爆破开采诱发周边岩体损伤破裂的数值模拟研究

发布时间：2018-04-22 14:21

本文选题：爆破开采 + 岩体　；参考：《金属矿山》2016年06期

【摘要】：基于连续-非连续单元方法(CDEM)中的朗道点火爆炸模型及拉剪复合应变软化模型,探讨了爆破开采与炮孔周边岩体损伤破裂程度的对应关系。通过量纲分析,确定了爆破诱发岩体损伤破裂的主要影响因素;通过应变软化的Mohr-Coulomb模型及最大拉应力模型,详细探讨了不同黏聚力及抗拉强度下,炮孔周边岩体的损伤因子随爆破距离的变化规律。数值计算结果表明:炮孔附近以压剪破坏为主,岩体处于完全损伤状态,出现具有一定半径的密集破碎带;在远离炮孔的区域,以张拉破坏为主,出现若干条贯通性的张拉裂缝;损伤因子随爆破距离的增加呈指数型衰减,并拟合获得了损伤因子与无量纲爆破距离、无量纲黏聚力及无量纲抗拉强度间的函数关系;强损伤区(损伤因子大于0.9的区域)的临界半径一般在2.5~5.5 m,仅受黏聚力控制;弱损伤区(损伤因子小于0.1的区域)的临界半径一般大于8 m,受黏聚力及抗拉强度的联合控制。
[Abstract]:Based on the Landau ignition explosion model and the tension shear strain softening model in continuous discontinuous element method (CDEMM), the corresponding relationship between blasting mining and damage and fracture degree of rock mass around the hole is discussed. Through dimensional analysis, the main influencing factors of rock mass damage and fracture induced by blasting are determined, and through the Mohr-Coulomb model of strain softening and the maximum tensile stress model, the different cohesive forces and tensile strength are discussed in detail. The variation of the damage factor of rock mass around the hole with the blasting distance. The numerical results show that the compressive shear failure is dominant in the vicinity of the borehole, the rock mass is in a completely damaged state, and there is a dense broken zone with a certain radius, and in the area far from the bore hole, the tensile failure is the main one. There are several tensile cracks with transfixibility, and the damage factor attenuates exponentially with the increase of blasting distance, and the functional relationship between damage factor and dimensionless blasting distance, dimensionless cohesion and dimensionless tensile strength is obtained by fitting the relationship between damage factor and dimensionless blasting distance, dimensionless cohesive force and dimensionless tensile strength. The critical radius of strong damage zone (area with damage factor > 0.9) is generally 2.5 ~ 5.5 m, which is only controlled by cohesive force, while the critical radius of weak damage zone (area with damage factor less than 0.1) is generally more than 8 m, which is controlled by the combination of cohesion and tensile strength.
【作者单位】：鞍钢集团鞍千矿业有限责任公司;中国科学院力学研究所;流固耦合系统力学重点实验室;
【基金】：中国科学院战略性先导科技专项(编号:XDB10030303) 国家自然科学基金青年基金项目(编号:11302230) 鞍钢矿业集团项目(编号:2014-科C12)
【分类号】：TD235.1

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