基于颗粒流模拟的硬岩CWFS模型等效塑性参数优化研究

针对目前粘结强度弱化-摩擦强度强化(CWFS)本构模型中两个关键参数ε^p_c 和ε^p_f 的确定问题, 以杏山铁矿-45 m水平采场区域为例, 基于颗粒流理论, 建立了片麻岩颗粒非均质几何模型, 对片麻岩的三轴压缩试验进行模拟; 结合AE声发射与PFC内置Crack数量记录程序的监测结果, 对PFC模拟和室内试验的应力-应变曲线规律进行了深入分析, 揭示了片麻岩破裂过程中的细观力学特性与强度参数的劣化规律。最后, 借助FLAC^2D有限差分软件, 对ε^p_c 和ε^p_f 的取值进行了优化和验证, 确定优化后的ε^p_c 和ε^p_f 取值分别为0.015和0.037。经参数优化后的CWFS模型模拟的岩石单轴压缩应力-应变曲线与室内刚性试验曲线比较吻合。研究成果对CWFS模型今后工程应用的推广有一定的参考价值。

Optimization Study of Equivalent Plastic Parameters for Hard Rock CWFS Model Based on Particle Flow Simulation

Aiming at determination of key parameters in CWFS model, heterogeneous geometric model is established for gneisses based on particle flow code, taking stope at -45 m level in Xingshan Iron Mine as an example. A simulation of triaxial compression test was performed for gneisses sample. Combined with monitoring results of acoustic emission and Crack number record program in PFC, microscopic mechanical characteristics and deterioration law of strength parameters were studied through comparative analysis of stress-strain curves from PFC simulation and laboratory test. Finally, with the help of finite difference software FLAC^2D, the value of ε^p_c and ε^p_f  is respectively determined to be 0.015 and 0.037 after optimization and verification. The achieved results indicate that stress-strain curves of rock under uniaxial compression obtained by optimized CWFS model basically coincide with the curves from laboratory test, which is of referential importance in the future application of CWFS model in engineering.