Safety factors according to EN 1997

Comments (1)

Description:

Check steel section for N+My+Mz

Annotation:

Table B.3 - Coefficients C_m equivalent of constant moment

Check bending with LTB

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 6/27/2016

Last updated: 8/29/2016

Description:

Check of bending with lateral torsional buckling

Annotation:

Image NB 3.1. - Values description and symbol convention during loading by F_z

Image NB 3.2. - Symetric cross sections - symetric to center or to the stiff axis

Table NB 3.1. - Coefficient values C₁ and C₃ when member is loaded by end moments dependent on coefficients k_z and coefficients y_f and k_wt

remark 1)

remark 2) 0,7L = fixed left end, 0,7R = fixed right end

Table NB 3.2. - Coefficient values C_1,C₂ and C₃ for different cases of perpendicular loading, dependend on coefficients k_y, k_z, k_w and coefficients y_f and k_wt

remark 1)

remark 2) Parameter ψ_f is for the center of the length

remark 3) Values of critical moment M_cr is for the section with M_max

Check of member buckling

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 6/27/2016

Last updated: 8/29/2016

Description:

Check member buckling

Annotation:

Table 6.1. - Coefficients of imperfections on buckling curvatures

Curvature of buckling strength	a0	a	b	c	d
Coefficients of imperfection a	0,13	0,21	0,34	0,49	0,76

Image 6.4 - Curvature of buckling strength

χ - Buckling coefficient

λ - Slenderness ratio

Table 6.2 - Assignment of curvatures of buckling strengths to cross sections

Check of circle rivet

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 7/7/2016

Last updated: 8/29/2016

Description:

Check of circle rivet

Annotation:

Table 3.9 - Geometric requirements on members which ends by rivet connections

A - the thickness t is defined

B - the geometry is defined

Image 3.11 - Rivet geometry

Check of high strength bolts

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 7/7/2016

Last updated: 8/29/2016

Description:

Check high strength bolts

Annotation:

Table 3.6 - Values of "ks"

Description	ks
Bolts in general openings	1,00
Bolts in bigger openings or short longer openings where axis of an opening is perpendicular on the load	0,85
Bolts in long longer openings where axis of an openings is perpendicular to load	0,70
Bolts in short longer openings where axis of an opening is parallel on the load	0,76
Bolts in long longer openings where axis of an openings is parallel to load	0,63

Table 3.7 - Coefficient of friction m for pre-stressed bolts

Surface friction class (see related codes 1.2.7; group 7)	m
Blasted surface without rust; or blasted surface with aluminium of zinc coat	0,50
Blasted surface with alkalic-zinc-silicate coat - thickness 50-80 mm	0,40
Surface cleaned by brush or flame	0,30
Without modifications	0,20

Check of shear

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 7/7/2016

Last updated: 8/29/2016

Description:

Check of shear

Annotation:

Check of shear

Check of shear and bending

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 7/7/2016

Last updated: 8/29/2016

Description:

Check of shear and bending moment

Annotation:

Check of shear and bending

Check of simple bending

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 7/7/2016

Last updated: 8/29/2016

Description:

Check of simple bending

Annotation:

Check of simple bending

Check of simple compression

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 7/7/2016

Last updated: 8/29/2016

Description:

Check steel section in simple compression

Annotation:

Check of simple compression

Check of simple tension

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 7/7/2016

Last updated: 8/29/2016

Description:

Check of simple tension

Annotation:

Check of simple tension

Check welds

EuroCode - EN 1993-1-1 -

Author: Design Forms s.r.o.

Created: 10/10/2016

Last updated: 11/15/2016

Description:

Check welds

Annotation:

Check welds

▶ EuroCode - EN 1992-1-1

Calculation of the anchor length

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 7/20/2016

Last updated: 9/27/2016

Description:

Calculation of the anchoring length of the reinforcement

Annotation:

Image 8.1 - Other ways of anchors then straight anchors

a) basic tensile anchor length lb, measured on center line for all shapes

b) equivalent anchor length for standard bend

c) equivalent anchor length for standard hook

d) equivalent anchor length for standard loop

e) equivalent anchor length for bar welded perpendicullar

8.4.2 Limit stress in cohesion

(1)P The ultimate bond stress shall be such that there is an adequate safety margin against bond failure.

(2) The design value of the ultimate bond stress, fbd, for ribbed bars may be taken as:

fbd = 2,25 * η1 * η2 * fctd

where fctd is design value of concrete tensile strength according to 3.1.6(2)P. Due to the increasing brittleness of higher strength concrete, fctk,0,05 should be limited here to the value for C55, unless it can be verified that the average bond strength increases above this limit

η1 coefficient related to the quality of the bond condition and the position of the bar during concreting

   (see Figure 8.2):

   η1 = 1,0 when ‘good’ conditions are obtained and

   η1 = 0,7 for all other cases and for bars in structural elements built with slip-forms, unless it can be shown that ‘good’ bond conditions exist

η2 is related to the bar diameter: η2 = 1,0 for φ ≤ 32 mm η2 = (132 - φ)/100 for φ > 32 mm

Image 8.2 - Description of cohesion conditions

[A] - concreting direction

a) and b) ‘good’ conditions of cohesion for all bars

c) and d) not-hatched area - ‘good’ conditions of cohesion; hatched area - ‘bad’ conditions of cohesion

Table 8.2 - Coefficient values fora₁, a₂, a₃, a₄, a₅

Influencing factor	Type of anchorage	reinf. bar in tension	reinf. bar in compression
Shape of bars	Straight Other than straight (see Figure 8.1 (b),(c) and (d))	α1 = 1,0 α1 = 0,7 if cd>3*ϕ otherwise α1 = 1,0(see Fig. 8.4 for values of cd)	α1 = 1,0 α1 = 1,0
Concrete cover	Straight Other than straight (see Figure 8.1 (b),(c) and (d))	α2 = 1 – 0,15 (cd – φ)/φ; ≥ 0,7; ≤ 1,0 α2 = 1 – 0,15 (cd – 3φ)/φ; ≥ 0,7; ≤ 1,0; (see Fig. 8.4 for values of cd)	α2 = 1,0 α2 = 1,0
Confinement by transverse reinforcement not welded to main reinforcement	All types	α3 = 1 – K*λ; ≥ 0,7; ≤ 1,0	α3 = 1,0
Confinement by welded transverse reinforcement*	All types, position and size as specified in Figure 8.1 (e)	α4 = 0,7	α4 = 0,7
Confinement by transverse pressure	All types	α5 = 1 – 0,04p; ≥ 0,7; ≤ 1,0	-

where: λ = (ΣAst - ΣAst,min)/ As

ΣAst cross-sectional area of the transverse reinforcement along the design anchorage length lbd

ΣAst,min cross-sectional area of the minimum transverse reinforcement = 0,25 As for beams and 0 for slabs

As area of a single anchored bar with maximum bar diameter K values shown in Figure 8.3

p transverse pressure [MPa] at ultimate limit state along lbd

* See also 8.6: For direct supports lbd may be taken less than lb,min provided that there is at least one transverse wire welded within the support. This should be at least 15 mm from the face of the support.

Concrete cover

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 7/20/2016

Last updated: 8/29/2016

Description:

Calculation of cover of the reinforcement

Annotation:

Value Dc_dev, which should be used is in the national annex. The recommended value is 10 mm.

Value Dc_dur,st, kwhich should be used is in the national annex. The recommended value without any other specification is 0 mm.

Value Dc_dur,g, which should be used is in the national annex. The recommended value is 0 mm.

Value Dc_dur,add, which should be used is in the national annex. The recommended value without any other specification is 0 mm.

Table 4.1 – Enviroment effect degree according to EN 206-1

Table 4.3 – Recommended modification of the construction classification

Table 4.4 – Min concrete cover c_min,dur required due to durability of reinforcement according to EN 10080

Table 4.5N – Min concrete coverc_min,dur required due to durability of reinforcement

Check shear reinforcement

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 7/25/2016

Last updated: 8/29/2016

Description:

Check of shear reinforcement

Annotation:

NP 45: Values C_Rd,c, vmin and k1, which are used in state may be found in national annex.

Recommended value for C_Rd,c is 0,18 / g_c, for v_min is defined by formuls(6.3N) and for k₁ is 0,15.

