Observation and auscultation of the geotechnical behaviour of a slope in an open cast mine influenced by old underground mining (South-western part of France)
International audienceThe final slopes of a French open pit mine of the "Charbonnage de France" Company which final depth will be 300 metres, have been designed after a Standard geotechnical survey. This one has taken into account the geomechanical, hydrogeological, structural parameters äs well äs the" decohesion", induced by former mining subsidence. However some slopes can locally present risks of slipping (increasing with the depth of the pit) induced by old Underground mining. A methodology has been defined concerning the slope auscultation and its behaviour including the use of numerous measuring tools (topographic measurement, inclinometer, equipped cable bolts...). Two auscultation cases are presented, one on a slope slipping, another one on a potential slide. In the first case, the instrumentation checked that the reinforcement is satisfactory. In the second case, the instrumentation allows to analyse that the correct measures have been taken to prevent any risk
