破碎岩体压实特性的三维离散元数值计算方法研究

An approach to determine the compaction characteristics of fractured rock by 3D discrete element method

研究破碎岩体的压实特性是矿井地下工程的基础工作之一,由于破碎岩体所处环境的隐蔽性与危险性,常采用实验室测试和数值计算的研究方法。提出了一种三维破碎岩体模型构建方法,即在3D Voronoi建立完整岩体数值模型的基础上,通过预定孔隙率,随机删除完整岩体中的块体反演破碎岩体结构,测定破碎岩体的压实特性。该方法可较真实地反映破碎岩体的块度特征、碎胀特性与压实特性,与现有研究方法有较高的吻合度,为矿山地下工程的安全控制提供了新的有效的研究方法。

The study on compaction characteristics of fractured rock mass is considered as one of the basic work of underground engineering in coal mines. Since fractured rock mass exists in the hidden and dangerous environment, laboratory experiments and numerical simulations are normally applied to determine the compaction characteristics indirectly. To construct three-dimensional（3 D） model of fractured rock mass, this paper presented a novel method which was based on the 3 D Voronoi numerical model of intact rock mass. In this model, the porosity was pre-determined and the structure of fractured rock mass was retrieved by randomly removing the blocks in the intact rock mass. Moreover, the Weibull distribution was introduced to describe mechanical parameters of joints. In addition, uniaxial compression experiments were conducted to investigate the compaction characteristics. Compared with existing theoretical and experimental results, this method demonstrated good agreements with them. It is proved that this parametric method can reflect the fragmentation, bulking and compaction characteristics of fractured rock mass more accurately. Therefore, this study provides a new and effective method for the safety control of underground engineering in coal mines, which can be widely used in the gravel experiments.