kenyan timber stresses

7/29/2019 Kenyan Timber Stresses

1/99

Issue: Page

P.O. Box Date:

Revised by: GM

Checked by: GM

CODE OUTPUT

DATA

UNITS

M.

KN/M

N/mm2

M2

Kg/M3

Kg PITCH, 22.5 Degrees 0.3925

2.6143825

N 2.4155736

Rafters & Bottom Tie 100 x 50 0.005 m2

Truss Webs 100 x 50 0.005 m2

GCI Sheeting Purlins 75 x 50 0.00375 m2

Tiling Battens 50 x 50 0.0025 m2

Ceiling Brandering 50 x 50 0.0025 m2

Intermediate Rafter 100 x 50 0.005 m2

Underpurlins 100 x 50 0.005 m2

Density of Wood 500 Kg/m3

Weight

Bottom-Tie Length 7.2 m 18.00 Kg

Total Rafter Length 9.09 m 22.73 KgTotal Web Length 8.18 m 20.46 Kg

Truss Spacing 1.2 m 61.19 Kg

Tiling Battens Spacin 0.3 m

Purlin Spacing 1.2 m

Brandering Spacing 0.6 m

Intermediate Rafer 0.6 m

Weight of Truss

Weight of Main plate 61.2 Kg

Weight of Nailing plate 15.3 Kg

Weight of Nails 7.6 Kg

84.1 Kg = 0.84 kN/truss

Weight of Tiles 0.7 kN/m2

7.64 kN/trus 0.70

Weight of tiling battens (50x50) 0.015 kN/Batte 0.45 " 0.04

Weight of GCI Sheeting 0.1 kN/m2

1.09 " 0.10

Weight of Purlins (75x50) 0.0225 kN/Purlin 0.17 " 0.02

9.35 kN/truss

Roof imposed load 0.25 kN/m2

Weight of Ceiling 0.25 kN/m 2.16 kN/truss

Issue: Page

P.O. Box Date:

Revised by: GMDEVELOPMENT ON BLOCK 40/(2,3,4&5)

Project:DEVELOPMENT ON BLOCK 40/(2,3,4&5)

MAVOKO

1

CALCULATIONS

Nairobi2


2/99

Checked by: GM

REF OUTPUT

Weight of Ceiling Brandering (75x50) 0.015 kN/Brand 0.45 "

2.61 "

Total Load per Truss = 12.81 kN/truss

No. Panels 0n the Rafter 4 On Rafter

No. Panels 0n the Bottom-Tie 3 On Bottom Tie

Truss Loading at Rafter Level 2/3 of Total Load = 8.54Nodal Loading at Rafter Level

Truss Loading at Ceiling Level 1/3 of Total Load = 4.27

Nodal Loading at Ceiling Level

CP3 WIND LOAD x

CP3 Chp V Basic Wind Speed for NAIROBI V = 28 m/s V = 28 m/s

Pt2 4.3 Topography factor S1 = 1.0 S1 = 1.0

Statistical factor S2 = 0.9 S1 = 0.9

Topography factor S3 = 1.0 S1 = 1.0

CP3 Chp V Height to Eaves, h = 16.2 Pitch = 22.5

5.4 Building Class = B Width = 7.9

Table 3 Ground roughness Category = 3

Height (eaves to apex) = 1.64

CP3 Chp V Total height to apex, H = 17.84 m

5.6

Design Wind Speed Vs = VxS1xS2xS3 = m/s

28 x 1 x 0.9 x 1 = 25.2

Vs= 25.2

6.0 Dynamic Pressure q = KVs x Vs Where K = 0.613

therefore, q= 0.613 x 0.613 x 0.613 = 389 N/m2

N

= 0.389 N/m2

KN

External Pressure Coefficients, Cpe

Height to eaves, h = 16.2 m

Width w = 9.425 m h/w = 1.719

CP3 Chp V Slope = 22.5 Deg. Cpe = -0.575 Wind on

Table 8 Cpe = -0.5 Side

Cpe = -0.8 Wind on

Cpe = -0.65 End

Internal Pressure Coefficients, Cpi

CP3 Cpi = 0.2

Appendix E ./ ( ) - x Cpi = -0.3

CP3 Wind Load F = (Cpe -Cpi).q.A A =

7.2

Max. roof Uplift = (-0.8-0.2)qA = -0.389

Min Downward Load = (-0.8--0.3)qA = -0.195

UPLIFT

Design for Uplift force of Fmax = -0.389

Fmin = -0.195

Truss Spacing = 1.2 m xTruss Span = 7.2 m

Overall Span = 7.2 m 1.2x7.2 = 8.64 m2

therefore. Max. Uplift = Fmax = 3.37 kN/truss

Fmin = 1.682 kN/truss

Issue: Page

P.O. Box Date:

Revised by: GM

Checked by: GM

MAVOKO

CALCULATIONS

Nairobi3

tributary area to

truss


MAVOKO

ributary area to trus


3/99

REF OUTPUT

Battens

Area Supported / Batten, Ab = 0.3x0.6

Batten Spacing = 0.3 m Ab = 0.18

Batten Span = 0.6 m Max. Batten Uplift = 13 x 0.18 = -0.071 kN/batten

GRAVITY LOADS

Imposed Load:

Imposed Load = 0.25

Dead Loads :

Truss self Weight = 84 Kg = 0.84 kN

Distributed Load = 0.84 / 7.2 x 1.2 = 0.10 kN/m2

Tiles+ Battens = 0.75 kN/m2

GCI Sheets + Purlins = 0.12 kN/m2

total = 0.97

Ceil ing + Brandering = 0.28 kN/m2

1) At the rafter level 0.97 KN/M2

Total DL = 8.39 = 5.6

kN/truss

Total IL = 2.16 = 1.44 kN/truss

total 7.04

2) At the Ceiling level

1.87

kN/truss

0.72

total 0.72

3) Batten

Imposed = = 0.05 KN

Dead = 0.75 x 0.3 x 0.6 = 0.07 KN

CP3 LOAD SUMMARY x

BS 5268 Total Span = 9092

Pt 2 1996 Load Type of Load

2.8 and Duration Load Batten Duration

Table 14 Rafter Level Ceiling Level Factor K3

Long Dead 7.04 1.87 0.07 1.0

Term Only

Medium Dead + 7.04 1.87 0.070

Term Temp. Li 1.44 0.72 0.05

TOTAL 8.48 2.59 0.120 1.25

Very Short Dead + 7.04 1.87 0.07

Term Wind 3.37 -0.071

TOTAL 3.67 0.00 1.75

Issue: Page

P.O. Box Date:

Revised by: GM

Checked by: GM

REF OUTPUT

BATTEN DESIGN Span , L 0.6 m

Load Case (i) (DL+LL) Load Case (ii) (DL+WL)

DL + LL = F = 0.120 kN DL + WL = F = -0.001 kN

0.25 x 0.3 x 0.6

Total DL =

CALCULATIONS

Project:

CALCULATIONS

Typical Load

Nairobi4

DEVELOPMENT ON BLOCK 40/(2,3,4&5)

