A tricky way, with two voices for beats 2 & 3.
(2nd violin part) Enter this, with a 6:12x and a 3:6x tuplets (and force duration):
Edit: it works also with a single 9:18x tuplet
Add the tremolos:
And again 22 and 22 for the next two ones. Result:
It’s OK but we miss the beams for beats 2 and 3.
Let’s add an unisson voice (just eights notes without tuplets):
Then remove the rests, put both voices down stem, voice 2 in voice column index 0, and adjust the beams:
