负泊松比岩体颗粒流模型及模拟分析

Particle flow code model and simulation of rock mass with negative Poisson's ratio

为了从微观结构角度研究岩体特殊的负泊松比效应,基于颗粒流理论和颗粒流程序（PFC）,提出采用颗粒流数值模拟方法。从已知具有负泊松比效应的无机晶体材料出发,研究其内部特殊的微观结构,进而建立符合岩体情况的颗粒流模型。利用所生成模型进行单轴压缩模拟试验,得出泊松比随应力的变化曲线。基于所建模型,对岩体在低荷载水平作用下的负泊松比现象机理进行分析。研究结果表明：当轴压为0～3 MPa时,岩体试样泊松比为负值,最小泊松比为-0.059。模拟结果与室内试验结果大致吻合,验证了该颗粒流模型用于研究岩体负泊松比现象的可靠性。

In order to study the specific phenomenon of negative Poisson＇s ratio of rock mass in the perspective of microstructure, a method of numerical simulation using particle flow theory and particle flow code（PFC） was proposed. An applicable PFC model of negative Poisson＇s ratio of rock mass was constructed by studying the specific internal microstructure of inorganic crystals materials. A Poisson＇s ratio curve of rock specimen was obtained in a numerical experiment of rock uniaxial compression using the PFC model. Based on the PFC model, the mechanism of negative Poisson＇s ratio of rock specimen at low load level was interpreted. The results show that Poisson＇s ratio is negative when the axial compression is 0 to 3 MPa, and the minimum value is-0.059. The results of numerical simulation agree with the test data. The reliability of the PFC model used to study negative Poisson＇s ratio of rock mass is verified.