TBM边缘滚刀组合破岩特性及其影响因素敏感性评价

Rock-breaking Characteristics of TBM Gage Disc Cutters and Sensitivity Analysis of Their Influencing Factors

盘形滚刀是全断面硬岩掘进机(Tunnel boring machine,TBM)破碎岩石的关键部件,边缘滚刀因其安装位置的特殊性,破岩行为不同于正面滚刀。为了研究边缘滚刀组合破岩特性以及破岩参数对其破岩性能的影响,采用颗粒离散元法建立边缘滚刀组合破岩模型,研究边缘滚刀组合破碎花岗岩与石灰岩时岩体裂纹演化过程、应力分布特征以及刀具载荷变化规律。在此基础上,建立基于敏感度熵权的边缘滚刀破岩参数综合评价模型,研究边缘滚刀破岩敏感性参数对破岩效率、裂纹扩展能力等的影响程度。研究结果表明:不同岩石条件下,滚刀破岩特性以及破岩参数敏感度有所区别;滚刀间倾角差、刀盘圆弧半径和刀刃角对边缘滚刀破岩性能影响最为显著,刃宽与贯入度影响次之,刀盘转速影响最小。

The disc cutter is the key part of a tunnel boring machine(TBM). The rock-breaking behaviors of the gage cutter are different from those of the normal cutter due to its special installation position. To investigate the rock-breaking mechanisms of gage cutters and the effects of rock-breaking parameters on the rock-breaking performance, a simulation model of rock fragmentation for the gage cutters interacting with the granite and limestone is established, and the evolution process of rock cracks, the regularities of changes in the stress distribution and the cutter load are presented. Based on the simulations, the effects of rock-breaking sensitivity parameters on the rock-breaking performance of gage cutters are obtained using a comprehensive assessment model of attribute recognition on the basis of entropy weight of sensitivity. The results show that the rock-breaking characteristics of gage cutters and the sensitivities of their rock breaking parameters are different under different rock conditions. The main influence factors on the cutter rock-breaking performance are the dip between adjacent cutters, the arc radius of cutterhead and the cutting edge angle, then the next are the width of cutter ring and the penetration. Finally the minor influence factor is the rotational speed of cutterhead.