关键词: 露天转地采, 复合型人工境界矿柱, 结构设计, 经济效益

Abstract: Based on the project of Guilaizhuang Gold Mine in Shandong Gold Group，and combining with theoretical analysis and engineering project，an effective construction and mining program of compound artificial boundary pillar with artificial false roof and concrete filling body is proposed，including scope of artificial boundary pillar，structure of artificial boundary pillar，formation of artificial boundary pillar，rebar connection of filling unit，concrete interface treating of filling unit，structure of artificial boundary pillar in narrow ore body area and bottom isolated layer of artificial boundary pillar. Groove breccia slope surface uses metal nets as temporary support，and metal nets are fastened with tubular bolts and rebar belts. Economic benefits from compound artificial boundary pillar and the ore body below compound artificial boundary pillar are studied. The researches show that the compound artificial boundary pillar effectively solves the problem of output stability during transition from open-pit to underground mining in Guilaizhuang gold mine，increases recovery rate of resource and reaches targets of safe and efficient mining，which produces significant economic benefits for Guilaizhuang gold mine.

Key words: Transition from open-pit to underground mining, Compound artificial boundary pillar, Structural design, Economic benefits