Publications & Testimonials

“A primary benefit of utilising the geophysical measurements is the ability to extrapolate geotechnical knowledge between sparsely distributed and more costly investigation methods (e.g. boreholes, CPT investigations, and test pits) towards increasing spatial sampling density so that background and anomalous conditions can be identified early in the investigation.”

Pancha, A., and R. A. Apperley. ”Multidisciplinary site investigations: refraction microtremor surveys.” Journal of Seismology, 22 Apr. 2022, https://doi.org/10.1007/s10950-022-10088-7.

“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 the world.”

Louie, J.N., Pancha, A. & Kissane, B. ”Guidelines and pitfalls of refraction microtremor surveys.” J Seismol, vol. 26, no. 4, 7 June 2021, pp. 567–582, https://doi.org/10.1007/s10950-021-10020-5.

“Our results confirm the ability of the ReMi technology to image deep velocity structure, including depths exceeding 1 km. We refer to this new methodology as deep ReMi. As demonstrated by this study, deep ReMi can characterize shear-velocity sections down to geophysical basement at 1 km depth, using overlapping subsets of instruments and defining lateral changes that allow derivation of basin structure and geometry.”

Aasha Pancha, et al. “Determination of 3D Basin Shear‐Wave Velocity Structure Using Ambient Noise in an Urban Environment: A Case Study from Reno, Nevada.” Bulletin of the Seismological Society of America, vol. 107, no. 6, 7 Nov. 2017, pp. 3004–3022, https://doi.org/10.1785/0120170136.

“Data from the Parcel Map contributes valuable information toward earthquake-hazard assessment by identifying soil properties to >30 m depth. The 1D velocity–depth profiles obtained for the Parcel Mapping presented in this study frequently obtained velocity structure as deep as 100 m and provide information regarding near-surface shear-wave velocity values, soil thicknesses and interface depths, maximum depth limits for soils, depths to bedrock, and soil resonant frequencies. The Rayleigh-wave velocity–depth profiles thus provide many of the assessment parameters required for more sophisticated classifications than required by the IBC (IBC, 2009; ICC, 2009), NERHP Provisions (BSSC, 1997), and Eurocode 8 (2004), for determination of loading standards for building code compliance.”

Aasha Pancha, et al. “Large‐Scale Earthquake‐Hazard Class Mapping by Parcel in Las Vegas Valley, Nevada.” Bulletin of the Seismological Society of America, vol. 107, no. 2, 28 Feb. 2017, pp. 741–749, https://doi.org/10.1785/0120160300.

“The work performed at the Cedar Canyon landslide of October 11, 2011 is a case study of using seismic surface wave profiling to assist in characterization of landslides and landslide deposits. Since surface wave velocity is related to shear wave velocity and thus material strength, interpreted low surface wave velocity zones have the potential to indicate planes or zones of weakness in a geo-material mass. Such distinctions may be interpretable using appropriate seismic methods even when they are not observable in drilling and sampling operations.”

Rucker, Michael L, et al. “Refraction Microtremor Characterization of a Landslide SR 14, Cedar Canyon, Utah.” Geo-Congress 2013, 25 Feb. 2013, https://doi.org/10.1061/9780784412787.021.

“Numerous surface methods have been developed and utilized to obtain Vs in the upper several hundred meters. Results of this blind comparison study in Santa Clara Valley, California, support the use of ReMi and MASW in urban areas as viable techniques for obtaining Vs to as deep as 100 m, a depth important for earthquake hazards assessment. At three of the sites, ReMi data [exceeded MASW depths and] could be interpreted to at least 160 m.”

Stephenson, W. J., et al. “Blind Shear-Wave Velocity Comparison of ReMi and MASW Results with Boreholes to 200 M in Santa Clara Valley: Implications for Earthquake Ground-Motion Assessment.” Bulletin of the Seismological Society of America, vol. 95, no. 6, 1 Dec. 2005, pp. 2506–2516, https://doi.org/10.1785/0120040240.

Published in 2001…

“Current techniques of estimating shallow shear velocities for assessment of earthquake site response are too costly for use at most construction sites. They require large sources to be effective in noisy urban settings, or specialized independent recorders laid out in an extensive array…the refraction microtremor technique quickly produces good results from a wide range of hard and soft sites…Even home builders might now be able to afford a shear-velocity evaluation at every home site. If engineers and builders find this technique useful, seismologists can look forward to an explosion in the number of available shallow site characterizations.”

Louie, John N. “Faster, Better: Shear-Wave Velocity to 100 Meters Depth from Refraction Microtremor Arrays.” Bulletin of the Seismological Society of America, vol. 91, no. 2, 1 Apr. 2001, pp. 347–364, https://doi.org/10.1785/0120000098.

ADDITIONAL RESOURCES

ReMi 1dS™ software analysis (left) correlated with borehole result (right). Black Eagle Consulting, Reno, NV, USA will use the ReMiDAQ™ system (Terean.com/products) to model entire project areas to save cost and time by reducing the number of boreholes required for project in addition to getting a project-wide view of the subsurface.

ReMi 2dS™ profile (courtesy of Aurecon - Wellington, New Zealand) correlating with borehole data to provide a comprehensive subsurface view of the entire project.