CATCHMENT AREA METHOD

CATCHMENT AREA METHOD

By Catchment Area Method you calculate Column load ,

HOW TO DO IT ?

1) Suppose you want to calculate load on cOLUMN c1 AS sHOWN IN FIGURE , NOW AS SHOWN IN FIGURE , Purple Hatched one are columns and Blue Hatched one are Beams and i Have Marked Area with Inclined Pink Lines

Now Catchement means Hatchmed pink line area is Catchment on Column C1 , means Half of Slab Area and Half of Horizontal Beam and Half of VErtical Beam is the total catchment area on Column C1

How To Calculate Load on COlumn C1 ?

1) Consider Slab area first

in it You have Live load , finishes load or any other uniform pressure load in psf

now to COnvert that uniform pressure load in psf into point load which will be Load on COLUMN C1 , for that you have to multiply Pressure load (in psf ) by area of slab(in ft^2) ,

Area will be Pink Hatched area as shown in Figure

2) Consider Beam now

Above Beams you have Wall Load which is in Kip/ft

Now to Convert that Wall load into point load which will be Load on Column C1 , for that you have to multiply wall load (in Kip/ft) by half length of beam

As shown in Figure , it is clearly shown that half length of horizontal beam and half length of vertical beam will be catchment length on column C1

now first find out Horizontal half length and vertical half length and then for horizontal half length multiply it by Wall load which is in kip/ft and for vertical half length multiply it by wall load which is in kip/ft , now that will be the Point Load in Kips on Column C1

FOR EXAMPLe

LOAD ON SLABS :

1) LIVE LOAD = 60 psf
2) Finishes Load = 36 psf
3) sunk Load = 90 psf

Wall Load on Beam :

1) Height of Wall is 10 feet , thickness of wall is 6 inch then Wall load will be 10 x (6/12) x 0.144 = 0.72 kip/ft

Size of Column is 6" x 24" and width of beam is 6 inch , and length of Horizontal Beam is 10 feet and Length of Vertical Beam is 12 feet ,

Now you have to calculate Load on Column C1 from Slab and Beam , as i described above ,

If any confusion then ask please , this is Initial means beginers stage catchment area example , in sha ALLAH i will share more typical one , but first see and learn about catchment area method from this