Hillerborg Strip Method

[Sasas2]

Hey,
Can anybody tell me if the hillerborg strip method is appropriate for designing a basement wall fixed at the ends and base and free at the top. im assuming that moment is taken by the base from a triangle (inclined at 30 degrees) at the bottom of the wall..Thanks!

 

[vaquers]

Dear Sasas2,
I wouldn't use the strip method except for slabs of an irregular shape. You should look after this textbook: "Tables for Analysis of Plates, Slabs and Diaphragms based on the Elastic Theory" by Richard Bares. There you can find the moment, shear and deformation for typical cases. Attached you can find your case. Regards,

Sebastian

 

[cap4000]

I recommend you get the "Strip Method Design Handbook" by Hillerborg. I have Nilson's concrete design book but it does not have your case.

 

[cap4000]

vaquers,

Your table is for 3 sides fixed.

 

[vaquers]

Dear cap400,
Meaby I missunderstood, but Sasas2 wrote: "basement wall fixed at the ends and base and free at the top". I thought he meant 3 sides fixed and the other free.

 

[BAretired]

If the load is from soil pressure, it is not uniform, so you may want to use a triangular loading, although the actual soil pressure is not precisely known.

I believe the Hillerborg strip method is a good method to use. You could use Yield Line Theory too, but Hillerborg is probably more conservative.

BA

 

[cap4000]

vasquers,

I think your are right. In which case the Nilson concrete book has the 3 sides fixed and 1 free edge loading diagram.

 

[Sasas2]

Thanks guys!Suppose im going to have to get down to some moment redistribution now too!

 

[rscassar]

I guess it would depend on the height to width ratio. If the wall is particularly wide compared to its height then the wall would need to be designed as a cantilever wall in the vertical direction. If the height:width ratio creates two-way interaction then I would look at using something like hilleborg strip to distribute moments.

 

[sdz]

Yes, Hilleborg's strip method is an appropriate method if you want to use it. It is fairly simple and straight forward but make sure you understand it first.

 

[RHTPE]

I would be caution about considering the base of the wall as being fixed. That would have to presume that the footing will not rotate - how much rotation will effectively negate any fixity you think you may have?


Ralph
Structures Consulting
Northeast USA

 

[hokie66]

Agree with Ralph. As well, modelling the corners with complete fixity is not appropriate with the usual corner reinforcement detailing. Nillson's book talks about efficiency of various types of corner details.