Abstract

During a series of investigations involving residual soils and weathered rocks in Singapore, correlations have been established between weight sounding test resistance (WST), ram sounding test resistance (RST) and the standard penetration test (SPT) resistance. Equality of blow counts between SPT and corrected RST is suggested for values of N less than 30. Above that, SPT blow counts were consistently higher, and a value of N_SPT = 1.5 N_RST was more typical. Weight sounding results have also been found to correlate well with SPT blow counts.

The soil type aand the shape of tips used in each test are considered important in explaining the trends of the correlation curves. In sandy soils or soils with a low clay content, the dynamic friction is negligible. In stiff to hard cohesive soils, plugging of the SPT samples and dynamic friction effects on the interior of the tube may explain the high SPT blow counts compared with those from RST.

The main disadvantage of using ram and weight sounding methods rather than the SPT is that samples are not usually recovered. However, each provides continuous profiles of penetration resistance measured at closer intervals than SPT, both quickly and economically without a borehole.