Problem $1$

Footing dimensions $=1m2m$

Soil unit weight : ${}_{\text{d}\text{r}\text{y}}=17k\frac{N}{m^3}($above gwt$){}_{\text{s}\text{a}\text{t}}=17\mathrm{.}5k\frac{N}{m^3}($below gwt$)$

The vertical load the footing can carry is $300.$

Calculate the factor of safety when,

$($a$)$ Groundwater table is $2$ m below ground surface $(c^{\text{'}}=20$kPa,${}^{\text{'}}=25)$

$($b$)$ Groundwater table is $1$ m below ground surface $(c^{\text{'}}=20$kPa,${}^{\text{'}}=25)$

$($c$)$ Groundwater table is $0\mathrm{.}25$ m below ground surface $(c^{\text{'}}=20$kPa${}^{\text{'}}=25)$

$($d$)$ Groundwater table is $0\mathrm{.}25$ m below ground surface $(\{$:$c_u=30$kPa,${}_u=0)$