Studies to date have failed to consider gage disc cutters’variable cutting depth and the constraints of cutter-head welds,and have ignored the coupling mechanism between the profile of the full-face rock tunnel-borin...Studies to date have failed to consider gage disc cutters’variable cutting depth and the constraints of cutter-head welds,and have ignored the coupling mechanism between the profile of the full-face rock tunnel-boring machine(TBM)cutter-head and the assembled radius layout of the disc cutters.To solve these problems,an adaptive design method for studying cutter layout was proposed.Taking the bearing stress of the outermost gage disc cutter as an index,the profile of the cutter-head was determined.Using a genetic algorithm and based on the principles of equal life and equal wear,the assembled radii of the cutters were optimally designed.Boundary conditions of non-interference between the cutters,manholes,muck buckets and welding lines were given when a star layout pattern was used on cutters.The cutter-head comprehensive evaluation model was established by adopting relative optimization improvement degree of evaluation indices to achieve dimensional consistency.Exemplifying the MB264-311-8030 mm tape TBM cutter-head,the calculations show that compared with the original layout scheme,among the 51 disc cutters,the largest gap of the cutters’assembled radiuses is only 25.8 mm,which is 0.64%of the cutter-head’s radius and is negligible.The cutter-head’s unbalanced radial force decreases by 62.41%,the overturning moment decreases by 33.22%,and the cutter group’s centroid shift increases by only 18.48%.Each index is better than or approximately equal to the original cutter-head layout scheme,and the equivalent stress and deformation are both smaller;these results fully verify the feasibility and effectiveness of the method.展开更多
Achieving highly efficient extrication of the tunnel boring machine(TBM)cutter-head driving system from the collapsed surrounding rock has become a key problem globally,and significant effort has been directed to impr...Achieving highly efficient extrication of the tunnel boring machine(TBM)cutter-head driving system from the collapsed surrounding rock has become a key problem globally,and significant effort has been directed to improve TBM cutter-head extricating ability.In this study,the characteristics of a hydro-viscous device have been investigated to improve extricating performance of the TBM cutter-head.A numerical method based on an explicit pressure-linked equation is presented for computing the film parameters of the HVC,which is then applied to investigate extrication characteristics of a TBM cutter-head with a hydro-viscous clutch(HVC).The explicit pressure-linked equation is derived from the Navier–Stokes equations and the conservation equation,where boundary conditions are involved.The model of a cutter-head driving system with an HVC is established,and the extrication characteristics of the cutterhead driving system are analyzed and compared with three extrication strategies.The variation in extrication torque shows that the linear strategy or positive parabolic strategy are preferred for their relatively high extrication efficiency and low rigid impact,and the effects of throughflow rate on torque transmission are also investigated.The test rig of the TBM cutter-head driving system was set up to validate the numerical method and the model of a cutter-head driving system,and the feasibility of the proposed numerical method for researching the extrication of the TBM cutter-head is verified.展开更多
基金Projects(51275339,51575379,51675374)supported by the National Natural Science Foundation of ChinaProject(2013CB035402)supported by the National Hi-tech Research and Development Program of China
文摘Studies to date have failed to consider gage disc cutters’variable cutting depth and the constraints of cutter-head welds,and have ignored the coupling mechanism between the profile of the full-face rock tunnel-boring machine(TBM)cutter-head and the assembled radius layout of the disc cutters.To solve these problems,an adaptive design method for studying cutter layout was proposed.Taking the bearing stress of the outermost gage disc cutter as an index,the profile of the cutter-head was determined.Using a genetic algorithm and based on the principles of equal life and equal wear,the assembled radii of the cutters were optimally designed.Boundary conditions of non-interference between the cutters,manholes,muck buckets and welding lines were given when a star layout pattern was used on cutters.The cutter-head comprehensive evaluation model was established by adopting relative optimization improvement degree of evaluation indices to achieve dimensional consistency.Exemplifying the MB264-311-8030 mm tape TBM cutter-head,the calculations show that compared with the original layout scheme,among the 51 disc cutters,the largest gap of the cutters’assembled radiuses is only 25.8 mm,which is 0.64%of the cutter-head’s radius and is negligible.The cutter-head’s unbalanced radial force decreases by 62.41%,the overturning moment decreases by 33.22%,and the cutter group’s centroid shift increases by only 18.48%.Each index is better than or approximately equal to the original cutter-head layout scheme,and the equivalent stress and deformation are both smaller;these results fully verify the feasibility and effectiveness of the method.
基金Supported by Major State Basic Research Development Program of China(973 Program,Grant No.2013CB035400)National Natural Science Foundation of China(Grant Nos.51275451,51575476)Science Fund for Creative Research Groups of National Natural Science Foundation of China(Grant No.51221004)
文摘Achieving highly efficient extrication of the tunnel boring machine(TBM)cutter-head driving system from the collapsed surrounding rock has become a key problem globally,and significant effort has been directed to improve TBM cutter-head extricating ability.In this study,the characteristics of a hydro-viscous device have been investigated to improve extricating performance of the TBM cutter-head.A numerical method based on an explicit pressure-linked equation is presented for computing the film parameters of the HVC,which is then applied to investigate extrication characteristics of a TBM cutter-head with a hydro-viscous clutch(HVC).The explicit pressure-linked equation is derived from the Navier–Stokes equations and the conservation equation,where boundary conditions are involved.The model of a cutter-head driving system with an HVC is established,and the extrication characteristics of the cutterhead driving system are analyzed and compared with three extrication strategies.The variation in extrication torque shows that the linear strategy or positive parabolic strategy are preferred for their relatively high extrication efficiency and low rigid impact,and the effects of throughflow rate on torque transmission are also investigated.The test rig of the TBM cutter-head driving system was set up to validate the numerical method and the model of a cutter-head driving system,and the feasibility of the proposed numerical method for researching the extrication of the TBM cutter-head is verified.
