Doweling into existing foundation

[htex404040]

Hello all,

I have an existing block foundation which is 15ft by 7ft, not sure of the depth yet but let's assume it is 5ft deep. This footprint is fine to support the existing piece of machinery that is on it now, but it will soon be replaced, the replacement will have a larger footprint which will be 16'-6" by 7ft. So what I need to do is extend the foundation 1'-6", which brings me to my question, the plan is to dowel into the existing foundation to make the connection between the old and the new, me being an EIT I haven't ran into this since I've been working with this company and was wondering what all I need to look at to find out how many dowels I need and how far I need to dowel into the existing concrete to make a sufficient connection.

Any other possible solutions to this problem are very welcome, I may be taking the wrong approach.

This is just in the preliminary stages and I plan to eventually show all my work to my mentor, but just want to make sure I start off on the right foot as to what exactly I need to be looking at as far as making sure my dowels are adequate.

Thanks everyone in advance!

 

[shin25]

All these kind of joints need to be designed per shear friction theory. See ACI 318 chapter-11. Once you are good per shear, check if you have adequate moment capacity.

 

[shin25]

Also, as far as embedment, you have to use adhesive. SIKA has different adhesive for this kind of application. You have to go thru their catalog to find out the kind that fits your purpose.

 

[jike]

Be aware that some adhesives are most sensitive and others are moisture insensitve. I would think that for a foundation or below grade applications or a wash down area you might want one that is moisture insensitive.

Also you might want to consider the working time that the contractor has to install it and the type of environment (temperature, humidity, etc.) he has to work in.