Screw driving sounding: a new test for field characterisation

Abstract

Various in situ testing techniques are commonly employed to obtain geotechnical parameters for use in analyses and design. Some of the more popular field tests include standard penetration tests (SPTs), cone penetration tests (CPTs) and Swedish weight sounding (SWS). SPT and CPT are commonly preferred for large-scale projects, but they are expensive when implemented for small-scale constructions. SWS is highly portable and economical but poor in classifying soils. The screw driving sounding (SDS) test, which has been recently developed in Japan, is an improved version of SWS and can measure more parameters, including the required torque, load, speed of penetration and rod friction, and thereby provides a robust way of characterising soil stratigraphy. It is cost efficient and uses a machine-driven and portable device, making it suitable for testing in confined areas. Moreover, with a testing depth of 10–15 m, it is ideal for characterising shallow deposits. In this paper, the SDS test is introduced and the results of its application to various New Zealand sites are discussed. Moreover, a number of correlations between SDS parameters and CPT/SPT data are presented. The results prove that SDS can be an effective alternative for soil characterisation, particularly in residential areas and roading projects.