复杂边界条件下VCR法采场安全破顶厚度研究  

Safe Roof Blasting Thickness of VCR Stope Under Complex Boundary Condition

作　　者：汪伟[1] 罗周全[1] 齐飞祥 曹胜祥[2] 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083 [2]凡口铅锌矿,广东韶关512325

出　　处：《东北大学学报（自然科学版）》2016年第5期721-725,共5页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(51274250)

摘　　要：为确定凡口矿某VCR法采场安全破顶厚度,构建了“三固一简”边界条件下破顶层极限承载分析模型,推导分析了破顶层承载能力随厚度变化关系,并从力学角度计算最小破顶厚度为4.6 m.为获得塑性区体积、竖向最大位移、安全率等指标随破顶厚度变化规律,对不同厚度破顶层的稳定性进行数值分析.研究表明,破顶厚度由5 m减至4 m时,塑性区由部分贯通发展至完全贯通,安全指标突变至不利状态,与力学计算结果相印证.参考类似矿山安全系数取值,确定试验采场安全破顶厚度为6~7 m.实际爆破中,预留破顶层（厚约6.5 m）始终稳定,表明研究结果与实际情况的吻合度较好.In order to determine safe roof blasting thickness of a VCR stope in Fankou mine, a mechanical ultimate-bearing analysis model of roof blasting under complex boundary condition （three sides fixed and one side supported） was constructed, the relationship between bearing capacity and roof blasting thickness was derived, and the minimum roof blasting thickness was calculated as 4. 6 m. Accordingly, numerical simulations of blasting roof stability under various thicknesses were carried out to obtain the changing law between indexes （plastic zone volume, maximum vertical displacement and safety coefficient） and thickness. Research results show that safety indexes change obviously and plastic zone develops into complete connection when roof blasting thickness decreases from 5 m to 4 m, which proves the rationality of mechanical analysis. Referring to safety coefficient of similar mines, safe roof blasting thickness is revised as 6 -7 m. In practice, the fact that the blasting roof of 6. 5 m thickness keeps safe all the time indicates that the results fit well with actual situation.

关 键 词：VCR采矿法 破顶层 边界条件 塑性极限分析 数值模拟 

分 类 号：TD853[矿业工程—金属矿开采]