MAVOKO

Truss

Total IL =

0.25 x 7.2 x 1.2 =

0.97 x 7.2 x 1.2 =


4/99

Mmax =FL/8 = 0.009 kNm Mmax =FL/8 = 0.000 kNm

Reaction FL/2 = 0.036 kN Reaction FL/2 = 0.000 kN

Bending Check

Zreq. = M/dm

Permissible stress in bending parrallel to grain, dm = grade .K3.K7.K8 =

dgrade = 5.00 N/mm2

K3 = 1.75 Load Duration Factor K7 = 1.1 Load Sharing Factor

K8 = 1.17 Depth Factor

dm = 11.26 N/mm2

M = 0.009

Zreq. = M/dm = 799.201 mm3

25x50

For 25 x 50 mm Battens

Zprov. = bd2/6 = 10417 mm3

therefore Bending OK

Deflection Check

Emin = 3600 N/mm2

Emin = 3600 N/mm2

I = bd3/12 = 260417 mm4

Max deflection, dmax dmax = 0.15 mm

Max allowable deflection = 0.003L = = 1.8 mm

1.8 > 0.15

Deflection OK

Adopt

BS 5268 TRUSS T1- FORCE

Pt 2 1996 Design for Medium Term Loading

2.8 and Total Load at Rafter = 8.48 Cantileverd end = 750 mm

Table 14 Total Load at Ceiling = 2.59 Total Truss Load = = 11.07 kN

Total No. of Panels on Rafter = 4 Truss Span = 7200 mm

Total No. of Panels on Bottom Tie = 3 Total Span = 8700 mm

P1 = 8.48/4= 2.120 2.593= P3 = 0.863

P2 = 2.12/= 1.060 P4 = 0.432

R = 11.07/= 5.535 -0.432 = 5.103 kN

Member length coeff force unit force

1 2098 3.92 8.31374 kN 1.31 kN

2 2098 3.54 7.50284 kN 1.31 kN

3 2098 0.92 1.95879 kN 0.00 kN

4 2098 3.62 7.68152 kN 0.00 kN

5 2098 3.54 7.50284 kN 1.21 kN

6 2098 0.92 1.95879 kN 1.21 kN

Issue: Page

P.O. Box Date:

Revised by: GMChecked by: GM

REF OUTPUT

RAFTER DESIGN

Critical Member is: 1

BS 5268 F = 8.31 kN Compression

Pt 3 L = 2098 mm 50x150

6.5.5 Le = 1888.2 mm Effective Length Le = 0.9 x L

Try GS grade Cypress = 50 x 150

Project: DEVELOPMENT ON BLOCK 40/(2,3,4&5)MAVOKO

25x50

TENSION

C

OMP.

5

CALCULATIONS

Refer to Truss Diagram above

Nairobi


5/99

BS 5268 Slenderness ratio l = Le/r r SQRT(I/A) I = bd3/12 = 1E+07

Pt 2 r = 43.30 A = 7500

2.11.4 l = 43.61 Zprov. = bd2/6 = 2E+05

< 180 Slender Ratio OK

2.11.5 ince l > 5 l SQD = 1901 Multiply grade stress by K12 x

BS 5268 h = 0.005 l = 0.218 N = 1.5 dgrade = 6.00 N/mm2

Pt 2 pSQD = 9.877551 dc = 6x1.25= 7.5 K3 = 1.25 For very short term( ) = 1.5123548 )SQD = 2.287 () = 1.662 K12 = 1.12

Annex B K3 = 1.5 K12 = 1.00

dadm(c) = dgrade x K3K12 = Emin = 3600 N/mm2

dadm(c) = 10.096 N/mm2

(Permissible Compression Stress)

da(c) F/A = = 1.108 N/mm2

(Applied Compression Stress)

< 10.096 Section OK

BS 5268 Check for Combined Compression and Bending for Rafter

Pt 3 Man Point Load P = 0.9 kN K3 = 1.5 Duration Factor

6.4.2 F = 8.3137 kN K7 = (300/d)^0.11

L = 2098 mm K7 = 1.08 Depth Factor

Le = 1888.2 mm K8 = 1.1 Load Sharing F.

Mmax = PLe/4 = 0.425 kNm (Max Bending Moment, PL/4)

dadm(b) = dgrade x K3K7K8 =

= 10.684 da(b) .= M/Z = 2.27 N/mm2

(Applied Bending Stress)BS 5268 da(c) = 1.108 + 2.27 de = PI^2E 35559

Pt 2 adm(c) dadm(b) (1-1.5dadm(c) x K1 10.0963 10.6844 0.9 l 2 1901.5

2.11.6 de de = 18.701

= 0.110 + 0.236 = 0.3454

Adopt 50x150 since < 1

BOTTOM TIE DESIGN

Critical Member is 4

F = 7.6815 kN Tension


I = bd3/12 = 2.8E+07 use 100x150

A = 15000

BS 5268 bd2/6 = 375000

Pt 2

2.12 dgrade = 3.00 N/mm2

K14 = (300/d)^0.11K14 = 1.08

dadm(t) = dgrade x K14

= 3.24 N/mm2

(Permissible Tensile Stress)

da(t) F/A = 0.51 N/mm2

(Applied Tensile Stress)

< 3.24

Issue: Page

P.O. Box Date:

Revised by: GM

Checked by: GM

REF OUTPUT

INTERNAL MEMBER DESIGNCritical Member is 6



dgrade = 3.00 N/mm2

K14 = (300/d)^0.11 A = 5000 mm2

K14 = 1.13


= 3.39 N/mm2


da(t) F/A = 0.39 N/mm2



MAVOKO

CALCULATIONS

.+ da(b)

100x150

Section OK

Nairobi

50x100

6

187500

14062500


6/99

< 3.39



Pt 3 L = 2098 mm 50x100

6.5.5 Le = 1888 mm Effective Length Le = 0.9 x L



Pt 2 r = 28.87 A = 5000

2.11.4 l = 65.40 Zprov. = bd^2/6 = 83333


2.11.5 ince l > 5 l SQD = 4277 Multiply grade stress by K12 x

BS 5268 h = 0.005 l = 0.327 N = 1.5 dgrade = 6.00 N/mm2

Pt 2 pSQD = 9.88 dc = 6x1.75= 10.5 K3 = 1.75 For very short term

Annex B ( ) = 0.86 )SQD = 0.74 () = 0.53 K12 = 0.82

K3 = 1.5


dadm(c) = 7.34 N/mm2

(Permissible Comp. Stress)

da(c) F/A = = 0.39 N/mm2

(Applied Comp. Stress)

< 7.34461 Section OK

CP3 LOAD SUMMARYBS 5268 Total Span = 8700


2.8 and Duration Load Duration

Table 14 Rafter Level Factor K3

Long Dead 3.52 1.0

Term Only

Medium Dead + 3.52

Term Temp. Li 0.72

TOTAL 4.24 1.25

Very Short Dead + 1.76

Term Wind 1.69

TOTAL 0.08 1.75

Issue: Page

P.O. Box Date:

