Precision of Seismic Wave Propagation Methods in Construction Applications

Seismic wave propagation methods provide in situ wave velocity profiles from which various elastic moduli can be determined. The tests are applicable to a wide range of civil engineering materials, including soil and portland cement concrete (PCC). Wave velocities obtained from seismic testing can also be used to calculate other salient design properties such as Poisson's ratio. Although the accuracy of seismic surveying is well researched and accepted by the engineering community, little research has been reported on uncertainty or precision of parameters obtained from the tests. In this study, a large sample of replicate field data was collected from multiple borehole and surface tests. Measurements of vertical (SV) shear waves were obtained at two independent soil sites. Seismic surveying was conducted at one PCC site to obtain measurements of compression (P) and Rayleigh waves. From this data, variation in seismic wave velocities collected from typical seismic testing was determined. In addition, variation in seismic wave velocities was used with error propagation techniques to evaluate uncertainty of Poisson's ratio. Based upon data presented within this study, coefficients of variation of SV, P, and Rayleigh wave velocities indicate a high degree of precision for these velocities. Also, the coefficient of variation for Poisson's ratio attests to the high precision of determining this property with seismic surveying techniques.