When the hole is dugging in the initial stage the the verticalsides from 0m to 2.40m

So average height is \(\displaystyle{h}={\frac{{{0}+{2.40}{m}}}{{{2}}}}={1.20}{m}\)

We know the formula for the gauge pressure is

\(\displaystyle{P}_{{{g}{a}{u}\ge}}=\rho{g}{h}\)

\(\displaystyle={\left({10}^{{3}}{k}\frac{{g}}{{m}^{{3}}}\right)}{\left({9.8}\frac{{m}}{{s}^{{2}}}\right)}{\left({1.20}{m}\right)}\)

\(\displaystyle={11.76}\cdot{10}^{{3}}\frac{{N}}{{m}^{{2}}}\)

Now the formula for the force the watercauses on the foundation wall is

\(\displaystyle{F}={\left({P}_{{{g}{a}{u}\ge}}\right)}{A}\)

\(\displaystyle={\left({11.76}\cdot{10}^{{3}}\frac{{N}}{{m}^{{2}}}\right)}{\left({2.40}{m}\right)}{\left({9.60}{m}\right)}\)

\(\displaystyle={270.9}\cdot{10}^{{3}}{N}\)

So average height is \(\displaystyle{h}={\frac{{{0}+{2.40}{m}}}{{{2}}}}={1.20}{m}\)

We know the formula for the gauge pressure is

\(\displaystyle{P}_{{{g}{a}{u}\ge}}=\rho{g}{h}\)

\(\displaystyle={\left({10}^{{3}}{k}\frac{{g}}{{m}^{{3}}}\right)}{\left({9.8}\frac{{m}}{{s}^{{2}}}\right)}{\left({1.20}{m}\right)}\)

\(\displaystyle={11.76}\cdot{10}^{{3}}\frac{{N}}{{m}^{{2}}}\)

Now the formula for the force the watercauses on the foundation wall is

\(\displaystyle{F}={\left({P}_{{{g}{a}{u}\ge}}\right)}{A}\)

\(\displaystyle={\left({11.76}\cdot{10}^{{3}}\frac{{N}}{{m}^{{2}}}\right)}{\left({2.40}{m}\right)}{\left({9.60}{m}\right)}\)

\(\displaystyle={270.9}\cdot{10}^{{3}}{N}\)