1.
If someone or something bears down on you, they move quickly towards you in a threatening way.
A group of half a dozen men entered the pub and bore down on the bar...
= advance
PHRASAL VERB : V P on n , also V P
2.
To bear down on something means to push or press downwards with steady pressure.
The roof support structure had collapsed and the entire weight was bearing down on the ceiling.
PHRASAL VERB : V P on n , also V P