【作者】 周旭；

【导师】 何清华；

【作者基本信息】 中南大学 ， 机械设计及理论， 2009， 博士

【摘要】 液压静力压桩机是利用高压油产生的强大静压力,平稳、安静地将预制桩快速压入地基的一种新型桩工机械。与其它桩工机械相比,液压静力压桩机具有无振动、无噪音、无污染、安全、快速、经济等特点,其使用日益广泛。为了便于对液压静力压桩机进行设计、改进和加快压桩进度,减少压桩过程中夹桩机构的应力、变形和静压预制桩的损伤,提高压桩质量,论文对液压静力压桩机压桩系统的夹桩机构及其夹桩箱体、液压系统进行了理论和试验研究。完成的主要工作如下：1、论述液压静力压桩机的结构、工作原理和特点,论述液压静力压桩机压桩系统国内外研究现状与存在的问题和发展趋势,阐述了课题研究的意义。2、分析了多点均压式夹桩机构的结构,就液压静力压桩机多点均压式夹桩机构和预制桩静态受力进行了分析和研究,推导出了多点均压式夹桩机构所能传递的最大压桩力的计算公式,对夹桩机构所能传递的压桩力随夹桩力的变化进行了理论研究。对夹桩力的选取方法进行了理论研究。得出的结论有利于多点均压式夹桩机构的设计和应用。3、利用ANSYS软件建立了液压静力压桩机夹桩机构的有限元模型,设置了模型中的主要参数,利用有限元系统内嵌的命令流式程序设计语言APDL编辑了夹桩机构命令流式程序,对夹桩机构进行了系列化有限元仿真分析,得出了夹桩机构和预制桩的等效应力云图、最大等效应力和最大合变形,并对仿真结果进行了分析和研究。得出了有利于夹桩机构设计和改进的结论。4、为了有利于夹桩箱体的设计和使用,利用ANSYS软件建立了液压静力压桩机夹桩箱体的有限元模型,设置了模型中的主要参数,利用APDL编辑了夹桩箱体命令流式程序,对压桩和拔桩时的夹桩箱体进行了系列化有限元仿真分析,得出了夹桩箱体的等效应力云图、最大等效应力、最大合变形,并对仿真结果进行了分析和研究。分析了拔桩时夹桩箱体的等效应力。5、对液压静力加力压桩的液压系统进行了分析,利用AMESim仿真平台建立了准恒功率液压静力加力压桩系统的动力学模型,设置了模型中的主要参数,并进行了动力学仿真。对仿真结果进行了分析和研究；得出的结论有利于液压系统的设计和改进。6、基于对夹桩机构及其夹桩箱体的有限元模型的实用性验证要求,以湖南山河智能机械股份有限公司的液压静力压桩实验机为平台进行试验研究,检验了模型的有效性和实用性。并通过实验对夹桩机构所能传递的压桩力随夹桩力的变化进行了分析研究。总之,通过对液压静力压桩机压桩系统的夹桩机构及其夹桩箱体、液压系统进行的理论和试验研究,论文为液压静力压桩机压桩系统的夹桩机构及其夹桩箱体、液压系统的设计和使用提供了一套理论与研究方法,对液压静力压桩机的设计与使用具有重要的理论和工程应用价值,极大地丰富和发展了液压静力压桩机的设计理论。更多还原

【Abstract】 Hydraulic static pile driver is a new machine with which pre-fabricated piles are hydraulically jacked-in accurately into the ground. This machine works calmly and placidly using strong static pressure produced by high pressure oil. Comparing with other pile machinery the major advantages of the machine include:no noise and vibration, no pollution, safety, speed, economy and so on. More and more hydraulic static pile drivers have being used. For being convenient for designing and improving on the machine and quickening the course of pile driving, cutting down the stress and displacement of pile clamping mechanism and the damage of pre-fabricated piles in the process of pile driving of hydraulic static pile divers, improving quality of pile driving, the theoretic researches and test evaluation have been carried through on hydraulic system, pile clamping mechanism and its pile clamping box of system of pile driving of hydraulic static pile driver. The main research works are as follows:1. The framework, working principle, characteristics of hydraulic static pile divers were discussed. The current researches, developing trends, and problems and issues of system of pile driving of hydraulic static pile divers at home and abroad are investigated and summarized. At the same time, the significance of this research is stressed and expounded.2. The structure of multipoint and iso-pressing pile clamping mechanism of hydraulic static pile drivers was analyzed. The static forces of multipoint and iso-pressing pile clamping mechanism and pre-fabricated pile were researched and analyzed; the equation of maximum transmission pile driving force of multipoint and iso-pressing pile holder mechanism of hydraulic static pile driver was obtained. The theoretic researches on maximum transmission pile driving force of pile clamping mechanisms vs pile clamping force have been carried through. The theoretic researches on the selection method of pile clamping force have been carried through. The educed conclusion is propitious to the design and use of multipoint and iso-pressing pile clamping mechanism. 3. The model of pile clamping mechanism of hydraulic static pile drivers was constituted in ANSYS; the main parameters of the model were set. The command streams were programmed with APDL standing for ANSYS Parametric Design Language. And then the serialization simulation analysises of pile clamping mechanism were achieved; the cloud diagrams of Von Mises stresses and the maximal Von Mises stresses and displacement vector sums of pile clamping mechanism and pre-fabricated pile were elicited. The simulation results were analyzed and researched. The educed conclusion is propitious to the design and amelioration of pile clamping mechanism.4. For being convenient for the design and use of pile clamping box, the model of pile clamping box of pile clamping mechanisms was constituted in ANSYS; the main parameters of the model were set. The command streams were programmed with APDL. And then the serialization simulation analysises on pile clamping box in the process of pile driving and pile pulling were achieved; the cloud diagrams of Mises stresses and the maximal Mises stresses and displacement vector sums of pile clamping box were elicited. The simulation results were analyzed and researched. The Mises stresses of pile clamping box under pile pulling were analyzed and researched.5. The hydraulic system of pile driving under adding force of hydraulic static pile divers was analyzed. The hydraulic system of pile driving under adding force was modeled in AMESim. The main parameters of the model of the hydraulic system were set; and then the dynamics simulations of the hydraulic system were achieved. The simulation results were analyzed and researched. The conclusions that are propitious to improvement and design of the hydraulic system were achieved.6. In order to verify the validity of finite element models of pile clamping mechanisms and pile clamping box, the experiments were conducted by means of employing the testing machine for hydraulic static pile drivers in Hunan Sunward Intelligent Machinery Co. Ltd,. The experimental results verify that the simulated models in this study were effective and practical. The experiments about maximum transmission pile driving force of pile clamping mechanisms vs pile clamping force were conducted by means of employing the testing machine for hydraulic static pile drivers.In a word, the design theories and experimental verification proposed in this dissertation are of both theoretical significance and practical value to design and use of hydraulic static pile drivers. At the same time, they also have enriched and developed the design theories of hydraulic static pile drivers.更多还原