应力差和节理角度对水压爆破岩体损伤影响研究

Study on the influence of stress difference and joint angle on rock mass damage caused by hydraulic blasting

为研究应力差和节理角度对水压爆破破岩效果的影响规律,在对水压爆破应力波在岩体的透射、反射机制进行分析的基础上,采用ANSYS/LS-DYNA数值模拟软件,研究不同应力差和节理角度条件下的水压爆破裂纹扩展过程、分布特征及岩体损伤范围。结果表明,应力差对岩体损伤区域影响明显,且对非线性破坏区的影响明显大于压碎区。在节理角度一定的条件下,翼裂纹的张开角度随着主应力差的增加而增大;节理角度对于应力入射波和反射波的叠加作用效果具有直接影响,导致翼裂纹的长度及扩展方向、层裂区损伤范围等发生变化。节理角度为90°时,节理外侧岩体损伤最小,但是内侧层裂区损伤严重,随节理角度降低,层裂区损伤量减小,翼裂纹长度增加,贯穿裂缝逐步沿节理方向延伸,直至节理角度降低至0°时,层裂区损伤达到最小,翼裂纹和贯穿裂缝重合。

In order to study the influence of stress difference and joint angle on the effect of hydraulic blasting rock,on the basis of analyzing the transmission and reflection mechanism of hydraulic blasting stress waves in rock mass,ANSYS/LS-DYNA numerical simulation software was used to study the propagation process,distribution characteristics and rock damage range of hydraulic blasting fracture under different stress difference and joint angle conditions.The results show that the stress difference has a significant effect on the damage area of the rock mass,and the effect on the nonlinear failure area is significantly greater than that on the crushed area.Under certain conditions of joint angle,the opening angle of the wing crack increases with the increase of the main stress difference;The joint angle has a direct impact on the superposition effect of stress incident waves and reflected waves,resulting in changes in the length and expansion direction of the wing crack,and the damage range of the layer crack area.When the joint angle is 90°,the damage of the rock mass outside the joint is the smallest,but the damage of the inner layer fracture area is serious,and with the reduction of the joint angle,the damage of the layer fracture area decreases,the length of the wing crack increases,and the penetrating crack gradually extends along the joint direction,until the joint angle is reduced to 0°,the damage of the laminar fracture area is minimized,and the wing crack and the penetrating crack coincide.