(Solved): The answer is 11.6m, please show all workings: A 600mm square concrete pile is to be built to sup ...
The answer is 11.6m, please show all workings: A
600mmsquare concrete pile is to be built to support a working compression load of
300kNor a working tension load of
200kNat a site with two layers of soil. The top layer is
6.0mthick and consists of sands and gravels with bulk unit weight of
22k(N)/(m^(3))and angle of friction of
\phi _(crit )^(')=35\deg . The bottom layer is composed of clay with bulk unit weight of
18k(N)/(m^(3))and undrained shear strength of
60kPa. Determine the necessary minimum pile length immediately following construction assuming that the water table is at the depth of
2.0mfrom the ground surface involved. The average adhesion factor may be taken as 0.4 for the clay layer. Assume that the horizontal effective stress at any depth is equal to
(1-sin\phi _(crit)^('))times the vertical effective stress at the same depth, and that the angle of friction between the concrete and the sand is equal to
0.6\phi _(crit )^('). It may be assumed that the end bearing capacity factor is equal to 9 for the present conditions. The shaft resistance safety factor may be taken as 2.0 , while the end bearing safety factor may be taken as 2.5 .
