Figure $3$ shows a square footing with $B=2\mathrm{.}5m.$ The water table is deep enough to be

ignored. The footing rests at depth, $D=1\mathrm{.}5m$ from the ground surface. The dry unit

weight and cohesion of the surrounding dense silty sand are $20k\frac{N}{m^3}$ and $10k\frac{N}{m^2},$

respectively. Use Terzaghi's method to solve this problem.

Figure $3.$ Square footing on dense silty sand

If the shear strength $()$ of the silty sand at depth $(D)=1\mathrm{.}5m$ is given as $38\mathrm{.}2k\frac{N}{m^2},$ determine the

corresponding friction angle $()$ value $($in deg$).$

If now the friction angle $()$ has a value of $40,$ determine the ultimate bearing capacity $(g_u)$ of the square

footing in $k\frac{N}{\frac{?}{?}}{m}^2$

From the question immediately above, determine the factor of safety $($FOS$)$ if the allowable bearing

If the ground water table were to rise to the existing ground surface and subsequently maintains

hydrostatic equilibrium, assess the new ultimate bearing capacity $(g_w)$ in $k\frac{N}{m^2}.$ Friction angle $40$

Continuing from the immediate question above, how do you expect the new ultimate bearing capacity to

change?

With the aid of the design chart given$|$evaluate the settlement $($in $mm)$ of the above square footing under

the influence of the water table if the allowable bearing pressure $(g_{\text{v}\text{h}\text{l}\text{o}\text{w}})$ is given as $2,500k\frac{N}{\frac{?}{?}}{m}^2.$

If the immediate next column to this particular one settles $110\mathrm{.}4mm$ and the column spacing is $6\mathrm{.}6m,$

what is the angular distortion $($dimensionless$)$ of the building at this location?

Using the appropriate chart provided in$,$ how critical is the structural health of the building?

Angular distortion

$=$ differential settlement $()/$ spacing between $2$ successive columns $($L$)$

Table $11\mathrm{.}6$ Angular olistortion Efinits

$\backslash$table$[[\backslash$Delta $/$L$,$Critical structural situation$],[1/5000,\backslash$table$[[$Hair eracks observed in unreinforced brickworks load$-$bearing walls subject$],[$to hogging$]]],[1/3000,$Visible cracks in load$-$bearing walls$],[1/1000,$Visible cracks in brick in$-$fill panels$],[1/750,$Prectical limit to prevent unbelance of sensitive machinary$],[1/600,$Level of overstress in diagenal members becomes significant$],[1/500,\backslash$table$[[$Practical limit to prevent serious eracking in framed buildings and modern$],[$constructions$]]],[1/300,\backslash$table$[[$Damage to bulding frames and panel walls; misolignment problems in overhead$],[$cranes$]]],[\backslash$table$[[1/250],[1/150]],\backslash$table$[[$Tilting noticeablo in high$-$rise bluildings$],[$Structural damage to mest buildinas expected$]]]]$

After Skempton and MacDonald $(1956),$'Bjorrum $(1983),$ Burland and Wroth $(1975)$