Wiktionary
vb. 1 (context transitive English) to completely block or obstruct. 2 (context intransitive English) to be completely blocked or obstructed.
WordNet
Usage examples of "block up".
Line the block up carefully and be as gentle as you can this time.
Then they walked an extra block up Orson Street and reached the top of Cathedral Square before looking back to the corner and noticing that they had already gone past Jefferson.
I parked one block up, just around the corner, and walked back to the house.
I jogged a block up Hartland, crossed Hamilton and plastered myself against the brick wall of an all-night convenience store.
Thorsen, who was invariably standing at her kitchen window washing dishes, then into the street, another half block up, through a gap in the chain-link fence around Tuscola City park, and from there, wherever he wanted to go.
Brian showed up thirty seconds later, doing the same half a block up.
The gunge that would ooze out of Paddington would block up the drains of these flats for weeks.
He suggested inquiring at the Idle Hour, half a block up the street.
From the corner of his eye he could see the gray roadster slowing to a stop about half a block up the street.