| Full Face Rock Tunnel Boring Machine(TBM)are widely used in the construction of railway tunnels,water conservancy and hydropower tunnels in hard rock geology due to their high drilling efficiency,good construction quality and continuous operation.In addition,the tilted installation of the disc hob can improve the rock breaking effi ciency of the disc hob and reduce the specific energy of rock breaking.Therefore,it is important to study the spacing between the cutters of the pan hob in the tilting installation method to improve the rock breaking efficiency of the roadheader.The main research elements of this paper are as follows:(1)Based on the model of rock breaking by inclined-mounted disc hobs,the formulae for the micro-displacement of the rock breaking front point,the arc length of rock breaking at one time and the amount of side-slip are derived for disc hobs when completing a rock breaking.By comparing the breakage arc length and side slip of the tilted and forwardmounted disc hobs,it is concluded that the tilted installation can reduce the wear and tear of the disc hobs and extend their life.(2)Using the TB880E TBM cutter as a prototype,simulate the three-dimensional circular hobbing breaking situation of the 17-inch disk hob under the tilting installation method through ABAQUS software,find out the optimal cutter spacing for the first 30 disk hobs under the tilting installation method at penetration degrees of 6mm,8mm and 10mm respectively,and fit the prediction formula for the optimal cutter spacing under the tilting installation to provide a basis for the arrangement of the remaining disk hobs on the cutter.(3)Taking into account the tilting mounting method and the optimal tool spacing,three models of the TB880E TBM cutter were rebuilt and simulated to analyse the cutter thrust and torque.Compared with the original cutter,the cutter thrust and torque are reduced by 6.51%and 16.89%respectively with the optimal cutter spacing and inclined installation method,indicating that the inclined installation method of the disc-shaped hob and the arrangement of the disc-shaped hob according to the optimal cutter spacing can improve the drilling efficiency of the full-section rock tunneling machine.(4)According to the prediction formula of the optimum blade spacing for inclined and offset wedge shaped disc hobs,the optimum blade spacing for a penetration degree of 6 mm is calculated respectively. |
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