20. Structural Planning Process
20.2 Loading Imposed on the Building II
3. Wind Load
Wind analysis : the method of analysis and the basic wind data.
Stated by the wind study, the wind pressure is large towards the corner which faces the gap between the K.K. Leung Building and the Phase IV Building.
Basic wind load data are given as followings :
At the front facade facing the Bonham Road, the point considered as the adjacent to the wind work face of the building ( The entrance level of the gallery ). It is considered to be the ground level for counting the wind pressure at the beginning. From this point to the 10 m height of the building, the design wind pressure is 1.2 kPa. From 10 m to the 30 m height of the building, the value is 2.2 kPa and finally, from the height of 50 m to the top of the building, the design wind pressuer is 3.0 kPa.
For the rear facade with R.C. decking, the entrance level for this platform is considered as the ground level for calculating th edesaign wind load. Again, from this level to the height 10m of the building, the design wind pressure value is value is 1.2 kPa. ( 10 m - 30 m, the value is 2.2 kPa ) ( 30 m - 50 m, the value is 2.5 kPa ) ( 50 m - the top of the building, the value is 3.0 kPa. )
Since the ground level for calculating the design wind load of the two sides of the building is different, the teo sides are exerted by different wind pressure for the same floor level.
As for anothere two sides of the building ( near the Swire Hall Building and near th e Fung Ping Shan Museum ), since they rested on different slopes of the site, the ground level for calculating the wind pressure should be considered individually. Take the average level of the slpoe as the ground level instead.
The method of wind load analysis is by computer program and they are in charge by the Building Department. The wind load data is referred from the Code of Practice On Wind Affects ( HK ) - 1983. ( Table 1 appendix )
As there is a curtain wall at the fire escape staircases, wind load is the major factor for structural design of framing element used at the corner.
Cross-beam at the roof is exposed to support the tie-beam and acted ass a bracing for the column-and-beam structure to resist the torsion force created by wind load and settlement.
Core wall for the lift and lift lobby and column-and-beam rigid frame with the diaphragm wall are important structural elements to resist the wind load.
