RISUD Research Seminar - Chemical Effect on Hydro-Mechanical Behavior of Compacted Bentonite Used as Buffer Material

In China, Gaomiaozi (GMZ) bentonite has been selected as the first choice of buffer/backfill material and the Beishan area in Gansu Province has been considered as the most potential repository site for high-level waste (HLW) disposal. Near the repository, the chemical effect on the barrier properties of compacted bentonite might lead to its performance failure threatening the long-term safety of HLW repositories. This presentation focus on the C-H-M effects on the swelling and compression behavior of compacted GMZ bentonite under different conditions. Salt solutions was prepared to simulate the chemical environment near the repository site. Finally, a constitutive model of compacted GMZ bentonite will be established to describe its behavior considering the C-H-M effect. Based on the model, numerical simulations will be conducted to evaluate the deformation performance of bentonite under the salt solution conditions. The expected results could provide a theoretical basis for design and construction of repository.