Week 10 Challenge

1.

Aim- To calculate number of purlins and girts for building.

Given-

Rafter span = 50 m

Bay spacing = 8 m

Roof slope = 1 in 10

Height of column = 12 m

Brick wall height = 2 m

Purlin spacing = 1.2 m

Girt spacing = 1.5 m

Procedure-

• Create model of structure with given dtat in staad.
• Open Staad>cretae file>define nodes and beams>create model>join purlins and girts.

Roof slope=1/10=inverse of tan0.1=5.71m

Middle column height=50cos5.71=50m

Also mid height of node=50tan5.71=5m

No. of purlins=50/1.2=42

No of girts=12-2=10/1.5=7

Draw and assign the columns as per given condition

Provide brick wall at 2m height.

2.

Aim- To taper the beam with BMD envelope given.

Introduction- Here we can taper the beam as per given data.Tapering means carry the loading condition.

Given- Attachment of file

Procedure:

• Check all conditions are assigned completely.
• Taper the beam as per conditions such as reduce the size of section RI.

Go to design parameters such as utility ratio, chec code etc.

After run analysis and check BMD envelope

3.

Aim- To determine wind load for certain category and condition as per IS 875 part 3:2015

Given

Industrial plan 10x5 dimensions.Height of column=6m.

Building Situated in Chennai.

Assume wall opening as 15%.So 6x0.15=0.9m=1m

So wall opening=6-1=5m

Bay Spacing=2.5m.Assume angle of slope=10 degree.

Procedure-

• Define nodes and beams>Create model.
• Go to translation>apply bay spacing>ok
• Go to propertis>define section>tapered section choose>put all data.

• Go to support>create support>apply ok.
• Go to loading>add dead load,live load and wind load>go to case details add and assign load to structure.
• Dead load=5 KN/m^2
• Live load= 5 KN/m^2 Wind load as per IS 875 Part 3
• Location- Chennai
• Basic Wind speed= 50M/s
• Probability factor K1=1
• Terrain roughness and height factor=K2=1
• Topography factor=K3=1
• The importance factor for cyclonic region=K4=1.15
• Design wind speed=Vb*K1*K2*K3*K
• Design wind speed=50*1*1*1.15
• Wind pressure=1.984 KN/m^2=0.6x57.5^2
• Wind directionality factor Kd=1
• Area averaging factor Ka=0.83
• Combination factor Kc=0.9
• Design wind pessure=1.984x1x0.83*0.9
• Design wind pressure=1.984KN/m/62=1.482x6=8.89 KN/m
• Internal pressure coefficient=+/-0.5
• External pressure coefficient=

0 degree EF -0.9

0 degree GH -0.4

90 degree EG -0.8

90 degree FH -0.4

4.

Aim- To find support reaction for given load.

Introduction- Here given is a mono sloped structure.We find the support reactions.It is a reaction on which the support acts.

Given-

• Mono sloped Structure
• Angle of slope= 20 degree
• Width=10m
• Length=30m
• Bay spacing=6m
• No wall sheeting(fully open all around)
• Apply dead load,live load and wind load on the structure and find the support reaction.
• Also perform static check of the total load applied on the structure is captured in support reaction for each load case.
• Self weight factor=1.1
• Roof Sheet loading=0.5 KN/m^2
• Purlin load=6 KN/m^2
• Live load of roof=1.5KN/m^2
• Wind load on rafter(pressure)=2 KN/m^2
• Assume column height= 5m

Procedure:

• Create model of structure.
• Open staad>Create new file> define nodes and beams.
• Mid height of roof=5tan20=1.81m
• Go to translation>apply bay spacing>ok
• Go to propeerties>define section>tapered section choose>put all data.

Go to support>create support>apply ok

Go to loading>add dead load,live load and wind load> go to case details add and assign load to structure.

Roof sheeting load=0.5 KN/m^2

Purlin load=6 KN/m^2

Total dead load=6+0.5=6.5 KNm^2=6.5x6=39 KN/m

Live load=1.5KN/m^2=1.5x6=9 KN/m

Wind load=2KN/m^2=2x6=12 KN/m

Go to run Analysis>choose IS 800 LSD>add and assign design parameters>run analysis>check results.