# Notching on Beams

NSCP 2001
When rectangular shaped girders, beams or joists are notched at points of supports on the tension side, the horizontal shear stress at such point shall not exceed:

$F_v = \dfrac{3V}{2bd'}\left( \dfrac{d}{d'} \right)$

Where

$d$ = total depth of beam
$d'$ = actual depth of beam at notch

When girder, beams or joists with circular cross section are notched at points of support on the tension side, the actual shear stress at such point shall not exceed:

$f_v = \dfrac{3V}{2A_n} \left( \dfrac{d}{d_n} \right)$

Where:

$A_n$ = cross-sectional area of notched member
$d$ = total depth of beam
$d_n$ = actual depth of beam at notch

When girders, beams or joists are notched at point of support on the compression side, the shear at such point shall not exceed:

$V = \dfrac{2}{3}F_v b \left[ d - \dfrac{d - d'}{d'}e \right]$

Where:

$d$ = total depth of beam
$d'$ = actual depth of beam at notch
$e$ = distance notch extends inside the inner edge of support

NSCP 2010
When rectangular-shaped girder, beams or joists are notched at points of support on the tension side, they shall meet the design requirements of that section in bending and in shear. The horizontal shear stress at such point shall be calculated by:

$f_v = \dfrac{3V}{2bd'}\left( \dfrac{d}{d'} \right)^2$

Where:

$d$ = total depth of beam.
$d'$ = actual depth of beam at notch