NP 47: Limit values cot q, which are used in state may be found in national annex. Recommended limitations are defined by formula 1 < cotq q < 2,5.

Coefficient a_I(equation 6.4):

a_I = l_x/l_pt2 < 1,0 for the prestressed reinforcement

a_I = 1,0 for other kinds of prestressing;

Check longitudinal reinforcement

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 7/25/2016

Last updated: 8/29/2016

Description:

Check of longitudinal reinforcement

Annotation:

Design compression and tension strength

(1)P Design concrete compression strength is defined by formula (3.15)

where γ_cis partial factor of conctrete, see 2.4.2.4;

αcc coefficient taking account of long term effects on the compressive strength

remark - α_cc is defined by national annex, it maybe 0,8 - 1,0, recommended value is 1 (NP12)

(2)P Design concrete tension strenght is defined by formula (3.16)

where γ_c is partial factor of conctrete, see 2.4.2.4;

α_ct coefficient taking account of long term effects on the tensile strength

remark - value α_ct is defined by national annex, recommended value is 1 (NP13)

Interaction diagram

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 8/26/2016

Last updated: 8/29/2016

Comments (1)

Description:

Interaction diagram of concrete section (N-My)

Annotation:

Interaction diagram

Check reinforcement ratio of concrete cross section

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 8/29/2016

Last updated: 8/29/2016

Description:

Check reinforcement ratio of concrete cross section

Annotation:

Check reinforcement ratio of concrete cross section

Check response

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 10/19/2016

Last updated: 10/19/2016

Description:

Check response of concrete cross section

Annotation:

Calculates and draws stress-strain response of the concrete cross section.

Calculation of crack width

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 10/20/2016

Last updated: 10/20/2016

Description:

Calculation of crack width

Annotation:

Stress in the reinforcement s_s1 may be defined by calculation from bending moment M_Ed

or it can be set manually (when M_Ed = 0).

And _p‘ is area beforehand of afterwards stressed reinforcement in area A_c,eff

A_c,eff effective area of tension concrete surrounded by reinforcement of prestressed reinforcement in height h_c,ef (see image 7.1)

h_c,ef is smaller from:

2,5(h - d)

(h - x)/3

Image 7.1 - Effective tension area (typical cases)

a) beam

b) plate

c) member in tension

[A] - center of gravity of reinforcement

[B] - effective tension area, Ac,eff

[C] - effective tension area near top suface, Acb,eff

x is ration of strength of prestressed reinforcement and reinforcement according to the table 6.2 in 6.8.2:

k₁ is coefficient of coherent parameters of reinforcement:

= 0,8 bars with big cohesion;

= 1,6 bars with smooth surface (e.g. presstresing bars);

k₂ is coefficient of ratio of deformation :

= 0,5 for bending;

= 1,0 for simple tension.

In cases of eccentric tension or local areas - the values k₂should be used, it is calculated by this formula:

k₂ = (e₁ + e₂)/2e₁

where e₁ is bigger ande₂ is smaller tension deformation ratio on edges of cross section, which is weakened by crack.

Values k3 and k4, which are used may be found in the nationa annex. The recommended values in Czech Republic (see NA 2.74):

k3 = 3,400

k4 = 0,425.

Table 7.1N - Recommended values w_max (mm)

Image 7.2 - The crack on the concrete surface dependent on the distance from the bar

[A] - neutral axis

[B] - surface of tensioned concrete

[C] - expected crack width according to (7.14)

[D] - expected crack width according to (7.11)

[E] - real crack width

Internal forces on the cracking limit

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 11/2/2016

Last updated: 11/2/2016

Description:

Calculation of combination on the cracking limit

Annotation:

Template calculates combination of internal forces which causes limit tensional stress in the concrete.

Template takes input combination of internal forces { N, My, Mz } and iterates coefficient "R" to obtain new combination {N, R*My, R*Mz} which causes limit tensional stress in the concrete.

It means that normal force is not changed, it remains. Bending moments are modified to obtain limit stress.

Check long and shear reinforcement

EuroCode - EN 1992-1-1 -

Author: Design Forms s.r.o.

Created: 11/9/2016

Last updated: 11/9/2016

Description:

Check long and shear reinforcement

Annotation:

Check longitudinal and shear reinforcement on general cross section.

▶ EuroCode - EN 1995-1-1

Check buckling

EuroCode - EN 1995-1-1 -

Author: Design Forms s.r.o.

Created: 8/19/2016

Last updated: 8/29/2016

Description:

Check timber member buckling

Annotation:

Value of coefficients b_cshould be according this (paragraph 6.3.2):

Material	b_c
Solid timber	0,20
Glued timber and LVL	0,10

Value of coefficients k_mshould be considered according to (paragraph 6.1.6):

Material	Cross section	k_m
Solid timber, glued timber, LVL	rectangle cross sections	0,70
Solid timber, glued timber, LVL	other cross sections	1,00
other conxtruction members based on timber	all cross sections	1,00

Table 6.1 - Effective length as distance ratio

Check combination N+My+Mz

EuroCode - EN 1995-1-1 -

Author: Design Forms s.r.o.

Created: 8/19/2016

Last updated: 8/29/2016

Description:

Check timber member on combination N+My+Mz

Annotation:

Value of coefficients b_cshould be according this (paragraph 6.3.2):

Material	b_c
Solid timber	0,20
Glued timber and LVL	0,10

Value of coefficients k_mshould be considered according to (paragraph 6.1.6):

Material	Cross section	k_m
Solid timber, glued timber, LVL	rectangle cross sections	0,70
Solid timber, glued timber, LVL	other cross sections	1,00
other conxtruction members based on timber	all cross sections	1,00

Table 6.1 - Effective length as distance ratio

Check tension

EuroCode - EN 1995-1-1 -

Author: Design Forms s.r.o.

Created: 8/19/2016

Last updated: 8/29/2016

Description:

Check timber member on tension

Annotation:

A_net - net area of cross section (without bolt holes, slots, etc.)

Value coefficients b_cshould be considered according to(paragraph 6.3.2):

Material	b_c
Solid timber	0,20
Glued timber and LVL	0,10

Connection timber-steel

EuroCode - EN 1995-1-1 -

Author: Design Forms s.r.o.

Created: 8/19/2016

Last updated: 11/7/2016

Comments (2)

Description:

Check of connection timber-steel

Annotation:

Image 8.3 - Kind of breaches for connection steel - timber

Image 8.4 - Definition t1, t2

a) on shear plane; b) two shear planes

Image 8.5 - Covering nails

Image 8.7 - Distances from ends and edges

a) distances paraller with grain in the line and paraller to grain between lines; b) distances from ends and edges

(1) - loaded end

(2) - un-loaded end

(3) - loaded edge

(4) - un-loaded edge

1 - connection

2 - fibers direction

▶ Invariant - Statics

Statics of simple beam

Invariant - Statics -

Author: Design Forms s.r.o.

Created: 8/20/2016

Last updated: 8/29/2016

Comments (2)

Description:

Bending moment and shear force on simple beam

Annotation:

Bending moment and shear force on simple beam

Statics of console

Invariant - Statics -

Author: Design Forms s.r.o.

Created: 8/29/2016

Last updated: 8/29/2016

Description:

Statics of console

Annotation:

Statics of console

General cross section parameter

Invariant - Statics -

Author: Design Forms s.r.o.

Created: 9/19/2016

Last updated: 9/19/2016

Description:

Calculate parameters of general cross section

Annotation:

Calculate parameters of general cross section

▶ EuroCode - EN 1996-1-1

Check of masonry in compression

EuroCode - EN 1996-1-1 -

Author: Design Forms s.r.o.

Created: 8/23/2016

Last updated: 8/29/2016

Description:

Check of masonry in compression

Annotation:

Check of masonry in compression

Check of masonry in concentric compression

EuroCode - EN 1996-1-1 -

Author: Design Forms s.r.o.

Created: 8/23/2016

Last updated: 8/29/2016

Description:

Check of masonry in concentrated compression

Annotation:

Check of masonry in concentrated compression

Check of masonry loaded by lateral force

EuroCode - EN 1996-1-1 -

Author: Design Forms s.r.o.

