Annular Raft Under 1250 Cum OHR
Annular Raft Under 1250 Cum OHR
Annular Raft Under 1250 Cum OHR
= 2553 MT α = 0.333
b = 0.722
C.L
250
500
6.00m
aα = 3.0m
a = 9.00m
WEIGHT OF FOUNDATION TO BE CONSIDERED (SUBMERGED UNIT WEIGHT HAS BEEN DEDUCTED FROM THE CONCRETE UNIT WEIGHT)
(18.02 6.02 ) 0.625 (avg.) (2.5 0.8)
4
= 240.33 MT SAY 240 MT
2783
BEARING PRESSURE = 12.3 T/m 2 12.5 T/m 2 HENCE O.K
(18.02 6.02 )
4
2752.5 4
ADDITIONAL BEARING PRESSURE = M/Z = 9.0 = 4.87 T/m2
(9.04 3.04 )
TOTAL STRESS = 12.30+4.87 17.17 T/m2 < 1.5 X 12.5 =18.75 T/m2 OK
FOR ALL OTHER CASES,SOIL INVESTIGATION REPORT TO BE SENT TO PLANNING WING FOR DETERMINATION FOUNDATION.
25428
STRUCTURAL DESIGN OF THE RAFT :- p = KN/m2 112 KN/m2
(18.0 2 6.02 ) =112.42 SAY
4
REFERRING TO TABLE - 6.3 & 6.4 OF "DESIGN OF TALL CHIMNEYS" BY S.N MANOHAR
corresponding pt = 0.482% => 3205.3 mm2/m => 25mm dia bars @ 150mm C/C (Radial steel)
Table - 3,SP-16
corresponding pt = 0.156% => 1021.8 mm2/m => 16mm dia bars @ 175mm C/C (Tangential steel)
Table - 3,SP-16