Analyze the following two $-$way slab using equivalent frame method. Use SAP for analysis after defining the required stiffness values of columns and beam$-$slab members.

Design of flat plate floor by equivalent frame method. An office building is planned using a flat plate floor system with the column layout as shown in Fig. $13\mathrm{.}19.$ No beams, drop panels, or column capitals are permitted. Specified live load is $4\mathrm{.}9k\frac{N}{m^2},$ and dead load will include the weight of the slab plus an allowance of $1\mathrm{.}0k\frac{N}{m^2}$ for finish floor plus suspended loads. The columns will be $450mm$ square, and the floor$-$to$-$floor height of the structure will be $3\mathrm{.}6m.$ Design the interior panel $C,$ using material strengths $f_y=420$MPa and $f_c^{\text{'}}=28$MPa. Straightbar reinforcement will be used.