考虑水软化-化学风化作用的岩石单轴压缩试验离散元模拟

DEM numerical simulation of rock under the influence of water softening and chemical weathering and chemical weathering in uniaxial compression test

西南地区以岩石地形为主,较为潮湿。而岩石在工程长期运行中,会受到水和化学风化作用的影响,分别表现出软化、强度降低以及力学性能劣化的特性。因此研究岩石在水、化学风化作用影响下的力学性质极其重要。本文采用离散单元法(DEM)模拟水软化-化学风化因素作用下岩石的单轴压缩试验,得到应力应变曲线以及破坏后微观信息图,从宏微观角度分析岩石受水、化学风化作用下力学性质,破坏模式的变化。模拟结果表明:随着岩石饱和度的增加,岩石的峰值强度、弹性模量不断减小,破坏模式由压剪扭破坏为主逐渐转变为拉剪扭破坏为主;随着化学风化程度增大,岩石峰值强度也随之减小,脆性破坏特征越来越不明显,与室内试验结果相吻合。

Rock is the major terrain in the southwest region,and the southwest area is humid.During the long-term operation of the project,the mechanical properties of rock are greatly affected by water and chemical weathering.As a result,the water softening of rock and the degradation behavior of rock happen.So it’s significant to analyze the mechanical properties of rock under the influence of water and chemical weathering,which brings difficulties to exploitation.This paper use discrete element simulation(DEM)to simulate the uniaxial compression test on rock under the influence of water and chemical weathering,in which we get the stress-strain curves and microscopic information map.We can analyze the variety of the mechanical properties and failure mode of rock under the influence of water and chemical weathering from both the macroscopic and microscopic points of view.The simulation suggests that the peak strength and elastic modulu reduce with increasing saturation of rock,and failure mode of rock changes from compression shear failure to tension-shear failure.As the degree of chemical weathering increases,the peak strength of rock decreases and its brittle failure characteristics become more invisible.