shear lug-concrete strength

huangyhg

shear lug-concrete strength
aisc design guide 7 - industrial buildings. on page 33, for shear lugs or column embedments bearing in the direction of a free edge of the concrete, appendix b of aci 349-01 states that in addition to considering bearing failure in the concrete, 鈥渢he concrete design shear strength for the lug shall be determined based on a uniform tensile stress of acting on an effective stress area defined by projecting a 45掳 plane from the bearing edge of the shear lug to the free surface.鈥?the bearing area of the shear lug (or column embedment) is to be excluded from the projected area. use a ? equal to 0.75 (0.65 in aci-318'02). this criterion may control or limit the shear capacity of the shear lug or column embedment details in concrete piers. on pages 38 and 39 , the author performs a calculation that calculates the projected area of the failure plane at the face of the pier. somehow, the procedure is not 100% clear to me. i know that an approximation of the area is being calculated, i just can't follow it exactly. "b", the depth of projection, is calculated as bearing depth plus edge distance?? i would appreciate input of anyone who has caculated using this procedure.