Numerical Simulation Of Stress Wave Reflection Method Analysis And Practice Of Research

Low strain dynamic test method is the most representative and popular way of pile integrity testing presently. It has been generally accepted for its virtues such as portability, celerity , economy and high veracity. However, this method is still one developing practical technique. It has not only a lot of problems remaining to solve in practical application, but also its own scope of application and limitation. Using in a large amount must bring misunderstanding and confusion, and unreasonable application must influence its science and accuracy, hinder its development normally.Firstly, the thesis introduces the development of dynamic testing method for foundation piles. It also introduces briefly some puality problems easily occurred in common pile types and spot measuring & testing techniques of low strain dynamic test method. Based on a kind of numeric analysis expert system of low strain dynamic test method named PIT-S, the dynamic response curves are simulated under the conditions of different kinds of numeric value models. The propagation characteristic of stress wave in perfect piles with the influence of pile material damping and the soil damping , in different kinds of defect piles and several liable misjudging situations are briefly simulated . Considering practical project situations , all kinds of situations are analyzed and summarized. Finally , totally summing up low strain dynamic test method from applied analysis , applicable scope , parameter of testing results, characteristics and influence of shaking source , fixation of sensor , synthesis applications of different kinds of test methods and its importance by example.The results of the paper are significant to make clear the influence of variable defects under actual situation and useful for reference to practical work of pile integrity testing.