Revised by: GM

Checked by: GM

REF OUTPUT

INTERMEDIATE RAFTER DESIGN Span , L 3 m


DL + LL = F = 4.240 kN DL + WL = F = 1.685 kN

Mmax =FL/8 = 1.590 kNm Mmax =FL/8 = 0.632 kNmReaction FL/2 = 6.360 kN Reaction FL/2 = 2.528 kN

Bending Check

Zreq. = M/dm

Permissible stress in bending parrallel to grain, dm = grade x K3K7K8 =

dgrade = 5.00 N/mm2

K3 = 1.75 Load Duration Factor

K7 = 1.1 Load Sharing Factor


CALCULATIONS

Typical Load


MAVOKO

4166666.7

83333.3

Nairobi7

Section OK


7/99

dm = 11.26 N/mm2

M = 1.590

Zreq. = M/dm = 141192 mm3 50x150

For 50 x 150 mm

Zprov. = bd2/6 = 187500 mm

3therefore Bending OK

Deflection Check

Emin = 3600 N/mm2

I = bd3/12 = 2E+06 mm4 Max deflection, dmax dmax = 53 mmMax allowable deflection = 0.003L = = 9 mm

9 > 53

Deflection NOT O

Adopt Redesign


8/99

Design Worx Limited Issue: Design

P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

CODE OUTPUT

DATA

UNITS

M.

KN/M

N/mm2

M2

Kg/M3

Kg PITCH, 15 Degrees 0.26167

3.86561806

N 3.73403308


Truss Webs 100 x 50 0.005 m2







Weight




Tiling Battens Spacing 0.3 m




Weight of Truss




77.5 Kg = 0.77 kN/truss

Weight of Decra Tiles 0.25 kN/m2

2.48 kN/trus 0.25

Weight of tiling battens (50x50) 0.015 kN/Batten 0.41 " 0.04


0.99 " 0.10


4.05 kN/truss


Weight of Ceiling 0.25 kN/m2

2.04 kN/truss

Weight of Ceiling Brandering (75x50) 0.015 kN/Brande 0.41 "

2.45 "


Nairobi

Project:truss

CALCULATIONS


9/99




P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT

Truss Loading at Rafter Level 2/3 of Total Load = 4.86

Nodal Loading at Rafter Level



CP3 WIND LOAD x





CP3 Chp V Height to Eaves, h = 16.2 Pitch = 15

5.4 Building Class = B Width = 7.9Table 3 Ground roughness Category = 3



5.6


28 x 1 x 0.9 x 1 = 25.2

Vs= 25.2


therefore, q= 0.613 x 0.613 x 0.613 = 389 N/m2

= 0.389 N/m2



Width w = 9.425 m h/w = 1.719

CP3 Chp V Slope = 15 Deg. Cpe = -0.575 Wind onTable 8 Cpe = -0.5 Side

Cpe = -0.8 Wind on

Cpe = -0.65 End


CP3 Cpi = 0.2



7.2



UPLIFT

Design for Uplift force of Fmax = -0.389Fmin = -0.195

Truss Spacing = 1.2 m x

Truss Span = 6.8 m

Overall Span = 6.8 m 1.2x6.8 = 8.16 m2



Nairobi

Project:truss

CALCULATIONS

tributary area to

truss

tributary area to truss


10/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT

BattensArea Supported / Batten, Ab = 0.3x0.6


Batten Span = 0.6 m Max. Batten Uplift = 13 x 0.18 = -0.071 kN/batte

GRAVITY LOADS

Imposed Load:

Imposed Load = 0.25

Dead Loads :





total = 0.52



Total DL = 4.25 = 2.84

kN/truss


total 4.20


0.95

kN/truss

0.68

total 0.68

3) Batten

Imposed = = 0.05 KN

Dead = 0.3 x 0.3 x 0.6 = 0.03 KN

CP3 LOAD SUMMARY x





Long Dead 4.20 0.95 0.03 1.0

Term Only

Medium Dead + 4.20 0.95 0.030

Term Temp. Li 1.36 0.68 0.05

TOTAL 5.56 1.63 0.080 1.25


Term Wind 3.18 -0.071

TOTAL 1.02 -0.041 1.75

Design Worx Limited Issue: DesignP.O. Box 7136-001 Date:

Nairobi

Project:truss

CALCULATIONS

0.52 x 6.8 x 1.2 =

0.25 x 6.8 x 1.2 =

Total DL =

Total IL =

0.25 x 0.3 x 0.6

Typical Load

Truss

Nairobi


11/99

Revised by: Test1

Checked by: Test2

REF OUTPUT

BATTEN DESIGN Span , L = 0.6 m


DL + LL = F = 0.080 kN DL + WL = F = -0.041 kN

Mmax =FL/8 = 0.006 kNm Mmax =FL/8 = -0.003 kNmReaction FL/2 = 0.024 kN Reaction FL/2 = -0.012 kN

Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 0.006

Zreq. = M/dm = 532.8005 mm3

25x50


Zprov. = bd2/6 = 10417 mm3


Deflection CheckEmin = 3600 N/mm

2Emin = 3600

I = bd3/12 = 260417 mm4

Max deflection, dmax dmax = 0.1

Max allowable deflection = 0.003L = = 1.8

1.8 > 0.1

Deflection OK

Adopt



2.8 and Total Load at Rafter = 5.56 Cantileverd end = 750

Table 14 Total Load at Ceiling = 1.63 Total Truss Load = = 7.19

Total No. of Panels on Rafter = 6 Truss Span = 6800

Total No. of Panels on Bottom Tie = 6 Total Span = 8300

P1 = 5.56/6= 0.930 1.636= P3 = 0.272

P2 = 0.93/= 0.465 P4 = 0.136R = 7.19/= 3.595 -0.136 = 3.459 kN


1 2098 9.66 8.987562 kN 1.93 kN

2 2098 9.66 8.987562 kN 1.93 kN

3 2098 7.73 7.19005 kN 1.93 kN

4 2098 2.12 1.969702 kN 0.00 kN

5 2098 2.39 2.227297 kN 0.00 kN

6 2098 9.34 8.681627 kN 1.87 kN

7 2098 7.47 6.945302 kN 1.87 kN

8 2098 5.60 5.208976 kN 1.87 kN


Revised by: Test1

Project:truss

CALCULATIONS

25x50


COMP.

