Weird textures on top of "U" shaped mesh

(Sorry for using “weird” to describe the problem. I really don’t know what is going on with the textures.)

Hello, everyone. I’m a beginner on blender and recently I had a problem that I couldn’t find a solution to.
I’ve finished the Andrew Price’s modeling a subway tunnel recently, and I’ve decided to do it again but with a slight different shape. I’m trying to do a U-shaped tunnel, sort of like the ones you see on sewers.
So, I tried to texture it (without UV unwrapping or anything like that, Andrew doesn’t uses that on the tutorial and all of my attempts to unwrap it were a failure), but I’m getting a weird texture on the top of the tunnel.
I’ve tried a bunch of things, like changing the texture projection from flat to tube, changing the repeat of the texture mapping, changing the X Y and Z things on the texture mapping, flipping and recalculating normals, and some other things that I can’t remember now.
So, how can I fix it?
By the way, in the end of the tunnel, the textures are… expanded. Is there any way to fix that? Increasing the image mapping X repeat made the tiles closer to the camera look smaller and shrinked.

My blender version is 2.65, if that helps. I’ve added a picture below of how it is looking like.
Thanks for the attention.

you will need to learn how to unwrap someday so why not now? The problem is IMO insoluble without unwrapping - because of the two curves, one on top and one at the end, no projection texture mapping method will work. After unwrapping the problem will just go away. This is not even a challenging unwrap - select all your faces deselect and reselect one that is particularly nice and square and do follow active quads. This should lay out your geometry nicely unless there is something quite strange that I can’t see. If your texture is small and shaped like your quads you might just be able to unwrap reset and have it repeat just right with one repeat per quad. Good luck.

Hey, sorry for the late answer. Thanks for responding, but I got another way around to make it work. I changed the projection to cube, so that it doesn’t extends and changed the X Y and Z settings until I got something that worked for me.
Again, thanks for taking your time to answer this, and next time I’ll try to unwrap it first.