There is a pit that is $7\text{'}6"$in length and I need to know if a $75$lb psf uniform load can be held on two W$2$x$6$s$,$also with stringers that run across both, and on top of that a $3/4"$piece of plywood would lay across to created a platform. The $2$x$6$s on the pit sides are bolted to it$.$I need to know if a $75$psf uniform load can be put upon the form being created and if it can hold more than that. If it can hold more than $75$psf send over the calculation of why one psf may be better than the other also make a moment diagram and a shear diagram for it$.$Please ask me questions if you do not understand. P$.$S$.$You can change the length of the stringers and change the $2$x$6$members to anything that works better. If your a Civil Engineer PLEASE ANSWER.