Created: 8/24/2016

Last updated: 8/29/2016

Description:

Check of masonry loaded by lateral force

Annotation:

Check of masonry loaded by lateral force

▶ EuroCode - EN 1997-1-1

Geostatic stress

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 9/19/2016

Last updated: 9/19/2016

Description:

Calculation of geotechnic stress

Annotation:

Calculation of geotechnic stress

Bearing capacity of bored piles according ULS

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 9/22/2016

Last updated: 9/22/2016

Description:

Bearing capacity of bored piles according to Masopust theory (ČSN 73 1002)

Annotation:

Bearing capacity of bored piles according to Masopust theory (ČSN 73 1002)

Bearing capacity of group of piles

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 9/22/2016

Last updated: 9/22/2016

Description:

Bearing capacity of pile group according to the Masopust theory (ČSN 73 1002)

Annotation:

Bearing capacity of pile group according to the Masopust theory (ČSN 73 1002)

Bearing capacity of single micropile

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 9/26/2016

Last updated: 7/31/2017

Description:

Bearing capacity of single micropile

Annotation:

Bearing capacity of single micropile

Check bearing capacity of pad foundation

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 11/7/2016

Last updated: 11/9/2016

Description:

Check bearing capacity of pad foundation

Annotation:

Check bearing capacity of pad foundation.

Checks:

Check drained bearing capacity

Check drained sliding resistance

Check undrained bearing capacity

Check undrained sliding resistance

Check stability of gravity wall

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 12/5/2016

Last updated: 12/5/2016

Description:

Check stability of gravity wall

Annotation:

Calculation of earth pressure coefficients and earth pressures

Horizontal earth pressure coefficients are calculated according to EN 1997-1 Annex C 2. By using this method, it is possible to calculate coefficients of horizontal active and passive earth pressure for variable soil conditions, terrain inclination, construction inclination and soil strength parameters.
- Partial coefficient of horizontal earth pressure for vertical loading on the surface:

(1)

Partial coefficient of horizontal earth pressure for cohesion

(2)

Partial coefficient of horizontal earth pressure for soil weight

(3)

In the formulas (1) - (3), b is the angle from the horizontal to the soil surface (positive when the soil surface rises away from the wall),Q is the angle between the vertical and the wall direction (positive when the soil overhangs the wall), f is the angle of internal friction and KN is the coefficient of the normal earth pressure acting on the wall from a unit pressure normal to the surface. Further detail can be found in EN 1997-1 Annex C 2.

The inclusion of the mobilisation of earth pressure in front of the wall is optional. Height of the soil in front of the wall hp is an input parameter. User has 2 possible alternatives:
- No earth pressure in front of the wall is taken into account,
- 1/2 passive earth pressure + 1/2 earth pressure at rest

Check wall stability

Degree of utilization in the case of toppling is calculated according to the formula (5), where MED,dst and MED,stb are destabilizing and stabilizing moment around the construction toe.

(5)

Safety factors according to EN 1997

It is possible to use 9 different partial factors:
- gG- partial factor of safety for the unfavorable permanent load (Action),
- gG,fav- partial factor of safety for the favorable permanent load (Action),
- gload - partial factor of safety for the surface load - for higher versatility treated as separate factor (Action),
- gRh- partial factor of safety for sliding resistance (Resistance),
- gRv- partial factor of safety for bearing resistance (Resistance),
- gangle- partial factor of safety for the angle of internal friction (Material),
- gcohesion- partial factor of safety for the cohesion (Material),
- gweight,soil- partial factor of safety for the soil unit weight (Material),
- gweight,wall- partial factor of safety for the wall unit weight (Material).

Appropriate combination of partial factors can be chosen for required design approach.

Earth pressure in front of the wall is taken as favorable action.

Bearing capacity of strand anchors

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 12/13/2016

Last updated: 12/13/2016

Description:

Bearing capacity of strand anchors

Annotation:

Anchor parameters

Type of strand		15,5/1620	15,5/1800	15,7/1770
Nominal diameter [mm]		15,5	15,5	15,7
Nominal Cross-section [mm²]		141,5	141,5	150,0
Forces and stresses
at limit strength	F_m [kN]	229,2	255	265,5
at limit strength	f_p [MPa]	1620	1800	1770
at limit 0,2	F_p0,2 [kN]	194,8	217	235,5
at limit 0,2	f_p0,2 [MPa]	1377	1532	1570
at limit 0,1	F_p0,1 [kN]	-	178	-
at limit 0,1	f_p0,1 [MPa]	-	1620	-
Ductility [%]		3,0	3,5	3,5
Elastic modulus [GPa]		200 ± 10 %	200 ± 10 %	195
Nominal weight [kg]		1,12	1,12	1,15
Nominal bearing capacity [kN]		120	140	142

Bearing capacity of bar anchors

EuroCode - EN 1997-1-1 -

Author: Design Forms s.r.o.

Created: 12/15/2016

Last updated: 12/15/2016

Description:

Bearing capacity of bar anchors

Annotation:

Anchor parameters

Anchor parameters are obtained from manufacturer's table

Anchor parameter	Anchor CPS	Anchor Dywidag
	Anchor CPS	Steel 835/1030			Steel 1080/1230
	Ø32	Ø26,5	Ø32	Ø36	Ø26,5	Ø32	Ø36
Nominal diameter [mm]	32	26,5	32	36	26,5	32	36
Screw pitch [mm]	17	13	16	18	13	16	18
Cross-section area [mm²]	777	551	804	1018	551	804	1018
Weight [kg/m]	6,78	4,48	6,53	8,27	4,48	6,53	8,27
Ultimate strength [kN]	776	568	828	1049	678	989	1252
Stress at ultimate strength [MPa]	1000	1030			1230
Limit anchor force [kN]	415	284	414	524	339	495	626

▶ EuroCode - EN 1991

Wind load

EuroCode - EN 1991 - Wind

Author: Design Forms s.r.o.

Created: 1/10/2017

Last updated: 2/22/2017

Description:

Basic wind speed and pressure

Annotation:

Dialogue

National annex selector

Combobox "National Annex" is used for selecting proper annex for calculation of the wind load.

Wind load requires selection the national annex, because in Standard EN is many national decisions possible.

For explanation of the National annex parameters related to wind load select national annex from the list below.

BS National Annex

ČSN National Annex

DIN National Annex

ELOT National Annex

IS National Annex

LU National Annex

NBN National Annex

NEN National Annex

NF National Annex

ÖNORM National Annex

PN National Annex

SFS National Annex

SIST National Annex

SR National Annex

STN National Annex

General properties

General properties are similar to all wind load forms.

Checkbox "Print headline" represent official name for calculation. User can change it by uncheck "Print headline" and check "Print user defined headline" and write his own headline into appropriate string line.

Wind parameters

This group of parameters depend on selected national annex.

BS National Annex

Wind azimuth in degrees is used in calculation of directional factor c_dir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

Fundamental value of the basic wind velocity from the map v_b,map in metres per second. Map can be found in National annex page, Figure NA.1

Turbulence intensity from the diagram I_v(z)map. Diagram can be found in National annex page, Figure NA.5

Turbulence intensity factor from the diagram k_I,T. Diagram can be found in National annex page, Figure NA.6

CSN National Annex

Wind region is from I to V according map of the wind regions. Map can be found in National annex page.

DIN National Annex

Wind region is from WZ1 to WZ4 according map of the wind regions. Map can be found in National annex page.

ELOT National Annex

No special wind parameters are necessary for ELOT National annex.

IS National Annex

LU National Annex

No special wind parameters are necessary for LU National annex.

NBN National Annex

Wind region is from 1 to 4 according map of the wind regions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor c_dir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

NEN National Annex

Wind region is from I to III according map of the wind regions. Map can be found in National annex page.

NF National Annex

Wind region is from 1 to 4 according map of the wind regions. Map can be found in National annex page.

Direction zone is from 1 to 3 according map of the wind directions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor c_dir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

ONORM National Annex

According selected state in Austria can be selected the municipality which is the nearest to the construction site. Table of all possible municipalities can be found in National annex page.

PN National Annex

Wind region is from 1 to 3 according map of the wind regions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor c_dir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

SFS National Annex

Wind regions in SFS are defined as:

a) Mainland in the entire country

b) Sea areas: open sea, scattered islands out in the open sea

c) In Lappland: at the top of mountains

d) In Lappland: at the bottom of mountains

SIST National Annex

Wind region is from 1 to 3 according map of the wind regions. Map can be found in National annex page.

