The Studies Of Damage Detection For Pile Based On Genetic Algorithm

With the development of construction industry, pile foundation has become one of the most important foundation forms. But some kind of detects such as gapping, broaching, break, separation were usually found in bored cast-in-place pile, which maybe reduces bearing value of pile and does harm to the superstructure. Furthermore, these detects can lead to ruin of a building .Some measurements can be taken to strengthen defective piles after accurately judging defect's type, location and degree. Otherwise it must threaten the safety of building and human beings'life. Thereafter, test for integrity of pile foundation is a problem, which engineers pays close attention to. This paper emphasized on quantitative study of defect's degree and Genetic Algorithm is introduced into this paper to fitting the measurement waveform, and by the fitting get the defective degree.At first, the one dimension longitudinal vibration pile mode was established. The influences of the top response of pile with same soils and different defection were considered into the model. The numerical technique was used for the solution of the model and a calculation program of this question was designed.Second, model piles were tested by the reflecting wave numerical method on low strain and its results were analyzed. The top response of the model pile was calculated by using the model and the correctness of the model was verified by reference of the measurement waveform. The influences on the waveform generated by the parameters of pile lateral soil and pile toe soil, and frequency of strike, and the defections of the pile were discussed.Last, calculation waveform and measurement waveform of the model piles were fitted by Genetic Algorithm, and the defective degree was obtained.