Contact Information
2284 NW Thurman St.
Portland, Oregon, 97210
Voice: (503) 227-7659
Fax: (503) 227-1074

 
EARTH DYNAMICS
Geophysics - Vibration & Noise - Rock Mechanics


Providing Quality Geophysical Consulting Services since 1984

Vibration and Acoustic Analysis Capabilities

Earth Dynamics has more than twenty-five years of experience conducting a wide range of vibration and acoustic related studies. Examples of recently completed studies include final environmental impact analysis for construction of an extension to the light rail system in Portland, Oregon, remote monitoring of vibration levels at sensitive equipment locations during construction projects, on-going monitoring and analysis of vibrations from quarry operations throughout the Pacific Northwest, vibration analysis of quarry operations in support of land use applications for quarry operations. Earth Dynamics is also an “on-call” vibration and acoustic contractor for the Tri-County Metropolitan Service district in Oregon.

Earth Dynamics routinely provides remote vibration monitoring with instant notification. Remote monitoring is a cost effective method for monitoring vibration emissions from construction and quarry operations.  Monitoring seismographs are connected to Earth Dynamics' office based server via wireless or land-line telemetry.  Text and/or email messages are immediately sent to key personnel if measured vibrations exceed established limits. Call us to discuss your short term or long term vibration monitoring needs.

Earth Dynamics maintains a large inventory of accelerometers and frequency analysis instrumentation.  This equipment is capable of measuring vibrations from 0.2 micro-g to one thousand g.  Spectral analysis is typically used to evaluate ambient micro-vibration levels, conduct transfer mobility testing, or to perform machinery diagnostics.

Vibration and Acoustic Services

  • Environmental site analysis
  • Transfer mobility testing
  • Vibration monitoring and analysis
  • Remote vibration monitoring
  • Noise monitoring and analysis
  • Real-time narrow-band and octave-band frequency analysis
  • Mechanical equipment evaluation
  • Preventative maintenance programs
  • Vibration and acoustic isolation design
  • Blast design
  • Pre-construction and pre-blast surveys

Vibration monitoring during pile-driving

Remote monitoring seismograph installation.  The tri-axial geophone is buried in the soil and the electronics are housed in a weatherproof enclosure.

Current Equipment List

  • Ten 4-channel Instantel MiniMate Plus Seismographs
  • One 8-channel Instantel MiniMate Plus Seismograph
  • Five White Industrial mini-seisII seismographs
  • Five Geosonics, Inc. micro-seismographs
  • An 8-channel IOTech ZonicBook Vibration analysis and Monitoring System
  • A Bruel & Kjaer Dual Channel Real-time Frequency Analyzer, Type 2144
  • A 4-channel Sound Technology SpectraPLUS FFT Spectral Measurement System
  • Three Larson Davis Type 1, precision integrating and statistical data logging sound level meters. (Two Larson Davis Model 812 and one Larson Davis Model 820).

Selected Vibration and Acoustic Projects

CLIENT DESCRIPTION
BLASTING:  
ASI Construction/US Army Corps of Eng., Blue River, OR Blast and pressure monitoring during lake tap at Cougar Dam, Blue River, OR
Knife River Corporation, Portland OR Vibration monitoring during production blasting at basalt rock quarries in the Portland Metropolitan area.
US Army Corps of Engineers and Guy F. Atkinson Co. San Francisco, CA Installed borehole accelerometers, reviewed blast designs and monitored blast vibrations during excavation of basalt near Bonneville Dam, OR
CONSTRUCTION:  
Hamilton Construction, ODOT Vibration monitoring during pile driving for Interstate 5 widening project in North Portland.
City of Portland Water Bureau Long term remote vibration monitoring during installation of a water line in SE Portland, Oregon.
Morrison-Knudsen Corp. and South Corridor Constructors. Tri-Met Light Rail Portland, OR Vibration monitoring and analysis during pile driving and other construction activities to ensure that nearby structures are not impacted by construction and operation of new Light-Rail corridors.
Granite Construction and US Army Corps of Engineers Portland, OR Evaluation of vibrations due to excavation of a tunnel through John Day Dam, OR
H.S. Wright Construction and Pittsburgh Testing Lab Portland, OR Evaluation of the effects of pile driving vibrations on 'green' concrete at U.S. Bank Tower, Portland, OR
ENVIRONMENTAL IMPACT STUDIES:  
TW Environmental and Tri-Met. Portland, OR Evaluation of potential vibration impact of proposed South Corridor Light Rail in Portland, OR. Study included transfer mobility testing in accordance with Federal Transit Authority guidelines.
SITE EVALUATIONS:  
Oregon Natural Gas Co. Portland, OR Monitoring and evaluation of possible ground motions associated with underground gas storage.
SEH America and Performance Contracting Inc. Vancouver, WA Analysis of building vibrations to certify vibration levels in a new clean room. Vibrations of sensitive instrumentation were also evaluated and design recommendations were provided.
Siltec Silicon and Takenaka (USA) Portland, OR Evaluation of ambient ground vibrations and noise prior to construction of a silicon wafer plant. Vibration isolation design recommendations were also provided.
Port of Portland and Geoengineers, Inc. Portland, OR Monitoring and evaluation of ground vibration and air overpressure near the Portland International Airport.
EQUIPMENT ANALYSIS:  
Oregon Iron Works, Inc., Portland, Oregon Vibration analysis of nuclear waste shield doors during factory acceptance testing.
IPEC Planar and Intel Corp. Portland, OR Vibration analysis of bearings in silicon wafer polishing machines.
ShinEtsu, SEH America Vancouver, WA Vibration analysis of silicon wafer slicing machine. Data were used to help improve production rate.
SAIF Corporation
Portland, OR
Analysis of the vibration produced by a chain saw. These data were used to help determine the validity of a worker’s compensation claim for vibration disease.
Pacific Fluid Systems Portland, OR Vibration analysis of plywood lathe. Special attention was given to evaluation of the effects of lathe vibrations on servo hydraulic valves.