The reinforcement in the splitting/bursting zone is checked in accordance with LRFD 5.9.4.4.1 (pre-2017: 5.10.10.1). The area of shear reinforcement in the splitting zone is computed as

Av = SUMMATION(Number of Legs)(Bar Size)(Length)/(Spacing)

Length is the length of the stirrups zone that is contained within the splitting zone.

Example

Zone Length = 2.00 ft

Av = 2(0.31 in2)(1.00 ft)/(0.5 ft) + 2(0.31 in2)(1.00 ft)/(0.75 ft) = 2.066 in²

‍NOTE: WSDOT standard practice deviates from the LRFD specifications as outlined a June 2001 Design Memorandum