Soft highly organic soils are widespread in the foundation layers of the built environment all over the world. They contain organic matter, roots and fibres, which improve their mechanical response. However, these soils are extremely vulnerable to climate-related hazards. Increasing climatic stresses, such as heat waves, drought, and more frequent intense precipitation accelerate the degradation of organic soils, by increasing their drying and shrinkage rate above the water table and their decomposition rate under water, with gas generation and exsolution. Both these mechanisms, drying and gas exsolution, ultimately contribute to significant land subsidence and reduction in available resistance. Quantifying the geotechnical engineering consequences of seasonally varying loads, including drying-wetting, temperature cycles and degradation, on organic soils is extremely challenging due to the complexity of a proper description of multi-physics gas-liquid-solid interaction. The project aims at deepening the understanding and the modelling of these coupled processes, to mitigate the climate-related hazard in natural soils and to assist in the design of durable innovative green solutions.
The twofold aim of the PhD project is:
– To experimentally investigate the coupled hydro-mechanical behaviour of organic soils subjected to cycles of environmental (e.g. drying and wetting, temperature) and mechanical loads. Soft soils reinforced with natural and artificial organic fibres will be tested, to quantify the role played by fibres, gas and fabric on their mechanical behaviour.
– To enhance existing constitutive models in order to include the effects of environmental factors such as drying-wetting cycles, temperature cycles and degradation in the prediction of their geotechnical properties.
The PhD candidate will benefit from advanced experimental laboratory facilities including unsaturated triaxial apparatus, biaxial plane strain apparatus, large-scale testing facility, geotechnical centrifuge and imaging facilities already available in the Faculty of Civil Engineering and Geosciences of TU Delft and partner institutions, and the support of experienced technical staff.
More information in the attached document: PhD_position_TU_Delft_TUD01486
The closing date for the applications is 17 October 2021.