Estimation of rippability and excavation conditions in calcrete deposits with seismic refraction methods

Abstract

Seismic P-wave velocities in surficial materials, determined from seismic refraction surveys, can be used to assess excavation conditions at engineering sites such as roads and pipelines. These velocities are important in establishing whether and to what extent blasting is required. Certain contractors have produced rippability versus seismic velocity charts which are widely used to assess excavation conditions on a preliminary basis. Unfortunately these charts are limited in the number of rock types included and fail to take account of other complicating factors such as degree of weathering and nature of occurrence. They are particularly limited in treating surficial deposits such as calcrete, the nearest charted equivalent being caliche which may or may not be equivalent to calcrete.