Giren: edge columns are $0\mathrm{.}40\mathrm{.}4m,$ each column load is $1000KV$

Central columns are $0\mathrm{.}60\mathrm{.}6m,$ each colnmu load is $2000KN$

Spacing center to center is $6m,$ width of the strip is vdotsm

Sectlement of the strip is $2cm,f_c=30$MPa,$E_c=30SP,$

Aszume uniform soil pressure under the strip.

a$)$ Find the required depth of the strip.

b$)$ Can we design the strip using flexible method, use thickness of the strip as $0\mathrm{.}7m.$