真三轴状态下盘形滚刀破岩特性

Rock Breaking Characteristics of Disc Hob under True Triaxial Condition

为揭示真三轴状态下盘形滚刀的破岩特性,基于Drucker-Prager强度理论和CSM刀岩接触模型,借助表征中间主应力相对大小的系数β,建立了滚刀破岩理论模型和仿真分析模型,并利用仿真模型研究高地应力条件下岩石的破碎特征和滚刀受力特性.研究结果表明:岩石损伤破碎后,垂直力极值显著下降,滚动力和侧向力的波动区间变化不大,侧向力始终较小但方向不断变化,造成了刀具的振动与偏磨;随着中主应力效应的增强,破碎单元数量呈指数型减少,最大垂直力、滚动力和侧向力均呈指数型增加,其中侧向力的增加幅度最小;随着贯入度的增大,破碎单元数量和各向破岩力均增大,且增加幅度也越来越大,其中侧向力的增幅最大;现场实测值、理论计算值和仿真值三者之间的相对误差较小,验证了理论模型和仿真模型的可靠性.

To reveal the rock breaking characteristic of disc hob under true triaxial condition,the Drucker-Prager strength theory,CSM model and intermediate principle stress coefficientβwere used to establish a theoretical calculation model and a simulation analysis model,which can be used to study the fracture characteristic of rock and the stress characteristic of hob under high ground stress.The results show that the extreme value of vertical force decreases remarkably after rock is damaged,while the range of rolling force and lateral force changes little.The lateral force is always smaller with constantly changing direction,leading to the vibration and uneven wear for cutters.With the increase of intermediate principal stress effect,the number of crushing elements decreases exponentially,and the maximum force in vertical,rolling,and lateral directions increases exponentially,in which the increase of the lateral force is the smallest.With the increase of penetration,the number of crushing units and the rock breaking force in creases simultaneously,and the increase extent also becomes larger,in which the increase of the lateral force is the largest.The relative errors among actual values,theoretical calculation values and simulation results are very small,which can verify the reliability and accuracy of the theoretical model and simulation model.