ZYB液压静力压桩机夹桩钳口研究

【作者】 贺淑云；

【导师】 胡均平；

【作者基本信息】 中南大学 ， 机械设计与理论， 2002， 硕士

【摘要】 随着高层建筑对桩基础提出的更高要求，新的桩型和施工方法应运而生，因而对新一代桩基础施工设备的研制也提出了迫切的要求。我国己将专用桩工机械设备列为“十五”期间的重点发展项目。 随着PHC管桩的广泛应用，要求对桩机的夹桩钳口尺寸进行更精确的计算，这一问题的解决将为钳口与PHC桩的适配提供理论依据。 论文结合中南大学液压所研制的ZYB系列液压静力沉桩机的工作原理和实际压桩情况，从桩身宏观受力和钳口使用性能出发，独立设计了一套新型调心钳口结构。并注意到了由于桩身受力的不均匀性，夹桩钳口与桩身的实际接触状态与理想状态之间的差异性，对夹桩钳口的尺寸提出了一套更精确的算法。 论文着重考虑了夹桩力在桩身纵截面内产生的弯曲应力，注意到了钳口与桩身的实际接触弧长与钳口长度的密切关系，并分析了在夹桩力和压桩力作用下，钳口长度的变化对桩身应力分布的影响，从而将钳口长度确定为钳口设计中的关键尺寸。在进行钳口长度计算时，综合运用弹性力学，接触力学和材料力学的知识对PHC桩在施工时应力分布规律与钳口长度之间的关系进行了理论分析与计算；采用单元应力法对桩身的应力状况进行了分析，对三向主应力进行了计算；在综合研究了混凝土构件多轴强度的基础上，确定了相对桩身微观强度的钳口长度计算准则；并运用运算功能强大的MATLAB软件设计了一套适应不同终止压力和桩径的钳口尺寸的算法。 本文旨在为夹桩钳口的尺寸设计提供可靠的理论依据，避免由经验估算带来的不确切性，保证管桩的顺利施工和桩基工程的质量。更多还原

【Abstract】 As high buildings’ popularizing, pile foundation’s construction must be improved. The promotion of construction asks for new pile equipments as well as for types and methods of pile. China has already set special pile machinery equipments as one of the key items during "ten-fives" period.Pretensioned spun high siieuglh coucrcic pile, a new generation of pile, has been used widely now. However, there are still many problems such as the dimension of the clamp system is not precision enough. There needs a new method to calculate the dimensions of pile for the stress in the pile is not well-distributed. The solution of the problem will supply the theory foundation for using PHC pile.After combining the working principle of the ZYB series hydraulic static pile-driver with the practical situation at the working site and studying the macroscopic force of the pile and microscopic strength of concrete, the author has designed a new set of clamps - adjusting clamps independently.This thesis has emphasized that the effective contact area between the pile and the clamp is not as the design dimension but restricted by the length of the clamp and the press force of the pile-driver. Also the stress’ distributing and size in the pile is related with the length of clamps. So, the length of clamps is set as the key dimension in the thesis. After analyzing both the distribution of stress and strength of the pile, with the knowledge of elastic mechanics, contact mechanics and material mechanics, the thesis has offered a new sei of algorithm to calculate the length of the clamps. "MATLAB software is used to search the appropriate length of the clamp for the complicated calculation.更多还原