Composite Formation Of Shield Machine Cutter Disc And Cutter Optimization Design And Engineering Application

As a special equipment for tunnel construction,shield machine is widely used in urban subways,municipal pipe networks,highway tunnels and other projects.The cutter head is the core component of the shield machine.It directly undertakes the excavation of the soil cutting task.Whether the cutter disc structure design and the tool selection arrangement can be adapted to the geology is directly related to the success or failure of the tunnel construction.This paper relies on a highway tunnel project in the Yangtze River in China,using shield tunnel construction,the length of the line is 5530m,and the diameter of the lining is 14.5m.The hydrogeological conditions of the project are complex,with large excavation section,shallow overburden thickness,long tunneling distance and high water pressure in the incision.Especially in the upper-soft lower-hard stratum of the middle section of the river,the base rock content exceeds 65%,and the value of the average uniaxial compressive strength exceeds 40 MPa.Based on the comparative analysis of the existing theoretical research of cutterhead cutters,this paper selects the theoretical design,numerical simulation and engineering application to optimize the design and engineering application of the shield cutter of the composite formation shield machine.The main tasks are as follows:1.According to the complex hydrogeological conditions of the project,the tool selection analysis of the shield cutter is carried out,and then the cutter structure design of the large-diameter shield machine is carried out.The finite element software is used to analyze the force of the cutter head under three different working conditions.The strength and stiffness of the surface meet the design and construction requirements.Through the modal analysis,the natural frequency of the cutter head is obtained,and it is known that resonance does not occur during construction,and the structure is safe and reliable.At the same time,in order to meet the construction requirements,the cutter head function configuration was further improved,and the atmospheric pressure cutter replacement device and method were developed to reduce the risk of tool change and provide construction efficiency.2.In terms of tool selection,on the basis of studying the rock breaking mechanism and arrangement rules of the tool,the various types of tools in the project are selected reasonably,and the arrangement method and arrangement parameters are determined.When the local layer is changed,the layout parameters such as the height and quantity of the tool are optimized and adjusted to ensure that different ground excavation requirements are met.3.Analyze the application effect of the cutter head tool through engineering practice,and analyze the technical parameters of the cutter head and the tool selection configuration.According to the analysis of construction data,the actual thrust and torque values of the cutterhead structure are smaller than the design value,thus verifying that the cutterhead structure design meets different working conditions.The compatibility between the cutter head and the geology is further verified by the adaptability analysis of the cutters in different formations.Through the analysis of the hob wear,three kinds of failure modes and causes are obtained,and the tool parameters are further optimized.The heavy-duty hob cutter ring is used,and the surface of the drum is hardened and hardened.The construction data before and after optimization is compared,and the rock breaking capacity of the hob and the efficiency have been improved to verify the rationality of the hob and construction parameters optimization.