If I understand correctly you want to split the alignments (horizonal and vertical) that are referenced by a single corridor. If that is the case, I think you will need to separate your corridor as well. How I would go about the actual splitting of the alignments is probably very dependent on how they were generated. I would probably duplicate the alignment file and trim the horizontal. In the vertical I would probably drop the profile, delete the unneeded portions and re-complex/set active. From there I would likely export and reimport those to have clean files/content. For the corridors, depending on complexity, I would again duplicate that file and use the Corridor Reattach command to link the two new corridors back to the respective geometry. 

Steve

Video-How to split an alignment - OpenRail Wiki - OpenRail - Bentley Communities

Video-How to split an alignment - OpenRail Wiki - OpenRail - Bentley Communities

Thanks for your support