SR National Annex

Fundamental value of the basic wind velocity from the map in metres per second. Map can be found in National annex page.

STN National Annex

Wind region is from I to II according map of the wind regions. Map can be found in National annex page. For higher altitude, two more regions are available.

Terrain parameters

Standard values exist. Different parameters can be defined in National annex.

Standard values

Terrain category is standardly from 0 to IV. Different terrain categories can be defined in National annex page.

Checkbox "Calculate orographic factor" allows calculation of orographic factor. In National annex can be specified procedure to calculate orographic factor. Standard procedure is in Annex A.3.

BS and IS National Annexes

Three terrain categories are available in BS. Sea, Country and town. More information about BS terrain categories can be found in National annex page.

Roughness factor c_r,diag is determined from the diagram Figure NA.3 Diagram can be found in National annex page.

Roughness correction factor c_r,T is determined from the diagram Figure NA.4 Diagram can be found in National annex page.

Exposure factor c_e,diag is determined from the diagram Figure NA.7 Diagram can be found in National annex page.

Exposure correction factor c_e,T is determined from the diagram Figure NA.8 Diagram can be found in National annex page.

Distance upwind to shoreline in km is used in the diagrams mentioned above.

Distance inside town terrain in km is used in the diagrams mentioned above.

Checkbox "Calculate orographic factor" is used, if orographic factor should be calculated according Annex A.3

Orographic factor - Recommended Annex A.3 input

Orographic terrain can be Cliffs and escarpments or Hills and ridges.

Horizontal distance of the site from the top of the crest in metres. Use positive value for downwind slope and negative value for upwind slope.

Effective height of the hill in metres.

Actual length of the upwind slope in the wind direction in metres.

Actual length of the downwind slope in the wind direction in metres.

Construction parameters

Construction parameters depend on selected National annex.

Reference height above terrain in metres is the most important parameter. It define in which height is calculated wind pressure. If is necessary to calculate wind pressure in more heights, repeat calculation with propper height z.

Checkbox "Temporary structure or execution phase" is used, if season construction is designed and season factor is necessary.

Checkbox "Use accurate information about the obstructions height" is used, if average height of neighbouring structures is know in Terrain category IV.

Calculation

Basic values

Basic wind velocity is calculated as v_b = c_dir • c_season • v_b,0 in metres per second.

Fundamental value of the basic wind velocity v_b,0 is defined in selected National annex in metres per second.

Directional factor c_dir = 1.0 in standard. Different value can be defined in National annex page.

Season factor c_season = 1,0 in standard. A different value can be defined in National annex page.

Reference height above terrain in metres is the height in which is peak velocity pressure calculated. It is one of the most important values in the calculation.

Mean wind velocity

For DIN and ONORM are this and follows paragraphs unavailable. Instead of it, there is block "Wind parameters" where is calculation of wind parameters according National annex.

Mean wind velocity in metres per second is calculated as v_m = c_r • c_O • v_b

Terrain roughness factor c_r depends on height above ground level and selected terrain category.

for z_min ≤ z ≤ z_max

for z ≤ z_min

where:

z₀ is the roughness length

k_r is terrain factor

where:

z_0,II = 0,05 (terrain category II, Table 4.1)

z_min is the minimum height defined in Table 4.1

z_max is to be taken as 200 m

Table 4.1 - Terrain categories and terrain parameters

Terrain category	z₀ [m]	z_min [m]
0 Sea or coastal area exposed to the open sea	0,003	1
I Lakes or flat and horizontal area with negligible vegetation and without obstacles	0,01	1
II Area with low vegetation such as grass and isolated obstacles (trees, buildings) with separations of at least 20 obstacle heights	0,05	2
III Area with regular cover of vegetation or buildings or with isolated obstacles with separations of maximum 20 obstacle heights (such as villages, suburban terrain, permanent forest)	0,3	5
IV Area in which at least 15 % of the surface is covered with buildings and their average height exceeds 15 m	1,0	10

Orography factor c_O = 1 in normal cases.

Where orography increases wind velocities by more than 5 % the effects should be taken into account using the orography factor. Recommended procedure is given in Annex A.3. Different procedure can be specified in National annex.

Orographic factor - Recommended procedure according to Annex A.3

1) Calculation of the upstream slope

2) Decision if the calculation of orography factor is necessary

The effects of orography should be taken into account in the following situations:

a) For sites on upwind slopes of hills and ridges:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ L_u / 2

b) For sites on downwind slopes of hills and ridges:

- where Φ < 0,3 and x < L_d / 2

- where Φ ≥ 0,3 and x < 1,6 • H

c) For sites on upwind slopes of cliffs and escarpments:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ L_u / 2

d) For sites on downwind slopes of cliffs and escarpments:

- where Φ < 0,3 and x < 1,5 • L_e

- where Φ ≥ 0,3 and x < 5 • H

3) Orography factor is than defined by:

Orographic factor	Limits
c_O = 1	Φ < 0,05
c_O = 1 + 2 • s • Φ	0,05 < Φ < 0,3
c_O = 1 + 0,6 • s	Φ > 0,3

where:

s is the orographic location factor

Φ is the upwind slope H/L_u in the wind direction

L_e is the effective length of the upwind slope

L_u is the actual length of the upwind slope in the wind direction

L_d is the actual length of the downwind slope in the wind direction

H is the effective height of the feature

x is the horizontal distance of the site from the top of the crest

z is the vertical distance from the ground level of the site

Values of the effective length L_e

Type of slope (Φ = H/L_u)
Shallow (0,05 < Φ < 0,3)	Steep (Φ > 0,3)
L_e = L_u	L_e = H/0,3

Orographic location factor s for cliffs and escarpments

Orographic location factor s for hills and ridges

a) upwind section for all orography

For the ranges

take

where

when

take

s = 0

b) downwind section for cliffs and escarpments

For the ranges

take

where

For the range

interpolate between values for

when

use the values for

when

take

s = 0

c) downwind section for hills and ridges

For the ranges

take

where

when

take

s = 0

Displacement height - Recommended procedure according Annex A.5

For building in Terrain category IV, can be reference height of building on the upwind side lowered by displacement height h_dis due to closely spaced buildings and other obstructions.

h_dis = min(0,8 • h_ave; 0,6 • h) for x ≤ 2 • h_ave

h_dis = min(1,2 • h_ave - 0,2 • x; 0,6 • h) for 2 • h_ave ≤ x ≤ 6 • h_ave

h_dis = 0 for x ≥ 6 • h_ave

Peak velocity pressure

Function for calculation peak velocity pressure at height z can be defined in National annex. Recommended formula is:

where:

ρ is the air density, which depends on the altitude, temperature and barometric pressure. ρ can be defined in National annex, recommended value is 1,25 kg/m³.

v_m is mean wind velocity

I_v is turbulence intensity. It can be defined in National annex. Recommended formula is:

for z_min ≤ z ≤ z_max

I_v = I_v(z_min) for z ≤ z_min

k_I is turbulence factor. It may be defined in National annex. Recommended value is 1,0

Explanation of symbols

A - Construction site altitude above sea level [m]

A_E1 - Altitude above sea level in east direction in 500 m from the site [m]

A_E2 - Altitude above sea level in east direction in 1000 m from the site [m]

A_N1 - Altitude above sea level in north direction in 500 m from the site [m]

A_N2 - Altitude above sea level in north direction in 1000 m from the site [m]

A_O1 - Altitude above sea level in west direction in 500 m from the site [m]

A_O2 - Altitude above sea level in west direction in 1000 m from the site [m]

A_S1 - Altitude above sea level in south direction in 500 m from the site [m]

A_S2 - Altitude above sea level in south direction in 1000 m from the site [m]

c_dir - Directional factor

c_e,diag - Exposure factor from the diagram

c_e,T - Exposure correction factor from the diagram

c_O - Orography factor

c_r,diag - Roughness factor from the diagram

c_r,T - Roughness correction factor from the diagram

c_r - Roughness factor

c_season - Season factor

Dir - Wind azimuth [°]

DisShore - Distance upwind to shoreline [km]

DisTown - Distance inside town terrain [km]

h - Height of the construction [m]

H - Effective height of the hill [m]

h_ave - Average height of buildings in the city [m]

h_dis - Height in the distance in terrain category IV [m]

I_v(z)flat - Turbulence intensity from the diagram

I_v - Turbulence intensity

k_I,T - Turbulence intensity factor from the diagram

L_d - Actual length of the downwind slope in the wind direction [m]

L_u - Actual length of the upwind slope in the wind direction [m]

q_b,0 - Fundamental value of basic wind pressure [kN/m²]

q_b - Basic wind pressure [kN/m²]

q_p - Peak velocity pressure [kN/m²]

T - The absolute air temperature at the load condition [K]

v_b,0,CHMI - Fundamental value of the basic wind velocity according CHMI [m/s]

v_b,0 - Fundamental value of the basic wind velocity [m/s]

v_b,map - Fundamental value of the basic wind velocity from the map [m/s]

v_b - Basic wind velocity [m/s]

v_m - Mean wind velocity [m/s]

v_p - Gust wind velocity [m/s]

x - Horizontal distance of the site from the top of the crest [m]

xDis - Site distance from the other building [m]

z - Reference height above terrain [m]

z₀ - Roughness length [m]

z_min - Minimum height [m]

ρ - Air density [kg/m³]

Wind load - Monopitch roofs

EuroCode - EN 1991 - Wind

Author: Design Forms s.r.o.

