Application of Microtremor Horizontal to Vertical Spectra Ratio (MHVSR) and Multichannel Analysis of Surface Wave (MASW) for Shallow Bedrock Mapping for Transportation Projects

Mapping bedrock layers and their stiffness is an important part of geotechnical site characterization, particularly for highway projects that require significant rock excavation. A variety of invasive and non-invasive techniques can be used for this purpose. In this study, microtremor horizontal to vertical spectra ratio (MHVSR) and multichannel analysis of surface wave (MASW) methods were utilized along a proposed highway alignment, where the bedrock conditions are expected to be very shallow and highly variable. Two/three peaks were observed for the majority of the MHVSR measurements. The origin of the peaks was investigated using the proposed eye shape method in the literature and it was observed that an eye-shape spectral pattern is not always an accurate indicator of a peak with stratigraphic origin. MHVSR peaks in this study were determine to be of stratigraphy origin as they correspond well with the sharp impedance contrasts in the Vs profiles and subsurface layering from the boring logs. It seems that for cases of MHVSR with multiple peaks at very shallow bedrock sites, the peaks are reliable and they typically have a stratigraphy origin. This suggests that the MHVSR technique is a suitable non-destructive, rapid, and cost-effective alternative for traditional drilling and sampling for shallow bedrock mapping.

Language

  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 622-632
  • Monograph Title: Geo-Congress 2020: Modeling, Geomaterials, and Site Characterization

Subject/Index Terms

Filing Info

  • Accession Number: 01736080
  • Record Type: Publication
  • ISBN: 9780784482803
  • Files: TRIS, ASCE
  • Created Date: Apr 13 2020 9:36AM