In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters ...In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.展开更多
为探究小断面TBM隧洞锚杆支护在地层围岩中的受力特性及支护参数的合理性,依托安徽桐城抽水蓄能电站自流排水洞工程,分别采用岩体力学法和数值模拟法计算得到隧洞Ⅲ类围岩工况下的锚杆内力和围岩位移,并在洞内TBM掘进段紧随TBM选取3个...为探究小断面TBM隧洞锚杆支护在地层围岩中的受力特性及支护参数的合理性,依托安徽桐城抽水蓄能电站自流排水洞工程,分别采用岩体力学法和数值模拟法计算得到隧洞Ⅲ类围岩工况下的锚杆内力和围岩位移,并在洞内TBM掘进段紧随TBM选取3个监测断面,分别采用锚杆应力计和多点位移计监测得到实际工况下的锚杆内力和围岩位移。对3种方法得到的结果进行对比分析后得出:1)数值模拟法和岩土力学法计算得到的轴力值变化趋势相近,均在锚杆中间部位出现轴力最大值,与中性点理论相符,最大轴力值为4.78 k N;2)3种方法得到的围岩位移值变化趋势相似,均在隧洞围岩表面出现位移最大值,在岩层内部围岩位移最小,最大位移为2.03 mm。进一步,与已有关于较大断面隧洞结构受力研究成果对比发现:小断面TBM隧洞的锚杆轴力及围岩变形均较小,锚杆支护作用未得到充分利用,据此提出了延迟、减少或取消小断面TBM隧洞锚杆支护的优化建议。展开更多
为了对比不同典型全断面岩石掘进机(TBM)刀盘的力学性能,对刀盘倾覆力矩计算模型进行了修正。在理想工况、上软下硬地质和部分刀具磨损3种工况下,计算得到刀盘倾覆力矩的分布情况,并采用有限元法模拟得到刀盘掘进过程中应力分布规律。...为了对比不同典型全断面岩石掘进机(TBM)刀盘的力学性能,对刀盘倾覆力矩计算模型进行了修正。在理想工况、上软下硬地质和部分刀具磨损3种工况下,计算得到刀盘倾覆力矩的分布情况,并采用有限元法模拟得到刀盘掘进过程中应力分布规律。结果表明:刀盘的径向载荷远小于刀盘倾覆力矩,倾覆力矩对刀盘性能的影响远大于径向载荷;刀盘正面滚刀受载产生的倾覆力矩最大,其次是边缘滚刀,中心滚刀受载产生的倾覆力矩最小;在刀具磨损工况下,A刀盘总倾覆力矩在2 800 k N·m以上,比理想工况下要大7%;星形布局刀盘B的倾覆力矩比螺旋线布局刀盘A小,其力学性能和强度特性优于螺旋线布局刀盘。展开更多
基金Project(51074180) supported by the National Natural Science Foundation of ChinaProject(2012AA041801) supported by the National High Technology Research and Development Program of China+2 种基金Project(2007CB714002) supported by the National Basic Research Program of ChinaProject(2013GK3003) supported by the Technology Support Plan of Hunan Province,ChinaProject(2010FJ1002) supported by Hunan Science and Technology Major Program,China
文摘In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.
文摘为探究小断面TBM隧洞锚杆支护在地层围岩中的受力特性及支护参数的合理性,依托安徽桐城抽水蓄能电站自流排水洞工程,分别采用岩体力学法和数值模拟法计算得到隧洞Ⅲ类围岩工况下的锚杆内力和围岩位移,并在洞内TBM掘进段紧随TBM选取3个监测断面,分别采用锚杆应力计和多点位移计监测得到实际工况下的锚杆内力和围岩位移。对3种方法得到的结果进行对比分析后得出:1)数值模拟法和岩土力学法计算得到的轴力值变化趋势相近,均在锚杆中间部位出现轴力最大值,与中性点理论相符,最大轴力值为4.78 k N;2)3种方法得到的围岩位移值变化趋势相似,均在隧洞围岩表面出现位移最大值,在岩层内部围岩位移最小,最大位移为2.03 mm。进一步,与已有关于较大断面隧洞结构受力研究成果对比发现:小断面TBM隧洞的锚杆轴力及围岩变形均较小,锚杆支护作用未得到充分利用,据此提出了延迟、减少或取消小断面TBM隧洞锚杆支护的优化建议。
文摘为了对比不同典型全断面岩石掘进机(TBM)刀盘的力学性能,对刀盘倾覆力矩计算模型进行了修正。在理想工况、上软下硬地质和部分刀具磨损3种工况下,计算得到刀盘倾覆力矩的分布情况,并采用有限元法模拟得到刀盘掘进过程中应力分布规律。结果表明:刀盘的径向载荷远小于刀盘倾覆力矩,倾覆力矩对刀盘性能的影响远大于径向载荷;刀盘正面滚刀受载产生的倾覆力矩最大,其次是边缘滚刀,中心滚刀受载产生的倾覆力矩最小;在刀具磨损工况下,A刀盘总倾覆力矩在2 800 k N·m以上,比理想工况下要大7%;星形布局刀盘B的倾覆力矩比螺旋线布局刀盘A小,其力学性能和强度特性优于螺旋线布局刀盘。
