ABSTRACT
With the rapid development of mining industry, the mining mode of many mines in China as well as oversea mines has been switched from open-pit to underground. When the underground extension of deposit is relatively large and the covering layer is thin, the upper layer of the mine is operated using typical open-pit method, whereas the remained deposit (primarily underground part) is mined with underground method. This mining method is so called transforming open-pit into underground mining. This method can save tremendous manpower and material resources. Meanwhile, using this mining method also reduces the risk of high and steep slope during open-pit. Therefore, transforming open-pit into underground mining is the optimal method of mining.
