In order to study rock breaking characteristics of tunnel boring machine(TBM) disc cutter at different rock temperatures,thermodynamic rock breaking mathematical model of TBM disc cutter was established on the basis o...In order to study rock breaking characteristics of tunnel boring machine(TBM) disc cutter at different rock temperatures,thermodynamic rock breaking mathematical model of TBM disc cutter was established on the basis of rock temperature change by using particle flow code theory and the influence law of interaction mechanism between disc cutter and rock was also numerically simulated.Furthermore,by using the linear cutting experiment platform,rock breaking process of TBM disc cutter at different rock temperatures was well verified by the experiments.Finally,rock breaking characteristics of TBM disc cutter were differentiated and analyzed from microscale perspective.The results indicate the follows.1) When rock temperature increases,the mechanical properties of rock such as hardness,and strength,were greatly reduced,simultaneously the microcracks rapidly grow with the cracks number increasing,which leads to rock breaking load decreasing and improves rock breaking efficiency for TBM disc cutter.2) The higher the rock temperature,the lower the rock internal stress.The stress distribution rules coincide with the Buzin Neske stress circle rules: the maximum stress value is below the cutting edge region and then gradually decreases radiant around; stress distribution is symmetrical and the total stress of rock becomes smaller.3) The higher the rock temperature is,the more the numbers of micro,tensile and shear cracks produced are by rock as well as the easier the rock intrusion,along with shear failure mode mainly showing.4) With rock temperature increasing,the resistance intrusive coefficients of rock and intrusion power decrease obviously,so the specific energy consumption that TBM disc cutter achieves leaping broken also decreases subsequently.5) The acoustic emission frequency remarkably increases along with the temperature increasing,which improves the rock breaking efficiency.展开更多
At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine （TBM） on-site data. This is not in line...At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine （TBM） on-site data. This is not in line with the actual rock-breaking movement of the disc cutter and impedes to some extent the research on the rock-breaking mechanism, wear mechanism and design theory. Therefore, our study focuses on the interaction between the slantingly installed disc cutter and rock, developing a model in accordance with the actual rock-breaking movement. Displacement equations are established through an analysis of the velocity vector at the rock-breaking point of the disc cutter blade; the func- tional relationship between the displacement parameters at the rock-breaking point and its rectangular coordinates is established through an analysis of micro-displacement vectors at the rock-breaking point, thus leading to the geometric equations of rock deformation caused by the slantingly installed disc cutter. Considering the basically linear relationship between the cutting force of disc cutters and the rock deformation before and after the leap break of rock, we express the constitutive relations of rock deformation as generalized Hooke＇s law and analyze the effect of the slanting installa- tion angle of disc cutters on the rock-breaking force. This will, as we hope, make groundbreaking contributions to the development of the design theory and installation practice of TBM.展开更多
合理设置TBM贯入度参数对于特定地质条件下的掘进效率至关重要。为研究TBM盘型滚刀在不同贯入度下的破岩效果,采用自主研发的滚刀破岩缩尺试验平台,在不同边界条件下对花岗岩开展盘型滚刀线性切割试验,通过使用FEM(finite element meth...合理设置TBM贯入度参数对于特定地质条件下的掘进效率至关重要。为研究TBM盘型滚刀在不同贯入度下的破岩效果,采用自主研发的滚刀破岩缩尺试验平台,在不同边界条件下对花岗岩开展盘型滚刀线性切割试验,通过使用FEM(finite element method)和SPH(smooth particle hydrodynamics)相耦合的数值模拟方法重现相关试验以验证模型的合理性,并在此基础上建立原尺双滚刀回旋破岩三维数值模型,研究TBM盘型滚刀不同贯入度下对花岗岩的破岩效果。研究结果表明:有侧限条件下滚刀受力和岩碴体积往往更大,且相邻贯入度之间的法向力和岩碴体积增长幅度随着贯入度的增大而减小,但无侧限条件下的破岩效率更高;滚刀破岩过程是阶跃性的,岩碴的产生主要集中在滚刀荷载跌落阶段,无论刀侧是否存在限制,刀下岩石均被碾压至极细的粉末,刀侧岩石崩出,且岩碴的大小与滚刀荷载跌落幅度正相关;刀下岩石破坏区域近似呈“V”形,随着贯入度的增大,滚刀间的“V”形破坏区域持续向安装半径内侧倾斜;滚刀破岩效率随着贯入度的增大先提高后减小,针对试验岩样,最佳贯入度为2~4mm;本研究所采用滚刀破岩缩尺试验与FEM-SPH数值模拟相结合的方法可以很好地重现花岗岩破裂过程,且两者切削力相对误差均在10%以内,可以为后续TBM滚刀破岩研究提供一定参考。展开更多
