Basically when powders get fine enough they may no longer flow easily (paint powders perhaps?). Powder can stick to the edges of the container leaving a hole in the middle ("ratholes") and it may also create "arches" or "bridges" consisting of self-supporting clumps of powder that stick together over the hole, so that the powder doesn't flow into the hole. The words bridge and arch should be immediately recognised by somebody working in the field.

It looks to me as if the text is discussing a certain set of circumstances and could be saying that in such a situation "assume that there is an abnormality in the powder flow and use vibration and other methods to break down any bridges". Of course, 起こす usually means to cause or form, but that doesn't seem logical to me in this context. IF (and it's hard to say without seeing the rest of the text) we're talking about powder flow, why would they want to deliberately create arches that impede that flow? Moreover, vibration is usually employed to get rid of arches and bridges. Note that one meaning of 起こす is to plough, turn over, or break up compacted material like soil or maybe in this case powder. You have the text in front of you, so give it some thought.

Anyway, the term itself is either bridge or arch.