4.3.14 Joint Reinforcing
Column ties extend at their typical spacing through all beam-column joints at exterior columns.
For buildings designed and constructed in accordance with the 1989 or later editions of Part 2, Title 24, the evaluator may consider this condition as mitigated, and no calculations are necessary. The deficiency is in the strength and ductility of the beam-column joint. Calculate the joint capacity, Ve, and the joint shear, Vj. The joint shear is calculated at a horizontal section at mid-height of the joint. The horizontal shear at the critical section is obtained from summation of horizontal forces in a free-body diagram of the upper half of the joint as Vj = (Tl + Tr) — Ve where Tl and Tr, the forces in the flexural tensile reinforcement in the beams on the left and right sides of the joint, respectively, are calculated assuming a steel stress equal to 1.25 fy. See Figure 4.3.14 for computation of Ve. The ratio Vj/Ve shall be less than or equal to 1. Conforming buildings which do not meet this criteria shall be placed in SPC 4.