Problem $05$

$40$pts

A retaining wall shown in the figure has a surcharge of $21$kPa.

For a $1m$ strip of wall,

a$.$ Determine the effective horizontal stress $($kPa$)$ acting on

the top of the backfill before the surcharge is applied.

b$.$ Determine the active earth force $(kN)$ acting on the wall

after the surcharge is applied.

c$.$ Determine the passive earth force $(kN$ acting on the wall.

d$.$ Assume that an anchorage will be placed on a location $1\mathrm{.}5m$ below the top of the backfill, compute the

tensile force $(kN)$ on the anchorage to keep the system in equilibrium.