How do I add the LaunchPad Icon to the Dock after upgrading fom Snow Leopard to Mavericks?
The Launchpad.app is located in your /Application Folder.

You can either


navigate with the Finder to your /Application Folder and drag it to your dock
search Launchpad.app in Spotlight and CMD+Click the App. Your Finder will open and you can drag the App to your dock