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In the absence of structural drawings or specifications, data will be supplied in the form of on-site investigations as well as targeted destructive and nondestructive testing of building materials and components. Architectural drawings show key member profiles consistent with field measurements. The on-going field testing program includes but is not limited to extracting small- 6.2 Data Collection Requirements diameter concrete cores for strength evaluation, Ground Penetrating Radar (GPR) scans of concrete faces for rebar below the surface, and hardness tests of exposed rebar to establish the proper grades. Considering the patterned nature of the perimeter moment frame and the heigtened focus on evaluating lower level framing members, we aim to attain a 'Comprehensive' Level of Knowledge and apply the associated knowledge factor, kappa, of 1.0. This is in line with the provision of 6.2.2 point #2. Nonlinear Response History Analysis is the principal approach, with Linear Response Spectrum 7.2 General Analysis Requirements Analysis (RSA) modified for assumed total damping per 7.2.3.6 as another form of validation. 7.2.3.2 Table 7-1 Torsion Required Number of Ground Motions As the lateral system surrounds the tower, shifting the center of mass in the computer models to account for accidentally eccentricity will be studied as a side issue but is not expected to significantly affect member demands. When using 3 ground motions for a Limited Performance Objective structure, the maximum values derived from the set shall be used. The capacity of force controlled members such as columns under axial load is the product of kappa and the lower-bound strength. The lower-bound strength, Qcl, Is defined as the meanCalculation of Component ActionTable 7-7 minus one standard deviation of the tested concrete compressive strength. For rebar, nominalCapacity: Nonlinear Procedures yield value for the grade indicated by Brinell hardness testing is used since the grade is already determined conservatively. Field testing of concrete compressive strength and steel reinforcement yield and ultimate strengths for grades indicated by field hardness testing of rebar exposed by chipping. Two bar10.2.2.1 Concrete Material Proprerties samples will be extracted and tension tested to demonstrate validity of the hardness testing approach. 10.2.2.2 Concrete Component Properties Several site walks were conducted to address the points listed. The coefficient of variation for field test results concerning concrete compressive test to date is well below 20%. Along with additional cores, scans and hardness tests performed at selected10.2.2.4.2 Comprehensive Data Collection levels and plan locations, test frequencies will be consistent with a comprehensive collection program for the perimeter moment frames. Table 10-5 10.3.2.3 Effective Stiffness Values Force-Controlled Actions Column Flexural Rigidity is directly proportional to the level of design gravity loads sustained. For perimeter moment frame columns, this was found to be beneath the 0.1Agfc threshold in nearly all instances. Therefore, a 0.3Eclg stiffness modifier is applied to the analysis model. Nonprestressed beams are permitted to use the same 0.3Eclg modifier though the design team recognizes that the deep beam/infill panel assembly is unlikely to experience that level of Procedures outlined in ASCE41-13 and ACI 318 are permitted to calculate member design strengths except that the strength reduction factor, 0, shall equal 1.0. Fig. 10-2 Isolated partial-elevation analysis models with detailed finite elements of beams and infill panels are used to establish the locations, percentages and lengths of rigid offsets at single-line moment Beam-Column Joint Modeling frame beams in the main model for equivalent lateral stiffness. Behavior is bracketed by including column capture above the floor in some models and minimizing it in other models. 10.3.4 10.4.2.3 Shear and Torsion Strength of Moment Frames "Where the longitudinal spacing of transverse reinforcement exceeds half the componenet effective depth measured in the direction of shear, transverse reinforcement shall be assumed not more than 50% effective in resisting shear or torsion." Spacing of column ties was found to be between d/2 and d, where d is the effective depth measured in the direction of shear. This minor shear resistance contribution will be included in calculations. Column shear strength is a function of the axial, shear, and moment demands under a given load combination. The most critical permutation will be identified to establish the governing concrete column shear capacities. For this voluntary seismic upgrade, Limited Performance Objectives of Life Safety and Collapse Prevention under 50%/50yr demands apply. Early analysis runs indicate that the damping devices have reserve capacity beyond the target 50%/50 year demands. The primary identified deficiency Energy Dissipation Systems -is the performance of the lowest level of columns between Ll -L3. On this story alone, eight 14.3.1 energy dissipation devices are in each principal direction of the buildings with four located onGeneral Requirements each side of the center of stiffness of the lowest story. As a demonstration of reserved capacity as required in point 14.3.1.1, the velocity dependent devices shall be capable of sustaining the force and displacement associated with 200% of the maximum calculated velocity for that device at the 50%/50yr level. To account for variability in the damper design properties, two analysis models will be run using Upper- and Lower-Bound Design upper and lower bound parameters. In line with the code recommendations, early comparisons14.3.2.4 between 1.15*nominal design property and 0.85*nominal design property will be conducted.and Analysis Properties Should a smaller range of variability required for acceptability, it will be specified.