基金Projects(51274252,51074180)supported by the National Natural Science Foundation of ChinaProject(2013CB035401)supported by the National Basic Research Program of China+1 种基金Projects(2012AA0418012012AA041803)supported by the High-Tech Research and Development Program of China
文摘In order to study rock breaking characteristics of tunnel boring machine(TBM) disc cutter at different rock temperatures,thermodynamic rock breaking mathematical model of TBM disc cutter was established on the basis of rock temperature change by using particle flow code theory and the influence law of interaction mechanism between disc cutter and rock was also numerically simulated.Furthermore,by using the linear cutting experiment platform,rock breaking process of TBM disc cutter at different rock temperatures was well verified by the experiments.Finally,rock breaking characteristics of TBM disc cutter were differentiated and analyzed from microscale perspective.The results indicate the follows.1) When rock temperature increases,the mechanical properties of rock such as hardness,and strength,were greatly reduced,simultaneously the microcracks rapidly grow with the cracks number increasing,which leads to rock breaking load decreasing and improves rock breaking efficiency for TBM disc cutter.2) The higher the rock temperature,the lower the rock internal stress.The stress distribution rules coincide with the Buzin Neske stress circle rules: the maximum stress value is below the cutting edge region and then gradually decreases radiant around; stress distribution is symmetrical and the total stress of rock becomes smaller.3) The higher the rock temperature is,the more the numbers of micro,tensile and shear cracks produced are by rock as well as the easier the rock intrusion,along with shear failure mode mainly showing.4) With rock temperature increasing,the resistance intrusive coefficients of rock and intrusion power decrease obviously,so the specific energy consumption that TBM disc cutter achieves leaping broken also decreases subsequently.5) The acoustic emission frequency remarkably increases along with the temperature increasing,which improves the rock breaking efficiency.
基金supported by the National Natural Science Foundation of China(51075147)863 Project(2012AA041803)
文摘At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine （TBM） on-site data. This is not in line with the actual rock-breaking movement of the disc cutter and impedes to some extent the research on the rock-breaking mechanism, wear mechanism and design theory. Therefore, our study focuses on the interaction between the slantingly installed disc cutter and rock, developing a model in accordance with the actual rock-breaking movement. Displacement equations are established through an analysis of the velocity vector at the rock-breaking point of the disc cutter blade; the func- tional relationship between the displacement parameters at the rock-breaking point and its rectangular coordinates is established through an analysis of micro-displacement vectors at the rock-breaking point, thus leading to the geometric equations of rock deformation caused by the slantingly installed disc cutter. Considering the basically linear relationship between the cutting force of disc cutters and the rock deformation before and after the leap break of rock, we express the constitutive relations of rock deformation as generalized Hooke＇s law and analyze the effect of the slanting installa- tion angle of disc cutters on the rock-breaking force. This will, as we hope, make groundbreaking contributions to the development of the design theory and installation practice of TBM.
文摘合理设置TBM贯入度参数对于特定地质条件下的掘进效率至关重要。为研究TBM盘型滚刀在不同贯入度下的破岩效果,采用自主研发的滚刀破岩缩尺试验平台,在不同边界条件下对花岗岩开展盘型滚刀线性切割试验,通过使用FEM(finite element method)和SPH(smooth particle hydrodynamics)相耦合的数值模拟方法重现相关试验以验证模型的合理性,并在此基础上建立原尺双滚刀回旋破岩三维数值模型,研究TBM盘型滚刀不同贯入度下对花岗岩的破岩效果。研究结果表明:有侧限条件下滚刀受力和岩碴体积往往更大,且相邻贯入度之间的法向力和岩碴体积增长幅度随着贯入度的增大而减小,但无侧限条件下的破岩效率更高;滚刀破岩过程是阶跃性的,岩碴的产生主要集中在滚刀荷载跌落阶段,无论刀侧是否存在限制,刀下岩石均被碾压至极细的粉末,刀侧岩石崩出,且岩碴的大小与滚刀荷载跌落幅度正相关;刀下岩石破坏区域近似呈“V”形,随着贯入度的增大,滚刀间的“V”形破坏区域持续向安装半径内侧倾斜;滚刀破岩效率随着贯入度的增大先提高后减小,针对试验岩样,最佳贯入度为2~4mm;本研究所采用滚刀破岩缩尺试验与FEM-SPH数值模拟相结合的方法可以很好地重现花岗岩破裂过程,且两者切削力相对误差均在10%以内,可以为后续TBM滚刀破岩研究提供一定参考。
