Interpreting DPSH penetration values in sand soils

Abstract

Site investigations to classify the underlying soil for geotechnical purposes often rely on in-situ penetrometer tests. Two common tests used in southern Africa are the Standard Penetration Test (SPT) and Dynamic Probe Super Heavy (DPSH) test. Although the specific work per blow is essentially the same in both tests, the resulting penetration values are not equivalent. The DPSH tends to be more variable than the SPT and has higher blow counts. A comparison of SPT and DPSH penetration values at a series of strata below sites has been undertaken. From this, new relative density descriptor boundaries, based on DPSH penetration values, are suggested for sand soils.