Tunnel boring machines require extensive maintenance and inspection effort to provide a high availability.The cutting tools of the cutting wheel must be changed timely upon reaching a critical condition.While one poss...Tunnel boring machines require extensive maintenance and inspection effort to provide a high availability.The cutting tools of the cutting wheel must be changed timely upon reaching a critical condition.While one possible maintenance strategy is to change tools only when it is absolutely necessary,tools can also be changed preventively to avoid further damages.Such different maintenance strategies influence the maintenance duration and the overall project performance.However,determine downtime related to a particular mainte-nance strategy is still a challenging task.This paper shows an analysis of the robustness to achieve the planned project performance of a maintenance strategy considering uncertainties of wear behavior of the cutting tools.A simulation based analysis is presented,imple-menting an empirical wear prediction model.Different strategies of maintenance planning are compared by performing a parameter vari-ation study including Monte-Carlo simulations.The maintenance costs are calculated and evaluated with respect to their robustness.Finally,an improved and robust maintenance strategy has been determined.展开更多
The Daqin Railway is China’s first electrified double-track heavy-haul railway line dedicated to coal transportation.Over the years of operation,the tunnels have been covered with a thick layer of coal dust,which als...The Daqin Railway is China’s first electrified double-track heavy-haul railway line dedicated to coal transportation.Over the years of operation,the tunnels have been covered with a thick layer of coal dust,which also pervades in the air.Worse is that the coal dust has even buried the rail joints in some sections,making the repair and maintenance of the line difficult.This paper introduces a coal-dust removal device for railway tunnels that integrates pipeline transportation with dust-collection techniques.The device is mainly composed of a power system,a conveying system,a dust-filtration and collection system,and a control and protection system.The key technical elements of the system,such as the dust-extraction method and dust-filtration and collection parameters,are optimized based on the characteristics of the coal dust in the tunnel(obtained via field trials),which greatly enhances the adaptability of the device.Coal-dust removal efficiency reached over 20 t/h,which improves the working environment,reduces the intensity of manual work required and solves the problem of coal-dust removal from the most polluted area—within 500 m of the tunnel entrance.展开更多
文摘Tunnel boring machines require extensive maintenance and inspection effort to provide a high availability.The cutting tools of the cutting wheel must be changed timely upon reaching a critical condition.While one possible maintenance strategy is to change tools only when it is absolutely necessary,tools can also be changed preventively to avoid further damages.Such different maintenance strategies influence the maintenance duration and the overall project performance.However,determine downtime related to a particular mainte-nance strategy is still a challenging task.This paper shows an analysis of the robustness to achieve the planned project performance of a maintenance strategy considering uncertainties of wear behavior of the cutting tools.A simulation based analysis is presented,imple-menting an empirical wear prediction model.Different strategies of maintenance planning are compared by performing a parameter vari-ation study including Monte-Carlo simulations.The maintenance costs are calculated and evaluated with respect to their robustness.Finally,an improved and robust maintenance strategy has been determined.
文摘The Daqin Railway is China’s first electrified double-track heavy-haul railway line dedicated to coal transportation.Over the years of operation,the tunnels have been covered with a thick layer of coal dust,which also pervades in the air.Worse is that the coal dust has even buried the rail joints in some sections,making the repair and maintenance of the line difficult.This paper introduces a coal-dust removal device for railway tunnels that integrates pipeline transportation with dust-collection techniques.The device is mainly composed of a power system,a conveying system,a dust-filtration and collection system,and a control and protection system.The key technical elements of the system,such as the dust-extraction method and dust-filtration and collection parameters,are optimized based on the characteristics of the coal dust in the tunnel(obtained via field trials),which greatly enhances the adaptability of the device.Coal-dust removal efficiency reached over 20 t/h,which improves the working environment,reduces the intensity of manual work required and solves the problem of coal-dust removal from the most polluted area—within 500 m of the tunnel entrance.
