快速释放与充分利用内排空间是露天矿实现安全、降本、高效、绿色开采的重要途径。为解决横采内排开采程序的排土线布置难题，强化内排，对内排土场基底倾角、采场工作线布置等相关因素与排土线布置关系展开研究。兼顾水平、倾斜煤层露天煤矿，应用3Dmine软件，构建了内排空间利用最大化的采场工作帮、内排土场、端帮和基底的空间几何模型;在建立内排空间利用最大化的工程条件基础上，推导了露天煤矿排土线布置的数学表达式，理论上揭示了采场工作线布置及边坡角、内排土场边坡角、基底倾角对排土线布置的影响规律，将此方法运用于某露天煤矿。研究结果表明:横采内排开采程序实现内排空间利用最大化的充要条件为:基底倾角α小于内排土场边坡角β_p;内排土场工作线布置方向θ_p与基底倾角α、采场工作帮边坡角β_c呈负相关，与内排土场边坡角β_p、采场工作线布置方向θ_c呈正相关;某露天煤矿横采区2023年计划采场工作线方向θ_c=90°，内排土场工作线布置方向θ_p=46.3°才能实现内排空间利用最大化。成果可用于优化排土工作线布置，弥补常用方法设计排土线布置试绘工作量大的不足，为横采内排追踪开采技术在工程实践上的应用提供理论基础。

Rapid release and full use of internal waste dump space is an important way in surface coal mining to achieve safety,cost reduction,high efficiency and green mining. To solve the problem of arranging the working line of internal waste dump in cross exploitation and inner dumping,the internal waste dump is strengthened,and the relationship between the relevant factors such as the basement dip angle and the layout of the working line in stope and the arrangement of the working line of internal waste dump were studied. Taking into account the horizontal and inclined coal seams in surface coal mining,the 3 Dmine was used to construct the spatial geometric model of the stope,internal waste dump,the end slope and the basement under maximizing utilization conditions. Based on the engineering conditions for maximizing the utilization of internal waste dump space,the mathematical expression of arranging the working line of internal waste dump was derived,and the influence of the layout of the working line and the slope angle in stope,the slope angle of internal waste dump,and the basement dip on the layout of internal waste dump was theoretically revealed. This method was applied to surface coal mining. The results showed that the necessary and sufficient conditions in cross exploitation and inner dumping to maximize the utilization of internal waste dump space are as follows: the dip angle of the basement α is less than the slope angle βp of internal waste dump; the arrangement direction of the working line of internal waste dump θc which is negative correlation to the dip angle of the basement α and the slope angle βc of stope is positively correlated with the slope angle βp of internal waste dump and the layout of the working line in stope θc. In 2023 of the horizontal mining area of an open-pit coal mine,the working line direction of stope θc= 90° is planned,and the layout direction of the working line of internal waste dump θp= 46. 3° can be used to maximize the utilization of space. The results can be used to optimize the layout of the working line in the inner dump to make up for the large workload of the test drawing of the layout of the working line in common methods.