Subsidence assessment of ghaplogh stope and pillar mine by using numerical analysis

Subsidence is a critical problem that may appear during mining operation and other underground constructions like tunneling. Surface subsidence can result in some adverse environmental impacts, especially in the forms of damages to surface structures, road and railways, and surface and underground water systems. This study predicts surface subsidence caused by extracting salt at Ghaplogh stope and pillar mine using numerical analysis based on a finite difference method. To this end, a critical section of Ghaplogh salt mine was considered to model surface subsidence in terms of vertical displacements in the different points of stopes, overburden, and ground surface. Results were compared with the subsidence results measured from the studied area surface. As a result, the major subsidence was appeared above the first and second pillars in the direction of SW-NE. The maximum subsidence was determined to be 5 cm above the third stope which is around the second pillar.