New opening in existing Tilt-Up wall

[struc100]

New opening will be cut (10 ft high x 10 ft wide) into an existing load bearing tilt up wall, I have attach a sketch and a support system with steel tube as a header beam and steel colmuns spaning from foundation to roof.

My idea is as follows:
1- The header beam will support the gravity load and the horizontal load from wind.
2- The column will span full ht supporting the reaction from the header beam (gravity and wind)

Is this approch reasnable ,is there any other way support this panel ,or any industry standard for a new opening

 

[msquared48]

A few comments:

1. Considering the arching action of the concrete panel wall, I think a channel after-set bolted to the bottom of the new panel opening, channel face vertical and to the panel inside, flush with the bottom or slightly above, would better suffice than the tube/multiple angle scenario.

2. Check the lateral due to seismic as well as wind. Depending where you are, seismic may control.

3. Other than that, you generally have the common solution in mind.

4. Sometimes, pre-reinforced knockout openings are provided in panels for future openings. I trust that this is not one of those situations. Do you have the panel drawings available?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[struc100]

msqumred48

I could not undrstand (channel after-set bolt) also if the channel is set under the panel in plane of the wall how would you connect it to the steel column.

I would appretiate if you could sketch this detail, it will be easier to undrestand.

Thank you in advance.

 

[msquared48]

I do not think that you would need to attach the channel to the steel columns. The concrete wall should be able to handle the extra vertical load, and much of the vertical load transfers to the side of the new opening before it gets to the channel.

The new vertical tube members are just wind columns and can be placed at the inside panel face. They will see no vertical load from the panel, and take all the lateral force transverse to the panel.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[csd72]

Agree with msquared48, openings in concrete walls do not generally require lintels. This is because they have tensile capacity as opposed to masonry which doesnt.

Use the google search at the top of the page to look for previous posts on the exact same topic.

As the opening is only 10 foot high in a 45 foot panel then you may be able to justify that the 7 foot of remaining panel can take the reduced moment at the top of the opening in combination with the axial load. I have used this method for quite a few panel walls before.

Check that this is not acting as a shear wall.

What is the footing support under?

There will be some cracking at the corners of this opening though this should be minor - I would always notify the client of this.

 

[TTUengr51]

I have a similar situation, but it involved a load bearing precast double T wall. In my scenario, the double T's are 8' wide and the opening is 12' wide. One edge will fall at a vertical joint between T's and the other will occur at the middle of the 8' wide double T.

With the opening spanning across more than one panel, considering arching action isn't possible. There are no connecting plates between the T's along the vertical joints.

Any thoughts on this scenario?

Nick Deal, P.E.
Michael Brady Inc.

http://www.michaelbradyinc.com

 

[struc100]

I undrestand that there will be arching action, but I just don't feel right not installing a lintel to support the wall.
(specialy I know the wall will crack at the corners)

csd72
you mention you have done few of this openings, could you please post a sketch on how did you detail the opening.

I am not concern about the shear wall because the wall is very long 300 ft long,the foundation is 2 ft wide strip footing reinf. at the bottom only.

Thanks

 

[csd72]

On some I could justify not adding anything and on others I did similar to what you are proposing (except usually not with a lintel.

It really depends on how the numbers work out.