Field monitoring of expansive soil behaviour in the Newcastle-Hunter Region

As part of a long term research project on the behaviour of expansive soils, twenty open-ground field sites which cover a range of soil, geological and geographic conditions were set up in the Newcastle-Hunter region. The sites were selected to provide detailed information on the distribution and nature of expansive soils and soil behaviours in the region. Seasonal ground movements, at various levels relative to the ground surface, were measured to a precision of 0.1 mm on a regular basis. In situ soil moisture content variation profiles were monitored by a neutron probe. This paper presents the results of the field monitoring over periods of up to 7 years. The site selection, instrumentation and laboratory testing results are discussed. A comparison of predicted design ground movement based on the method of AS2870 with the measured movements is also presented.