3极限跨度在进一步探讨矿柱设计前，我们应当探讨“极限跨度”问题，这是因为极限跨度影响矿柱的性态。极限跨度是指破坏前岩石在采场顶部所能横跨的最大跨度，或者，如果有矿柱，是指矿柱承受上覆岩上达到满负荷之前所应开采的跨度。有几种理论可用来计算大概的跨度，此值通常 3 Ultimate Span Before further discussion of pillar design, we should explore the “limit span” problem because the limit span affects the behavior of the pillar. The limit span means the maximum span a rock can span across the top of the stope before the destruction or, if any, the length of the pillar that should be mined prior to reaching full capacity on the overburden. There are several theories that can be used to calculate the approximate span, this value is usually