TBM滚刀与高压水射流布局对滚刀破岩效率影响的室内试验

Experimental Study on Effect of Layouts of TBM Cutter and High-pressure Water Jet on Cutting Efficiency

硬岩掘进机(TBM)在完整高强度岩体中掘进性能受限,可通过搭载高压水射流系统在工作面上切缝以提升滚刀破岩效率,然而相关大尺寸试验较少且缺乏系统性。为探究滚刀-高压水射流切割布局对滚刀破岩效率的影响,采用福建龙岩黑云母花岗岩先后进行了高压水射流切割与全尺寸滚刀破岩试验。试验包括滚刀沿双水刀切缝间、单水刀切缝上、三水刀切缝间、单水刀切缝一侧4种布局,同时也进行了无水射流切缝辅助的滚刀破岩以作对比。试验过程中采集了破岩滚刀力,收集了破岩产生的渣片并进行筛分。最后根据试验现象分析了不同布局下的裂纹扩展形态。结果表明:水刀滚刀切割轨迹重叠有助于滚刀贯入,滚刀力降低并促进侧向裂纹向斜上方自由面扩展,但产生的岩片尺寸有限;滚刀沿三水刀切缝的中间切缝破岩时,刃底一侧的侧向裂纹扩展可能受到抑制;滚刀沿两水刀切缝之间破岩性能最优,刃底两侧的侧向裂纹均能朝水刀切缝底部扩展并贯通以形成大岩片,且切缝深度越深滚刀破岩效率越高,但增幅逐渐变小。试验成果可为滚刀-高压水射流联合破岩TBM刀盘设计及破岩性能估计提供参考。

The performance of a tunnel-boring machine(TBM)is limited by an intact rock mass with high rock strength.A high-pressure water jet(HPWJ)system can be used to cut kerfs on the tunneling face to promote the cutting efficiency of the cutter.However,only a few pertinent large-scale tests have been conducted,which were not systematic.To study the effect of the layouts of the TBM cutter and high-pressure water jetting(HPWJ)on the cutting efficiency,linear cutting tests using the HPWJ and full-scale cutter were successively performed on biotite granite specimens from Longyan,Fujian.Four cutting layouts were designed including cutter cuts along the midline of two kerfs,on a single kerf,along the middle of three kerfs,and on the sides of a single kerf.Cutting without the assisted HPWJ kerf was also performed for comparison.The cutter forces were obtained during the tests,and rock mucks were collected and sieved.Finally,the patterns of crack propagation under different cutting layouts were analyzed based on the observations.The following findings were drawn:The overlapping cutting trajectories of the HPWJ and cutter prove beneficial for cutter penetration,resulting in reduced cutter forces.In addition,this facilitates the oblique expansion of the lateral cracks to the upward free surface;however,the size of the rock chips is small;When the cutter cuts along the middle one of the three kerfs,the expansion of lateral cracks on one side of the cutter may be suppressed;The best cutting performance is achieved by rotating the cutter between the two kerfs cut by HPWJ.This facilitates the propagation of lateral cracks on both sides of the cutter toward the bottom of the kerfs,forming large rock chips.The cutting efficiency of the cutter increases with the deeper kerfs.This study can serve as a reference for the design of a TBM cutterhead utilizing both cutters and HPWJs,as well as for estimating its performance.