The Analysis Of Influence On Interference Factors To Pile Integrity Wave

Low Strain Reflection Wave Method is an effective way for pile integrity test at home and abroad, it welcomed in engineering filed for it has advantages of clear mechanism, simple testing method, reliable discrimination, lower cost and easy to survey for pile engineering. So there are far-reaching meanings to research on low strain reflected wave for pile integrate test, and we should do such research further more.Pile testing is an important job. There are many unforeseen factors, such as the smoothness of the pile head, the location of detector, the selection of exciting frequency and friction resistance around pile and so on, which all may influence the accuracy of testing. So, it requires us to analyze the condition thoroughly in order to avoid those disadvantageous factors in the course of the test. And we should try to seek the best testing method to get the most accurate assessment.Low strain reflection wave method is based on the theory of stress wave, the theory of stress wave is introduced in this paper. Diagnosing pile integrity is based on the theory of integrity and mainly because the change of impedance of pile, and we should notice the impedance of signal singularity during the process of diagnosing pile integrity, the basis of judgment introduced in this paper.The devolvement of low strain reflection wave method should combined with other disciplines, this has accredited by academic field, and many researchers devote to this research, for example combine the wavelet theory or neural network, so it can be more effective to analysis the test wave, and developed than before. The conception of wavelet theory is introduced in this paper.Engineering practices indicate that low strain reflection wave method still has some limitation. The detecting of level of defect is still qualitative, not quantitative. It mainly relies on the degree of the reflected signal from the deficient position or from the bottom of piles. If we want to assess the characteristic of the deficiency accurately, we must be familiar with many other conditions, especially the construction technique and the condition of stratum. There are some law which influence of the construction technique and the condition of stratum to the test wave. Summarize the rules will be helpful to diagnosing pile integrityThis paper make an analysis according to the test wave of pile which effected by factors of non-deficit. The factors of non-deficit include the condition of pile soil, the smoothness of the pile head, the location of detector, the selection of hammer, soil disturbance and pile group effect and so on, those influence mainly exist in reflection and transmission of stress wave. There mainly make an analysis for the influence with the condition of pile soil, the smoothness of the pile head and the location of detector in this paper. In addition, the feasibility of the method is verified with experimental and engineering data as well.