Created: 1/11/2017

Last updated: 2/22/2017

Description:

Wind load on the monopitch roofs

Annotation:

Dialogue

National annex selector

Combobox "National Annex" is used for selecting proper annex for calculation of the wind load.

Wind load requires selecion the national annex, because in Standard EN is many national decisions possible.

For explanation of the National annex parameters related to wind load select national annex from the list below.

BS National Annex

ČSN National Annex

DIN National Annex

ELOT National Annex

IS National Annex

LU National Annex

NBN National Annex

NEN National Annex

NF National Annex

ÖNORM National Annex

PN National Annex

SFS National Annex

SIST National Annex

SR National Annex

STN National Annex

General properties

General properties are similar to all wind load forms.

Checkbox "Print headline" represent official name for calculation. User can change it by uncheck "Print headline" and check "Print userdefined headline" and write his own headline into appropriate string line.

Wind parameters

This group of parameters depend on selected national annex.

BS National Annex

CSN National Annex

Wind region is from I to V according map of the wind regions. Map can be found in National annex page.

DIN National Annex

Wind region is from WZ1 to WZ4 according map of the wind regions. Map can be found in National annex page.

ELOT National Annex

No special wind parameters are necessary for ELOT National annex.

IS National Annex

LU National Annex

No special wind parameters are necessary for LU National annex.

NBN National Annex

NEN National Annex

Wind region is from I to III according map of the wind regions. Map can be found in National annex page.

NF National Annex

ONORM National Annex

According selected state in Austria can be selected the municipality which is the nearest to the construction site. Table of all possible municipalities can be found in National annex page.

PN National Annex

SFS National Annex

SIST National Annex

Wind region is from 1 to 3 according map of the wind regions. Map can be found in National annex page.

SR National Annex

Fundamental value of the basic wind velocity from the map in metres per second. Map can be found in National annex page.

STN National Annex

Wind region is from I to II according map of the wind regions. Map can be found in National annex page. For higher altitude, two more regions are availabile.

Terrain parameters

Standard values exist. Different parameters can be defined in National annex.

Standard values

BS and IS National Annexes

Three terrain categories are availabile in BS. Sea, Country and town. More informations about BS terrain categories can be found in National annex page.

Roughness factor c_r,diag is determined from the diagram Figure NA.3 Diagram can be found in National annex page.

Roughness correction factor c_r,T is determined from the diagram Figure NA.4 Diagram can be found in National annex page.

Exposure factor c_e,diag is determined from the diagram Figure NA.7 Diagram can be found in National annex page.

Exposure correction factor c_e,T is determined from the diagram Figure NA.8 Diagram can be found in National annex page.

Distance upwind to shoreline in km is used in the diagrams mentioned above.

Distance inside town terrain in km is used in the diagrams mentioned above.

Checkbox "Calculate orographic factor" is used, if orographic factor should be calculated according Annex A.3

Orographic factor - Recommended Annex A.3 input

Construction parameters

Construction parameters depend on selected National annex.

Reference height above terrain in metres is the most important parameter. It define in which height is calculated wind pressure. If is necessary to calculate wind pressure in more heights, repeat calculation with propper height z.

Checkbox "Temporary structure or execution phase" is used, if season construction is designed and season factor is necessary.

Checkbox "Use accurate informations about the obstructions height" is used, if average height of neighbluring structures is know in Terrain category IV.

Calculation

Basic values

Basic wind velocity is calculated as v_b = c_dir • c_season • v_b,0 in metres per second.

Fundamental value of the basic wind velocity v_b,0 is defined in selected National annex in metres per second.

Directional factor c_dir = 1.0 in standard. Different value can be defined in National annex page.

Season factor c_season = 1,0 in standard. Different value can be defined in National annex page.

Reference height above terrain in metres is the height in which is peak velocity pressure calculated. It is one of the most important values in the calculation.

Mean wind velocity

For DIN and ONORM are this and follows paragraphs unavailabile. Instead of it, there is block "Wind parameters" where is calculation of wind parameters according National annex.

Mean wind velocity in metres per second is calculated as v_m = c_r • c_O • v_b

Terrain roughness factor c_r depends on height above ground level and selected terrain category.

for z_min ≤ z ≤ z_max

for z ≤ z_min

where:

z₀ is the roughness length

k_r is terrain factor

Terrain category	z₀ [m]	z_min [m]
0 Sea or coastal area exposed to the open sea	0,003	1
I Lakes or flat and horizontal area with negligible vegetation and without obstacles	0,01	1
II Area with low vegetation such as grass and isolated obstacles (trees, buildings) with separations of at least 20 obstacle heights	0,05	2
III Area with regular cover of vegetation or buildings or with isolated obstacles with separations of maximum 20 obstacle heights (such as villages, suburban terrain, permanent forest)	0,3	5
IV Area in which at least 15 % of the surface is covered with buildings and their average height exceeds 15 m	1,0	10

Orographic factor - Recommended procedure according Annex A.3

1) Calculation of the upstream slope

Orographic factor	Limits
c_O = 1	Φ < 0,05
c_O = 1 + 2 • s • Φ	0,05 < Φ < 0,3
c_O = 1 + 0,6 • s	Φ > 0,3

Type of slope (Φ = H/L_u)
Shallow (0,05 < Φ < 0,3)	Steep (Φ > 0,3)
L_e = L_u	L_e = H/0,3

Orographic location factor s for cliffs and escarpments

Orographic location factor s for hills and ridges

a) upwind section for all orography

For the ranges

take

where

when

take

s = 0

b) downwind section for cliffs and escarpments

For the ranges

take

where

For the range

interpolate between values for

when

use the values for

when

take

s = 0

c) downwind section for hills and ridges

For the ranges

take

where

when

take

s = 0

Displacement height - Recommended procedure according Annex A.5

For building in Terrain category IV, can be reference height of building on the upwind side lowered by displacement height h_dis due to closely spaced buildings and other obstructions.

h_dis = min(0,8 • h_ave; 0,6 • h) for x ≤ 2 • h_ave

h_dis = min(1,2 • h_ave - 0,2 • x; 0,6 • h) for 2 • h_ave ≤ x ≤ 6 • h_ave

h_dis = 0 for x ≥ 6 • h_ave

Peak velocity pressure

Function for calculation peak velocity pressure at height z can be defined in National annex. Recommended formula is:

for z_min ≤ z ≤ z_max

I_v = I_v(z_min) for z ≤ z_min

k_I is turbulence factor. It may be defined in National annex. Recommended value is 1,0

Explanation of symbols

Wind load - Signboards

EuroCode - EN 1991 - Wind

Author: Design Forms s.r.o.

Created: 1/17/2017

Last updated: 2/22/2017

Description:

Wind load - signboards

Annotation:

Dialogue

National annex selector

BS National Annex

ČSN National Annex

DIN National Annex

ELOT National Annex

IS National Annex

LU National Annex

NBN National Annex

NEN National Annex

NF National Annex

ÖNORM National Annex

PN National Annex

SFS National Annex

SIST National Annex

SR National Annex

STN National Annex

General properties

Wind parameters

This group of parameters depend on selected national annex.

