Assume the support system described in Problem $1$ utilizes soldier piles and lagging in

lieu of sheet piling. Soldier piles are spaced at $7$ ft$.$ center to center with struts occurring

at every third soldier pile $(21$ ft centers$).$ Use A$36$ and a $1\mathrm{.}5$ FOS for all steel members.

a$)$ Assume the maximum soil pressure is $1500$ psf$.$ Compute the maximum bending

moment in a unit width $(1)$ of lagging board. Draw neat freebody, shear and moment

diagrams. $(10$ pts$.)$

b$)$ Based on your answer to a$)$ above and an allowable bending stress of $2000$ psi in

the wood lagging boards determine the minimum board thickness required. $(10$ pts$.)$

c$)$ Assume the maximum soil pressure is $1500$ psf$.$ compute the maximum shear in kips

and bending moment in kip$-$ft$.$ in the soldier pile. Consider the lower hinge point to be

$3$ below the bottom of the excavation. Draw neat freebody, shear and moment

diagrams. $(10$ pts$.)$

d$)$ Based on using A$36$ steel and a $1\mathrm{.}5$ FOS and the answer from c$)$ what is the

minimum size H pile we could use for soldier piles? $(10$ pts$.)$

e$)$ Assume the maximum soil pressure is $1500$ psf$.$ Compute the maximum shear in

kips and bending moment in kip$-$ft$.$ in the walers. For purposes of these calculations

assume the lowest soldier pile hinge point to be three feet below the bottom of the

excavation. Draw neat freebody, shear and moment diagrams. $(10$ pts$.)$

f$)$ Assume the maximum soil pressure is $1700$ psf$.$ Compute the maximum

compressive load in the struts. For purposes of these calculations assume the lowest

soldier pile hinge point to be three feet below the bottom of the excavation. $(10$ pts$.)$

g$)$ Redo $2$b$.$ using steel plates instead of wood lagging with the A$36$ steel mentioned

above and change the Max Bending Moment to $9,000$ ft$-$lbs$.(10$ pts$)$