If the bottom plate is still exposed the process is the same as if it were a new construction on an existing pad with one additional step.
How to install floor anchors.
The solution is to fit a lock or floor anchor.
If the anchors are installed too close together it can cause an interaction of the forces thus reducing the holding power of the anchors.
Next you could install concrete sleeve anchor which is probably the most common type of cement anchors.
The best option is a heavy duty ground anchor that s bolted into concrete but even a wall anchor screwed into a wooden shed panel or fencepost.
If your shed is already built on a concrete pad which is also its floor but has no anchors holding it to the concrete you can install x 7 concrete expansion anchors.
How to install concrete wedge anchors.
A hammer drill must also be used because it will drill the hole correctly and is designed to break up the base material as it hammers.
Carbide tipped drill bits that meet ansi standards must be used as they are tolerance matched to the concrete fastener.
In order to install them you have to drill a hole the same diameter as the anchor tap the sleeve anchor in the wall and use a wrench to fasten the bolt.
To install a concrete anchor a hole must be drilled in the base material.
Use wedge anchors to fasten studs to concrete.
Wedge anchors are fasteners that rely on expanding sleeves to anchor two by fours permanently.