BS National Annex

Wind azimuth in degrees is used in calculation of directional factor cdir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

Fundamental value of the basic wind velocity from the map vb,map in metres per second. Map can be found in National annex page, Figure NA.1

Turbulence intensity from the diagram Iv(z)map. Diagram can be found in National annex page, Figure NA.5

Turbulence intensity factor from the diagram kI,T. Diagram can be found in National annex page, Figure NA.6

CSN National Annex

Wind region is from I to V according map of the wind regions. Map can be found in National annex page.

DIN National Annex

Wind region is from WZ1 to WZ4 according map of the wind regions. Map can be found in National annex page.

ELOT National Annex

No special wind parameters are necessary for ELOT National annex.

IS National Annex

LU National Annex

No special wind parameters are necessary for LU National annex.

NBN National Annex

Wind region is from 1 to 4 according map of the wind regions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor cdir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

NEN National Annex

Wind region is from I to III according map of the wind regions. Map can be found in National annex page.

NF National Annex

Wind region is from 1 to 4 according map of the wind regions. Map can be found in National annex page.

Direction zone is from 1 to 3 according map of the wind directions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor cdir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

ONORM National Annex

According selected state in Austria can be selected the municipality which is the nearest to the construction site. Table of all possible municipalities can be found in National annex page.

PN National Annex

Wind region is from 1 to 3 according map of the wind regions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor cdir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

SFS National Annex

SIST National Annex

Wind region is from 1 to 3 according map of the wind regions. Map can be found in National annex page.

SR National Annex

Fundamental value of the basic wind velocity from the map in metres per second. Map can be found in National annex page.

STN National Annex

Wind region is from I to II according map of the wind regions. Map can be found in National annex page. For higher altitude, two more regions are available.

Terrain parameters

Standard values exist. Different parameters can be defined in National annex.

Standard values

BS and IS National Annexes

Three terrain categories are available in BS. Sea, Country and town. More information about BS terrain categories can be found in National annex page.

Roughness factor cr,diag is determined from the diagram Figure NA.3 Diagram can be found in National annex page.

Roughness correction factor cr,T is determined from the diagram Figure NA.4 Diagram can be found in National annex page.

Exposure factor ce,diag is determined from the diagram Figure NA.7 Diagram can be found in National annex page.

Exposure correction factor ce,T is determined from the diagram Figure NA.8 Diagram can be found in National annex page.

Distance upwind to shoreline in km is used in the diagrams mentioned above.

Distance inside town terrain in km is used in the diagrams mentioned above.

Checkbox "Calculate orographic factor" is used, if orographic factor should be calculated according Annex A.3

Orographic factor - Recommended Annex A.3 input

Construction parameters

Calculation

Basic values

Basic wind velocity is calculated as vb = cdir • cseason • vb,0 in metres per second.

Fundamental value of the basic wind velocity vb,0 is defined in selected National annex in metres per second.

Directional factor cdir = 1.0 in standard. Different value can be defined in National annex page.

Season factor cseason = 1,0 in standard. A different value can be defined in National annex page.

Reference height above terrain in metres is the height in which is peak velocity pressure calculated. It is one of the most important values in the calculation.

Mean wind velocity

For DIN and ONORM are this and follows paragraphs unavailable. Instead of it, there is block "Wind parameters" where is calculation of wind parameters according National annex.

Mean wind velocity in metres per second is calculated as vm = cr • cO • vb

Terrain roughness factor cr depends on height above ground level and selected terrain category.

for zmin ≤ z ≤ zmax

for z ≤ zmin

where:

z0 is the roughness length

kr is terrain factor

where:

z0,II = 0,05 (terrain category II, Table 4.1)

zmin is the minimum height defined in Table 4.1

zmax is to be taken as 200 m

Table 4.1 - Terrain categories and terrain parameters

Terrain category	z0 [m]	zmin [m]
0 Sea or coastal area exposed to the open sea	0,003	1
I Lakes or flat and horizontal area with negligible vegetation and without obstacles	0,01	1
II Area with low vegetation such as grass and isolated obstacles (trees, buildings) with separations of at least 20 obstacle heights	0,05	2
III Area with regular cover of vegetation or buildings or with isolated obstacles with separations of maximum 20 obstacle heights (such as villages, suburban terrain, permanent forest)	0,3	5
IV Area in which at least 15 % of the surface is covered with buildings and their average height exceeds 15 m	1,0	10

Orography factor cO = 1 in normal cases.

Where orography increases wind velocities by more than 5 % the effects should be taken into account using the orography factor. Recommended procedure is given in Annex A.3. Different procedure can be specified in National annex.

Orographic factor - Recommended procedure according to Annex A.3

1) Calculation of the upstream slope

2) Decision if the calculation of orography factor is necessary

The effects of orography should be taken into account in the following situations:

a) For sites on upwind slopes of hills and ridges:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ Lu / 2

b) For sites on downwind slopes of hills and ridges:

- where Φ < 0,3 and x < Ld / 2

- where Φ ≥ 0,3 and x < 1,6 • H

c) For sites on upwind slopes of cliffs and escarpments:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ Lu / 2

d) For sites on downwind slopes of cliffs and escarpments:

- where Φ < 0,3 and x < 1,5 • Le

- where Φ ≥ 0,3 and x < 5 • H

3) Orography factor is than defined by:

Orographic factor	Limits
cO = 1	Φ < 0,05
cO = 1 + 2 • s • Φ	0,05 < Φ < 0,3
cO = 1 + 0,6 • s	Φ > 0,3

where:

s is the orographic location factor

Φ is the upwind slope H/Lu in the wind direction

Le is the effective length of the upwind slope

Lu is the actual length of the upwind slope in the wind direction

Ld is the actual length of the downwind slope in the wind direction

H is the effective height of the feature

x is the horizontal distance of the site from the top of the crest

z is the vertical distance from the ground level of the site

Values of the effective length Le

Type of slope (Φ = H/Lu)
Shallow (0,05 < Φ < 0,3)	Steep (Φ > 0,3)
Le = Lu	Le = H/0,3

Orographic location factor s for cliffs and escarpments

Orographic location factor s for hills and ridges

a) upwind section for all orography

For the ranges

take

where

when

take

s = 0

b) downwind section for cliffs and escarpments

For the ranges

take

where

For the range

interpolate between values for

when

use the values for

when

take

s = 0

c) downwind section for hills and ridges

For the ranges

take

where

when

take

s = 0

Displacement height - Recommended procedure according Annex A.5

For building in Terrain category IV, can be reference height of building on the upwind side lowered by displacement height hdis due to closely spaced buildings and other obstructions.

hdis = min(0,8 • have; 0,6 • h) for x ≤ 2 • have

hdis = min(1,2 • have - 0,2 • x; 0,6 • h) for 2 • have ≤ x ≤ 6 • have

hdis = 0 for x ≥ 6 • have

Peak velocity pressure

Function for calculation peak velocity pressure at height z can be defined in National annex. Recommended formula is:

where:

ρ is the air density, which depends on the altitude, temperature and barometric pressure. ρ can be defined in National annex, recommended value is 1,25 kg/m3.

vm is mean wind velocity

Iv is turbulence intensity. It can be defined in National annex. Recommended formula is:

for zmin ≤ z ≤ zmax

Iv = Iv(zmin) for z ≤ zmin

kI is turbulence factor. It may be defined in National annex. Recommended value is 1,0

Explanation of symbols

A - Construction site altitude above sea level [m]

AE1 - Altitude above sea level in east direction in 500 m from the site [m]

AE2 - Altitude above sea level in east direction in 1000 m from the site [m]

AN1 - Altitude above sea level in north direction in 500 m from the site [m]

AN2 - Altitude above sea level in north direction in 1000 m from the site [m]

AO1 - Altitude above sea level in west direction in 500 m from the site [m]

AO2 - Altitude above sea level in west direction in 1000 m from the site [m]

AS1 - Altitude above sea level in south direction in 500 m from the site [m]

AS2 - Altitude above sea level in south direction in 1000 m from the site [m]

cdir - Directional factor

ce,diag - Exposure factor from the diagram

ce,T - Exposure correction factor from the diagram

cO - Orography factor

cr,diag - Roughness factor from the diagram

cr,T - Roughness correction factor from the diagram

cr - Roughness factor

cseason - Season factor

Dir - Wind azimuth [°]

DisShore - Distance upwind to shoreline [km]

DisTown - Distance inside town terrain [km]

h - Height of the construction [m]

