Laboratory and in-situ testing
Laboratory element testing of soil and rock is an essential part of the geotechnical research programme at the NCG. Its main purpose is to provide high-quality experimental data for behaviour of soil and rock under well-controlled stress conditions. This data is then used to validate constitutive models developed to describe the stress-strain behaviour of geotechnical materials in general stress states. In addition to laboratory testing, the NCG also has strong research interests and expertise in the development of modern in-situ soil testing for site investigation.
Past research in the area of laboratory testing at Nottingham has been focused on rock behaviour around underground excavations and exposed rock slopes, as well as soil behaviour under repeated loading conditions with applications to pavements.
In recent years, however, significant investment has been made to build up a wider range of state-of-the-art soil and rock testing equipment. In particular, we have recently commissioned a hollow cylinder apparatus, a high-pressure triaxial apparatus, a dynamic triaxial apparatus, and a simple shear apparatus. We have also built a large triaxial apparatus for testing railway ballast.
In the rock-mechanics laboratory, we have completely updated the control system for the major items of existing rock-testing equipment, including the 100 tonne RDP stiff press, the 150mm shear box and the instrumented drilling rig. The experimental data obtained from this new equipment will provide the necessary data to support some of our cutting-edge research on constitutive modelling. To support the research effort on in-situ testing, we have recently commissioned a truck-based, mobile soil-testing facility.
This will allow a direct comparison between the results of laboratory testing of soil samples and those of field testing of the same soils in-situ. In this way, the effect of soil disturbance during the sampling process may be investigated. The results from field tests will also provide an essential experimental database for the development of theoretical interpretation methods for deriving fundamental soil properties from field measurements.