Research On System Of Pile Driving Of Hydraulic Static Pile Driver

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.