Lisø PhD Dissertation Manuscript - NTNU

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Frequency 25 20 15 10 5 0 highest proportion of the annual precipitation total. We have estimated the total annual rainfall values to be 550, 2050, 650 and 700 mm, respectively, for Oslo, Bergen, Trondheim and Tromsø. Multiplying directional rainfall values by the respective average wind speeds during rainfall events for each ARTICLE IN PRESS Bergen Moderate/heavy All types 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Fig. 3. Relative frequencyof observations coded as moderate or heavyand observations coded as some form of rain vs. wind direction for the period 1974–2003 at Bergen. mm/yr (a) mm/yr (b) mm/yr (c) mm/yr (d) 50 40 30 20 10 0 500 250 0 90 60 30 0 150 100 50 0 J.P. Rydock et al. / Building and Environment 40 (2005) 1450–1458 1455 Oslo 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Bergen 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Trondheim 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Tromsø 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Fig. 4. Driving rain (in mm/yr) vs. wind direction for the period 1974–2003 for (a) Bergen, (b) Trondheim, (c) Oslo and (d) Tromsø. wind direction yielded a measure of the directional driving rain amount at each station. This methodology is almost identical to that used byLacyin his pioneering articles on driving rain in the 1960s [6,7]. He used the product of total annual precipitation and average wind speed (not average wind speed during rainfall, which
1456 was unavailable at that time) to create a scalar-value driving rain index, and present weather observations to develop driving rain roses showing relative directional dependence at different stations. Lacy, however, stopped short of combining the two into a single index that could be used to quantitativelycompare directional dependence at different locations. Multiplying directional rainfall by wind speed yields a driving rain index that is expressed in units that are not intuitive (Lacyused m 2 /s, for example). Lacyfound, in a studyof 75 rainfall events over a 16-year period, that 1m 2 /s corresponded to 0.206 m (or 206 mm) driving rain on a vertical surface [7]. We have adopted this conversion factor in the presentation of our driving rain data below. Directional driving rain totals for the four stations are shown in Figs. 4a–d. As the directional dependence of the mean wind speed is relativelysmall, and the mean wind speeds at the four stations considered here are roughlycomparable, the distributions shown in Fig. 4 are qualitativelyquite similar to those shown in Fig. 2. Next, we used the data in Figs. 4a–d to calculate a driving rain wall index (I y) for anydirection y (which represents the angle between north and a line normal to mm/yr (a) mm/yr (b) mm/yr (c) mm/yr (d) 300 200 100 0 2000 1500 1000 500 0 600 400 200 0 600 400 200 0 ARTICLE IN PRESS J.P. Rydock et al. / Building and Environment 40 (2005) 1450–1458 the wall): I y ¼ 0:206 X vDrD cosðD yÞ; (1) D where I y is expressed in mm/yr, 0.206 is the conversion factor (in s/m) from Lacy [6], discussed above, nD is the average annual wind speed (in m/s) from direction D, rD is the average annual rainfall (in mm) with wind from direction D, D is the wind direction (angle from north). The summation is taken over all angles D representing a wind blowing against the wall (This includes the sector from y 801 to y+801.) Note: We do not applythe 8/9 exponent to the rD term in Eq. (1), commonlydone when calculating driving rain intensities from hourly rain and wind data [3,4], because an exponential dependence has not been shown to be valid for rain data expressed as average annual values. The results from the four stations are shown in Figs. 5a–d. 4. Comparison with earlier work As Hoppestad’s work [2] is still the onlynationwide driving rain compilation available in Norway, it is Oslo 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Bergen 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Trondheim 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Tromsø 10 40 70 100 130 160 190 220 250 280 310 340 Degrees from north Fig. 5. Driving rain wall index (I y (mm/yr)) vs. wind direction for the period 1974–2003 for (a) Bergen, (b) Trondheim, (c) Oslo and (d) Tromsø.
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Building envelope performance asses
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Lisø, K.R./ Building envelope perf
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BUILDING RESEARCH &INFORMATION (200
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LisÖ et al. on how to cope with an
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LisÖ et al. the exposure to contin
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LisÖ et al. business premises. The
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LisÖ et al. construction industry
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Research in Building Physics, Carme
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4 CLIMATE CHANGE SCENARIOS FOR NORW
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with large amounts of precipitation
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will most likely be worse, even wit
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Graves, H.M. & Phillipson, M.C. 200
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766 Nordvik and Lisø The topic of
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768 Nordvik and Lisø into the futu
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770 Nordvik and Lisø climate chang
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772 Nordvik and Lisø 0 Â Â = p d
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774 Nordvik and Lisø probably to a
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BUILDING RESEARCH &INFORMATION (200
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cost of repairing process-induced b
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change in quality (Mehus et al., 20
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on the impacts of different climati
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different strategies: risk-based, p
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Learning from experience - an analy
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An important aspect of the programm
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Concrete walls 32 % LECA masonry 10
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construction industry, and academic
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BUILDING RESEARCH &INFORMATION (JAN
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greater variations (Lisø et al., 2
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Typical problem areas and recommend
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Figure 3b Recommended design of win
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Figure 7 Example showing the recomm
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Figure 11a Poor solution for a £as
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Acknowledgements This paper was wri
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Climate adapted design of masonry s
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2. Masonry defects in Norway 2.1. S
Page 111 and 112: Fig. 2. Example illustrations of th
Page 113 and 114: The presented results are in good a
Page 115 and 116: appropriate in a more severe type o
Page 117 and 118: screen in a two-stage weatherproofi
Page 119 and 120: INCREASED SNOW LOADS AND WIND ACTIO
Page 121 and 122: The hurricane (Beaufort number 12)
Page 123 and 124: The extensive revisions of the code
Page 125 and 126: The number of buildings investigate
Page 127 and 128: As is apparent from the values in t
Page 129 and 130: climate change is now dominated by
Page 131: TABLE 3. Summary of findings Struct
Page 134 and 135: Lisø, K.R./ Building envelope perf
Page 136 and 137: temperature of -4°C or less. See F
Page 138 and 139: Today, frost resistance of brick, c
Page 140 and 141: degree of saturation, freezing will
Page 142 and 143: accelerated frost damage or frost d
Page 144 and 145: A possible objection to the present
Page 146 and 147: [17] Dührkop H., Saretok V., Sneck
Page 149 and 150: Decay potential in wood structures
Page 151 and 152: Wood decaying fungi will only be ac
Page 153 and 154: to promote decay prevails. Two of t
Page 155: Acknowledgements This paper has bee
Page 158 and 159: (a driving rain gauge), however, is
Page 160 and 161: Fig. 1. Map of Norwayshowing the lo
Page 164 and 165: interesting to compare those result
Page 167 and 168: Effects of wind exposure on roof sn
Page 169 and 170: In ISO 4355 ”Bases for design of
Page 171 and 172: variety of roofs and wind exposures
Page 173 and 174: Li and Pomeroy [13] evaluated hourl
Page 175 and 176: Fig. 5. Exposure coefficients for 3
Page 177 and 178: meteorological stations are expecte
Page 179 and 180: Many of the meteorological stations
Page 181 and 182: the ground with return period of 30
Page 183: References [1] Standards Norway. De
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