Multichannel Analysis of Surface Waves (MASW) is a geophysical method that uses surface wave (Rayleigh wave) propagation to profile the subsurface. An MASW survey profiles subsurface shear wave velocity (shear stiffness). Surveys can be designed to provide high resolution near surface results, or to profile up to 60 meters depth.
Features
Accelerated Weight Drop high energy source for efficient, low frequency response
24-96 channel land streamer for rapid 2D profiling (1 km per day)
Modular system – large multichannel arrays possible
Use of latest analysis software and data interpretation routines
Active and Passive source data collection
Add on precision GNSS survey for accurate georeferencing and locational information
Highly trained and experienced geophysics/geotechnical field and office teams
Advantages
Rapid site investigation: 1D or 2D Vs Profiles
Non-intrusive / non-destructive test method - no ground disturbance necessary
Effective in environments with high background seismic noise
Sensitive to low velocity layers and velocity inversions at depth
Rapidly deployed and highly portable
MASW and SRT data sets may be collected simultaneously
Applications
Vs profiling for seismic site classification (Vs30), without a borehole
Ground stiffness evaluations
Liquefaction assessment, particularly in gravels and cobbles where SCPTu is not possible
Site reconnaissance prior to drilling and in-situ testing
Bedrock or glacial till mapping
Dam and Levee investigations
Backfill testing
Ground improvement QA/QC
Basement and indoor geotechnical evaluations
Delineation of “soft zones”, potential voids, other anomaly detection
Linear structure foundation evaluations (rail, highway, pipeline, road)
