Laboratory Column Experiments (FORGE) - Mock-up Experiment

A mock-up experiment was also installed at GTS in June 2010 as part of the FORGE project. Its purpose is to simulate the cavern seal of a L/ILW cavern (i.e. with a cement backfill of the emplacement cavern and a sand-bentonite seal) on an intermediate scale and under well controlled boundary conditions.


A steel cylinder (Fig. 1) is filled with a compacted sand/bentonite (S/B) seal (brown/yellow area in Fig. 1) and two porous mortar disks at both sides (grey areas). To prevent preferential water and gas flow along the interface between the S/B body and the steel cylinder the outer ring space was sealed with pure bentonite powder (yellow area).

As shown in the experiment schedule, the S/B mixture will first be saturated with water, followed by gas injection tests to assess gas migration behaviour at a decimetre scale. At the end of the testing, the experiment will be dismantled in order to analyse in detail the cement-clay interfaces.

3D Drawing of the FORGE mock-up experiment at Grimsel

Figure 1: Drawing of the mock-up experiment with the steel cylinder confining the experiment, mortar discs at moth ends (grey/brown), the S/B seal (brown/yellow), the pure bentonite (yellow) and the ring-TDRs (black). Instruments are schematically indicated to show the locations of the monitoring levels.

Experiment Schedule

 

2009

2010

2011

2012

2013

Planning

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Setup

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Water injection

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gas injection

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Dismantling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Modelling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lab programme

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Impressions from Emplacement:

Impressions from the FORGE mock-up creation and emplacement

Impressions from the FORGE mock-up creation and emplacement - members

Laboratory Column Experiments (FORGE)

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.