mathcad - 02. design loads

National Technical Training Institute Reinforced Concrete Design in Mathcad

(Design Loads) . (Load on Slab)

.: - La 4m- Lb 5m (compute the slab thickness)

hminPerimeter

F=

2 La Lb F

=

hmin = Perimeter = F = 150 200

hmin2 La Lb

170105.882 mm

hs Ceil hmin 10mm 110 mm

Lectured by: SOK RASMEY, M. Eng, Page 13


1. (Uniformly distributed dead loads)

- (Self-weigth of slab)

Slab hs 25kN

m32.75

kN

m2

- (Ceramic + bedding)

Covering 50mm 22 kNm3

1.1kN

m2

- (Plastering)

Plastering 20mm 20 kNm3

0.4kN

m2

- (Gypsum board ceiling)

Ceiling 0.2kN

m20.4

kN

m2

=

- (Mechanical and electricity)

Mechanical 0.24kN

m2

- (Partition or Others)

Partition 1.5kN

m2

DL Slab Covering Plastering Mechanical Partition 5.99 kNm2

2. (Uniformly distributed live load)

LL 2.4kN

m2 () ( 10)

3. ACI (Load combination according to ACI Code) - (Service limit state, SLS)

ws DL LL 8.39kN

m2

- (Ultimate limit state, ULS)

wu 1.2DL 1.6LL 11.028kN

m2



. (Loads on beam)

.: -

RatioLa

Lb0.5=

RatioLb

La2.0=

0.5 RatioLa

Lb1.0=

1.0 RatioLb

La2.0=

La = Lb =

a. B1 La 4.5m Lb 5.0m

RatioLa

Lb0.9

Slab "is two-way action." 0.5 Ratio 1.0if"is one-way action." otherwise

Slab "is two-way action."



b. B1 La 4.0m Lb 5.0m

RatioLa

Lb0.8

Slab "is two-way action." 0.5 Ratio 1.0if"is one-way action." otherwise

Slab "is two-way action."1. B1 .:

B1 B2: LB1 5.0m LB2 4m

hminLB1

21238.095 mm

(Alternatively):

(Girder): L8

L

10

L

10

L

15

L

15

L

20

hmin

1

10

1

15

LB1 500 333.333( ) mm

h 400mm/ b 0.3 0.6( )h 120 240( ) mm



b 200mm2. ( Distributed dead load)

- B1 b h hs 25 kNm3

1.45kN

m

-

Viod 30mm( )2

4180 mm 4 508.938 cm3

Wall10 120mm55

m2Viod

20 kN

m31.84

kN

m2

Wall20 220mm110

m2Viod

20 kN

m33.28

kN

m2

hw 3.2m 40cm 2.8 mwwall Wall10 hw 5.152

kN

m ()

-

wslab1 DL4.5m

2 13.477 kN

m ( )

wslab2 DL4m

2 11.98 kN

m ( )

3. (Distributed live load)

wLL1 LL4.5m

2 5.4 kN

m

wLL2 LL4m

2 4.8 kN

m

4. ( )

k 1 22 3=a1

4.5m

22.25 m a2

4m

22 m

1a1

LB10.45 2

a2

LB10.4

k1 1 212 13 0.686

k2 1 222 23 0.744



5. (Load combination) 5.1 (Ultimate limit state, ULS)

wu1 1.4 B1 wwall wslab1 k1 wslab2 k2 34.668 kNmwu2 1.2 B1 wwall wslab1 k1 wslab2 k2 1.6 wLL1 k1 wLL2 k2 wu2 41.357

kN

m

wu max wu1 wu2 41.357 kNm5.2 (Service limit state, SLS)

wa B1 wwall wslab1 k1 wslab2 k2 wLL1 k1 wLL2 k2 wa 32.039

kN

m



6. (Calculate the moments)

.: ACI (a) (b) (c) 3m (d)



.: . : ACI

(interior span)



.: - (Ultimate Limit State) (clear span)

Ln1 LB1 30cm 4.7 m ()



Ln2LB1 LB2

230cm 4.2 m ()

Mu.neg1

11wu Ln22 66.322 kN m ()

Mu.pos1

16wu Ln12 57.099 kN m ( )

- (Service Limit State)

Ma.neg1

11wa Ln22 51.379 kN m ()

Ma.pos1

16wa Ln12 44.234 kN m ( )

. (Load on Column)

.:



.: 3D

B 4m L 4.5m AT B L 18 m2 n 9 () H0 2.9m Hmez 2.5m H 3.2m



1. (dead load) PD.slab DL AT n 970.38 kN (slab load)

PBeam b h hs B L( ) 25 kNm3

n 110.925 kN (beam load)

Pwall H0 h Hmez h H h( ) n 3( )

B L( ) Wall10 334.727 kN

5% 7% PColumn PD.slab PBeam Pwall 5 % 70.802 kN

PDL PD.slab PBeam Pwall PColumn 1486.833 kN

2. (Live load) (Live load reduction factor) RLL

RLL 0.254.57m

KLL AT 0.4=

KLL = (live load element factor) KLL 4 (interior column)

RLL max 0.254.572m

KLL AT 0.4

0.789

PLL LL AT RLL n 1( ) 272.615 kN ()

PLr 1.0kN

m2AT 18 kN ()

3. (Load combination) Pu 1.2PDL 1.6PLL 0.5 PLr 2229.383 kNPa PDL PLL PLr 1777.448 kN



wuPu

AT n13.762

kN

m2 wu 1.403

tonnef

m2

waPa

AT n10.972

kN

m2 wa 1.119

tonnef

m2

wu 12 18( )kN

m2=

wa 10 14( )kN

m2=

. (Roof Loads)

.: - H 1.909m- L 2 2.75 m 5.5 m- atan H

0.5L

34.768 deg

- CPAC: wtile 40kgf

m20.392

kN

m2 ( CPAC)

- (Purlin):

spurlin 320mm



25x25x1:

w25x25x1 25mm 25 mm 25mm 1mm 2( ) 25mm 1mm 2( )[ ] 7850kgf

m3

w25x25x1 0.754kgf

m

wpurlinw25x25x1 1 m

spurlin 1 m cos ( )2.867

kgf

m2 wpurlin 0.028

kN

m2

- (Rafter)

srafter 600mm

w40x80x1.8 40mm 80 mm 40mm 1.8mm 2( ) 80mm 1.8mm 2( )[ ] 7850kgf

m3

w40x80x1.8 3.289kgf

m

wrafterw40x80x1.8 1 m

srafter 1 m cos ( )6.674

kgf

m2 wrafter 0.065

kN

m2

- (king post) spost 3.6m Hpost 1.6m

wpost

20cm 20 cm Hpost 25kN

m3

spostL

2

0.162kN

m2

- (ridge beam) Lridge 3.6m

wridge

20cm 30 cm Lridge 25kN

m3

LridgeL

2

0.545kN

m2



wDL wtile wpurlin wrafter wpost wridge 1.193kN

m2

Lr 0.96 R1 R2= 0.58kPa Lr 0.96kPa

R1 =

R2 =

AT spostL

2 9.9 m2 ()

Slope HL

2

69.418 %

F 0.12 Slope%

8.33

R1 1 AT 18.58m2if

1.20.011

m2AT

18.58m2 AT 55.74m2if

0.6 otherwise

R1 1

R2 1 F 4if1.2 0.05 F( ) 4 F 12if

0.6 otherwise

R2 0.783

Lr 0.96kN

m2R1 R2 0.752

kN

m2

wLr max Lr 0.58kN

m2

0.752

kN

m2


mathcad - 02. design loads

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