Rock mass characterisation and stope design

加拿大的大多数地下采矿使用一种称为空场采矿的方法提取矿石。 采场是一个大型的地下挖掘，矿石已经被爆破和移除，这些开口通常可以是十层公寓楼的大小。 这些开口的上盘和下盘遵循矿石和废物之间的接触。 在采矿过程中，废石从这些墙壁上脱落或脱落，与矿石混合，稀释了品位。 废石的这种坍塌被称为采场贫化，由于这种材料必须与矿石一起运输到地面、破碎和研磨，因此会给矿山带来显著的额外费用。减少采场贫化是许多地下采矿作业的主要目标。 控制上盘稀释的主要因素之一是岩体的强度。 本研究的目的是提高采场设计中岩体性质的测量和应用。 在实现这一目标的过程中，将通过更好的数据收集、解释和分析来改进预测上盘稳定性和稀释度的方法。 目前用于评估岩体性质的方法导致单一的岩石分类编号。 用于确定该值的方法对于测量岩体性质的改进的、更精确的方法相对不敏感。 自20世纪70年代初以来，根据主要在土木工程隧道工程中进行的观察，用于将各种岩体特性联系起来以获得单一数字的方法已经固定下来。 采场测量数据提供了一个未开发的信息来源，将开口几何形状和岩体特性与岩石稳定性联系起来，以破坏深度或上盘稀释度来测量。 这项研究将改善量化岩体特性的方法，并通过减少采场贫化来帮助加拿大矿山节省资金。

The majority of the underground mining in Canada uses a method of extracting the ore called open stoping.  A stope is a large underground excavation where the ore has been blasted and removed and these opening can often be the size of a ten story apartment building.  The hanging wall and footwall of these openings follow the contact between the ore and the waste.  Waste rock failing or sloughing off these walls during mining mixes with the ore and dilutes the grade.  This sloughing of waste rock is called stope dilution and can create significant additional expense for mines since this material has to be hauled to surface, crushed and milled with the ore.Reducing stope dilution is major goal for many underground mining operations.  One of the main factors governing hanging wall dilution is the strength of the rock mass.  The goal of this research is to improve the measurement and application of rock mass properties for stope design.  In the process of reaching this goal, methods of predicting hanging wall stability and dilution will be improved through better data collection, interpretation and analysis.  The current approach for assessing rock mass properties results in a single rock classification number.  The approach for determining this value is relatively insensitive to improved, more accurate methods of measuring the rock mass properties.  The methods used to link the various rock mass properties to obtain a single number have been fixed since the early 1970s, based on observations made primarily in civil engineering tunnel work.  Stope survey data present an untapped source of information linking opening geometry and rock mass properties to rock stability, measured as a depth of failure or hanging wall dilution.  This research will improve methods of quantifying rock mass properties as well as assist operating Canadian mines save money through reduced stope dilution.