| ABSTRACT:Since the21st century, hard rock tunnel boring maching (TBM) has been more and more widely used in construction of national life. Disc cutter is excavation main tool of TBM, research on rock-breaking characteristics of disc cutter is a key issue to improve rock-breaking efficiency and accelerate the process of TBM localization. Based on consulting a large number of domestic and foreign literatures, disc cutter layout features are analyzed, rock-breaking resistance force and rock damage characteristics under the effect of disc cutter when disc cutter under different cutting sequences are researched, and finally optimal layout of disc cutter is optimized. The main contents are as follows:(1) Rock-breaking resistance force finite element models of disc cutter under different sequences are established by software ANSYS/LS-DYNA. Influence of geological conditions, cutter spacing, penetration, installation radius and cutterhead rotating rate on rock-breaking resistance force is studied. In addition, the coupling impact of the various factors on rock-breaking resistance force is researched through orthogonal test. Ultimately numerical simulation is validated by experiment.(2) Discrete numerical models to study rock damage characteristics when disc cutter under different sequences are established by software PFC. Process of disc cutter intrusive rock is analyzed and crack propagation characteristics of rock are studied. Three different modes of rock damage characteristics and damaged rock area are summarized, influence of cutter spacing and penetration on modes is studied.(3)Forces of cutterhead are analyzed, objective functions and constraints of disc cutter optimal layout are set, weights of layout objective functions are calculated by Fuzzy Analytic Hierarchy Process. An optimization layout model of disc cutter is established, the model is solved by genetic algorithms and optimal layout parameters of disc cutter are obtained. Performance of cutterhead after optimal layout is improved. |
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