激光辅助TBM盘形滚刀压头侵岩缩尺试验研究

为了验证高能激光技术能够辅助隧道掘进机(tunnel boring machine，简称TBM)盘形滚刀（以下简称滚刀）实现高效破岩，以滚刀破岩过程中基本的运动形式——侵岩为研究对象，参照17 inch（432 mm）工程用滚刀，按1:8的比例制备了缩尺比例滚刀压头（以下引述为滚刀压头），开展了以孔孔距（2、3、4、5 mm）、刀孔距（3、4、5、6、7 mm）为变量的激光辅助滚刀压头侵岩L20(4×5)正交试验以及无激光作用的对照组试验。试验研究结果表明：随着刀孔距的增加，滚刀压头的破岩量与岩石破碎块度均增加，而垂直力和比能耗均降低，最优刀孔距为6 mm；随着孔孔距的增加，破岩量、垂直力和岩石侵入难度系数均降低，而岩石破碎块度和比能耗均增加，最优孔孔距为3 mm。与传统滚刀回转滚压破岩方式相比，在激光辅助作用下，可促进岩石张拉裂纹的产生，提高了滚刀侵岩效率。所提出的激光辅助滚刀耦合破岩模式在未来TBM极硬岩层隧道掘进中具有一定的应用前景。

Scale model test on laser-assisted rock indentation by TBM disc cutter indenter

To verify the efficient rock breaking ability of high-energy laser technology using for tunnel boring machines (shorted for TBM) disc cutters (hereinafter referred to as disc cutters), taking the basic movement form of the hob in the process of rock breaking-rock intrusion as the research object, a reduced scale hob indenter is prepared with a ratio of 1:8 (the following is the hob indenter) referring to the 17 inch (432 mm) engineering hob, orthogonal tests of rock invasion by hob indenter L20 (4×5) with laser assist and comparative tests without laser assist were carried out with different hole spacing (2, 3, 4, 5 mm) and cutter-hole spacing (3, 4, 5, 6, 7 mm) as variables. The experimental results show that with the increase of indenter-hole distance, both volumes of rock breakage and rock fragmentation size increase; with the increasing laser hole distance, rock breakage volume, vertical forces and the difficulty of rock breaking decrease, while rock fragmentation size and specific energy increase. The optimal indenter-hole distance and laser hole distance are 6 mm and 3 mm respectively. Compared with the traditional rock-breaking method by disc cutters, laser-assisted rock cutting would promote the generation of rock tensile cracks, and improve the rock-breaking efficiency of indentation by the cutters. The research results also show the prospects for application of the proposed laser-assisted rock cutting model to TBM tunneling under the extremely hard rock grounds in the future.