Seeking a reference for design of steel baseplate with stiffeners (BS) 3

[ST04]

Hi,
I have been searching for a while for a good reference guide to design steel baseplate with stiffeners, unfortunately the BS5950 doesn't cover baseplate with stiffeners.

The reference is preferred to be related to British standards.

Thanks in advance
Regards

 

[dik]

You might discuss the costs with a steel fabricator. Unless there are a lot that they can be set up in a semi-automatic fashion, it is normally less costly to design a thicker base plate.

Dik

 

[MrStohler]

I highly recommend Blodgett's "Design of Welded Structures". Although it was written several years ago and refers to the AISC code its methods are still applicable no matter what your jurisdiction.

It can be purchased directly from the publisher at a very reasonable cost

https://ssl.lincolnelectric.com/lincoln/apdirect/store.asp?PID=16&cat=8

 

[delagina]

which particular blodgett book is more recommended. i plan to buy.

design of weldments

or

design of welded structures

 

[slickdeals]

Design of Welded Structures

 

[dhengr]

Add “Solutions to Design of Weldments” to the list, and get all three. There is some overlap, but all three contain enough original and different material to make them complementary. Their cost is small in comparison to the wealth of good design and analysis info. contained in them. If you do much steel design they are very good additions to a starter library. They help an engineer think through a problem in a logical, clean, simple fashion to get a handle on how the structure or component actual works. The approaches and solutions as presented by Omer Blodgett don’t even need FEA to present a picture which helps the engineer understand the basic parts of the problem.

 

[ST04]

Thanks a lot dear colleagues

Best regards

 

[ST04]

If i'm having a member that alternate between tension and compression, and it is having large values of either compression or tension. Is it possible to just have thick plate without stiffeners?

 

[pwht1]

Yeh, depends on the forces of course....

To design base plates you will need to undertake a plastic analysis and don't forget prying when checking the bolt capacity.

 

[ST04]

Thanks pwht1

I was especially asking about (Tension case) because what I have heard is that for columns on tension (some truss chords) you 'have' to provide stiffeners to the base plate.

 

[pwht1]

Nope, there's a bit of material out there that deals with just base-plates on there own. I did my thesis on column base-plates with tension, not that that means much. When designing them I use Hogan and Thomas 'Design of Structural Connection', but that's an Aussie publication.

As long as your yield line/plastic analysis is compatible with your building code stiffeners aren't absolutely necessary, but they could be more economical.

How big a tension load are you looking at?

 

[ST04]

Hi pwht1
Sorry I didn't notice your comment
Thanks for the clarification

It - (Tension)- could reach up to 3600 kN but mostly around 1500-2000 kN.

I have been through some recommendations of providing stiffeners if you have considerable tension also if you have big bending moment.

 

[pwht1]

I could be wrong but a baseplate and hold-down bolts doesn't sound like a cost-effective answer for those sorts of loads. Wouldn't you be better off embedding the steel column into a concrete pier with shear connectors to transfer the load.

 

[a2mfk]

pwht1's last recommendation is good, but you will have to think out the construction sequencing (or the contractor will). They hate to mix trades like that and also not be able to adjust the column on top of the footing. You have to be dead on. But on that similar thought, I forgot what it is called exactly, but you can have tension rods that attach directly to the face of the column and thus bypass the base plate...

 

[ST04]

Thanks a lot dear colleagues
I will see if there is a possibility to do that.

I have one small last question, if you have combined bending moment acting on the column, how would you deal with it on baseplate?
would you consider each axis with its own bending?
or
combine them and find the angle of the axis of the resultant bending relative to x-axis?
or
would you deal with it as a footing with combined bending?

I didn't read or see much talking about such case in the textbooks I have been through.

Best regards

 

[pwht1]

This sounds like a very unusual job high tensile forces and large moments. I'd consider re-looking at the structure so no moments are transferred through the column.

Anyhow, if that can't be done first design the bolt group. Then work out each bolt reaction from the combined biaxial moment/tension. Using those forces you can work backward to determine the plate capacity with a yield line analysis.

A job like this may warrant an FEA, you don't want to stuff it up by assuming the wrong yield line pattern.

 

[ST04]

Thanks pwht1
The last question was not related to the first one.

I appreciate your helpful information.
Best regards