H - Effective height of the hill [m]

have - Average height of buildings in the city [m]

hdis - Height in the distance in terrain category IV [m]

Iv(z)flat - Turbulence intensity from the diagram

Iv - Turbulence intensity

kI,T - Turbulence intensity factor from the diagram

Ld - Actual length of the downwind slope in the wind direction [m]

Lu - Actual length of the upwind slope in the wind direction [m]

qb,0 - Fundamental value of basic wind pressure [kN/m2]

qb - Basic wind pressure [kN/m2]

qp - Peak velocity pressure [kN/m2]

T - The absolute air temperature at the load condition [K]

vb,0,CHMI - Fundamental value of the basic wind velocity according CHMI [m/s]

vb,0 - Fundamental value of the basic wind velocity [m/s]

vb,map - Fundamental value of the basic wind velocity from the map [m/s]

vb - Basic wind velocity [m/s]

vm - Mean wind velocity [m/s]

vp - Gust wind velocity [m/s]

x - Horizontal distance of the site from the top of the crest [m]

xDis - Site distance from the other building [m]

z - Reference height above terrain [m]

z0 - Roughness length [m]

zmin - Minimum height [m]

ρ - Air density [kg/m3]

Wind load - Duopitch roofs

EuroCode - EN 1991 - Wind

Author: Design Forms s.r.o.

Created: 2/2/2017

Last updated: 2/22/2017

Requests (2)

Description:

Wind load - Duopitch roofs

Annotation:

Dialogue

National annex selector

BS National Annex

ČSN National Annex

DIN National Annex

ELOT National Annex

IS National Annex

LU National Annex

NBN National Annex

NEN National Annex

NF National Annex

ÖNORM National Annex

PN National Annex

SFS National Annex

SIST National Annex

SR National Annex

STN National Annex

General properties

Wind parameters

This group of parameters depend on selected national annex.

BS National Annex

CSN National Annex

Wind region is from I to V according map of the wind regions. Map can be found in National annex page.

DIN National Annex

Wind region is from WZ1 to WZ4 according map of the wind regions. Map can be found in National annex page.

ELOT National Annex

No special wind parameters are necessary for ELOT National annex.

IS National Annex

LU National Annex

No special wind parameters are necessary for LU National annex.

NBN National Annex

NEN National Annex

Wind region is from I to III according map of the wind regions. Map can be found in National annex page.

NF National Annex

Wind region is from 1 to 4 according map of the wind regions. Map can be found in National annex page.

Direction zone is from 1 to 3 according map of the wind directions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor cdir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

ONORM National Annex

According selected state in Austria can be selected the municipality which is the nearest to the construction site. Table of all possible municipalities can be found in National annex page.

PN National Annex

SFS National Annex

SIST National Annex

Wind region is from 1 to 3 according map of the wind regions. Map can be found in National annex page.

SR National Annex

Fundamental value of the basic wind velocity from the map in metres per second. Map can be found in National annex page.

STN National Annex

Wind region is from I to II according map of the wind regions. Map can be found in National annex page. For higher altitude, two more regions are available.

Terrain parameters

Standard values exist. Different parameters can be defined in National annex.

Standard values

BS and IS National Annexes

Orographic factor - Recommended Annex A.3 input

Construction parameters

Calculation

Basic values

Mean wind velocity

For DIN and ONORM are this and follows paragraphs unavailable. Instead of it, there is block "Wind parameters" where is calculation of wind parameters according National annex.

Mean wind velocity in metres per second is calculated as vm = cr • cO • vb

Terrain roughness factor cr depends on height above ground level and selected terrain category.

for zmin ≤ z ≤ zmax

for z ≤ zmin

where:

z0 is the roughness length

kr is terrain factor

where:

z0,II = 0,05 (terrain category II, Table 4.1)

zmin is the minimum height defined in Table 4.1

zmax is to be taken as 200 m

Table 4.1 - Terrain categories and terrain parameters

Terrain category	z0 [m]	zmin [m]
0 Sea or coastal area exposed to the open sea	0,003	1
I Lakes or flat and horizontal area with negligible vegetation and without obstacles	0,01	1
II Area with low vegetation such as grass and isolated obstacles (trees, buildings) with separations of at least 20 obstacle heights	0,05	2
III Area with regular cover of vegetation or buildings or with isolated obstacles with separations of maximum 20 obstacle heights (such as villages, suburban terrain, permanent forest)	0,3	5
IV Area in which at least 15 % of the surface is covered with buildings and their average height exceeds 15 m	1,0	10

Orographic factor - Recommended procedure according to Annex A.3

1) Calculation of the upstream slope

2) Decision if the calculation of orography factor is necessary

The effects of orography should be taken into account in the following situations:

a) For sites on upwind slopes of hills and ridges:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ Lu / 2

b) For sites on downwind slopes of hills and ridges:

- where Φ < 0,3 and x < Ld / 2

- where Φ ≥ 0,3 and x < 1,6 • H

c) For sites on upwind slopes of cliffs and escarpments:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ Lu / 2

d) For sites on downwind slopes of cliffs and escarpments:

- where Φ < 0,3 and x < 1,5 • Le

- where Φ ≥ 0,3 and x < 5 • H

3) Orography factor is than defined by:

Orographic factor	Limits
cO = 1	Φ < 0,05
cO = 1 + 2 • s • Φ	0,05 < Φ < 0,3
cO = 1 + 0,6 • s	Φ > 0,3

Type of slope (Φ = H/Lu)
Shallow (0,05 < Φ < 0,3)	Steep (Φ > 0,3)
Le = Lu	Le = H/0,3

Orographic location factor s for cliffs and escarpments

Orographic location factor s for hills and ridges

a) upwind section for all orography

For the ranges

take

where

when

take

s = 0

b) downwind section for cliffs and escarpments

For the ranges

take

where

For the range

interpolate between values for

when

use the values for

when

take

s = 0

c) downwind section for hills and ridges

For the ranges

take

where

when

take

s = 0

Displacement height - Recommended procedure according Annex A.5

For building in Terrain category IV, can be reference height of building on the upwind side lowered by displacement height hdis due to closely spaced buildings and other obstructions.

hdis = min(0,8 • have; 0,6 • h) for x ≤ 2 • have

hdis = min(1,2 • have - 0,2 • x; 0,6 • h) for 2 • have ≤ x ≤ 6 • have

hdis = 0 for x ≥ 6 • have

Peak velocity pressure

Function for calculation peak velocity pressure at height z can be defined in National annex. Recommended formula is:

for zmin ≤ z ≤ zmax

Iv = Iv(zmin) for z ≤ zmin

kI is turbulence factor. It may be defined in National annex. Recommended value is 1,0

Explanation of symbols

Wind load - Multispan roofs

EuroCode - EN 1991 - Wind

Author: Design Forms s.r.o.

Created: 2/14/2017

Last updated: 2/22/2017

Description:

Wind load - multispan roofs

Annotation:

Dialogue

National annex selector

BS National Annex

ČSN National Annex

DIN National Annex

ELOT National Annex

IS National Annex

LU National Annex

NBN National Annex

NEN National Annex

NF National Annex

ÖNORM National Annex

PN National Annex

SFS National Annex

SIST National Annex

SR National Annex

STN National Annex

General properties

Wind parameters

This group of parameters depend on selected national annex.

BS National Annex

CSN National Annex

Wind region is from I to V according map of the wind regions. Map can be found in National annex page.

DIN National Annex

Wind region is from WZ1 to WZ4 according map of the wind regions. Map can be found in National annex page.

ELOT National Annex

No special wind parameters are necessary for ELOT National annex.

IS National Annex

LU National Annex

No special wind parameters are necessary for LU National annex.

NBN National Annex

NEN National Annex

Wind region is from I to III according map of the wind regions. Map can be found in National annex page.

NF National Annex

Wind region is from 1 to 4 according map of the wind regions. Map can be found in National annex page.

Direction zone is from 1 to 3 according map of the wind directions. Map can be found in National annex page.

Wind azimuth in degrees is used in calculation of directional factor cdir. Wind azimuth is from 0 ° to 360 ° from North in a clockwise direction.

ONORM National Annex

According selected state in Austria can be selected the municipality which is the nearest to the construction site. Table of all possible municipalities can be found in National annex page.

