220 likes | 377 Views
Data Acquisition Interface to Support Seismic Retrofit. Kenneth Hanson Cerritos College. Overview- Retrofit Project. Long Beach Public Safety Building CSULB Involved in Unique Project Data collection during seismic retrofit Correlate data with construction progress
E N D
Data Acquisition Interface to Support Seismic Retrofit Kenneth Hanson Cerritos College
Overview- Retrofit Project • Long Beach Public Safety Building • CSULB Involved in Unique Project • Data collection during seismic retrofit • Correlate data with construction progress • Identify changes in structural characteristics as construction progresses • Critical facility-Down Town Long Beach • Fire station • Police station • City jail • Emergency response services
Overview- Retrofit Project • 6-story, Steel-Frame • Undergoing a $30M seismic retrofit • Dense Instrumentation • Data Collection • Before retrofit • During retrofit • After retrofit
Acceleration Measurements • Project: Automate Ambient Vibration Measurements • Very important, especially during construction • National Instruments • NI-4472 PCI data acquisition • 24-bits • Synchronized timing
Acceleration Measurements • K-2 Data Recorders • Kinemetrics Inc. • Automatic recording when earthquake event happens • Threshold-based recording
Structural Health Monitoring • Measurements of building structural response • Compare model predictions to measured responses • Modeling • Finite element model • Linear • Nonlinear • Model response to earthquakes • Historical earthquake records • Pre-retrofit • Post-retrofit
Statement of the Problem: Ambient vibration data must be acquired before, during and after the retrofit. Presently stored data is manually taken twice a week at the building location. To perform real time data measurements the output of the existing system does not interface with the National Instruments Data Acquisition (DAQ) system.
Solution to the problem: Design and fabricate an interface that would allow data to be routed around existing hardware to provide real time data acquisition, measurement and display.
Instrumentation • Vibration measurements • Accelerometers • Strain measurements • Strain gages • Fiber-optic strain sensors • Displacement measurements • Laser based displacement • Acoustic Emission Sensors
LASER-BASED FLOOR DISPLACEMENT. Install during retrofit. LFD 2-axis EPI Sensor STRONG MOTION ACCELEROMETERS. Installed pre-retrofit EPI Sensor STRONG MOTION ACCELEROMETERS. Post-retrofit installation. STRAIN GAGES. Installation during retrofit. SG ACOUSTIC EMISSION SENSORS. Post-retrofit installation. AE FO SG FIBER-OPTIC STRAIN GAGES. Post-retrofit installation. DATA ACQUISITION . Pre- and Post-retrofit installation. K2 recorder Instrumentation: Installation Time Line
EPI Sensor 6th Floor 2-axis EPI Sensor SG EPI Sensor 5th Floor 3-axis EPI Sensor SG LFD LFD LFD LFD LFD LFD EPI Sensor 4th Floor 2-axis EPI Sensor SG FO SG EPI Sensor 3rd Floor 2-axis EPI Sensor SG RS232 SG K2 recorder EPI Sensor 2nd Floor 3-axis EPI Sensor AE AE K2 recorder PC EPI Sensor 1st Floor 2-axis EPI Sensor K2 recorder SG RS232 Instrument cabinet on 1st floor Basement
Retrofit Project • The Long Beach Public Safety Building
Starting from Scratch LBPSB Retrofit Phase
Sensor Locations Fig. 1. Three Dimensional Numerical Model of Pre-retrofit Long Beach Public Safety Building
Post-Retrofit Measurements New Shear Wall Strain Gages to be Installed
Acceleration Measurements FBA - Accelerometer 3-axis Installed in LBPSB 2nd Floor
Acceleration Measurements K2 Recorders Instrument cabinet
Acceleration Measurements Computer Cabinet Installed in LBPSB
Acceleration Measurements Typical Acceleration Measurements Time History
Post-Retrofit Activities • Remote Capabilities • Long Term Role of CSULB