Pinned top??

[boricuastructural]

I have a retaining wall that Im also using as vertical support for a 8ft - 6in slab. Then, can I assume a pinned top for the wall?

 

[Lion06]

I would say yes since even if you provide enough steel and pour it monolithically, the footing interface will be much stiffer and the top will act as pinned.

 

[shin25]

May be or may be not, depends on -

- The connection design.
- Structural layout that will allow a positive load path for the horizontal thrust from the retaining system.

What kind of structure is it? What are the measures that you are taking for the load transfer?

 

[csd72]

Put a bond breaker at the top of the wall and put dowels in the middle of the wall and then it will definately act as pinned.

Dowels are then there to transfer lateral load only.

csd

 

[Lutfi]

Csd72,

Will ACI allow you to transfer lateral loads via the bars??
I am thinking that you can achieve shear transfer via “shear friction” that will be eliminated by your suggestion of adding a bond breaker.





Regards,
Lutfi

 

[boricuastructural]

The structure is an addtion to an existing structure. Its kind of a balcony. At the end of the existing structure there is a frame of rc columns and a beam and 8 ft apart is going to be the retaining wall. The 6 in slab is going to be supported by the frame of columns at one end and the retaining wall at the other end.

 

[csd72]

I cant see why they wouldnt - it is no different to having chemical anchors into the top of a wall.

I have done a similar detail using threaded bars into ferrules at the top of precast walls and have had no problems with it.

csd

 

[shin25]

What is the depth of soil behind the retaining wall? Is the thrust from the retaining wall too great? Can the existing structure effectively transfer the load to foundation without distress?

 

[boricuastructural]

The soil is on the full height. What do you mean by thrust? (Sorry but english is my second language). The existing structure is approx. 100' by 45' 3 story RC structure, and it has shear walls in both directions for seismic and gravity loads (im in a seismic zone). The addition is going to be a balcony for the first floor only. The columns that are going to support the other side of the slab I have to design them using the same consideration as the building (mostly seismic considerations).

 

[shin25]

I am assuming that the balcony is along the 100' length of the building?

Full height of soil behind the retaining wall and any additional surcharge on top of this soil are going to create some force that needs to be considered. You have consider the design capacity of the shear wall, as this force is going to be additive with the seismic force. Also, the global stability of the structure needs to be checked. This lateral force will create additional overturning moment and sliding force on the shear walls.

By thrust, I meant lateral force on the building from the retaing wall.