前言在建筑物下、水体下和铁路下(简称为“三下”)采矿是当前我国有色金属矿山老矿挖潜和延长矿山寿命中出现的一个带普遍性的问题。过去,为了保护地表建筑物和目的物,我国主要是采用留设保安矿柱的方法。但是,这不仅大量地积压和丢失资源,而且会给井下生产和运输带来困难。锡矿山是具有悠久开采历史的老矿山。五十年代,为了保护地表河床、南炼厂、俱乐部等重要建筑物而留设了保安矿柱。这些保安矿柱,开采条件复杂,曾被人们称为不可开采的 Preface Mining under the water, under the water and under the railway (referred to as the “three underneath”) is a common problem that appears in the old mine of China's non-ferrous metal mines and the extension of mine life. In the past, in order to protect surface buildings and objects, our country mainly adopted the method of leaving security pillars. However, this not only backs up and loses resources in large quantities, but also poses difficulties in downhole production and transportation. Tin mines are old mines with a long history of mining. In the fifties, security pillars were set up to protect important structures such as surface riverbed, south refinery and clubs. These security pillars, mining conditions are complicated, once known as non-mining