Project 1

Aim: To calculate dead load, IRS live load, Earth Pressure load, Wind load & Seismic load and apply it in the Staad model and do the analysis in Staad pro.

Given data:

Unit weight of soil = 18 kN/m3

Solution:

Dead load:

Self-weight command will be used to see the effect of dead load.

Soil load calculation:

Height between the top of the wall to the bottom of the wall = 20 m

Consider the soil is at rest condition, So Ka=0.5

Pressure due to soil at the bottom = 18*20*0.5 = 180 kN/m2

IRS live load:

Metro rail load of each axle having a load of 170 kN to be applied.

wind load:

City:Ahemdabad

Wind speed= 39 m/s

k1= risk coefficient =1.05

k2=terrain factor =1 (for height 0 to 10 m)

k3= topography factor =1

k4 = importance factor for cyclone reigion = 1

Design wind speed (Vz)= 39 x 1.05 x 1 x 1 = 41 m/s

Wind pressure = 0.6 x Vz^2 = 1009 N/m2

Design wind pressure = Kd x Ka X Kc X Pz

Kd= 0.9,Ka=1,Kc=0.9

Design wind pressure = 817.29 kN/m2

Seismic Load:

Seismic Zone -III

Response reduction Factor =1

Importance Factor =1.5

It is to be noted that, as the structure is fully underground, Wind load is not applied.

Load application in Staad Pro.

i) IRS load applied can be seen below.

ii) Seismic parameters considered can be seen below.

Then Seismic load case is created in booth X and Z direction.

iii)Soil Pressure applied is shown below.

Results:

D-wall:

Maximum Bending moment observed =844 kN.m/m

Load case-Seismic (+X)

Base slab:

Maximum Bending moment observed =2022 kN.m/m

Load case- Dead Load

Concourse Slab:

Maximum Bending moment observed =985 kN.m/m

Load case- Seismic (+X)

Roof Slab:

Maximum Bending moment observed =695 kN.m/m

Load case- Dead Load