Tectonic strain in salt rock mass based on measurements

The measurement method with the application of an extensometer for detection manifestation tectonic strain is presented in this paper. instrument operated underground construction engineering purposes, and authors applied it a deeply placed old mine gallery Bochnia Salt Mine, just at boundary Outer Carpathians which commonly considered to be tectonically active zone. study characterized by two basic features. first placement measurements deep environment free atmospheric factors disturbing signal. second combination routine carried out purposes research enabling extension observation displacements space outside workings, inside rock mass that has been penetrated probes. extensometric have made using three 7-meter long sections. results showed differentiation displacement rates points side walls: southern profile, annual are approximately 1.5 mm northern one – 1 mm. combined result corresponds amount convergence value determined classical surveys excavation where made. What more, ongoing wall involve entire part probe, but only observed 2 m mass. This interpreted as being acting from south exerted Carpathians.