Study Of Vibratory Hammer’s Driveability Based On The Hysteretic Nonlinear Resistance

Vibratory pile hammer is a new type of environmental-friendly pile machine which depends on eccentric block rotation to generate exciting force and force the soil to vibrate so that the soil can be destroyed to realize easy pile sinking. At present, vibratory pile driving technique is focused on the development and testing of the pile hammer on equipment in the mechanical engineering field all over China. The mechanism of vibratory pile, especially in the analysis of vibro_driveability lacking of research.To solve the problem above, this paper has done the following work:(1) Based on the model of Ramberg-Osgood,hysteretic nonlinear model was established of vibro_driveability in sand. Analyzed the exciting force and pile resistance in detail and get the pile penetration criterion.(2) Comprehensively analyzed the parameters of equipment, pile and subsoil effecting on the vibro_driveability. Studied the rule of tip resistance, pile side resistance, displacement and velocity, power and torque changed with geological parameter during the pile driving process.(3) Applied the vibro_driveability model of hysteresis nonlinear. Studied the "bring to an end" criterion in vibratory piling process. Proposed the program of using the average speed of the last two minutes of hammer as the "bring to an end" criterion. Deduced the calculation formula of the average speed of the last two minutes of hammer.(4) Experimental research has carried to test pile’s penetration speed on ZZY40A type hydraulic vibration hammer. The experiment verified the rationality of the theoretical research.The study has great practical value on the fields of predicting vibratory hammer’s resistance and penetration speed, influencing factors of vibro_driveability, and choosing reasonable parameters to improve the efficiency of piling etc. It provides useful reference of the application of vibratory pile hammer in pile foundation engineering.