内聚力和内摩擦角对岩样峰值强度影响规律探讨

The Discussion on Effect of Cohesion and Internal Frictional Angle on the Peak Strength of Rock

为了探讨内聚力C和内摩擦角φ对岩样峰值强度的影响规律,采用数值模拟手段,获取岩样轴向应力、轴向位移、峰值强度随C、φ值逐渐下降的变化规律。研究结果表明:内聚力C和内摩擦角φ数值的降低,均会导致应力位移曲线峰后平缓;当内摩擦角φ值降低40%时,峰值强度降低39.5%,峰值强度阶段降幅最大值为10.53%,峰值强度随次数的增加向一极值发展,且峰值强度阶段降幅有减小趋势;而当内聚力C值减小40%时,峰值强度降低29.82%,阶段降幅最大值7.98%;对比说明内摩擦角φ对峰值强度的影响程度要比内聚力C更大。

In order to study influence of cohesion and internal frictional angle on the peak strength of rock sample,the change rules of axial stress,axial displacement and peak strength with the decline of C and φ were obtained by means of numerical simulation. The results showed that the declined cohesion and internal frictional angle would cause stress- displacement curve after the peak smooth. When internal frictional angle value was reduced by 40% and the peak strength was decreased by 39. 5%,the maximum value of decline of peak strength stage was 10. 53%,the peak strength approached an extreme value with increased times and the decline of peak strength stage had a decreasing trend. When the cohesion value was reduced by 40%,peak strength was decreased by 29. 82%,the maximum value of decline of peak strength stage was 7. 98%. Making a comparison of the data,the influence degree of internal frictional angle on the peak intensity was greater.