Towards the determination of surface collapse type over abandoned mines in the Lorraine iron basin

Surface collapse is a major problem that follows many active or abandoned underground workings. Collapses result from roof deformation of underground workings, and/or controlled or uncontrolled rock caving. The uncontrolled rock caving could result in surface instability problem and loss of materials and/or human life. Over the past 90 years, ans as a result of underground-uncontrolled rock caving, 16 major accidents "surface collapse" has been reported in the French Lorraine iron basin.