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Effective depth from cover and bar sizes

Effective depth of a beam with one or two layers of bars from the nominal cover and bar diameters. Reference: IS 456:2000 Cl. 26.4, Table 16.

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# Data
D := 600 mm
c_nom := 30 mm
phi_v := 8 mm
phi := 20 mm
s_layers := 25 mm
# The nominal cover depends on the exposure condition (Table 16).

# One layer
d_1 := D - c_nom - phi_v - phi/2 =

# Two layers
d_2 := D - c_nom - phi_v - phi - s_layers/2 =

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