Q$1)$ For the mat foundation shown below, with the column dimentions of $40cm**40cm$ :

a$)$ Calculate the base pressure at the marked points

b$)$ Take strip AE with the width of $2\mathrm{.}5m,$ determine the effective thickness $($d$)$ of the mat assuming $f_c=25$MPa and the load factor equal to $1\mathrm{.}6($based on the punching shear$)$

c$)$ Check the rigidity assumption

d$)$ Find only the modified column loads. $(55\%)$

$\backslash$table$[[$Column$,$Lond $($kav$)],[$A$.,Q1=1400$