Development of Testing Method for Performance of TBM Disc Cutters in Circular Rock Cutting

根据其在TBM刀盘上的安装位置，TBM盘形刀具可分为两组;一组是端面刀具，另一组是量规刀具。在本研究中安装的岩石切割装置允许我们测试两种类型的圆盘刀具的性能。此外，钻机便于岩石切割沿着圆形轨道以及传统的线性切割。实验室实验，使用圆形岩石切割钻机是有希望的预测性能的隧道掘进机和天井钻机，因为这些机器在圆形切割模式工作。试验台上的测力计不仅可以测量刀具力的三个垂直分量，还可以测量刀具力的扭转量，通过对TBM保径刀具的试验，给出了一个新的经验公式，可以预测保径刀具在给定的贯入度下所需的推力和扭矩。该公式表明，就刀具力而言，与机器推力的切入角为α的规铣刀应等同于附加刃角为2 α的面铣刀。从而对规铣刀比面铣刀承受更大的有害阻力给出了合理的解释。进一步研究了减小保径铣刀阻力、延长保径铣刀寿命的对策。实验结果表明，只要开挖面法线的倾角接近规刀的切入角α，规刀的切削力就可以保持与面刀一样低。

TBM disc cutters can be clustered into two groups depending on their locations mounted on the cutter head of a TBM ; ones are face cutters and others are gauge cutters. A rock cutting rig which has been installed in the present investigation allows us to test the performance of both types of disc cutters. In addition, the rig facilitates rock cutting along circular tracks as well as conventional linear cutting. Laboratory experiments using a circular rock cutting rig are promising for predicting the performance of TBMs and raise bore machines since these machines work in circular cutting mode. A dynamometer which is dedicated to the test rig allows us to detect not only the three perpendicular components of tool force, but the twist around the thrust.The experiment using a TBM gauge cutter provided newly empitical formulae by which we can predict thrust and torque needed to a given penetration of a gauge cutter. The formulae suggest that a gauge cutter with a plunge angle of alpha from the machine thrust should be equivalent to a face cutter with an additional edge angle of 2alpha, as far as tool force is concerned. Accordingly the formulae give a rational explanation for gauge cutters being subject to more harmful resistance than face cutters. Further investigations were carried out to explore the counter measures to reduce the resistance exerted on gauge cutters and to prolong their life-spans. The experimental results showed that the tool force for a gauge cutter could remain as low as for a face cutter whenever the normal of excanvated rock surface has an inclination being close to the plunge angle alpha of a guage cutter.