Retaining wall - various calculations

[dwing]

A mass retaining wall having a vertical rear face is 0.4 m thick at the top and 0.8m thick at the base, is1.6m high and made of concrete of specific weight 24kN/m3. It holds back Earth with a specific weight of 18kN/m3 and an angle of internal friction of 20˚. The coefficient of friction under the base of the wall is 0.7.

(a) calculate the factor of safety against sliding

(b) calculate the factor of safety against overturning

(c) calculate the minimum and maximum stresses to which the soil under the wall
is subjected

(d) what is the net increase in bearing stress under the toe of the wall if the
retained surface is the original ground level?


I don't seem to be able to find any equations to apply. Please help.

Thanks

 

[pongo38]

Can you draw the pressure distribution at the back of the wall, and put values to it? Can you calculate the weight of a 1 m length of wall and locate its centroid?