An Optimal Design Method for Slope Shape in Open Pit Mine

Abstract

The invention provides an optimum design method for the shape of an open-pit mine slope. The optimum design method comprises the following steps: continuously increasing a slope angle alpha with regard to a certain slope height H; judging that the slope is in a limit equilibrium state when the curve of the slope surface shape of the slope in a limit state, which is obtained through a slip-line field theory, and the slope surface line of the slope are intersected at a slope toe, wherein the slope angle alpha is a limit slope angle alpha cr at this moment; and fitting a series of slope heights H with the limit slope angle alpha cr to obtain the optimum slope surface shape of the open-pit mine slope, wherein the shape is a convex curve. A single straight-line excavation form of a limit equilibrium method is changed, and the ore stripping volume can be reduced, the production benefits can be improved and the mine age can be prolonged compared with the principle of space mechanics; and the method provides a new analysis way for an optimum design for the shape of the open-pit mine slope.

Description

technical field [0001] The invention belongs to the technical field of open-pit mine slope engineering, and in particular relates to a shape optimization design method for open-pit mine slopes. Background technique [0002] Most of the large and medium-sized open-pit mines in our country were built in the 1950s and 1960s, and most of them have entered deep concave mining. The excessive stripping ratio has made many mines fall into trouble, and the work of seeking to reduce the amount of waste rock stripping has attracted increasing attention. [0003] On the one hand, with the increase of the mining depth and the heightening and steepening of the slope, the failure probability of the slope and the difficulty of mining will increase; considerable. Therefore, how to coordinate the relationship between the two and design the optimal slope angle is a difficult problem faced by every open-pit mine, which will have a significant impact on the production safety and economic benefi...

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Problems solved by technology

When the limit equilibrium method is used for analysis, the excavation shape of the slope is generally linear. When calculating the safety factor, it is necessary to assume and search for the critical slip surface. The safety factor can be written as a function of the critical slip surface. The minimum safety factor is In order to find the minimum value of the function, the function has non-convexity and multi-extreme value, the former hinders the use of conventional mathematical methods, and the latter makes the search method easy to fall into the local minimum, so it is difficult to determine the limit state, while numerical analysis The biggest difficulty is how to determine that the slope is in the limit state, that is, there is no better way to determine the instability criterion. At present, it can only be analyzed and evaluated by human judgment and trial calculation.

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