The Research On Theory And Techniques Of Service Life Management Of TBM Disc Cutters

With the geographic features and geographic allocations of water resources in China taken into consideration, the adoption of full-face TBM has been offered broad prospects. Successful construction of some hydraulic projects such as Datonghe-Qinwangchuan Water Diversion project, Shangxi Yellow River Diversion project and Dahuofang Reservoir's Water Diversion project, and some remarkable tunnels like Qinlin Tunnel, Taohuapu Tunnel and Mogoulin Tunnel, which met many of the nation's physical challenges and were built with TBM playing an important role, has induced the growing attention of related government departments and businesses to the investment in the employment of TBM in the underground tunnel projects.To date, the research on management of service life of disc cutters of TBM is still in its initial stage, which is the frontier of the research on application of TBM disc cutters, as well as a key issue waiting to be further explored. Based on wide reading and in-depth study of the related articles and books centering on the rock breaking theory, abrasion of disc cutters and management of disc cutters' service life, and existing experimental data, and concrete situations of disc cutter abrasion of TBM adopted in Qinlin Tunnel construction, a theoretical framework of this research on the theory of management of disc cutters' service life and its relevant techniques comes into being, following this procedure: construction of models, theoretical study, software development and its practical use. The main contents fall into five parts as follows:Part one (chapter 1 and chapter 2): This part makes an introduction of the working characteristics of TBM which provides a basis for the exploration of parameters of objects operated, then the study of geological features of tunnels, and measures taken against possible hazards during the construction with TBM.Part two (chapter 3): In this part, through the analysis of rock breaking motion of TBM disc cutters and on the review of some related study, a dimensional model of rock breaking motion of disc cutters regularly mounted on the TBM plate is set up, with relevant theoretical studies carried out. Accordingly, an equation is set forward in terms of the rock strain resulted from the interaction between disc cutters and rocks during the process of rock breaking with disc cutters set at certain parameters and in certain sizes, hence the equation of vertical force, rolling force and side force, which is analyzed in relation with experimental data.Part three (chapter 4) mainly gives an analysis of the forces acting on the cutterhead during the operation, which can be shown by an equation, further resulting in another equation for mounting disc cutters, which is examined with relevant data. Linked to some project cases, the study of motion patterns of some specific rock breaking point explores an equation of its displacement on the rock, thereby making research on abrasion during the process and putting forth the concept of abrasion coefficient, and side abrasion, rolling abrasion, penetrating abrasion, arc abrasion as well. The empirical research has been conducted in this regard in connection with some particular projects.Part four (chapter 5), on the basis of the study of layout patterns of disc cutters, constructs a management model of disc cutter service life, and develops a software program, a guidance for the replacement of disc cutters, equipped with functions such as data input of the disc cutter abrasion and the corresponding data analysis.Part five (chapter 6) ends with conclusions of the research and suggestions for further study and problems to be settled.