| With the rapid development of underground engineering in China,the full-face tunnel boring machine(TBM)has improved the construction environment and improved the construction safety in the excavation of underground rock strata.It is widely used in highway,railway,water conservancy and other tunnel engineering construction.Due to the complexity of the stratum,the traditional TBM disc cutter is subjected to a large force in the process of rock breaking,and the wear is more serious.In order to reduce the force of the cutter and improve the efficiency of rock breaking,new TBM cutter rock breaking technology is constantly emerging.High-pressure hydraulic coupling rock breaking technology is a rock breaking method that uses a high-pressure water jet to cut out a free surface on the rock mass before the cutter rolls over it,and then the cutter rolls the rock mass.On the cutterhead of high pressure hydraulic coupling rock breaking TBM,different relative positions of disc cutter and high pressure water jet nozzle form different rock breaking modes of free face combination,which has a great influence on the force of disc cutter in rock breaking process and rock breaking efficiency of disc cutter.Therefore,based on previous research on rock breaking by cutters both domestically and internationally,according to the layout of cutters on the cutterhead of high-pressure hydraulic coupling rock breaking TBM,this thesis studies the rock breaking mode and influencing factors of high-pressure hydraulic coupling TBM cutters by experimental and numerical simulation methods.The main research contents are as follows:(1)Aiming at the layout of disc cutter and high-pressure water jet nozzle on the cutterhead of high-pressure hydraulic coupling rock breaking TBM,six different rock breaking modes of free face combination were analyzed,and the influence of disc cutter penetration on different rock breaking modes and different free face dip angles,cutting depth,spacing and different penetration degrees on rock breaking by disc cutter was obtained.By comparing and analyzing the stress-strain response characteristics of the rock,the displacement vector diagram,and the peak load of the hob,three optimal rock breaking modes with double free surfaces were proposed.(2)The experiment of disc cutter linear cutting double-grooved free face rock breaking mode rock was carried out.The variation curves of rolling force and specific energy consumption with the cutting depth of free face were analyzed.The influence of cutting depth of free face on rock breaking morphology,rolling force and specific energy consumption of disc cutter was obtained.(3)Under three kinds of double free face rock breaking modes,the specific energy consumption of disc cutter linear cutting rock with different free face inclination,spacing,cutting depth and penetration was studied.The variation curves of average vertical force,average rolling force and specific energy consumption were compared and analyzed.The influence of free face inclination,spacing,cutting depth and disc cutter penetration on the specific energy consumption was obtained under three kinds of double free face rock breaking modes.The accuracy of the model was verified by comparing the curves of rolling force and specific energy consumption with the cutting depth of the free surface in the test and numerical simulation.(4)Through the numerical simulation of cutter rotary cutting double grooving free surface rock breaking model rock,the influence of confining pressure,blade width and cutter speed on the rock breaking effect,vertical force,rolling force and specific energy consumption of cutter was obtained.The results show that the vertical force,rolling force and specific energy consumption of disc cutter were almost unchanged with the increase of confining pressure.With the increase of blade width and cutter speed,the vertical force,rolling force and specific energy consumption of hob increase.The results provide a reference for utilizing high-pressure hydraulic coupling rock breaking TBMs in practical engineering. |
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