The following assumes you have a Host Named Site Collection.
Backup:
backup-spsite http://oilshop.beaversoil.com -Path e:\MyServerPath\MyFilename.bak -UseSQLSnapShot -force
Technet: http://technet.microsoft.com/en-us/library/ff607901(v=office.15).aspx
Notice nothing special needs to be done in regards to the host named site collection when performing the backup.
Restore:
Restore-SPSite http://oilshop.beaversoil.com -Path \\file_server\share\site_name.bak -HostHeaderWebApplication http://server_name.beaversoil.com
Notice how the actual web application is referenced, this is key
Technet: http://technet.microsoft.com/en-us/library/ff607788(v=office.15).aspx
