extreme wind pressure distributions on low-rise building models. J. Wind Eng. Ind. Aerodyn. 89, 1635-1646.
[23] Whalen, T., Simiu, E., Harris, G., Lin, J., Surry, D., 1998. The use of aerodynamic databases for the effective estimation of wind effects in main wind-force resisting systems: application to low buildings. J. Wind Eng. Ind. Aerodyn. 77&78, 685-693.

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