All these photos look very flatly lit. I'm guessing that your light was provided by handheld flashlight or on camera flash?
If using a handheld flashlight, do not light from directly behind your camera, or no shadows can be seen. Step to the side as far as you can go to draw out the shadows and make them visible in the shot. On the corrugated tunnel lining, place your flashlight as close to the wall as possible to make the corrugation jump out. Shadows make for contrast, contrast is interesting.
Here's one of mine from a different Titan 1 silo:
I was still learning this technique in the above shot. Subtle difference but very noticeable in the overall feeling.
For sharper shadows, limit the amount of movement around the origin of the light. Don't wave your flashlight back and forth 3 feet. keep the same position but rotate the flashlight from the wrist without moving your elbow. This makes harder edged shadows.
Here's another corrugation example with nice shadows/contrast:
Decent composition in 1 and 7. The centered compo works great here. Keep practicing.
-free