Restoring Initial Conditions in a Deep Argillaceous Rock with Induced Suction on Retrieval

EasyChair Preprint no. 4318

Abstract

The natural plastic Ypresian clays (Ycs) – one of the potential host rock formations in Belgium for the geological disposal of radioactive waste – has been experimentally studied to determine the swelling pressure using an updated and improved isochoric cell. The Ycs samples were retrieved between 300 and 450 m depth at Kallo (Belgium). The combination of the high matric suctions (between -2.6 and -3.4 MPa) – induced by the undrained retrieval - and the relatively low air entry values associated with dominant largest pores led to a slightly desaturation of the soil samples. The hydration was performed on an instrumented axisymmetric and isochoric cell under controlled hydraulic boundary conditions with pressure / volume controllers and equipped with three total stress sensors located at the top and the laterals of the cell. Thereby, the cell allowed reducing the suction while the expansion of soil volume was constrained leading to the development of the swelling pressure, tracking the swelling anisotropic features with the total stress sensors.

Keyphrases: argillaceous rock, retrieval, suction

@Booklet{EasyChair:4318,
  author = {Nuria Sau Valenzuela and Enrique Romero Morales and Hervé Van Baelen},
  title = {Restoring Initial Conditions in a Deep Argillaceous Rock with Induced Suction on Retrieval},
  howpublished = {EasyChair Preprint no. 4318},

  year = {EasyChair, 2020}}