Full-scale Engineered Barriers Experiment (FEBEX) II - Dismantling of the Concrete Plug

The first stage of the excavation phase was the dismantling of the FEBEX concrete plug :

The first stage in the operation involved dismantling of the existing concrete plug (2.7 meters long - shown below) and exposure of the bentonite blocks that lay behind. Initially, a series of boreholes were drilled into the concrete plug:

The concrete plug prior to dismantling

Drilling boreholes into the concrete plug
The concrete plug was broken up by a hydraulic splitting techniques. As this continued, samples were also taken of the interface between the plug and the host rock

Hydraulic splitting of the concrete

Taking samples from the rock/plug interface
Eventually the bentonite was reached (shown left). The excavation of the bentonite is shown in the next section (FEBEX II - Excavation phase - Bentonite excavation).


Full-scale High Level Waste Engineered Barriers (FEBEX) - Excavation Phase

The GTS underground facilities are also available to interested 3rd parties for underground testing and research. The GTS offers cost-effective access to a fully developed, well characterised underground research facility with round the year logistical support - please contact Dr. Ingo Blechschmidt, Head of the Grimsel Test Site, for further details.