$($a$)$ Design a reinforced earth retaining wall using galvanized steel strip reinforcement in a granular backfill as shown in Figure $3$ using the data given in Table $3.$ Check the internal and external stability. Assume the corrosion rate of the galvanized steel is $0\mathrm{.}025m\frac{m}{?}$ year and the life span of the structure to be $50$ years. Required $F{S}_B=FSp=3.$

${}_2$;${}_2$;$c_2$

Table $3.$ Data for MSE wall stability analysis.

$\backslash$table$[[$Wall dimension$/$Surcharge$,$Steel Reinforcement,Backfill,Base soil$],[H$

$(m),b^{\text{'}}$

$(m),a^{\text{'}}$

$(m),q$

$k\frac{N}{m^2},$w $($mm$),S_v$

$(m),\backslash$table$[[$Sh$],[($m$)]],{}_u^o,{}_1^o,{}_1$

$(k\frac{N}{m^3}),{}_2^o,\backslash$table$[[c^{\text{'}}$