Development of a new temperature-controlled oedometer

Department of Civil and Environmental Engineering, Imperial College London, United Kingdom

^* Corresponding author: adk10@ic.ac.uk

Abstract

A new temperature-controlled oedometer has been designed at Imperial College London and commissioned to investigate the thermo-hydro-mechanical behaviour of soils. Under oedometric conditions, temperature can be varied between 5°C and 70°C, by submerging the specimen in a temperature-controlled water bath. This temperature range is appropriate for the proposed applications of the research: design of ground-source heating/cooling systems, and design of geological disposal facilities for nuclear waste. In this paper, an overview of the new equipment is given: its design, development, and calibration. First, the literature on temperature-controlled oedometer schemes is reviewed. A description of the equipment follows, with further details on the innovations and limitations of this design. As the equipment has been modified and improved over the course of the research, so too has the calibration procedure. These developments are discussed, again with the focus on innovations and limitations. Finally, a test programme and preliminary results are presented, for saturated KSS, an artificial mixture of kaolin clay, silt, and sand. These include isobaric (constant-pressure) heating tests, for a variety of loading histories. Over-consolidation ratio is found to affect the thermally-induced volume change.