Structural changes and failure mode of open-pit slope under underground mining disturbance

The field detection results of high-density electrical method showed that the rock mass occurrence state, structure characteristics and mechanical properties in east open-pit slope take changes on the influence of Laohutai underground mining, which had a major influence on slope stability. The distribution of disturbance area and spatial position relation between the slope and disturbance area was stood by application of three zones theory. The rock mass structure characteristics and main failure mode in different parts of the slope was pointed out as following: Rock mass integrity in the caving zone is bad and broken seriously, so it is easy to take local collapse and block topple instability; Abscission layer and vertical joints develops well in the rock mass of fracture zone, so it mainly takes crooked-toppling instability; Rock mass integrity in bending zone is well, which still keeps the stratified structural, and is likely to take local crooked-toppling instability; Rock mass in tension area is under powerful tensioning action, so it mainly takes pulling damage.