Determining conditions of using draglines in single-tier internal dump formation

purpose. The scientific and practical task of the study is to establish the dependences of the safe distance of dragline excavators on the height of a singletier internal dump of the overburden rocks and the level of its flooding, taking into account the physical and mechanical properties of rocks. methodology. To achieve these goals, the following research methods were used: computer modelling using "Slide" software to build the most stressful sliding surfaces of the dumped rock mass. The calculations were performed in manual and automatic search modes for the most stressed (weak) sliding surface on several calculated sliding surfaces. The obtained data of calculations of the width of the prism of a possible landslide were analyzed and their dependence on the height of the singletier dump and the water level in the open pit space was established by the method of least squares. The formula for calculating the value of the dis tance from the safety embankment to the axis of movement of the excavator is obtained using the cosine theorem and a number of trigonometric identities.