Cantilevered Concrete Staircase Landing 3

[otto_eng]

Hi folks,

I have a relatively easy question for the more experienced structural engineers.. I have designed cantilevered balcony slabs for residential buildings in the past but have never done a cantilevered staircase landing for a public space, a school in this case. The location is not in the earthquake zone.
Due to the geometry of the space, there is no backspan of the landing so the plan is to have it directly cantilever it from a concrete wall. In my opinion, by providing sufficient reinforcement and the anchorage length within the wall, this should be doable; however, the dynamic approach of this landing is something that gets in between my progress. Considering this is a school, there will be kids jumping and running around the staircase area.. Would you run an eigenfrequency analysis in this case ?
Has anyone of you done such a similar type of a landing? This is nothing new in the game but I have not seen any references made on this one ? That would be nice if I can get some opinions or references on that !

Cheers!

 

[HTURKAK]

Not sure if statically it is fine. I would have concern for deflection,creep, vibration of 4.0 m cantilever slab...

@loti_eng (Civil/Environmental)(OP),

If your main question is the method of construction of the landing , i will suggest you the use of threaded couplers with shear key .

https://www.maxfrank.com/intl-en/pr...ies/08-threaded-connection-MAX-FRANK-Coupler/

If i were , at least i would try the use of drop beam under the landing . Say My two cents only..


He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48

 

[BAretired]

If deflection is a problem, HTURKAK's drop beam would be worth considering.

 

[Eng16080]

Along the lines of the good ideas mentioned above, is it possible to design the (assumed) railing at the back of the landing as a beam/truss to increase stiffness?

 

[otto_eng]

I decided on having two cantilevered rectangular r.c beams deeper than the landing at each end of the r.c landing, and connecting the landing both to these cantilevered beams and to the wall as well so that the system is stiffer. As a result, I ended up having way better numbers in terms of eigenfrequencies .