I am working on a project that has three 2x12’s supporting a load of 12,000 lbs. similar, but not exactly, to how joists support a house.
The 2x12’s are supporting about 6,000 lbs. on each end.
The three 2x12’s are: a) Each cut to 90in.
b) The load takes up 24in. from each end of the 2x12’s leaving 42in. of free space in between.
c) The three 2x12’s are spaced parallel to each other, with one 2x12 being 24in. in front of the other.
d) The 6,000lb. (On each side) load is laying on a thick wooden plank (on each end) that is perpendicular to the three 2x12’s. Similar to this picture (I don't know if it will show up in the post) "J" is the joist but in this picture there are 4 joists.
e) The two thick wooden planks on each end of 2x12’s (mentioned in “d”) is securely fastened to the 1.5in. part of the 2x12’s, as well as having blocking and other bolted wooden members that leaves (as stated in “b”) 42 in. Of free space in between.
f) The three 2x12’s are only 12in. off the ground.
Everything is stable and strong without any issues except for one.
I need to lift this so that it is 14in. off the ground (lifting it 2 in. in total).
Removing the load; as well as dissembling is not an option.
This will have to be lifted with the three 2x12’s and everything above (including load) remaining intact.
My best option is to lift (with a hydraulic jack) the front most 2x12 to 14in. and then lift the back most 2x12 to 14in. -I’ve done this before with no problems.
The only problem, that I have now, is that directly under the 2x12 is things that I can not remove and is not strong enough jack it from.
The saddle of the jack is 2-3/4in. All wood is Kiln-Dried Douglas Fir #2 or better.
My plan is to grade 8 bolt a 4x4 cut to 7in. directly in the middle of the free space, mentioned in “b”; plus having the 4x4 cut to 7in. will provide more of a direct clamping force the will be directly in line of the upward force of the jack and the downward gravitational force of the joist when it is being jacked up.
This 4x4 will be bolted to the outward face of the 11.25in. part of the front most and back most 2x12’s.
Do you think is strong enough to support the load plus force of the jack or do you think it will just rip the 4x4 off of the 2x12; while also destroying the face of the 2x12’s?
P.S. This project is a hoppy type of thing I am doing and it is not anything that "construction" related.