How to make particle system for rectangle with random gaps?

Hi Unity community,

Just wanted to know if it is possible to generate straight rectangles with random gaps in them using the shuriken particle system. I am making a system for obstacle generation in a 2d game and need to make emitting waves with random gaps that the player must go through. Example of the rectangles I would need emitted (bursts):

---- ----- burst 1 (random gap near the middle)
- -------- burst 2 (random gap to the left)
------ --- burst 2 (random gap to the right), etc

Thanks in advance!