小汪沟铁矿露天转地下覆盖层形成方法研究

小汪沟铁矿在露天转地下开采过程中，采用诱导边坡岩体自然冒落的方法形成覆盖层，有效地扩展了露天与井下同时生产的空间条件，实现了露天转地下增产衔接。详细介绍诱导冒落方案、工艺技术与实施效果，并分析了影响冒落进程的主要因素。

Study on the Formation of Overburden Layer during the Transition from Open-pit to Underground Mining in Xiaowanggou Iron Mine

During the transition from open-pit to underground mining in Xiaowanggou iron mine，overburden layer for sublevel caving is formed through the induced caving process of open-pit slope.This process is effective in extending space conditions of simultaneous open-pit and underground mining，and achieving the production increase during the transition from open-pit to underground mining.The paper describes the schemes，techniques and implementation of induced caving，and analyzes the main factor of affecting the caving process.