A nonlinear elastic approach to modelling the hydro-mechanical behaviour of the SEALEX experiments on compacted MX-80 bentonite
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- 作者：A. P. Fraser Harris ; C. I. McDermott ; A. E. Bond…
- 关键词：Hydro ; mechanical (HM) coupled processes ; Bentonite ; Numerical modelling ; Radioactive waste disposal
- 刊名：Environmental Earth Sciences
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：75
- 期：22
- 全文大小：2,996 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：None Assigned
- 出版者：Springer Berlin Heidelberg
- ISSN：1866-6299
- 卷排序：75
文摘
Hydraulic seals using compacted sand–bentonite blocks are an important part of the closure phase of deep geological disposal facilities for the isolation of many categories of radioactive wastes. An understanding of the hydro-mechanical behaviour of these seals and the ability to model their behaviour is a key contribution to safety cases and licence applications. This work reports the development of a hydro-mechanically coupled model and its application to the simulation of a range of test conditions investigated in the SEALEX experiments conducted by IRSN at Tournemire URL. The work has been conducted as part of the recently completed DECOVALEX-2015 project. Richards’ equation for unsaturated fluid flow is coupled to a nonlinear elastic strain-dependent mechanical model that incorporates a moving finite element mesh, and calibrated against laboratory experiments. Stress and volumetric dependencies of the water retention behaviour are incorporated through the Dueck suction concept extended to take into account permanent changes in water retention behaviour during consolidation. Plastic collapse in laboratory results is modelled with the application of a source term activated by a threshold defined in terms of the net axial stress and net suction. The model is used to simulate both a 1/10 scale mock-up laboratory test and full-scale in situ performance test and is capable of reproducing the major trends in the data with just nine mechanical parameters and an experimentally defined stress threshold.