岩石隧道掘进机边缘滚刀破岩机理及刀具下岩体损伤演化研究

Due to the characteristics of the excavation method of tunnel boring machine (TBM), the interaction law between the disc cutters of TBM and rock mass is one of the most important issues for TBM mechanical design and excavation technology. The gage disc cutters of TBM have their special installing and layout mode, i.e. the inclined installing mode, which is different from the normal installing mode of face disc cutter. Thus the rock fragmentation mechanisms and damage evolution by the gage disc cutter are very different from those of the face disc cutters. During the TBM excavation process, if the design and operation parameters of the gage disc cutters do not match the rock mass conditions, the high abnormal wear of the gage disc cutters is often caused by the high side force and vibration of TBM cutterhead. On the other hand, the function of the gage disc cutter is also to control the precision of the cavity and the damage range of the cavity boundary. For the requirement for the excavation precision and damage range control, the process and characteristics of rock damage by TBM gage disc cutters should be deeply explored. According to the demands for these two aspects of the researches, the study will make use of the full scale linear cutting tests and numerical simulation to explore the rock fragmentation mechanism and rock damage evolution by the gage disc cutter, and analyze the influences of the different mechanical and operational parameters on the rock fragmentation and rock damage process by the gage disc cutter. The results obtained from the study will provide the theoretical guidance for the optimization of the TBM cutterhead design and operation parameters for the different demands of the engineering.

由于TBM机械开挖的特点，刀具与岩体的作用机理是TBM机械设计及开挖的最为关键的问题之一。边缘滚刀由于其具有倾斜式的安装方式，其破岩时的受力状态，破岩模式及岩体裂纹扩展模式都与正安装方式的正滚刀不同，与岩体不匹配的边缘滚刀的设计及运行参数往往引起大的刀具侧向力及刀盘振动，从而导致边缘滚刀极高的非正常磨损。另一方面，TBM边缘滚刀由于其位置的特殊性，同时具有掘进破岩，控制洞径及造成开挖面损伤破坏等作用。因此，对TBM开挖精度与损伤有极高要求的工程，应对TBM边缘滚刀的破岩损伤演化特征加以研究。基于以上两方面亟待解决的问题，本课题将应用室内全尺寸TBM滚刀线性破岩试验及数值模拟方法，对TBM边缘滚刀的破岩机理及刀具下岩体的损伤演化进行深入研究，分析多个破岩参数对边缘滚刀破岩机理及岩体损伤过程及范围的影响，为TBM边缘滚刀的优化布置及TBM运行参数优化提供理论指导。

由于TBM机械开挖的特点，刀具与岩体的作用机理是TBM机械设计及开挖的最为关键的问题之一。边缘滚刀由于其具有倾斜式的安装方式，其破岩时的受力状态，破岩模式及岩体裂纹扩展模式都与正安装方式的正滚刀不同，同时具有掘进破岩，控制洞径及造成开挖面损伤破坏等作用。本项目应用室内全尺寸TBM滚刀线性破岩试验及数值模拟方法，对TBM边缘滚刀的破岩机理及刀具下岩体的损伤进行了研究。首先通过应用多功能破岩实验平台，对旋转和线性两种破岩模式进行分析研究，研究了不同切割半径对滚刀破岩的影响，验证了边缘滚刀破岩采用线性切割模式的可行性。对正滚刀与不同倾角的边缘滚刀进行破岩试验研究，通过滚刀力、比能及碴片分布特征等试验数据，得出不同倾角滚刀破岩规律及破岩效率的影响因素。针对边缘滚刀破岩损伤区的研究，本项目对于岩石损伤区的声发射监测方法进行初步了初步研究及探讨，同时应用数值模拟方法及荧光法对不同破岩参数下的岩石损伤区进行了研究，得出不同破岩参数下损伤区的分布范围及特征,分析多个破岩参数（刀间距、贯入度、倾角、过渡半径）对边缘滚刀破岩机理及岩体损伤过程及范围的影响。本研究成果可为TBM边缘滚刀的优化布置及TBM运行参数优化提供理论指导。