Slides for discussion SOPAC/UCSD/UA

From Press Release Inertial Force-Limiting Floor Anchorage Systems for Seismic Resistant Building Structures UA/UCSD

Objectives Phase1: new friction dampers between walls and floors, expect lower accelerations (force) but larger displacement with increasing intensity Phase2: traditional wall-floor PSA connections, expect higher accelerations, more out of plane motion Question – if energy is dissipated in displacement, why doesn’t Phase1 have higher displacement than Phase2

Displacement comparison BE05 MCE Berkeley Design Basis Earthquake : M Loma Prieta earthquake recording at Los Gatos Presentation Center station Distance: 4 km from fault Actual recorded motion: 0.97g PGA For this experiment, scaled to 0.61g (Value for Berkeley from PSHA map, expected acceleration level at 2% probability) Design Basis Earthquake motions are MCE scaled by 1/1.5 Period scaled by 1/sqrt(2) for 1/4 scale building

RFNW Berkeley MCE Event (1.5xDBE) Phase1- New IFLFA vs Phase2- traditional PSA Peak displacement is similar Out-of-plane displacements are much larger for traditional PSA (bigger than EW!)

Displacement comparison BE05 DBE Berkeley Design Basis Earthquake : M Loma Prieta earthquake recording at Los Gatos Presentation Center station Distance: 4 km from fault Actual recorded motion: 0.97g PGA For this experiment, scaled to 0.61g (Value for Berkeley from PSHA map, expected acceleration level at 2% probability) Design Basis Earthquake motions are MCE scaled by 1/1.5 Period scaled by 1/sqrt(2) for 1/4 scale building

RFNW Berkeley DBE Event Phase1- New IFLFA vs Phase2- traditional PSA East North IFLFA damped after 7 s Peak displacement is smaller for IFLFA Out-of-plane Displacements are much larger for traditional PSA Why 7 sec? Why isn’t peak displacement smaller for DBE or MCE?

RFNW Berkeley DBE Event Phase1-IFLFA vs Phase2- traditional PSA (EAST) Integrated accelerations are significantly out of phase Integrated accelerations give different answer than GPS, because of rotation

RFNW Berkeley DBE Event Phase1-IFLFA vs Phase2- traditional PSA (North) Integrated accelerations are significantly out of phase Integrated accelerations give different answer than GPS, because of rotation

Plans Plot displacement comparisons for other pairs Calculate drift using GPS displacement at roof minus integrated acceleration (?) at base Plot drift as a function of acceleration Look at rotation Phase1 roof displacement (not drift) Phase2 roof displacement (not drift)

Rotations Much more out of plane motion and greater rotation for Phase 2 traditional PSA Phase 2 traditional PSA connections Phase 1 new IFLFA connections

Earthquake ground motions Seattle Maximum Considered Earthquake: Moderate Intensity 1979 Imperial Valley earthquake record M g PGA El Centro Array #5 station Distance: 28 km from fault Scaled to 0.59g Period scaled by 1/sqrt(2) for 1/4 scale building Design Basis Earthquake motions scaled by 1/1.5 Berkeley Maximum Considered Earthquake: High intensity 1989 Loma Prieta earthquake recording M g PGA Los Gatos Presentation Center station Distance: 4 km from fault Scaled to 0.61g Period scaled by 1/sqrt(2) for 1/4 scale building Design Basis Earthquake motions scaled by 1/1.5

Source: SOPAC NEES/UCSD LHPOST Inertial Force Limiting Anchorage System Experiments (December 2013 – January 2014) Four-Story Building Base Station Middle of Building Roof – Site MIDG SIO MEMS Acceleromet er Trimble NETR9 Site MIDG LHPOST: Large High Performance Outdoor Shake Table