What special detailing is required for concrete structures in seismic zones?

Seismic detailing ensures ductile behavior: (1) Special moment frames - close-spaced hoops in plastic hinge regions (within 2h from face), strong column-weak beam design, joint shear reinforcement, (2) Shear walls - boundary elements with confined concrete, distributed reinforcement, (3) Confinement - adequate ties increase concrete strain capacity for ductility, (4) Capacity design - prevent brittle failures (shear) before ductile failures (flexure), (5) Development lengths increased, (6) Splices located outside plastic hinge regions. ACI 318 Chapter 18 provides comprehensive requirements.