Experiment-Based Deployment With Experiment-Based Deployment With the Four Seasons Buildingthe Four Seasons Building

Steve KangSteve Kang

Department of Civil & Environmental EngineeringDepartment of Civil & Environmental Engineering

University of California, Los AngelesUniversity of California, Los Angeles

June 8, 2004June 8, 2004

UCLAUCLA

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Four Seasons Building

• “Yellow-tagged” following 1994 EQ

• Abandoned for 10 yrs.

• Scheduled for demolition

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A closer look….

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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

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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

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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

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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

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Field Testing

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Project Challenges

• Security/theft• Transients • No electricity• Broken glass/loose wires• Environmental concerns

– Mold– Asbestos

• Seismic Safety Standard

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Shaker Transportation

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Shaker locations

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34

56

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ABCD

N

MK-15 eccentric shaker

Linear inertial shaker

Eccentric mass shaker

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Shaker Installation

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Strain Gauge Installation

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Secure Rooms