| In recent years, with the need of rapid excavation of underground engineering and improving the science and technology level, shield has been the main construction method for the underground space engineering, and the technology of shield machine had a quick development in China. Development and application of shield machine has obtained the attention of related government departments and businesses.Shield excavate tunnel through cutter head which layout different kind of cutters. One kind of cutter couldn't adapt all of the construction because of complicated geological conditions in our country, and tools combination are usually adopted in the cutter head designing, so cutting performance of tools combination which change with the combination parameter is the key program, so the influence law of cutting performance of tools combination by the combination parameter should be studied, which has important significance to improve the cutting performance of tools combination, optimize the tool configuration and increase the cutter life.The rock-breaking mechanism of disc cutter is analyzed deeply. Under the force of the press head, the rock stress state is investigated. Based on the research on the influence of structure parameters and combination parameters in the disc cutter rotary cutting process, we conclude that the phase angle difference between adjacent disc cutters will cause the unevenness of the disc cutter tunneling interface. We can also obtain that the smaller the disc cutter installation radius is, the larger the inside and outside rock-breaking difference of the disc cutter will be. Finally, the three-axis force model of the disc cutter is established according to the rock-breaking mechanism.We have developed the rotary cutting test platform and the three-axis force model of disc cutter is tested by it. Through the obtained model, the disc cutter three-axis force with the structure parameters, work parameters and combination parameters is studied. Furthermore, the variation regularity of the disc cutter three-axis force with different parameters is summed up. Ultimately, the selection of combination parameters for projects is discussed briefly.According to analyze the cutting characteristics of the combination of the advanced knife and the scraper and the rock-breaking mechanism of tools, the combination cutting model is created by using ANSYS/LS-DYNA software. The combination cutting process of the advanced knife and the scraper is carried out through dynamic simulation. Then the ratio of broken rock and cutting force is defined as cutting efficiency. Furthermore, through the analysis of simulation results, the optimal height difference of the advanced knife and the scraper is obtained. The correctness of numerical simulation results is also verified by project cases. With the optimal height difference as known quantity, effects of cutting speed and depth on forces of the advanced knife and the scraper are discussed. Finally, the variation regularity of tools'cutting forces which change with the cutting velocity and depth is received. |
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