World Generation Problems - Intersecting abandoned mineshafts (Possibly a feature)

Seed= -2129711738
Around x:1175 y:35 and z:185 on the above seed there are intersecting abandoned mineshafts. It's possible this is a feature but the intersection caused the above mineshaft to generate without even a wooden floor.If mineshafts are to intersect they should have floors underneath them. See pictures for more details.