A pole is held vertically on a soil surface by three equally spaced wires tied to the top of the pole. Each wire has a tension of 1 kN and is inclined at 45 degrees to the vertical. Calculate:
a) The increase in vertical stress at a depth of 1 m below the surface
b) The amount of elastic settlement below the axis of the pole if E = 40 Mpa and v = 0.46