The Central Administration displayed the site in the sites list, but without any reference to the Content Database where it should have been created. No way to remove it using the web interface (all pages displaying information about the site had no content at all).

Then i thought to clean it up and remove via script.

A simple Get-SPSite returned a valid object. But a subsequent Remove-SPSite failed with the dreaded “Unknown SPRequest error.occurred”.

I had to find a quick solution, like a “force delete” when the site cannot be deleted.

Therefore I used a not so well-known operation on the Content Database object: Microsoft.SharePoint.Administration.SPContentDatabase::ForceDeleteSite (see http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.administration.spcontentdatabase.forcedeletesite.aspx).

With this simple PowerShell code I managed to work it out and clean the unwanted or corrupted site.

$site = Get-SPSite http://siteurl
$siteId = $site.Id
$siteDatabase = $site.ContentDatabase 
$siteDatabase.ForceDeleteSite($siteId, $false, $false)

As the Information clearly states in the image As the Information clearly states in the image

Reference: https://sharepoint.stackexchange.com/questions/133131/cannot-delete-site-collection-in-central-administration