Nairobi

TENSION


12/99

Checked by: Test2

REF OUTPUT

RAFTER DESIGN



Pt 3 L = 2098 mm 50x150

6.5.5 Le = 1888.2 mm Effective Length Le = 0.9 x LTry GS grade Cypress = 50 x 150


Pt 2 r = 43.30 A = 7500

2.11.4 l = 43.61 Zprov. = bd2/6 = 2E+05


2.11.5 Since l > 5 l SQD = 1901 Multiply grade stress by K12 x

BS 5268 h = 0.005 l = 0.218 N = 1.5 dgrade = 6.00 N/mm2

Pt 2 pSQD = 9.87755102 dc = 6x1.25= 7.5 K3 = 1.25 For very short ter

( ) = 1.51235477( )SQD = 2.287 () = 1.662 K12 = 1.12

Annex B K3 = 1.5 K12 = 1.00


dadm(c) = 10.096 N/mm2


da(c) F/A = = 1.198 N/mm2


< 10.096 Section OK



6.4.2 F = 8.98756 kN K7 = (300/d)^0.11





= 10.6844 da(b) .= M/Z = 2.27 N/mm2

(Applied Bending Stress)

BS 5268 da(c) = 1.198 + 2.27 de = PI^2E

Pt 2 dadm(c) dadm(b) (1-1.5dadm(c) x K1 10.09629 10.6844 0.89 l 2

2.11.6 de de =

= 0.119 + 0.238 = 0.357


BOTTOM TIE DESIGNCritical Member is 7



I = bd3/12 = 2.8E+07 use 100x150

A = 15000

BS 5268 bd2/6 = 375000

Pt 2

2.12 dgrade = 3.00 N/mm2

K14 = (300/d)^0.11

K14 = 1.08


= 3.24 N/mm2


da(t) F/A = 0.46 N/mm2


< 3.24


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT

truss

CALCULATIONS

Section O

Nairobi

Project:truss

CALCULATIONS

14062500

187500

.+ da(b)

100x150


13/99

INTERNAL MEMBER DESIGN

Critical Member is #REF!

F = #REF! kN Tension


dgrade = 3.00 N/mm2

K14 = (300/d)^0.11 A = 5000

K14 = 1.13dadm(t) = dgrade x K14

= 3.39 N/mm2


da(t) F /A = #REF! N/mm2


#REF! 3.39



Pt 3 L = 2098 mm 50x100




Pt 2 r = 28.87 A = 5000

2.11.4 l = 65.40 Zprov. = bd^2/6 = 83333



BS 5268 h = 0.005 l = 0.327 N = 1.5 dgrade = 6.00 N/mm2


Annex B ( ) = 0.86 )SQD = 0.74 () = 0.53 K12 = 0.82

K3 = 1.5




da(c) F/A = = 1.44 N/mm2



CP3 LOAD SUMMARY





Long Dead 2.10 1.0

Term Only

Medium Dead + 2.10

Term Temp. Li 0.68

TOTAL 2.78 1.25


Term Wind 1.59

TOTAL -0.54 1.75


Revised by: Test1

Checked by: Test2

REF OUTPUT

INTERMEDIATE RAFTER DESIGN Span , L = 3 m

Project:truss

50x100

#REF!

4166666.7

CALCULATIONS

83333.3

Typical Load

Nairobi


14/99


DL + LL = F = 2.780 kN DL + WL = F = 1.590 kN



Bending Check

Zreq. = M/dmPermissible stress in bending parrallel to grain, dm = grade x K3K7K8 =

dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 1.043

Zreq. = M/dm = 92574.09 mm3 50x150

For 50 x 150 mm

Zprov. = bd2/6 = 187500 mm


Deflection Check

Emin = 3600

I = bd3/12 = 1562500 mm

4Max deflection, dmax dmax = 34.75

Max allowable deflection = 0.003L = = 9

9 > 34.75Deflecti

Adopt Redesign


15/99

Page

1 of 3


16/99

Page

N

KN

1 of 3


17/99

Page

n

Page

1 of 3


18/99

N/mm2

mm

mm

mm

kN

mm

mm

Page

1 of 3


19/99

35559

1901.5

18.701

Page

1 of 3


20/99

mm2

Page

1 of 3


21/99

N/mm2

mm

mm

n NOT O


22/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

CODE OUTPUT

DATA

UNITS

M.

KN/M

N/mm2

M2

Kg/M3


3.86561806

N 3.73403308


Truss Webs 100 x 50 0.005 m2







Weight








Weight of Truss




77.5 Kg = 0.77 kN/truss


2.48 kN/trus 0.25



0.99 " 0.10


4.05 kN/truss



2.04 kN/truss


2.45 "


Nairobi

Project:truss

CALCULATIONS


23/99




P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT





CP3 WIND LOAD x









5.6


28 x 1 x 0.9 x 1 = 25.2

Vs= 25.2


therefore, q= 0.613 x 0.613 x 0.613 = 389 N/m2

= 0.389 N/m2



Width w = 9.425 m h/w = 1.719


Cpe = -0.8 Wind on

Cpe = -0.65 End


CP3 Cpi = 0.2



7.2



UPLIFT



Truss Span = 6.8 m

Overall Span = 6.8 m 1.2x6.8 = 8.16 m2



Nairobi

Project:truss

CALCULATIONS

tributary area to

truss



24/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT




GRAVITY LOADS

Imposed Load:

Imposed Load = 0.25

Dead Loads :





total = 0.52



Total DL = 4.25 = 2.84

kN/truss


total 4.20


0.95

kN/truss

0.68

total 0.68

3) Batten

Imposed = = 0.05 KN

Dead = 0.3 x 0.3 x 0.6 = 0.03 KN

CP3 LOAD SUMMARY x





Long Dead 4.20 0.95 0.03 1.0

Term Only

Medium Dead + 4.20 0.95 0.030

Term Temp. Li 1.36 0.68 0.05

TOTAL 5.56 1.63 0.080 1.25


Term Wind 3.18 -0.071

TOTAL 1.02 -0.041 1.75


Nairobi

Project:truss

CALCULATIONS

0.52 x 6.8 x 1.2 =

0.25 x 6.8 x 1.2 =

Total DL =

Total IL =

0.25 x 0.3 x 0.6

Typical Load

Truss

Nairobi


25/99

Revised by: Test1

Checked by: Test2

REF OUTPUT



DL + LL = F = 0.080 kN DL + WL = F = -0.041 kN


Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 0.006

Zreq. = M/dm = 532.8005 mm3

25x50


Zprov. = bd2/6 = 10417 mm3



2Emin = 3600

I = bd3/12 = 260417 mm4



1.8 > 0.1

Deflection OK

Adopt







P1 = 5.56/8= 0.700 1.638= P3 = 0.204

P2 = 0.7/= 0.350 P4 = 0.102R = 7.19/= 3.595 -0.102 = 3.493 kN


1 2098 13.53 9.470764 kN 1.93 kN

2 2098 13.53 9.470764 kN 1.93 kN

3 2098 11.60 8.117798 kN 1.93 kN

4 2098 9.66 6.764832 kN 1.93 kN

5 2098 2.12 1.482571 kN 0.00 kN

6 2098 2.39 1.67646 kN 0.00 kN

7 2098 2.74 1.915207 kN 0.00 kN

8 2098 13.07 9.148381 kN 1.87 kN

9 2098 11.20 7.841469 kN 1.87 kN

10 2098 9.34 6.534558 kN 1.87 kN

11 2098 7.47 5.227646 kN 1.87 kN

Project:truss

CALCULATIONS

25x50


COMP.

