- Direct-push Seismic testing for Shear and Compression Wave Velocities

Organized by: D. Marchetti (Studio Prof. Marchetti, Italy) and B. Cox (Utah State University, United States)
Keywords: compression wave velocity, direct push, DPCH, SCPT, SDMT, seismic testing, Shear Wave Velocity, Vp, Vs
Shear wave velocity Vs is a fundamental parameter for earthquake geotechnical engineering applications, including seismic site response analysis, liquefaction risk assessment and seismic design of shallow and deep foundations. The maximum shear modulus G0, directly derived from Vs, plays a key role in the G-gamma degradation curve required for equivalent-linear seismic site response analyses and advanced deformation analyses commonly employed in FEM calculation software. Compression wave velocity Vp is also a fundamental parameter that can provide important indications on soil saturation and porosity, particularly relevant in partially drained geomaterials such as in some Tailings Dams. Today, direct-push technology enables seismic testing in combination with other in-situ tests (CPT, DMT, SPT, etc) or independently with specific seismic-only probes (DPCH). Vs measurements via direct-push methods are of common practice onshore, nearshore or in shallow water depths (within 30-40 m), but very challenging in deeper offshore investigations. This minisymposium aims to collect/share contributions and experience from researchers and practitioners on advanced applications of direct-push seismic testing, including technological developments in equipment, test procedures, data interpretation, soil characterization and applications to design using Vs and/or Vp. The topics of the session include (but are not limited to): • Innovative technological developments • Seismic testing configuration and procedures • Wave sources and their deployment • Comparisons of data interpretation methods (true-interval, pseudo-interval, ray tracing, slope-based) • Vs predictions from other in situ tests (CPT, DMT, SPT, etc ) and comparisons with measured Vs • Nearshore/offshore seismic testing • Vs for liquefaction risk assessment • Estimation of advanced material properties (e.g., degree of saturation, porosity, Ko) • Methods for quantifying uncertainty • Measurements of wave anisotropy