Gas Migration in EBS and Geosphere (GMT) - Excavation of the EBS - Overview

The aims of the excavation and characterisation phase of the Gas Migration Test (GMT) were:

 

  • Evaluation of EBS following the gas test;
     
  • Determination of sand/bentonite properties
     
  • Detection of gas- and water-flow paths;
     
  • Assessment of the construction methods used;
     
  • Evaluation of interface properties (concrete silo/buffer concrete joint, instrumentation arms, risers);
     
  • Assessment of concrete silo performance and interaction of concrete and bentonite/sand effects
     
  • Recalibration of instrument

 

The excavation and characterisation of the silo was carried out in a series of eight steps (explained in greater detail in the sections shown in the side menu above):
 

Step 1: Depressurisation of GMT Cavern.

Step 2: Cutting through the concrete plug.

Step 3: Removal of backfill from GMT Cavern.

Step 4: Investigations from top of Layer 12.

Step 5: Removal of sand/bentonite by layers to top of concrete silo.

Step 6: Investigations in Layers 8 and 7.

Step 7: Removal of Layers 6-5.

Step 8: Restoration of GMT site.

 

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.