TENSION


26/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT

RAFTER DESIGN

Critical Member is: 1BS 5268 F = 9.47 kN Compression

Pt 3 L = 2098 mm 50x150




Pt 2 r = 43.30 A = 7500

2.11.4 l = 43.61 Zprov. = bd2/6 = 2E+05



BS 5268 h = 0.005 l = 0.218 N = 1.5 dgrade = 6.00 N/mm2


( ) = 1.51235477( )SQD = 2.287 () = 1.662 K12 = 1.12

Annex B K3 = 1.5 K12 = 1.00

dadm(c) = dgrade x K3K12 = Emin = 3600 N/mm

2

dadm(c) = 10.096 N/mm2


da(c) F/A = = 1.263 N/mm2


< 10.096 Section OK



6.4.2 F = 9.47076 kN K7 = (300/d)^0.11





= 10.6844 da(b) .= M/Z = 2.27 N/mm2


BS 5268 da(c) = 1.263 + 2.27 de = PI^2E


2.11.6 de de == 0.125 + 0.238 = 0.3634


BOTTOM TIE DESIGN




I = bd3/12 = 2.8E+07 use 100x150

A = 15000

BS 5268 bd2/6 = 375000

Pt 2

2.12 dgrade = 3.00 N/mm2

K14 = (300/d)^0.11

K14 = 1.08


= 3.24 N/mm2


da(t) F/A = 0.44 N/mm2


< 3.24


P.O. Box 7136-001 Date:

Nairobi

Project:truss

CALCULATIONS

14062500

187500

.+ da(b)

100x150

Section O

Nairobi


27/99

Revised by: Test1

Checked by: Test2

REF OUTPUT




Try GS grade Cypress = 50 x 100dgrade = 3.00 N/mm

2

K14 = (300/d)^0.11 A = 5000

K14 = 1.13


= 3.39 N/mm2




#REF! 3.39



Pt 3 L = 2098 mm 50x100




Pt 2 r = 28.87 A = 50002.11.4 l = 65.40 Zprov. = bd^2/6 = 83333



BS 5268 h = 0.005 l = 0.327 N = 1.5 dgrade = 6.00 N/mm2


Annex B ( ) = 0.86 )SQD = 0.74 () = 0.53 K12 = 0.82

K3 = 1.5




da(c) F/A = = 1.35 N/mm2



CP3 LOAD SUMMARY

BS 5268 Total Span = 8300Pt 2 1996 Load Type of Load



Long Dead 2.10 1.0

Term Only

Medium Dead + 2.10

Term Temp. Li 0.68

TOTAL 2.78 1.25


Term Wind 1.59

TOTAL -0.54 1.75


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2Project:

truss

Project:truss

CALCULATIONS

50x100

#REF!

4166666.7

83333.3

Typical Load

Nairobi


28/99

REF OUTPUT



DL + LL = F = 2.780 kN DL + WL = F = 1.590 kN



Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 1.043

Zreq. = M/dm = 92574.09 mm3 50x150

For 50 x 150 mm

Zprov. = bd2/6 = 187500 mm


Deflection Check

Emin = 3600I = bd

3/12 = 1562500 mm



9 > 34.75

Deflecti

Adopt Redesign

CALCULATIONS


29/99

Page

1 of 3


30/99

Page

N

KN

1 of 3


31/99

Page

n

Page

1 of 3


32/99

N/mm2

mm

mm

mm

kN

mm

mm


33/99

Page

35559

1901.5

18.701

Page

1 of 3


34/99

mm2

Page

1 of 3


35/99

N/mm2

mm

mm

n NOT O


36/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

CODE OUTPUT

DATA

UNITS

M.

KN/M

N/mm2

M2

Kg/M3


3.86561806

N 3.73403308


Truss Webs 100 x 50 0.005 m2







Weight








Weight of Truss




77.5 Kg = 0.77 kN/truss


2.48 kN/trus 0.25



0.99 " 0.10


4.05 kN/truss



2.04 kN/truss


2.45 "


Nairobi

Project:truss

CALCULATIONS


37/99




P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT





CP3 WIND LOAD x









5.6


28 x 1 x 0.9 x 1 = 25.2

Vs= 25.2


therefore, q= 0.613 x 0.613 x 0.613 = 389 N/m2

= 0.389 N/m2



Width w = 9.425 m h/w = 1.719


Cpe = -0.8 Wind on

Cpe = -0.65 End


CP3 Cpi = 0.2



7.2



UPLIFT



Truss Span = 6.8 m

Overall Span = 6.8 m 1.2x6.8 = 8.16 m2



Nairobi

Project:truss

CALCULATIONS

tributary area to

truss



38/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT




GRAVITY LOADS

Imposed Load:

Imposed Load = 0.25

Dead Loads :





total = 0.52



Total DL = 4.25 = 2.84

kN/truss


total 4.20


0.95

kN/truss

0.68

total 0.68

3) Batten

Imposed = = 0.05 KN

Dead = 0.3 x 0.3 x 0.6 = 0.03 KN

CP3 LOAD SUMMARY x





Long Dead 4.20 0.95 0.03 1.0

Term Only

Medium Dead + 4.20 0.95 0.030

Term Temp. Li 1.36 0.68 0.05

TOTAL 5.56 1.63 0.080 1.25


Term Wind 3.18 -0.071

TOTAL 1.02 -0.041 1.75


Nairobi

Project:truss

CALCULATIONS

0.52 x 6.8 x 1.2 =

0.25 x 6.8 x 1.2 =

Total DL =

Total IL =

0.25 x 0.3 x 0.6

Typical Load

Truss

Nairobi


39/99

Revised by: Test1

Checked by: Test2

REF OUTPUT



DL + LL = F = 0.080 kN DL + WL = F = -0.041 kN


Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 0.006

Zreq. = M/dm = 532.8005 mm3

25x50


Zprov. = bd2/6 = 10417 mm3



2Emin = 3600

I = bd3/12 = 260417 mm4



1.8 > 0.1

Deflection OK

Adopt







P1 = 5.56/4= 1.390 1.633= P3 = 0.543

P2 = 1.39/= 0.695 P4 = 0.272R = 7.19/= 3.595 -0.272 = 3.323 kN


1 2098 5.80 8.059814 kN 1.93 kN

2 2098 5.80 8.059814 kN 1.93 kN

3 2098 2.12 2.943963 kN 0.00 kN

4 2098 5.60 7.785459 kN 1.87 kN

5 2098 3.73 5.190306 kN 1.87 kN


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT

RAFTER DESIGN

Project:truss

CALCULATIONS

25x50


CO

MP.

