镶齿滚刀破岩机理及效率的旋转破岩试验

随着隧道工程建设的不断增多，镶齿滚刀已被广泛应用于多种开挖机械，如隧道掘进机、反井钻机、采掘机等，不同破岩参数下镶齿滚刀的破岩机理及破岩效率研究，对提高机械掘进效率、降低施工成本有重要意义。应用北京工业大学自主研制的多功能机械破岩试验平台，选用直径304.8 mm（12英寸）的镶齿滚刀对尺寸为1 000 mm×1 000 mm×600 mm的北山花岗岩进行旋转切割破岩试验研究。通过对排齿及整刀进行不同贯入度的旋转切割试验，并应用荧光裂纹检测法对侵入坑下方裂纹进行检测，研究镶齿滚刀的破岩规律。结果表明：①镶齿滚刀为"递进式"破岩，破岩开始于相邻小齿间距的球齿之间，而后发展到相邻的大排间距的球齿之间；②第3排球齿破岩效率最高，且整刀在贯入度为1.5 mm时破岩效率最高；③应用荧光裂纹检测法分析滚刀下方岩体裂纹分布特征，发现每排球齿下的裂纹扩展方向及范围存在较大差异。裂纹分布特征分析结果与通过滚刀力、岩片分析得出的镶齿滚刀破岩效率的结论相一致。该研究可为机械开挖设备滚刀布置、刀型优化及施工运行参数优化提供试验参考和理论依据。

Rock Fragmentation Mechanism and Efficiency Under Inserted-tooth Roller Cutter by Rotary Cutting Test

With the development of tunnel construction, the inserted-tooth roller cutter has been widely used for many types of excavation machines, including tunnel boring machines, raised drills, roadheaders, etc. Thus, it is significant to study the rock fragmentation mechanism and efficiency under the inserted-tooth roller cutter for improving mechanical excavation efficiency. For this issue, rotary cutting tests for the inserted-tooth roller cutter with diameter of 12 inches were conducted using the mechanical rock fragmentation platform of Beijing University of Technology. The rock sample used in the rotary cutting test was Beishan granite with dimensions 1000 mm×1000 mm×600 mm. A series of rotary cutting tests for the different rows of teeth and the whole cutter were conducted under different penetration depths. During the rotary cutting tests, the cutting force, rock chips, and rock fragmentation efficiency were measured collected and analyzed. Moreover, the distribution characteristics of cracks induced by the cutters were explored by fluorescence experiment to verify the rock fragmentation mechanism. The main conclusions can be summarized as follows. ① The mode of rock fragmentation by inserted-tooth roller cutter in a "progressive" way, in which rock breakage propagated from the adjacent single spherical tooth with small spacing to adjacent rows of teeth with large spacing; ② For the tests on different rows of teeth, the rock fragmentation efficiency of the third row is the highest. For the test of the whole cutter, the rock fragmentation is highest with penetration depth of 1.5 mm; ③ Based on the results of the fluorescence experiment, the distribution characteristics of the cracks induced by the cutter were identified, and there are obvious differences in the propagation direction and range of cracks under each row of teeth. The rock fragmentation efficiency obtained from crack distribution coincided with the analysis of cutter force and rock chips. The conclusions of this study can offer some guidance for the optimization of cutter layout, cutter type, and operating parameters of excavation machines.