Yes, there are runways numbered on only one side. 

For example, the third runway in the Frankfurt Airport (**18**, Runway west) is used only for takeoffs (to the south) and not for landings. Hence only number **18** is used. The other runways are used for both takeoffs and landings and are numbered 07C/25C, 07R/25L and 07L/25R.

[![enter image description here][1]][1]<BR>Thomas Römer/OpenStreetMap data [<a href="">CC BY-SA 2.0</a>], <a href="">via Wikimedia Commons</a>

This restriction is due to the fact that it will interfere with the traffic in other runways.