TENSI

ON

Nairobi

Project:truss

CALCULATIONS


40/99



Pt 3 L = 2098 mm 50x150




Pt 2 r = 43.30 A = 7500

2.11.4 l = 43.61 Zprov. = bd2/6 = 2E+05< 180 Slender Ratio OK


BS 5268 h = 0.005 l = 0.218 N = 1.5 dgrade = 6.00 N/mm2


( ) = 1.51235477( )SQD = 2.287 () = 1.662 K12 = 1.12

Annex B K3 = 1.5 K12 = 1.00


dadm(c) = 10.096 N/mm2


da(c) F/A = = 1.075 N/mm2


< 10.096 Section OK



6.4.2 F = 8.05981 kN K7 = (300/d)^0.11L = 2098 mm K7 = 1.08 Depth Factor




= 10.6844 da(b) .= M/Z = 2.27 N/mm2


BS 5268 da(c) = 1.075 + 2.27 de = PI^2E

Pt 2 dadm(c) dadm(b) (1-1.5dadm(c) x K1 10.09629 10.6844 0.9 l ^2

2.11.6 de de =

= 0.106 + 0.236 = 0.3421


BOTTOM TIE DESIGN




I = bd3/12 = 2.8E+07 use 100x150

A = 15000

BS 5268 bd2/6 = 375000

Pt 2

2.12 dgrade = 3.00 N/mm2

K14 = (300/d)^0.11

K14 = 1.08


= 3.24 N/mm2


da(t) F/A = #REF! N/mm2


#REF! 3.24


Revised by: Test1

Checked by: Test2

REF OUTPUT




14062500

187500

.+ da(b)

100x150

#REF!

Nairobi

Project:truss

CALCULATIONS


41/99


dgrade = 3.00 N/mm2

K14 = (300/d)^0.11 A = 5000

K14 = 1.13


= 3.39 N/mm2




#REF! 3.39


BS 5268 F = #REF! kN Compression

Pt 3 L = #REF! mm 50x100

6.5.5 Le = #REF! mm Effective Length Le = 0.9 x L



Pt 2 r = 28.87 A = 5000

2.11.4 l = #REF! Zprov. = bd^2/6 = 83333

#REF! 180 #REF!

2.11.5 Since l > 5 l SQD = #REF! Multiply grade stress by K12 x

BS 5268 h = 0.005 l = #REF! N = 1.5 dgrade = 6.00 N/mm2


Annex B ( ) = #REF! )SQD = #REF! () = #REF! K12 = #REF!K3 = 1.5


dadm(c) = #REF! N/mm2


da(c) F/A = = #REF! N/mm2


#REF! #REF! #REF!

CP3 LOAD SUMMARY





Long Dead 2.10 1.0

Term Only

Medium Dead + 2.10

Term Temp. Li 0.68

TOTAL 2.78 1.25


Term Wind 1.59

TOTAL -0.54 1.75


P.O. Box 7136-001 Date:Revised by: Test1

Checked by: Test2

REF OUTPUT



DL + LL = F = 2.780 kN DL + WL = F = 1.590 kN


Project:truss

50x100

#REF!

4166666.7

CALCULATIONS

83333.3

Typical Load

Nairobi


42/99


Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2


K7 = 1.1 Load Sharing Factor K8 = 1.17 Depth Factor

dm = 11.26 N/mm2

M = 1.043

Zreq. = M/dm = 92574.09 mm3 50x150

For 50 x 150 mm

Zprov. = bd2/6 = 187500 mm


Deflection Check

Emin = 3600

I = bd3/12 = 1562500 mm



9 > 34.75

Deflecti

Adopt Redesign


43/99

Page

1 of 3


44/99

Page

N

KN

1 of 3


45/99

Page

n

Page

1 of 3


46/99

N/mm2

mm

mm

mm

kN

mm

mm

Page

1 of 3


47/99

35559

1901.5

18.701

Page

1 of 3


48/99

mm2

Page

1 of 3


49/99

N/mm2

mm

mm

n NOT O


50/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

CODE OUTPUT

DATA

UNITS

M.

KN/M

N/mm2

M2

Kg/M3


2.92522668

N 2.74899093


Truss Webs 100 x 50 0.005 m2







Weight








Weight of Truss




79.0 Kg = 0.79 kN/truss


2.55 kN/trus 0.25



1.02 " 0.10


4.16 kN/truss



2.04 kN/truss


2.47 "


Nairobi

Project:truss

CALCULATIONS


51/99




P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT





CP3 WIND LOAD x









5.6


28 x 1 x 0.9 x 1 = 25.2

Vs= 25.2


therefore, q= 0.613 x 0.613 x 0.613 = 389 N/m2

= 0.389 N/m2



Width w = 9.425 m h/w = 1.719


Cpe = -0.8 Wind on

Cpe = -0.65 End


CP3 Cpi = 0.2



7.2



UPLIFT



Truss Span = 6.8 m

Overall Span = 6.8 m 1.2x6.8 = 8.16 m2



Nairobi

Project:truss

CALCULATIONS

tributary area to

truss



52/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT




GRAVITY LOADS

Imposed Load:

Imposed Load = 0.25

Dead Loads :





total = 0.52



Total DL = 4.25 = 2.84

kN/truss


total 4.20


0.95

kN/truss

0.68

total 0.68

3) Batten

Imposed = = 0.05 KN

Dead = 0.3 x 0.3 x 0.6 = 0.03 KN

CP3 LOAD SUMMARY x





Long Dead 4.20 0.95 0.03 1.0

Term Only

Medium Dead + 4.20 0.95 0.030

Term Temp. Li 1.36 0.68 0.05

TOTAL 5.56 1.63 0.080 1.25


Term Wind 3.18 -0.071

TOTAL 1.02 -0.041 1.75


Nairobi

Project:truss

CALCULATIONS

0.52 x 6.8 x 1.2 =

0.25 x 6.8 x 1.2 =

Total DL =

Total IL =

0.25 x 0.3 x 0.6

Typical Load

Truss

Nairobi


53/99

Revised by: Test1

Checked by: Test2

REF OUTPUT



DL + LL = F = 0.080 kN DL + WL = F = -0.041 kN


Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 0.006

Zreq. = M/dm = 532.8005 mm3

25x50


Zprov. = bd2/6 = 10417 mm3



2Emin = 3600

I = bd3/12 = 260417 mm4



1.8 > 0.1

Deflection OK

Adopt







P1 = 5.56/4= 1.390 1.633= P3 = 0.543

P2 = 1.39/= 0.695 P4 = 0.272R = 7.19/= 3.595 -0.272 = 3.323 kN


1 2098 7.31 10.16516 kN 1.46 kN

2 2098 6.11 8.493023 kN 1.46 kN

3 2098 6.63 9.214809 kN 1.46 kN

4 2098 1.27 1.77173 kN 0.00 kN

5 2098 1.27 1.77173 kN 0.00 kN

6 2098 2.75 3.821097 kN 0.00 kN

7 2098 6.87 9.552743 kN 1.37 kN

8 2098 4.12 5.731646 kN 1.37 kN


P.O. Box 7136-001 Date:

Project:truss

CALCULATIONS

25x50


Nairobi

TENSION

COMP.


