Guidelines and pitfalls of refraction microtremor surveys

Abstract The geotechnical industry has widely adopted the refraction microtremor shear-wave velocity measurement technique, which is accepted by building authorities for evaluation of seismic site class around world. Clark County and City Henderson, Nevada, populated their Earthquake Parcel Map with over 10,000 measurements code enforcement, made a 3-year period. 2D analysis now allows engineers to image lateral variations do passive subsurface imaging. Along experience at basic level, ability identify “no energy area” “minimum-velocity envelope” on slowness-frequency ( p-f ) helps practitioners assess quality ReMi data analysis. Guides grading quality, estimating depth sensitivity, velocity-depth tradeoffs, resolution also assist in deciding whether will meet investigation objectives. Commercial surveys use linear arrays, new criterion 2.2% minimum array direction users likelihood correct results. Unfortunately, any useful popular technique can be abused. Practitioners must follow collection, analysis, interpretation, procedures, or results cannot labeled “refraction microtremor” “ReMi” We present some common mistakes provide solutions objective establishing “best practices” template getting consistent, reliable models from measurements.