Work Zones About The Research FDOT Grant No. BDB-11 Report Title - PowerPoint PPT Presentation

Identifying Vibration Sensitive Work Zones

About The Research  FDOT Grant No. BDB-11  Report Title  Use of Nondestructive Techniques to Estimate the Allowable Vibratory Compaction Level During Construction.  Authors  N. Mike Jackson, Ph.D., P.E., University of North Florida  Michael Hammons, Ph.D., P.E., Applied Research Associates.  Robert Walker, Applied Research Associates.  Harold Von Quintus, P.E., Applied Research Associates.  Research Report Available Online at  http://www.dot.state.fl.us/research-center/Completed_StateMaterials.htm 2

Background  Asphalt Density  Critical for Pavement Performance  Quality Control Criteria for Hot Mix Asphalt  Compaction of Asphalt  Static Rollers  Vibratory Rollers – Construction Vibration 3

Construction Vibration  Human Annoyance  Infrastructure Damage  Architectural  Structural

Types of Waves P-Wave or Compression Wave (Seismic Body Wave) Push-Pull motion S-Wave or Shear Wave (Seismic Body Wave) Double Amplitude Wavelength Rayleigh or Surface Wave (Seismic Surface Wave) 5

Construction Induced Vibrations Energy Carried By Different Waves P-Wave S-Wave Rayleigh Wave 6

Falling Weight Deflectometer Deflection or particle velocity Time Sensor Locations Surface Waves Surface Waves 7

FWD vs. Roller  Falling Weight Deflectometer – Impact Load (Falling weight) – Peak load range: 1.5 to 27 kips – Typical peak load magnitude = 9 kips  Vibratory Roller – Continuous vibration – Operating weight range: 3 to 30 kips  Both induce ground vibration!

Identification of Vibration Sensitive Areas  A practical methodology for identifying vibration sensitive areas – Vibratory compaction not recommended  Use FWD time histories to predict the ground oscillation from vibratory rollers 9

Vibration Descriptor  Peak Particle Velocity (PPV)  Correlates well with damage and complaints  Particle movement is mostly in vertical direction  Measured by Falling Weight Deflectometer 10

Prediction of Ground Motion Normalize the distance by the square root energy scaling law 10 10 Peak Particle Velocity Peak Particle Velocity 1 1 0.1 0.1 0.10 1.00 10.00 0.10 1.00 10.00 Normalized (Scaled) Distance Distance or Sensor Offset 11

Ground Motion Predictor Curve  Upper 95% Confidence Interval of curve fitted through FWD data 10 Peak Particle Velocity, in/se 1 0.1 0.01 0.1 1 10 Scaled Range ft/(ft-lb)^0.5

Vibration Criteria  Human perception – Subjective; depends upon individuals and circumstances  Human annoyance – Subjective; uncomfortable for some individuals  Architectural damage – Superficial damage such as hairline cracks in plaster  Structural damage – Cracking in foundation, separation of masonry blocks, etc. 13

Office of Surface Mines – US Bureau of Mines 10  Based on Architectural damage of low-rise Peak Particle Velocity, in/se Architectural Damage Possible residential structures  Most often cited criteria 1  Used by FDOT for pile driving 0.1 1 10 100 Vibration Frequency, Hz Maximum Allowable PPV 14

DIN 4150 (Germany)  Based on human 10 annoyance Peak Particle Velocity, in/se  Recognizes two settings: – Offices and factories 1 – Residencial areas 0.1 1 10 100 Vibration Frequency, Hz Maximum Allowable PPV for Residential Areas Maximum Allowable PPV for Offices and Factories 15

Criteria Adopted by FDOT US OSM Criteria  Red – Architectural damage possible  Yellow – People may be annoyed, but architectural damage unlikely  Green - People may perceive vibration, but annoyance is unlikely German DIN 4150 Criteria 16

Analysis Procedures Obtain PPV Operating threshold Frequency of vibratory roller Predictor Curve CRITERIA FWD Use FWD to characterize site Convert scaled range to actual distance using the energy of the vibratory roller 17

Field Verification  Re-Paving Accelerated Pavement Test Tracks at the State Materials Office of the Florida Department of Transportation 18

Vibration Monitoring Plan Office N N Building 5304 5304 5305 5305 LEGEND LEGEND Units 5401 and Units 5401 and 5304 5304 Unit Number Unit Number 5532 were set 5532 were set to record full to record full Fixed Unit Fixed Unit 5298 5298 5401 5401 5532 5532 5303 5303 time histories time histories Moving Unit Moving Unit LANE 2 LANE 2 LANE 3 LANE 3 LANE 4 LANE 4 LANE 5 LANE 5 LANE 6 LANE 6 LANE 7 LANE 7 LANE1 LANE1 (Relocated as (Relocated as paving paving operations operations moved from moved from lane to lane) lane to lane) 19

Caterpillar CB-634C 20

Scaled Vibration From Compactor 10 Peak Particle Velocity, in/se 1 0.1 0.01 0.1 1 10 Scaled Range ft/(ft-lb)^0.5 21

FDOT Example  Public Complaint  Increased Vibration after Patch Installation  Human Annoyance  Plaster Wall Damage Asphalt Patch

FWD Survey Results  18 kip Single Axle Modeled  Building is Approx. 90 ft. from Pavement Edge  In Green Zone!!

Vibration Monitor Results  Vibration Monitored – 2 Monitors Set to Report PPV and Frequency – 2 different Days  All PPVs in Green zone 10 10.000 1 10 100 1 10 100 DAY 1 DAY 2 1 1.000 Peak Particle Velocity (in/sec) Peak Particle Velocity (in/sec) 0.1 0.100 0.01 0.010 0.001 0.001 Frequency (Hz) Frequency (Hz) On Brick Entrance to Office In Hedge by Entrance On Brick Entrance to Office On Entrance Driveway

Conclusion - FDOT Example  Building is in the Green Zone  Architectural Damage Unlikely

Implementation of Algorithm 26