ACI 550.6M-19 Acceptance Criteria for Special Unbonded Post- Tensioned Precast Structural Walls Based on Validation Testing and Commentary

ACI 550.6M-19 Acceptance Criteria for Special Unbonded Post- Tensioned Precast Structural Walls Based on Validation Testing and Commentary. Special u’all systems are likely to undergo inelastic resfh,xes durmç an evens similar to the anticipated maximum consulered earthquake ground motion (ASCEISEI 7-10). The design procedure should consider wall configurauon. equilibrium of forces, compatibility of defornutions, magnitudes of the lateral drifts, reversed cyclic displacements. the relative values of each nonvinal engineering design ‘tdue (Jimr example, shear, axial load, and moment—shear ratio), the possibility of excessive opening of hori:ontal joints between panels and between panels and she foundation, and the possibility of shear-slip along such joints. Vie Procedure should also use appropriate constitutive laws for nwterialx tiwl include considerations of efi’cts of cracking, l(NSdwg reversals, and inelasticity. The development of app roprrale nrultiplication fiulors so be applied to specified material strengths as a consequence of inelasticity aiui loading reversals is particularly important. To account for strum—hardening effects, multiplication factors should be applied to the specified yield strengths or reinforcing steels in the walls, and for reinforcing steel, metals. cout other materials used for connecting elements between walls. To account ft..r con] mement effi’cts in the compression :ones of the toes if the walls, factors should be applied to the spec jiled compressive strength of the concrete in that :one. The stiff ness of the structural walls is important for calculating the fimdamemal period if she prototype structure. The procedure used to determine the stiffness of the is’alls should be verified from the validation test results as described in Section 5.10. 3.2.1 Procedures shall be specified for calculating (he stiffness of the unbonded post-tensioned precast structural walls, and of coupled structural walk, that are applicable to all the unbonded post-tensioned walls of the prototype structure. 3.2.2 Procedures shall be specified for calculating the lateral strength of the unbondcd post-tensioned precast structural walls, and of coupled structural walls, applicable to all unbonded post-tensioned precast walls of the prototype structure. 3.13 Procedures shall be specified for designing and detailing the unbonded post-tensioned precast structural walls to achieve without lilure the minimum acceptable drift capacity specified for equivalence in Section 1.2,4,4, Item (2). The procedures shall cover wall shear strength, sliding shear strength, boundary tie spacing to prevent bar buckling, concrete confinement, limiting reinforcement strains in tension and compression. limiting strains for coupling device materials, wall web reinforcement details to prevent vertical splitting in the inelastic range...