workshop day-2.pptx

7/29/2019 WORKSHOP DAY-2.pptx

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Workshop OnStructural Analysis And Design

Using Staad.Pro

Civil Engineering DepartmentNational Institute of Technology, Warangal (AP)

March 2013

By

SHASHIKANT GADAG


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Area of the Plan = 100 m2

No. of Storey = 5 (G+4)

Height of each Storey = 4 m (GF)3.5 m (R


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Plan of the Building


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Dimensions of Elements

Thickness of Slab = 150mmBeam Section = 230 * 450 mm

Column Section = 230 * 500 mmWall Thickness = 300/200 mm


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Material Unit weightsBrick work 20 kN/m3

Plain concrete 24 kN/m3Reinforced concrete 25 kN/m3

Earth 16-18 kN/m3

Mortar, plaster

20 kN/m3

Steel 78.5 kN/m3

Water 10 kN/m3

Unit Weights of Materials


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Element Length

(m)

Breadth

(m)

Thickness

(m)

Density

(kN/m3)

Weight

(kN/m2)

Slab 1 1 0.15 25 3.75

Wall 1 1 0.25 20 4.6

Beam 0.23 0.45 1 25 3.45

Column 0.23 0.5 1 25 4.02

Unit Weights of Elements


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Type of floors Minimum Live Load,UDL

Residential building,

All class rooms and kitchen

2.0 kN/m2

Toilet and bath rooms 2.0 kN/m2

Corridors, passages, stair

cases

3.0 kN/m2

Hotels 2.0 kN/m2

X-ray rooms and operating

theatre

3.0 kN/m2

LiveLoads


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Storey Slab Walls Beams Column I.Load Total5 375 80 207 161 300 1123

4 375 1400 207 161 300 2443

3 375 1400 207 161 300 2443

2 375 1400 207 161 300 2443

1(GF) 375 1400 207 161 300 2443

Seismic Weights of Floors

Total = 10895 kN


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Data for Equivalent Static Method:Seismic zone: - Zone IIIDamping ratio: - 5%Seismic zone factor (Z):- 0.16 (Table 2)Importance factor (I):- 1(Table 6)Response reduction factor(R):- 3 (OMRF)


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Fundamental natural period (Ta) = 0.075(h).75

= 0.075x (18).75

= 0.655Sa/g is spectral acceleration = 1/T a = 1/ 0.655 = 1.53

Foundation soil type: - Hard soil

The total seismic Base shear is given byVB = AHW

AH = Design horizontal acceleration spectrum values and

it is determined by the following expression.W = total seismic weight of building


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AH = (Z/2)*(I/R)*(Sa/g)= (0.16/2)*(1/3)*(1.53)

= .0408

The total seismic Base shear

= .0408*10895

Vb= 446 kN


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Vertical Distribution of Base Shearto Different Floor Levels

Qi = VB *(WIhi2/Wihi

2)

Storey Height Qi4 18 m 180.24 kN

3 14.5 m 169.74 kN

2 11 m 97.70 kN1 7.5 m 45.41 kN

GF 4 m 12.92 kN


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Wind Load Calculations

The wind load is calculated as per IS 875(Part-III)

VZ = Vb*k1* k2* k3where ,

Vz = design wind speed at any height z in m/s;

k1 = probability factor (risk coefficient)

k2 = terrain, height and structure size factor

k3 = topography factor.


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Data available:

Vb= design wind speed at any height z in m/s=33 km/h

k1

= probability factor (risk coefficient) =1.0

k2 = terrain, height and structure size factor

=category 3; building class B

k3 = topography factor=1.0


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Design Wind Pressure:

PZ =0.6VZ2

where,PZ = design wind pressure in N/m

2 at height z

VZ = design wind velocity in m/s at height z


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Height K2 Vz(m/s)

Pz(kN/m2)

Up to 9 m

height

0.88 29.04 0.506

9m to 15m 0.94 31.02 0.577

15m to 18m 0.98 32.34 0.627


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workshop day-2.pptx

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