54/99

Revised by: Test1

Checked by: Test2

REF OUTPUT

RAFTER DESIGN



Pt 3 L = 2098 mm 50x1506.5.5 Le = 1888.2 mm Effective Length Le = 0.9 x L



Pt 2 r = 43.30 A = 7500

2.11.4 l = 43.61 Zprov. = bd2/6 = 2E+05



BS 5268 h = 0.005 l = 0.218 N = 1.5 dgrade = 6.00 N/mm2


( ) = 1.51235477( )SQD = 2.287 () = 1.662 K12 = 1.12

Annex B K3 = 1.5 K12 = 1.00


dadm(c) = 10.096 N/mm2


da(c) F/A = = 1.355 N/mm2

(Applied Compression Stress)< 10.096 Section OK



6.4.2 F = 10.1652 kN K7 = (300/d)^0.11





= 10.6844 da(b) .= M/Z = 2.27 N/mm2


BS 5268 da(c) = 1.355 + 2.27 de = PI^2E


2.11.6 de de =

= 0.134 + 0.241 = 0.3752

Adopt 50x150 since < 1BOTTOM TIE DESIGN


F = 9.55 kN Tension


I = bd3/12 = 2.8E+07 use 100x150

A = 15000

BS 5268 bd2/6 = 375000

Pt 2

2.12 dgrade = 3.00 N/mm2

K14 = (300/d)^0.11

K14 = 1.08


= 3.24 N/mm2


da(t) F/A = 0.64 N/mm

2

(Applied Tensile Stress)< 3.24


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

Project:truss

CALCULATIONS

.+ da(b)

100x150

Section O

Nairobi

Project:truss

14062500

187500


55/99

REF OUTPUT



F = 5.73 kN Tension


dgrade = 3.00 N/mm2

K14 = (300/d)^0.11 A = 5000K14 = 1.13


= 3.39 N/mm2


da(t) F/A = 1.15 N/mm2


< 3.39



Pt 3 L = 2098 mm 50x100




Pt 2 r = 28.87 A = 5000

2.11.4 l = 65.40 Zprov. = bd^2/6 = 83333



BS 5268 h = 0.005 l = 0.327 N = 1.5 dgrade = 6.00 N/mm2

Pt 2 pSQD = 9.88 dc = 6x1.75= 10.5 K3 = 1.75 For very short term

Annex B ( ) = 0.86 )SQD = 0.74 () = 0.53 K12 = 0.82

K3 = 1.5




da(c) F/A = = 1.84 N/mm2



CP3 LOAD SUMMARY



2.8 and Duration Load DurationTable 14 Rafter Level Factor K3

Long Dead 2.10 1.0

Term Only

Medium Dead + 2.10

Term Temp. Li 0.68

TOTAL 2.78 1.25


Term Wind 1.59

TOTAL -0.54 1.75


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT

Project:truss

CALCULATIONS

50x100

Section O

4166666.7

CALCULATIONS

83333.3

Typical Load

Nairobi


56/99



DL + LL = F = 2.780 kN DL + WL = F = 1.590 kN



Bending CheckZreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 1.043

Zreq. = M/dm = 92574.09 mm3 50x150

For 50 x 150 mm

Zprov. = bd2/6 = 187500 mm


Deflection Check

Emin = 3600

I = bd3/12 = 1562500 mm


Max allowable deflection = 0.003L = = 99 > 34.75

Deflecti

Adopt Redesign


57/99

Page

1 of 3


58/99

Page

N

KN

1 of 3


59/99

Page

n

Page

1 of 3


60/99

N/mm2

mm

mm

mm

kN

mm

mm

Page


61/99

35559

1901.5

18.701

Page

1 of 3


62/99

mm2

Page

1 of 3


63/99

N/mm2

mm

mm

n NOT O


64/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

CODE OUTPUT

DATA

UNITS

M.

KN/M

N/mm2

M2

Kg/M3


3.86561806

N 3.73403308


Truss Webs 100 x 50 0.005 m2







Weight








Weight of Truss




77.5 Kg = 0.77 kN/truss


2.48 kN/trus 0.25



0.99 " 0.10


4.05 kN/truss



2.04 kN/truss


2.45 "


Nairobi

Project:truss

CALCULATIONS


65/99




P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT





CP3 WIND LOAD x









5.6


28 x 1 x 0.9 x 1 = 25.2

Vs= 25.2


therefore, q= 0.613 x 0.613 x 0.613 = 389 N/m2

= 0.389 N/m2



Width w = 9.425 m h/w = 1.719


Cpe = -0.8 Wind on

Cpe = -0.65 End


CP3 Cpi = 0.2



7.2



UPLIFT



Truss Span = 6.8 m

Overall Span = 6.8 m 1.2x6.8 = 8.16 m2



Nairobi

Project:truss

CALCULATIONS

tributary area to

truss



66/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT




GRAVITY LOADS

Imposed Load:

Imposed Load = 0.25

Dead Loads :





total = 0.52



Total DL = 4.25 = 2.84

kN/truss


total 4.20


0.95

kN/truss

0.68

total 0.68

3) Batten

Imposed = = 0.05 KN

Dead = 0.3 x 0.3 x 0.6 = 0.03 KN

CP3 LOAD SUMMARY x





Long Dead 4.20 0.95 0.03 1.0

Term Only

Medium Dead + 4.20 0.95 0.030

Term Temp. Li 1.36 0.68 0.05

TOTAL 5.56 1.63 0.080 1.25


Term Wind 3.18 -0.071

TOTAL 1.02 -0.041 1.75


Nairobi

Project:truss

CALCULATIONS

0.52 x 6.8 x 1.2 =

0.25 x 6.8 x 1.2 =

Total DL =

Total IL =

0.25 x 0.3 x 0.6

Typical Load

Truss

Nairobi


67/99

Revised by: Test1

Checked by: Test2

REF OUTPUT



DL + LL = F = 0.080 kN DL + WL = F = -0.041 kN


Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 0.006

Zreq. = M/dm = 532.8005 mm3

25x50


Zprov. = bd2/6 = 10417 mm3



2Emin = 3600

I = bd3/12 = 260417 mm4



1.8 > 0.1

Deflection OK

Adopt







P1 = 5.56/4= 1.390 1.633= P3 = 0.543

P2 = 1.39/= 0.695 P4 = 0.272R = 7.19/= 3.595 -0.272 = 3.323 kN


1 2098 5.80 8.059814 kN 1.93 kN

2 2098 3.87 5.373209 kN 1.93 kN

3 2098 1.93 2.686605 kN 0.00 kN

4 2098 5.60 7.785459 kN 1.87 kN

5 2098 5.60 7.785459 kN 1.87 kN


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT

Project:truss

Project:truss

CALCULATIONS

CALCULATIONS

25x50


Nairobi

TENSI

ON

COMP.


