Using Brom's method $($section $9\mathrm{.}7\mathrm{.}3\mathrm{.}2$ of the FHWA NHI$-05-042$ Manual$),$ study the pile

support system of the retaining wall shown in the figure below, and determine the

maximum wall height that would make piles reach failure. Could the piles be shorter for

this wall height? If yes, compute the shortest pile length that could be used for that wall

height. Verify the results with a program for laterally loaded piles such as the one

presented in the class notes.

The piles are $0\mathrm{.}3m$ in diameter $($D$),10m$ in length $($L$),$ and the center$-$to$-$center spacing

in the wall direction is $3m.Ep=28$GPa,$f^{\text{'}}c=35$Mpa,$Ip=1\mathrm{.}35{10}^{-3}{m}^4,$

Assume that the lateral deflections do not control the design, and that the group effects

may be ignored.