ABSTRACT
A seismic piezocone SCPTu database from Guayaquil (EC), consisting of Holocene alluvial and estuarine deltaic soil deposits, is evaluated in this document through Vs mapping when comparing more than 600 CPTu profiles and 45 seismic downhole testing locations. Shear wave velocity downhole measurements were used to adjust CPT-based Vs estimates and compared with cone resistance values. A suitable fit is observed between Robertson (2009a) calculation and downhole measurements, but it tends to over-estimate by 20-30% in soft clayey soils. An age correction factor as a function of normalized su/σ’v ratio has been determined for clayey soils while a Vs-qt correlation is provided for clays and all soils. A Vs30 map has been developed based on proposed shear-wave velocity calibration.
