With reference to clauses of ACI-318 and UBC-97 as copied below, please let me know if these clauses are applicable in Moderate seismic zone (Zone 2B) specially the clause related to ratio of ultimate to yield strength of reinforcement to be used.
Applicability of Chapter 21
18.104.22.168 — In regions of moderate seismic risk or for structures assigned to intermediate seismic performance or design categories, intermediate or special moment frames, or ordinary, intermediate, or special structural walls shall be used to resist forces induced by earthquake motions. Where the design seismic loads are computed using provisions for special concrete systems, the requirements of Chapter 21 for special systems, as applicable, shall be satisfied.
21.2.5 — Reinforcement in members resisting earthquake-induced forces
Reinforcement resisting earthquake-induced flexural and axial forces in frame members and in structural wall boundary elements shall comply with ASTM A706. ASTM A 615 Grades 40 and 60 reinforcement shall be permitted in these members if:
(a) The actual yield strength based on mill tests does not exceed fy by more than 18,000 psi (retests shall not exceed this value by more than an additional 3000 psi); and
(b) The ratio of the actual tensile strength to the actual yield strength is not less than 1.25.
1922.214.171.124 Billet steel A 615 reinforcement. Billet steel A 615Grades 40 and 60 reinforcement shall be permitted to be used in frame members and wall boundary elements if
(1) the actual yield strength based on mill tests does not exceed the specified yield strength by more than 18,000 psi (124.1 MPa) [retests shall not exceed this value by more than an additional 3,000 psi (20.69MPa)], and
(2) the ratio of the actual ultimate tensile stress to the actual yield strength is not less than 1.25.
Kindly have a look and let me know what are your views about this.