68/99

RAFTER DESIGN



Pt 3 L = 2098 mm 50x150




Pt 2 r = 43.30 A = 75002.11.4 l = 43.61 Zprov. = bd2/6 = 2E+05



BS 5268 h = 0.005 l = 0.218 N = 1.5 dgrade = 6.00 N/mm2


( ) = 1.51235477( )SQD = 2.287 () = 1.662 K12 = 1.12

Annex B K3 = 1.5 K12 = 1.00


dadm(c) = 10.096 N/mm2


da(c) F/A = = 1.075 N/mm2


< 10.096 Section OK


Pt 3 Man Point Load P = 0.9 kN K3 = 1.5 Duration Factor 6.4.2 F = 8.05981 kN K7 = (300/d)^0.11





= 10.6844 da(b) .= M/Z = 2.27 N/mm2


BS 5268 da(c) = 1.075 + 2.27 de = PI^2E

Pt 2 dadm(c) dadm(b) (1-1.5dadm(c) x K1 10.09629 10.6844 0.9 l ^2

2.11.6 de de =

= 0.106 + 0.236 = 0.3421


BOTTOM TIE DESIGN


F = 7.79 kN Tension


I = bd3/12 = 2.8E+07 use 100x150

A = 15000

BS 5268 bd2/6 = 375000

Pt 2

2.12 dgrade = 3.00 N/mm2

K14 = (300/d)^0.11

K14 = 1.08


= 3.24 N/mm2


da(t) F/A = 0.52 N/mm2


< 3.24


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT



100x150

Section O

Nairobi

Project:truss

CALCULATIONS

14062500

187500

.+ da(b)


69/99



dgrade = 3.00 N/mm2

K14 = (300/d)^0.11 A = 5000

K14 = 1.13


= 3.39 N/mm2



(Applied Tensile Stress)#REF! 3.39


BS 5268 F = #REF! kN Compression

Pt 3 L = #REF! mm 50x100

6.5.5 Le = #REF! mm Effective Length Le = 0.9 x L



Pt 2 r = 28.87 A = 5000

2.11.4 l = #REF! Zprov. = bd^2/6 = 83333

#REF! 180 #REF!

2.11.5 Since l > 5 l SQD = #REF! Multiply grade stress by K12 x

BS 5268 h = 0.005 l = #REF! N = 1.5 dgrade = 6.00 N/mm2

Pt 2 pSQD = 9.88 dc = 6x1.75= 10.5 K3 = 1.75 For very short ter Annex B ( ) = #REF! )SQD = #REF! () = #REF! K12 = #REF!

K3 = 1.5


dadm(c) = #REF! N/mm2


da(c) F/A = = #REF! N/mm2


#REF! #REF! #REF!

CP3 LOAD SUMMARY





Long Dead 2.10 1.0

Term Only

Medium Dead + 2.10

Term Temp. Li 0.68

TOTAL 2.78 1.25


Term Wind 1.59

TOTAL -0.54 1.75


Revised by: Test1

Checked by: Test2

REF OUTPUT



DL + LL = F = 2.780 kN DL + WL = F = 1.590 kN

Project:truss

50x100

#REF!

4166666.7

CALCULATIONS

83333.3

Typical Load

Nairobi


70/99



Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2

K3 = 1.75 Load Duration Factor K7 = 1.1 Load Sharing Factor


dm = 11.26 N/mm2

M = 1.043

Zreq. = M/dm = 92574.09 mm3 50x150

For 50 x 150 mm

Zprov. = bd2/6 = 187500 mm


Deflection Check

Emin = 3600

I = bd3/12 = 1562500 mm



9 > 34.75

Deflecti

Adopt Redesign


71/99

Page

1 of 3


72/99

Page

N

KN

1 of 3


73/99

Page

n

Page

1 of 3


74/99

N/mm2

mm

mm

mm

kN

mm

mm

Page

1 of 3


75/99

35559

1901.5

18.701

Page

1 of 3


76/99

mm2

Page

1 of 3


77/99

N/mm2

mm

mm

n NOT O


78/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

CODE OUTPUT

DATA

UNITS

M.

KN/M

N/mm2

M2

Kg/M3


2.92522668

N 2.74899093


Truss Webs 100 x 50 0.005 m2







Weight








Weight of Truss




79.0 Kg = 0.79 kN/truss


2.55 kN/trus 0.25



1.02 " 0.10


4.16 kN/truss



2.04 kN/truss


2.47 "


Nairobi

Project:truss

CALCULATIONS


79/99




P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT





CP3 WIND LOAD x









5.6


28 x 1 x 0.9 x 1 = 25.2

Vs= 25.2


therefore, q= 0.613 x 0.613 x 0.613 = 389 N/m2

= 0.389 N/m2



Width w = 9.425 m h/w = 1.719


Cpe = -0.8 Wind on

Cpe = -0.65 End


CP3 Cpi = 0.2



7.2



UPLIFT



Truss Span = 6.8 m

Overall Span = 6.8 m 1.2x6.8 = 8.16 m2



Nairobi

Project:truss

CALCULATIONS

tributary area to

truss



80/99


P.O. Box 7136-001 Date:

Revised by: Test1

Checked by: Test2

REF OUTPUT




GRAVITY LOADS

Imposed Load:

Imposed Load = 0.25

Dead Loads :





total = 0.52



Total DL = 4.25 = 2.84

kN/truss


total 4.20


0.95

kN/truss

0.68

total 0.68

3) Batten

Imposed = = 0.05 KN

Dead = 0.3 x 0.3 x 0.6 = 0.03 KN

CP3 LOAD SUMMARY x





Long Dead 4.20 0.95 0.03 1.0

Term Only

Medium Dead + 4.20 0.95 0.030

Term Temp. Li 1.36 0.68 0.05

TOTAL 5.56 1.63 0.080 1.25


Term Wind 3.18 -0.071

TOTAL 1.02 -0.041 1.75


Nairobi

Project:truss

CALCULATIONS

0.52 x 6.8 x 1.2 =

0.25 x 6.8 x 1.2 =

Total DL =

Total IL =

0.25 x 0.3 x 0.6

Typical Load

Truss

Nairobi


81/99

Revised by: Test1

Checked by: Test2

REF OUTPUT



DL + LL = F = 0.080 kN DL + WL = F = -0.041 kN


Bending Check

Zreq. = M/dm


dgrade = 5.00 N/mm2




dm = 11.26 N/mm2

M = 0.006

Zreq. = M/dm = 532.8005 mm3

25x50


Zprov. = bd2/6 = 10417 mm3



2Emin = 3600

I = bd3/12 = 260417 mm4



1.8 > 0.1

Deflection OK

Adopt







P1 = 5.56/4= 1.390 1.633= P3 = 0.543

P2 = 1.39/= 0.695 P4 = 0.272R = 7.19/= 3.595 -0.272 = 3.323 kN


1 2098 7.31 10.16516 kN 1.46 kN

2 2098 5.85 8.13213 kN 1.46 kN

3 2098 4.39 6.099098 kN 1.46 kN

4 2098 1.46 2.033033 kN 0.00 kN

5 2098 1.70 2.362688 kN 0.00 kN

6 2098 6.87 9.552743 kN 1.37 kN

7 2098 6.87 9.552743 kN 1.37 kN

8 2098 5.50 7.642195 kN 1.37 kN


P.O. Box 7136-001 Date:

Project:truss

CALCULATIONS

25x50


COMP.

TENSION

Nairobi


82/99

Revised by: Test1

Checked by: Test2

REF OUTPUT

RAFTER DESIGN



Pt 3 L = 2098 mm 50x1506.5.5 Le = 1888.2 mm Effective Length Le =

kenyan timber stresses

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