Scholarlink

<p>The sand/bentonite (S/B) mixture is considered as a candidate sealing and backfilling material for Switzerland’s deep geological repository (DGR). Using S/B mixtures as sealing material offers key advantages, such as higher intrinsic gas permeability and lower swelling pressure, which enhance gas transport efficiency. These properties make the S/B mixture a strong candidate for use as a gas-permeable seal within the Engineered Gas Transport System (EGTS) concept. This study investigates the coupled hydro-mechanical and gas transport (HM-G) response of the S/B mixture, incorporating the effects of dynamic compaction-induced variability in dry density. Key properties of the S/B mixture, such as porosity-dependent and strain-dependent water retention curves (WRC), effective and intrinsic water and gas permeability, and mechanical parameters, were calibrated while accounting for the process-driven heterogeneity in dry density and effective gas permeability of the system. Laboratory-scale simulations of oedometer and swelling pressure tests were conducted to support the parametrization of the mechanical model. The calibrated parameters were then implemented in a 3D small-scale model to evaluate the THM-G response of the S/B mixture, accounting for material heterogeneity under conditions representative of GAST, involving sequential hydration and gas injection stages. The simulations were performed using CODE_BRIGHT, a Finite Element Method (FEM) program. Advanced geo-mechanical models, including the Barcelona Basic Model (BBM), the Barcelona Expansive Model (BExM), and a strain-dependent intrinsic permeability formulation, were employed to represent the material behaviour within a continuum framework.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Hydro-mechanical and gas transport (HM-G) characterization of sand/bentonite mixture within the framework of the Gas Permeable Seal Test (GAST)

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年4月13日

查看全文
  • Erdem Toprak,
  • Sebastia Olivella,
  • Enrique Romero,
  • Alessandro Fraccica,
  • George William Lanyon

摘要

The sand/bentonite (S/B) mixture is considered as a candidate sealing and backfilling material for Switzerland’s deep geological repository (DGR). Using S/B mixtures as sealing material offers key advantages, such as higher intrinsic gas permeability and lower swelling pressure, which enhance gas transport efficiency. These properties make the S/B mixture a strong candidate for use as a gas-permeable seal within the Engineered Gas Transport System (EGTS) concept. This study investigates the coupled hydro-mechanical and gas transport (HM-G) response of the S/B mixture, incorporating the effects of dynamic compaction-induced variability in dry density. Key properties of the S/B mixture, such as porosity-dependent and strain-dependent water retention curves (WRC), effective and intrinsic water and gas permeability, and mechanical parameters, were calibrated while accounting for the process-driven heterogeneity in dry density and effective gas permeability of the system. Laboratory-scale simulations of oedometer and swelling pressure tests were conducted to support the parametrization of the mechanical model. The calibrated parameters were then implemented in a 3D small-scale model to evaluate the THM-G response of the S/B mixture, accounting for material heterogeneity under conditions representative of GAST, involving sequential hydration and gas injection stages. The simulations were performed using CODE_BRIGHT, a Finite Element Method (FEM) program. Advanced geo-mechanical models, including the Barcelona Basic Model (BBM), the Barcelona Expansive Model (BExM), and a strain-dependent intrinsic permeability formulation, were employed to represent the material behaviour within a continuum framework.