Parametric study of thermo-hydro-mechanical response of claystone with consideration of steel corrosion

In this paper, the thermo-hydro-mechanical (THM) response of claystone is studied via a series of parametric studies, considering the evolution of mechanical properties and deformation behavior of corroded steel. The numerical simulations are performed by using a coupled THM finite element code and two different constitutive models: a visco-elastoplastic model for geological formation and a von Mises type model for steel liner. The mechanical properties and deformation behavior of corroded steel are described in a conceptual model. Finally, a disposal tunnel supported by a steel liner is studied and a series of parametric studies is defined to demonstrate the corrosion effects of steel liner on the THM response of the claystone. The comparison of different numerical calculations exhibits that the volumetric expansion related to corrosion products has an important impact on the stress and displacement fields in the claystone surrounding the disposal tunnel. However, the evolutions of temperature and liquid pressure in the claystone are essentially controlled by its THM properties and independent of the steel corrosion.