At 28,000 pounds, the modern full-size, 20 ton dump truck is a massive force when in motion. Our 6,000 pound trucks are at a disadvantage of almost 5:1 on mass alone. That you and your family survived is very simply, proof of God. The math doesn't support you surviving, not a chance. I felt the force of one of those truck only very minorly and it was impressive and I instantly knew my truck had no chance of moving his.
I've said before that the only reason I drive an expy is because I am making a choice to minimize dying in a car crash. Yes the room is nice but my kids are all long grown & gone. I'm still single(for a while anyway) but I know the value of mass combined with modern construction techniques and know that in an incident with most other vehicles, I'm at very low risk. Even my slk, while a fun 2 seater conv was selected because of it's Warthog-like passenger compartment with actual guardrails in ea door.
I'm happy for you & your family and frankly, amazed that any vehicle survived a minimum force of over 12,700 newtons if the truck was only moving approx 3' per second(@85mph, it would have been moving 41 times that) ......enough to keep it's occupants alive.
To put this into perspective;
2300 newtons will crush a human skull
Just amazing....someone in that was in your truck that day has a mission to fulfill......
jeff