Thermo-Hydro-Mechanical Coupled Modeling: Big-Ben Experiment, TC3. DECOVALEX-Phase 3

摘要

The report presents results of a finite element analysis for one of the test case(TC) problems identified for modeling during Phase III activities of the international cooperative project DECOVALEX (acronym for the DEvelopment of COupled models and their VALidation against EXperiments in nuclear waste isolation). The analysis was conducted for the TC problem called the Big-Ben Experiment (TC3) using the commercially available finite element code ABAQUS with the option of two types of discrete joint elements. The Big-Ben Experiment was designed to evaluate the heat transfer, water uptake, and swelling behavior in an engineered barrier system for underground disposal of high-level nuclear waste. The engineered barrier system consists of an electric heater, a carbon steel overpack, clay buffer material, and a cylindrical reinforced concrete block with a hole at the center. The buffer material between the overpack and concrete consisted of a partially saturated bentonite clay and sand mixture. The experiment consists of uniform heating and water injection into a thin gap between the buffer and concrete for a time period of 5 months. The ABAQUS results show good agreement with the experimental measurements of temperatures within the engineered barrier system.