Abstract: The cutter layout of a full-face tunnel boring machine (TBM) directly affects its tunneling efficiency. The revolving diameter of the center cutter is small, and the double-edged design results in its rock breaking mechanism and force characteristics being significantly different from those of the single-edged cutter. The gage cutter is installed on the transition arc of the cutterhead, and the installation inclination complicates its movement and force. In this paper, by taking sandstone as the research object, the composite rock breaking models of the center cutter group and the gage cutter group of a compound TBM are separately established based on the three-dimensional particle discrete element method. The numerical models are verified by comparing results with the full-scale rotary cutting laboratory test. From the view point of the force characteristics of a single cutter, the propagation of rock cracks between adjacent cutters, the overall mechanical properties of the cutterhead, the load characteristics and layout form of the double-edged center cutter, and the installation angle range of the gage cutter were studied. Results demonstrate that the use of a cross-shaped center cutter layout can reduce the force of a single cutter ring and the overall load of the cutterhead, which is conducive to TBM stability during tunneling. Therefore, it is recommended that a cross-shaped layout for the double-edged center cutter of a rock formation compound TBM should be used. To improve the stability and service life of the cutter, we recommend setting the installation angle of the innermost gage cutter of the rock formation compound TBM to about 9◦, and the installation angle of the outermost gage cutter should not exceed 70◦.

Key words: center cutter, gage cutter, load characteristics, layout form, installation angle, particle flow

摘要： 全断面隧道掘进机的滚刀布置直接影响其掘进效率。中心滚刀的旋转直径较小，且采用双刃设计，导致其破岩机理和受力特征与单刃滚刀有显著差异。边缘滚刀安装在刀盘的过渡弧上，安装倾角的存在使其运动和受力复杂。以砂岩为研究对象，基于三维颗粒离散元法，分别建立复合式隧道掘进机中心滚刀群和边缘滚刀群的复合破岩模型。全尺寸旋转切削室内试验结果验证了数值模型的正确性。研究了单滚刀的受力特征、相邻滚刀间岩石裂缝的扩展、刀盘的整体力学性能、双刃中心滚刀的载荷特征和布置形式、以及边缘滚刀的安装倾角范围。结果表明：十字形中心滚刀布置可以减少单刀圈的受力和刀盘的整体载荷，有利于隧道掘进机掘进的稳定。建议岩层复合式隧道掘进机的双刃中心滚刀采用十字形布置。为提高刀具的稳定性和使用寿命，建议岩层复合式隧道掘进机最内侧边缘滚刀的安装角度约为9º，最外侧边缘滚刀的安转角度不应超过70º。

关键词: 中心滚刀，边缘滚刀，荷载特征，布置形式，安装倾角，颗粒流