The prepared specimens were tested in three experiments. The series started with a quasi-static compression test. Slowly, pressure was set up to simulate the loads through the ground. The second one was a shock test. The bon-ding was hit by a weight that fell from a certain height onto the specimen. This should simulate the load of a cut with a spade at the building site. In the third test the gas tightness was tested. The T-piece was charged with the multiple of the normal operating pressure.