日本风荷载规范英文版正文

CHAPTER 6 WIND LOADS

6.1 General

6.1.1 Scope of application

(1) This chapter describes wind loads for the design of buildings that respond elastically in strong

winds.

(2) Two different wind loads are described. The first is for the design of structural frames, and the

second is for the design of components/cladding of buildings.

6.1.2 Estimation principle

(1) Wind loads for the design of buildings are individually specified for horizontal wind load for

structural frames, roof wind load for structural frames and wind load for components/cladding. The horizontal wind loads for the design of structural frames shall be individually determined in the along-wind, across-wind and torsional directions.

(2) For wind load for structural frames, combination of each horizontal wind load and combination of

horizontal wind load and roof wind load shall be considered according to A6.8. For components of cladding and structural frame or particular joints of cladding and structural frames, combination of horizontal wind load on structural frames and local wind load on cladding shall be considered. (3) The wind loads shall generally be determined from the design wind speed defined for each wind

direction given in A6.1.2.

(4) The reference height is generally the mean roof height of the building. The wind loads are

calculated from the velocity pressure at this reference height. However, wind loads on lattice type structures shall be calculated from the velocity pressure at each height, as shown in A6.6.

(5) The horizontal wind load on structural frames and the roof wind load on structural frames are given

by the product of the velocity pressure given in A6.1, the wind force coefficient given in A6.2, the gust effect factor given in A6.3 and the projected area or subject area as shown in 6.2 and 6.3. (6) The wind load on components/cladding is given by the product of the velocity pressure given in

A6.1, the peak wind force coefficient given in A6.2 and the subject area.

(7) For relatively flexible buildings with large aspect ratios, the horizontal wind loads on structural

frames in the across-wind and torsional directions given in A6.4 and A6.5 shall be considered. The criteria for this are described in 6.1.3(1).

(8) For flexible buildings with very large aspect ratios, the structural safety against vortex-induced

vibration and aeroelastic instability shall be checked. The criteria for this are described in 6.1.3(2).

The wind loads on structural frames and members of round sectional shape caused by vortex induced vibration shall be determined by A6.7.

(9) For small buildings and structures with large stiffness, a simplified procedure can be used, as given