盾构典型刀具组合破岩受力特性研究

【作者】 欧阳涛；

【导师】 夏毅敏；

【作者基本信息】 中南大学 ， 机械工程， 2011， 硕士

【摘要】 近年来随着地下空间工程建设的需要和科学技术水平的提高,盾构法作为地下空间工程施工的主要手段,盾构掘进机及施工技术在我国得到了广泛应用,盾构掘进机技术的发展也得到了国家相关部门和施工企业的高度重视。盾构主要是通过盾构刀盘上的盾构刀具切削破岩而完成掘进,但由于地质条件复杂多样,一种刀具往往无法适应多种地质条件,因此在工程中盾构刀盘往往采用多种刀具组合布置,此时多刀具组合切削破岩力学特性成为关键问题,因此必须对多刀具组合切削破岩力学特性展开研究,这对提升刀具的使用性能、优化刀具配置、提高刀具的使用寿命有重要意义。深入分析了单滚刀及滚刀组合切削的破岩机理,并对滚刀压头作用下,岩石材料的应力状态进行分析,通过滚刀结构参数及组合参数对滚刀回转切削过程影响的研究,提出相邻滚刀问相位差会引起滚刀掘进界面的不平整以及滚刀安装半径越小滚刀内外侧破岩量之差越大等结论,以此为基础并结合滚刀组合切削破岩机理,建立起滚刀回转切削三向力模型。搭建了回转式刀具切削性能测试试验台,借助该试验台对滚刀回转切削三向力模型进行实验验证,通过所得到滚刀切削三向力模型,展开对滚刀三向力随结构参数、工作参数以及滚刀组合参数变化特性的研究,得到滚刀回转切削三向力随不同参数的变化规律,最后对工程中各组合参数的选定作简要讨论。通过对先行刀与刮刀组合切削特点及切削类刀具破岩机理的分析,运用大型仿真软件ANSYS/LS-DYNA建立起先行刀与刮刀组合切削有限元模型,对先行刀与刮刀组合切削进行仿真模拟,定义破岩量与切削力的比值为先行刀与刮刀组合切削能效,通过对仿真所得切削能效及切削力的分析,最终得到先行与刮刀组合的最优高差组合,并利用某工程案例对仿真结果进行对比验证,证实了仿真结果的正确性,然后以最优组合高差为已知量,分析了切削速度与切深对先行刀及刮刀组合受力的影响,得到先行刀与刮刀组合切削力随切削速度及切深的变化规律。更多还原

【Abstract】 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.更多还原