Documentation

This document contains all National annex values, which are used in SDF - Basic package

Clause 4.2 Basic values, paragraph (1)P

Fundamental values of the basic wind velocity, vb,0, shall be determined according construction site place.
Mainland in the entire country vb,0 = 21 m/s
Sea areas: open sea, scattered islands out in the open sea vb,0 = 22 m/s
In Lappland: at the top of mountains vb,0 = 26 m/s
In Lappland: at the bottom of mountains vb,0 = 21 m/s

Clause 4.2 Basic values, paragraph (2)P, NOTE 1

No special calculation of altitude effects.

Clause 4.2 Basic values, paragraph (2)P, NOTE 2

Recommended value of the directional factor cdir = 1,0 for all wind directions.

Clause 4.2 Season factor cseason, paragraph (2)P, NOTE 3

Recommended value of the directional factor is cseason = 1,0

Clause 4.3.1 Variation with height, paragraph (1), NOTE 1

The recommended procedure given in Annex A.3 should be used.

Clause 4.3.1 Variation with height, paragraph (1), NOTE 2

Additional charts or tables are not stated.

Clause 4.3.2 Terrain roughness, paragraph (1)

The recommended procedure for determination of the roughness factor shall be used.
For the terrain category 0, however, the terrain factor is taken as kr = 0,18 instead of the value arising from Eq. (4.5).

Clause 4.3.3 Orography,, paragraph (1)

The recommended procedure given in Annex A.3 should be used.
Apart from situations stated in A.3, the orography coefficient is co = 1,0
The effect of thermal inversion surface should be used for buildings with height h > 100 m, but it is not supported by SDF calculation now

Clause 4.3.5 Closely spaced buildings and obstacles, paragraph (1)

The recommended procedure from A.5 can be used.

Clause 4.4 Wind turbulence, paragraph (1), NOTE 2

The recommended value of the turbulence factor is ki = 1,0

Clause 4.5 Peak velocity pressure, paragraph (1), NOTE 1

The recommended rule for determination of qp shall be used.

Clause 4.5 Peak velocity pressure, paragraph (1), NOTE 2

The recommended value of air density is ρ = 1,25 kg/m3 is used for most structures.
For the special slenderness structures liek transmission lines, the air density is calcualted according next formula from the temperature and altitude.
ρ = 353/T•e^(-0,00012•A)

Clause 6.1 General, paragraph (1)

The construction coefficient cscd is usually not separated.

Clause 6.3.1 Structural factor cscd, paragraph (1), NOTE 3

The Procedure 1 stated in Annex B shall be used.

Clause 7.2.1 General, paragraph (1), NOTE 2

The recommended procedure given in Standard shall be used.

Clause 7.2.2 Vertical walls of rectangular plan buildings, paragraph (2), NOTE 2

The recommended procedure given in Standard shall be used.

Clause 7.2.3 Flat roofs, paragraph (4)

The recommended values given in Standard should be used.

Clause 7.2.4 Monopitch roofs, paragraph (3)

The recommended values given in Standard should be used.

Clause 7.2.5 Duopitch roofs, paragraph (3)

The recommended values given in Standard should be used.

Clause 7.2.6 Hipped roofs, paragraph (3)

The recommended values given in Standard should be used.

Clause 7.2.8 Vaulted roofs and domes, paragraph (1)

The recommended procedure given in Standard shall be used.

Clause 7.3 Canopy roofs, paragraph (6)

The recommended distance given in Standard shall be used.

Clause 7.4.1 Pressure coefficients for free-standing walls and parapets, paragraph (1)

The recommended values given in Standard should be used.

Clause 7.4.3 The value of the horizontal eccentricity, paragraph (2)

The recommended value of the horizontal eccentricity e given in Standard should be used.