This script will move the site “ToBeMoved” to be under “ToBeMovedTo” and change its Url and Title to “Moved”
$w = Get-SPWeb 'http://servername/ToBeMoved'
$w.Url
$w.ServerRelativeUrl = '/ToBeMovedTo/Moved'
$W.Title = 'Moved'
$w.Update()
$w.Url
Please note that it will take some time to be updated.