Experiment-Based Deployment With the Four Seasons Building Steve Kang Department of Civil & Environmental Engineering University of California, Los Angeles June 8, 2004 UCLA

2 Four Seasons Building “Yellow-tagged” following 1994 EQ Abandoned for 10 yrs. Scheduled for demolition

3 A closer look….

4 Project Schedule Project start date – May 2003 Pre-testing analyses – April 2004 Building access granted – mid-April 2004 Mount shakers – May 2004 Install instrumentation – May 2004 Perform testing – June/July 2004

5 Pre-Testing Analyses Pre-testing numerical Modeling of existing building –Review original drawings of the building –3-D finite element modeling of existing building –Determine optimal locations for vibration shakers/sensors –System identification (mode shapes, periods, damping) Site characterization and Preliminary field investigation. –Detailed field investigations of structural damage –SEAOSC manometer survey

6 Summary of expected work Field testing with Eccentric mass shaker –Forced vibration tests in N-S, E-W translational vibrations and torsional vibration –Vibration tests before and after the removal of partitions to evaluate the effects of nonstructural elements Field testing with Linear inertial shaker –Simulations of building response using the LSSS test method Post-testing Numerical modeling and System identification studies –Evaluate modal properties of building; stiffness, damping –Numerical simulation of the building’s earthquake responses

7 Instrumentation Plan Floor accelerations –30 accelerometers Rocking motion –6 vertical accelerometer –24 Strain Gauges = 6 columns*4 faces For interstory drift –12 DCDT's = 3 bays*4stories Curvature measurement –8 DCDTs –70 strain gauges 36 Accelerometer channels 20 DCDT channels 94 Strain Gauge channels

8 Field Testing

9 Project Challenges Security/theft Transients No electricity Broken glass/loose wires Environmental concerns –Mold –Asbestos Seismic Safety Standard

10 Shaker Transportation

11 Shaker locations A B C D N MK-15 eccentric shaker Linear inertial shaker Eccentric mass shaker

12 Shaker Installation

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14 Strain Gauge Installation

15 Secure Rooms