PN National Annex

SFS National Annex

SIST National Annex

Wind region is from 1 to 3 according map of the wind regions. Map can be found in National annex page.

SR National Annex

Fundamental value of the basic wind velocity from the map in metres per second. Map can be found in National annex page.

STN National Annex

Wind region is from I to II according map of the wind regions. Map can be found in National annex page. For higher altitude, two more regions are available.

Terrain parameters

Standard values exist. Different parameters can be defined in National annex.

Standard values

BS and IS National Annexes

Orographic factor - Recommended Annex A.3 input

Construction parameters

Calculation

Basic values

Mean wind velocity

For DIN and ONORM are this and follows paragraphs unavailable. Instead of it, there is block "Wind parameters" where is calculation of wind parameters according National annex.

Mean wind velocity in metres per second is calculated as vm = cr • cO • vb

Terrain roughness factor cr depends on height above ground level and selected terrain category.

for zmin ≤ z ≤ zmax

for z ≤ zmin

where:

z0 is the roughness length

kr is terrain factor

where:

z0,II = 0,05 (terrain category II, Table 4.1)

zmin is the minimum height defined in Table 4.1

zmax is to be taken as 200 m

Table 4.1 - Terrain categories and terrain parameters

Terrain category	z0 [m]	zmin [m]
0 Sea or coastal area exposed to the open sea	0,003	1
I Lakes or flat and horizontal area with negligible vegetation and without obstacles	0,01	1
II Area with low vegetation such as grass and isolated obstacles (trees, buildings) with separations of at least 20 obstacle heights	0,05	2
III Area with regular cover of vegetation or buildings or with isolated obstacles with separations of maximum 20 obstacle heights (such as villages, suburban terrain, permanent forest)	0,3	5
IV Area in which at least 15 % of the surface is covered with buildings and their average height exceeds 15 m	1,0	10

Orographic factor - Recommended procedure according to Annex A.3

1) Calculation of the upstream slope

2) Decision if the calculation of orography factor is necessary

The effects of orography should be taken into account in the following situations:

a) For sites on upwind slopes of hills and ridges:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ Lu / 2

b) For sites on downwind slopes of hills and ridges:

- where Φ < 0,3 and x < Ld / 2

- where Φ ≥ 0,3 and x < 1,6 • H

c) For sites on upwind slopes of cliffs and escarpments:

- where 0,05 < Φ ≤ 0,3 and |x| ≤ Lu / 2

d) For sites on downwind slopes of cliffs and escarpments:

- where Φ < 0,3 and x < 1,5 • Le

- where Φ ≥ 0,3 and x < 5 • H

3) Orography factor is than defined by:

Orographic factor	Limits
cO = 1	Φ < 0,05
cO = 1 + 2 • s • Φ	0,05 < Φ < 0,3
cO = 1 + 0,6 • s	Φ > 0,3

Type of slope (Φ = H/Lu)
Shallow (0,05 < Φ < 0,3)	Steep (Φ > 0,3)
Le = Lu	Le = H/0,3

Orographic location factor s for cliffs and escarpments

Orographic location factor s for hills and ridges

a) upwind section for all orography

For the ranges

take

where

when

take

s = 0

b) downwind section for cliffs and escarpments

For the ranges

take

where

For the range

interpolate between values for

when

use the values for

when

take

s = 0

c) downwind section for hills and ridges

For the ranges

take

where

when

take

s = 0

Displacement height - Recommended procedure according Annex A.5

For building in Terrain category IV, can be reference height of building on the upwind side lowered by displacement height hdis due to closely spaced buildings and other obstructions.

hdis = min(0,8 • have; 0,6 • h) for x ≤ 2 • have

hdis = min(1,2 • have - 0,2 • x; 0,6 • h) for 2 • have ≤ x ≤ 6 • have

hdis = 0 for x ≥ 6 • have

Peak velocity pressure

Function for calculation peak velocity pressure at height z can be defined in National annex. Recommended formula is:

for zmin ≤ z ≤ zmax

Iv = Iv(zmin) for z ≤ zmin

kI is turbulence factor. It may be defined in National annex. Recommended value is 1,0

Explanation of symbols

Coefficients for the snow load

EuroCode - EN 1991 - Snow

Author: Design Forms s.r.o.

Created: 3/3/2017

Last updated: 3/3/2017

Description:

Coefficients for the snow load

Annotation:

Roof geometry

Roof slope

Roof slope is defined in the dialogue in degrees and used for calculation of the shape coefficients.

Shape coefficients

Snow shape coefficients are calcualted according roof slope.

Angle of pitch of roof α	0° ≤ α ≤ 30°	30° ≤ α ≤ 60°	α ≥ 60°
μ₁	0,8	0,8•(60 - α)/30	0,0
μ₂	0,8 + 0,8•α/30	1,6	--

Characteristic value of snow load on the ground

This value depend on the selected national annex, Clause 4.1(1). More information can be found on the National annex page.

Coefficients

Exposure coefficient

This value depend on the selected national annex, Clause 5.2(7). More information can be found on the National annex page.

Table 5.1 Recommended standard values of C_e for different tophographies

Topography	C_e
Windswept^a	0,8
Normal^b	1,0
Sheltered^c	1,2
^a Windswept topography: flat unobstructed areas exposed on all sides without, or little shelter afforded by terrain, higher construction works or trees. ^b Normal topography: areas where there is no significant removal of snow by wind on construction work, because of terrain, other construction works or trees. ^c Sheltered topography: areas in which the construction work being considered is considerably lower than the surrounding terrain or surrounded by high trees and/or surrounded by higher construction works.

Thermal coefficient

This value depend on the selected national annex, Clause 5.2(8). More information can be found on the National annex page.

Recommended value: C_t = 1.0

Explanation of symbols

C_e - Exposure coefficient

C_esl - Exceptional load coefficient

C_t - Thermal coefficient

s_k - Characteristic value of snow load on the ground [kN/m²]

α - Roof slope [°]

μ₁ - Shape coefficient

μ₂ - Shape coefficient

Snow load - Monopitch roof

EuroCode - EN 1991 - Snow

Author: Design Forms s.r.o.

Created: 3/3/2017

Last updated: 3/3/2017

Description:

Snow load - Monopitch roof

Annotation:

Calculation

Roof geometry, Characteristic value of snow load on the ground and Coefficients

These parts of calculation are described in the annotation for Coefficients for the snow load

Calculation of the snow load

Snow load s is calculated according to formula (5.1) in kN/m²

Snow load at the length of roof in kN/m

q = b•s

Explanation of symbols

b - Width of the roof [m]

q - Snow load at the length of the roof [kN/m]

s - Snow load on the roof [kN/m²]

Snow load - Duopitch roof

EuroCode - EN 1991 - Snow

Author: Design Forms s.r.o.

Created: 3/3/2017

Last updated: 3/3/2017

Description:

Snow load - Duopitch roof

Annotation:

Characteristic value of snow load on the ground and Coefficients

These parts of calculation are described in the annotation for Coefficients for the snow load

Geometry

Left and right slope is drawn here in degrees.

Left and right side shape coefficients are calculated.

Angle of pitch of roof α	0° ≤ α ≤ 30°	30° ≤ α ≤ 60°	α ≥ 60°
μ₁	0,8	0,8•(60 - α)/30	0,0

Calculation of the snow load

Case (i) - Undrifted snow

Snow loads s₁ and s₂ are calculated according formula (5.1) in kN/m²

Case (ii) and Case (iii) - Undrifted snow

Shape in these cases depend on selected national annex.

Standard shapes are calculated according formula (5.1) with proper coefficient μ_i

Explanation of symbols

s₁ - Snow load on the left side of the roof [kN/m²]

s₂ - Snow load on the right side of the roof [kN/m²]

α₁ - Roof slope on the left side of the roof [°]

α₂ - Roof slope on the right side of the roof [°]

μ_1(α1) - Shape coefficient on the left side of the roof

μ_1(α2) - Shape coefficient on the right side of the roof

Snow load - Multi-span roofs

EuroCode - EN 1991 - Snow

Author: Design Forms s.r.o.

Created: 3/23/2017

Last updated: 3/23/2017

Description:

Snow load - multispan roofs

Annotation:

▶ Invariant - Glass

Glass Balustrade Design

Invariant - Glass -

Author: Ciprian Popa

Created: 4/10/2017

Last updated: 7/16/2017

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