Theory And Application Of Foundation Pile Quality Testing Based On Low Strain Reflected Wave Testing Method

This paper is mainly about the pile foundation in architectural engineering industry.In recent years,China's architectural engineering industry has been developing vigorously with different architectural foundation forms.Pile foundation is one of the traditional architectural forms.It is widely applied in engineering practice.As a concealed work,it is influenced by defects like concrete pile neck,segregation and hole enlargement,so the bearing capacity of pile foundation is greatly lessened,which affects the upper structure safety of buildings.So,it has been a focus and target subject for universities and the construction industry to judge and control the quality of pile foundation simply,accurately and effectively,maximizing the possibility of accident,at present this technology has become the focus of the construction industry.The stress wave theory is the important basic theory in the pile foundation testing with the low strain reflected method.The integrity of the pile foundation is closely related to the morphology of the reflected wave.The integrity theory is the basic in the judgment of defects of the pile foundation.With the changes of abnormal points in reflected wave,the types and levels of defects is accurately judged.Such testing technique is closely connected with other subjects.With the application theory and neural network calculation method,the original waveform can be effectively filtered,thus getting the clear and accurate testing wave.On the basis of his practical work in a project,the author theoretically analyses the stress wave theory in the pile testing with the low strain reflected wave method.With the help of the present situation and development of testing technique home and abroad,the author introduces the frequently-used testing technique and selecting method.The author also analyses theoretical basis of the low strain reflected wave theory.Based on the stress wave theory and his practical work,the author does an analysis to the testing defects and has concluded the theoretical waves to different defected piles.What's more,the author makes an effective contrast among frequently-used methods.The author does a testing to the pile foundation of a bridge in a project with the wavelet filtering and high-pass filtering methods and theoretically concludes the procedures and methods of the pile foundation testing.In the end,the author analyses the existing problems in current pile foundation testing and proposes constructive suggestions.