Geomechanical design of cemented paste backfill systems (phase III)

地下采矿产生了巨大的空洞，必须回填这些空洞以支撑周围的岩石，并限制猛烈的岩爆和地面大移动的可能性。一种日益流行的充填形式是胶结膏体充填(CPB)，它可以相对较快地运送，从而加快采矿速度，从而提高矿产储量的净现值。它还重新利用了通常被泵到地面尾矿库的尾矿，因此对环境产生了积极的影响。在过去的二十年里，为提高CPB系统的效力和效率做了很多工作。然而，还有一些设计上的挑战，如果得到解决，可以极大地改善CPB对采矿作业的影响。需要改进的结构分析，以安全地设计和建造阻碍CPB与其他矿井巷道相隔的路障。需要更好地预测CPB从“泥浆”到“固体”的转变速度，以便该矿能够尽快恢复回填附近的生产爆破。并更好地理解CPB在受到破坏时如何能够自给自足，以便能够采取更有效的地雷规划战略。拟议的工作是一个正在进行的多年、由行业资助的项目的继续。NSERC参与这项工作的最后阶段将有助于扩大实验室研究的范围，产生新的测试技术以更好地预测施加在填充路障上的最大压力，并对CPB抗动态负载能力有新的了解。这些基本结果反过来将有助于更好地解释原型现场试验，并导致指定充填路障和在充填下采矿的新设计方法。

Underground mining creates large voids which must be backfilled to support the surrounding rockmass and limit the potential for violent rockbursts and large ground movements. An increasingly popular form of backfilling is Cemented Paste Backfill (CPB), which can be delivered relatively quickly and so accelerates the rate of mining, thereby enhancing the Net Present Value of the mineral reserve. It also re-uses tailings which would otherwise typically be pumped to a surface tailings pond, and so has positive environmental impacts. Much has been done in the last two decades to increase the effectiveness and efficiency of CPB systems. There are however a few design challenges left that, if addressed, can dramatically improve CPB's impact on mining operations. Improved structural analyses are required to safely design and construct the barricades that hold back CPB from the rest of the mine workings. Better predictions of how fast the CPB transitions from "slurry" to "solid" are needed so that the mine can resume production blasting near the backfill as quickly as possible. And an improved understanding of how CPB can be self-supporting when undermined is needed so that more effective mine planning strategies can be adopted.The proposed work is a continuation of an ongoing multi-year, industry funded project. NSERC's involvement in the final stage of this work will facilitate an expanded scope of laboratory research, generating new test techniques to better predict the maximum pressures exerted on fill barricades, and new knowledge about CPB resistance to dynamic loads. These fundamental results will in turn aid in a better interpretation of prototype field trials, and lead to new design approaches for specifying backfill barricades and for mining under backfill.