To assess the hydro-mechanical performance of the PRACLAY Seal, gas tests have been carried out in 2012 and 2013. The test method is based on applying an increasing gas pressure on four selected piezometer filters located at the bentonite/clay host rock interface of the seal. Through observing the gas outflow and eventually break-through, we can obtain a better picture of the mechanical stress state around these filters. In general, the results obtained from the different filters were consistent. The analysis of the gas breakthrough indicated an unstable flow, indicating a mechanism other than classical visco-capillary two-phase flow. In addition, other sensors (pore water and total pressure) were influenced, suggesting the presence of hydraulic connections in the seal structure.
|Number of pages||33|
|State||Published - May 2015|
|Publisher||Studiecentrum voor Kernenergie|