Safe mining depth constitutes the key to the open-pit mine development, it is significant to research the safe mining depth. First, According to the field geological investigation and geophysical exploration, the existing landslides were summarized and analyzed to obtain the potential destabilization and failure modes in mine, which laid the effective reference for the slope stability analysis in the Changshanhao mine. Then, The entire three-dimensional calculation model of north-east pit was established through FLAC3D software. According to the calculation results of displacement nephograms, plastic zone and shear strain, it was concluded that the entire instability might occur during excavation of the north-east pit in accordance with the designed final boundary. Following, ten sections of north-east pit were selected to calculate the slope stability through 3DEC software, and four types of mining depth elevation designed for each section were considered. According to the numerical calculations of each slope stability under different mining depths, for ensuring the mining safety of north-east pit, the boundary that is 84 m higher than the final boundary is recommended, thus the safe mining depth elevation and ultimate stable slope angle were determined as 1216 m and 38 degrees, respectively. Under the proposed safe mining depth condition, the slope of north-east pit can keep its stability, laying a basis for the safe mining depth determination of similar open-pit slopes.

中文翻译：

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长山好矿反倾角顺层边坡安全开采深度研究

安全开采深度是露天矿发展的关键，对安全开采深度的研究具有重要意义。首先，通过野外地质调查和地球物理勘探，总结和分析了现有的滑坡，获得了矿山潜在的失稳和破坏模式，为长山hao矿山边坡稳定性分析提供了有效的参考。然后，通过FLAC3D软件建立了东北矿坑的三维计算模型。根据位移云图，塑性区和剪切应变的计算结果，得出结论，按照设计的最终边界，在东北基坑开挖过程中可能会发生整体失稳。以下，通过3DEC软件选择东北坑的十个断面来计算边坡稳定性，并考虑了为每个断面设计的四种采矿深度标高。根据不同开采深度下各边坡稳定性的数值计算，为保证东北矿井的开采安全，建议边界比最终边界高84 m，从而安全开采深度标高和极限稳定边坡角分别确定为1216 m和38度。在建议的安全开采深度条件下，东北矿山边坡可以保持其稳定性，为确定类似露天矿山边坡的安全开采深度奠定了基础。根据不同开采深度下各边坡稳定性的数值计算，为保证东北矿井的开采安全，建议边界比最终边界高84 m，从而安全开采深度标高和极限稳定边坡角分别确定为1216 m和38度。在建议的安全开采深度条件下，东北矿山边坡可以保持其稳定性，为确定类似露天矿山边坡的安全开采深度奠定了基础。根据不同开采深度下各边坡稳定性的数值计算，为保证东北矿井的开采安全，建议边界比最终边界高84 m，从而安全开采深度标高和极限稳定边坡角分别确定为1216 m和38度。在建议的安全开采深度条件下，东北矿山边坡可以保持其稳定性，为确定类似露天矿山边坡的安全开采深度奠定了基础。