Project 1

Aim : To calculate the dead load, IRS live load, Earth pressure load, Wind load and seismic load for the bridge located in Ahmedabad metro rail project .

Given data :

Width of the bridge – 24 m

Span of the bridge is – 260 m

Unit weight of soil – 18 kn/m³

Load calculation :

• Dead load : By using the self weight the whole structure dead load will be assigned
• Live load : As per IRS the metro load can be defined.

KN	Distance
170	-
170	2.2
170	12.4
170	2.2

• Earth Pressure :

K = k₀ ɣ h

= 0.35 x 18 x 20

K = 105 KN/m²

• Wind load

Wind speed , V_z = V_b K₁ K₂ K₃ K₄

Basic wind speed, V_b = 39 m/s

K_{1 =} 1.06 as per IS 875 part 3

K₂ = 1.01 category 3

K₃ = 1

K₄ = 1.3

V_z = 39 x 1.06 x 1.01 x 1.3 = 54.27

Wind pressure, P_z = 0.6 x V_z²

P_z = 0.6 x 54.27² = 1.76 KN/m²

• Seismic load : This load can be directly defined in the Staad pro.

Aim : To define and assign the model in a STAAD Pro and perform the analysis and justify with the results.

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Defining the load cases .

Load case > add > click > selfweight > select > click assign to view > assign

Dead load was assigned

Loading > definition > vehicle definition > Add > define load

Load case > Add > load generation > add > give the range value to the exact loacation where the train will run.

Load case > add Earth pressure > click > add plate load > hydrostatic > select plates > enter the calculated value > assign

Earth pressure loads are assigned.

Loading > definition > wind load > select IS 875 part 3 > generate

load case detail > Add > wind load + X,- X, + Z, -Z direction

click each direction > give the ranges > assign

Wind loads are assigned

Loading > definition > seismic load > Add > select IS 1893 > generate > Add

Load > add > selfweight

Load case > add EQX > seismic > X direction > add

Load case > add EQY > seismic > Y direction > add

Seismic loads are defined and assigned.

Run analysis > go to post processing mode > Results

The reactions are generated at the end of the nodes .

• The maximum displacement in X direction is 1.091 mm due to earth pressure
• The minimum displacement in X direction is -1.091 mm due to earth pressure
• The maximum displacement in Y direction is 0.1 mm due to seismic load in Y direction
• The minimum displacement in Y direction is -0.628 mm due to dead load
• The maximum displacement in Z direction is 0.002 mm due to dead load
• The minimum displacement in Z direction is -0.02 mm due to dead load

• The maximum shear force in X direction is 6.63 kn due to seismic load in X direction
• The minimum shear force in X direction is -90.411 kn dead load
• The maximum shear force in Y direction is 102.148 kn live load generation
• The minimum shear force in Y direction is -102.148 kn live load generation
• The maximum shear force in Z direction is 4.166 kn dead load
• The minimum shear force in Z direction is -4.356 kn due to dead load

• The maximum bending moment in X direction is 82.486 knm due to dead load
• The minimum bending moment in X direction is -86.618 knm dead load
• The maximum bending moment in Y direction is 20.994 knm due to earth pressure
• The minimum bending moment in Y direction is -28.056 knm dead load
• The maximum bending moment in Z direction is 1029.880 knm due to earrth pressure
• The minimum bending moment in Z direction is -857.066 knm due to earth pressure

• The maximum shear stress at X direction is 112.879
• The minimum shear stress at X direction is -112.879
• The maximum shear stress at Y direction is 83.239
• The minimum shear stress at Y direction is 83.239

• Reports are taken printout which ever is necessary by using report option.
• In the report option we obtain the results of section forces, displacement, reactions, plate stresses.
• The exact report is to be taken further move to design process.