Shear Strength of C-Section Web with Holes C3.2.2 Hole reduction factor, qs 1). c/t > = 54, qs = 1.0 2). 5 <= c/t < 54, qs = c / (54 t) c = h/2 - dh/2.83 for circcular holes c = h/2 - dh/2 for non-circcular holes The limits for the above equation: dh/h < = 0.7 h/t < = 200 Holes centered at the mid-depth of web Clear distance between holes > = 18 in. Non-circular holes, corner radii > = 2t Non-circular holes, dh < = 2.5 in. and Lh < = 4.5 in. Circular holes, diameter < = 6 in. dh > = 9/16 in. dh - depth of hole h - depth of flat part of web t- thickness Lh - length of hole Combined Bending and Shear C3.3 ASD 1). For members with unreinforced webs: { [Ob. M / Mn]2 + [Ov .V / Vn]2 }0.5 < = 1.0 2). For members with transverse web stiffeners: 0.6 [Ob. M / Mn] + [Ov .V / Vn] < = 1.3 M - required allowable flexural strength V - required allowable shear strength Mn - Nominal flexural strength Vn - Nominal shear strength Ob - resistance factor for bending = 1.67 Ov - resistance factor for shear = 1.6 LRFD 1). For members with unreinforced webs: { [Mu / (fb.Mn)]2 + [Vu / (fv.Vn)]2 }0.5 < = 1.0 2). For members with transverse web stiffeners: 0.6 [Mu / (fb.Mn)] + [Vu / (fv.Vn)] < = 1.3 Mu - required flexural strength Vu - required shear strength Mn - Nominal flexural strength Vn - Nominal shear strength fb - resistance factor for bending fv - resistance factor for shear