Laboratory Test On Thermal Properties Of Saturated Silty Clay Under Heating-cooling Process

The study of the properties of clay concerning the influence of the temperature load in the field of geotechnical engineering is an important topic in recent years. It has important and practical value in the area of energy storage, nuclear waste disposal, geothermal resources development, heating pipe design, soft soil foundation reinforcement, etc. However, the study of the effect of temperature on the properties of clay is still at an early stage at present time.Therefore, the thermal characteristic of clay in circumstance under which the temperature varies is worth of further study.Based on the context above, this thesis, which includes experimental study and mechanism analysis, uses pressure chamber with temperature control to take out thermal experiments on saturated silty clay.Using pressure chamber with temperature control to carry out experimental study on saturated silty clay in a cyclic temperature load, where the temperature ranges from 25℃to 75℃, with a 6 time-cycle and a graduating confining pressure of 50kPa, 100kPa,150kPa. In each temperature, the cycle process includes, a heating up phase of temperature from 25℃to 75℃, an isothermal phase of 75℃, a cooling phase from 75℃to 25℃and finally an isothermal phase of 25℃, moreover, apart from the initial drainage consolidation phase, the pore water in the samples is at a non-discharge state in the remaining phases.Based on the experimental results, the paper analyzes the change process of the temperature, pore water pressure and confining pressure measured by the pressure of the interior volume strain at the different confining pressure and under heating-cooling process,and explained through the mechanism of thermal properties of the pore water pressure and the confining pressure measurement of the pressure chamber volume strain evolution. In addition, the paper also analyze the effect of temperature, pore water pressure and volume strain in the pressure chamber under the same confining pressure according to different heating rate.