Performance Driven On Shield Cutterhead Opening And Cutter Group Combination Layout Design

In recent years, composite EPB shield has been more and more widely used in our country. It has become the important technical method under geotechnical composite geological. It has the characteristics of high efficiency, safety and stability compare with the traditional artificial mining and blasting. The cutterhead as the forefront of shield is the only component action with the geotechnical. It bears the function of cutting rock soil and ruling out the waste residue. Its overall structure design rationality is the key to decide the success or failure of shield tunneling.This paper aim at the question of cutterhead mud cake and cutting head blinding during the actual construction. From the point of cutterhead opening mode and cutter group effect to research the rationality of whole cutterhead structure. At the same time develop the cutterhead assembly model automatic generation system. Finally through a concrete engineering construction of the cutterhead for structure optimization design, it can verify the feasibility of the method in this paper.The research content includes the following several aspects:(1) Research in cutterhead opening ways which is based on the analysis of the liquidity, through a summary of a large number of cutterhead opening mode at home and abroad, extracting the cutterhead typical topology, establishing different ways of opening the cutterhead models. To solve the problem of same and variable aperture ratio, Analyzing the liquidity of waste residue by CFD method, and also establishing the relationship between shield system pressure transmission and the cutterhead opening. All these can design for the cutterhead opening ways under the different geological basis.(2) Research in cutter group layout based on the dynamic cutting. For a variety of geological conditions, respectively on cutter and hob group of dynamic cutting simulation. From the respect of cutter cutting amount of overlap, the assembly inner angle and cutter arrangement to compare the cutting effect. Also researching on the hob cutting ability under soft soil mass, compared different assembly height difference of cutting effect under various geological conditions. All these can provided reference of composite EPB shield cutter design.(3) The cutterhead model of the system development. In view of the engineering on two of the most common cutterhead structure:four spokes four wheel and six spokes six wheel cutterhead. Developing the parameters of cutterhead structure, hob and cutter group assembly, designing artificial intelligence interface, creating the background database, and finally programming the automatic interference. All these can output 3D model of cutterhead and its parameters at the same time.(4) Optimizing the cutterhead of Nanjing subway project according the research methods of this article. It includes setting assembly inner angle of cutter, changing the cutter combination height difference, designing the cutterhead opening way again, optimization cutterhead is better than the original cutterhead in liquidity and cutting effect.Through the research of cutterhead opening and cutter group combination layout design, which can provide the basis for cutterhead design process, at the same time it can lay the foundation for concrete construction cutterhead optimization.