DDSS - Roof Truss Skip to main content

DDSS - Roof Truss

Design Of Roof Truss:
Design and Drawing of Steel Structure

If load from purlin, false ceiling etc are applied in between the nodes, then principal rafters or main ties are designed for combined stresses from bending and axial loads.

IS 800 - 2007 provides general design procedure for the angle Purlins conforming to steel grade of Fe 410 of O, S, W  and not exceeding slope more than 30 degree based on live load of 750 N/m2.

Loads on Trusses:

Dead Load, Live Load, Wind Load and Snow Load are types of loads on the truss. The main in Design of Truss in small truss and some Industrial Truss.

Dead Load (DL):

If spacing of Truss is 4 m and pitch of truss is 1:4 then self weight of the truss is taken as,
w = (l/3+6) of plan area .... in kN/m2.
Then add all the dead loads with this such as GI sheet, AC sheet and Purlins weight.
Then multiply with the plan area to get the actual DL.

Live Load(LL):

If the angle is less than 10 degree, then the LL will be directly taken as 750 N/m2.
If slope of truss is more than 10 degree, live load is taken as 
LL = 0.75 - 0.02( actual angle - 10) ... in kN/m2.
Then multiply with plan area to get the LL.

Wind Load (WL):

In wind load we need to find,
Vz = Vb.k1.k2.k3.k4
k1 is risk coefficient
k2 is terrian, height, structure size factor
k3 is topography factor
k4 is usually taken as 1
All of the above factors can be found from the IS 875 Part 3, Table 4 and Table 5.

Now, F = (Cep-Cpi).A.Pd
where,
Cpe = External Pressure Coefficient (Towards)
Cpi = Internal Pressure Coefficient (Away)
A = Surface Area of Structural Element
Pd = Pz = Design Wind Pressure in N/m2.

For Cpe:

Get it from Table 8 in the code

For Cpi: 

For Low permeability (less than 5% opening in wall area) = +-0.2
For Medium permeability ( 5- 20 % ) = +-0.5
For Large permeability  (>20%) = +-0.7

The calculate the final WL.

Comments

  1. I generally check this kind of article and I found your article which is related to my interest. Genuinely, it is good and instructive information about roof truss. Thanks for sharing an amazing article here. Dry Ice Blasting

    ReplyDelete
  2. Thank You so much for your comment. I share such short and on point blogs, do check then all.

    ReplyDelete
  3. Excellent information, This information will always help everyone for gaining knowledge. So please always share your valuable information. I am very thankful to you for providing good information. dry ice blasting services

    ReplyDelete
  4. You've written an excellent post, and you've shared it with us. Your article provided me with some unique and useful knowledge outdoor canopy uk. I appreciate you sharing this text with us.

    ReplyDelete
  5. You wrote this post very carefully. The amount of information is stunning and also a gainful article for us. Keep sharing this kind of articles,Hire Professional Roofing Contractors Wilmington Thank you.

    ReplyDelete
  6. Excellent post. I really enjoy reading and also appreciate your work. This concept is a good way to enhance knowledge. Keep sharing this kind of articles, Textile Architecture Thank you.

    ReplyDelete
  7. Excellent post. I really enjoy reading and also appreciate your work. This concept is a good way to enhance knowledge. Keep sharing this kind of articles, Thank you.roofing contractors san antonio

    ReplyDelete
  8. Post was pretty decent. I recently came upon your blog and wanted to let you know how much I've been enjoying reading your writings. I hope you will post soon again. Many thanks for the helpful information.single ply epdm roofing in dublin

    ReplyDelete
  9. Your article contained some good information. I was amazed by how well you were able to express this issue; it was informative for us. Thank you for sharing that.Waterproofing Of a Flat Roof

    ReplyDelete
  10. I esteem your undertakings which you have set into this article. Truly it is a useful article to fabricate our knowledge. Appreciation for share an article like this.Germantown Roofing Company

    ReplyDelete

Post a Comment

Thank You for visiting, if you have any questions please feel free to ask:

Popular posts from this blog

Great Man-Made River (GMR)

Libya's Great Man Made River: The Great Man-Made River in Libya is one of the most ambitious Civil Engineering Project in history of mankind.  In the year 1953, the Libya Government found out not only vast oil reserves but also vast quantity of fresh water locked under the strata, most of the water was trapped around 7000-30000 years ago which is divided in 4 different basins. The first basin is named Kufra basin which is neat Egypt Border which covers almost 35000 sq kilometer which is quite deep around 2000 m deep. The other basin is in Sirte Basin which cover 10000 sq kilometer, third in Murzuk Basin and the last in Jabal Fezzan Basin covering 4800 sq kilometers area.  The GMR project will be used to transfer water to North of the country to provide water for irrigation purpose for more than 6 million  people. This will be a changing point  for Libya and the Colonel Muammar Gaddafi called it the Eighth Wonder of World. The work started in 1984 of the project and estimated to be