Trump Tower -- the place Donald Trump calls home and work -- is being protected by a line of dump trucks all filled with sand ... and the endgame is to prevent terrorist attacks.
NYC Dept. of Sanitation vehicles showed up early Tuesday, forming a barrier to minimize an attack with explosive devices ... law enforcement tells TMZ.
A Dept. of Sanitation spokesperson tells us they've also got trucks set up at The Peninsula Hotel, Hilton Hotel and Javits Center for the same purpose.
There's also a heavy police presence outside the tower and at The Hilton in NYC ... where Donald's set to celebrate IF he wins.