某金属矿尾砂三轴压缩的颗粒流数值模拟

Particle Flow Numerical Simulation for Triaxial Compression of Tailings in a Metal Mine

为探究湖南某尾矿库尾砂的宏细观力学特性,利用颗粒流数值模拟软件(PFC^(3D))建立尾砂三轴固结不排水压缩试验数值模型。对比数值模拟试验和室内试验的结果,以应力-应变曲线、峰值强度和弹性模量的较高吻合程度作为确定颗粒流数值模拟细观参数的标准。运用PFC^(3D)软件进行数值试验,结果表明:不同围压作用下的尾砂试样PFC^(3D)模拟试验和室内试验结果基本趋于一致;与高围压相比,较低围压下模拟试验结果与室内试验结果的吻合程度更高;高初始孔隙率和高围压均对三轴试样的剪胀特性有一定的抑制作用;数值模型的初始配位数较大,在一定程度上说明该模型的接触程度良好。

In order to explore the meso-mechanical properties of tailings from a tailings pond in Hunan Province,the numerical models of consolidated undrained triaxial test were established by the particle flow numerical simulation software(PFC_(3D)).The simulation results were compared with the results of laboratory tests,and the high coincidence degree of stress-strain curves,peak strength and initial elastic modulus was taken as the criterion to determine the numerical simulation mesoscopic parameters of particle flow.After numerical tests by PFC_(3D)software,the results are found that the numerical simulation of tailings samples under different confining pressures is basically consistent with laboratory tests.Compared with the high confining pressure,the numerical simulation under the lower confining pressure is more consistent with the laboratory test.Both large initial porosity and high confining pressure can inhibit the dilatancy of triaxial samples.The initial coordination number of the numerical model is large,which indicates that the contact degree of the model is good to some extent.