| The non-destructive test of piles is a problem in the engineering field nowdays. Due to the particularity of pile structure and its working environment, the test on high-piled beam-slab wharf is more difficult than the test on single pile.Compared to the single pile structure, the high-pile wharf structure presents a clear a three-dimensional effect, which shows that shallow defects range are deeper and the deep defects reflects signal attenuation serious, leading to testing personnel is difficult to identify useful defect information among the receiving signals from the sensor. The adaptability of traditional detection methods is greatly reduced in the high-pile wharf pile testing. Consequently, finding an effective, comprehensive high-pile wharf detection method becomes an urgent problem of the engineering community.In this paper, based on the theory of dynamic test on pile, a suitable method has been found in the service of piled beam-slab wharf nondestructive testing. Through a comprehensive analysis, it can effectively identify defect signal with a certain depth, at the same time, the shallow defects can be effectively targeted, the specific research mainly divided into the following aspects:1. Analysis of the particularity of high-pile wharf structure and its working environment, combing with the basic principle of pile foundation inspection methods commonly used, focusing on sorting out the theoretical basis of the low strain reflected wave method, and to analyze the problems existing in the pile foundation inspection; and analysis of the various defects that may exist in high-pile wharf pile foundation as well as the time domain signal characteristics of different types of defects speed.2. Understanding the basic principle of the law of inverse filtering method in the seismic data processing, Careful comparison of the similarity artificial seismic exploration and pile testing in principles and operation, using the inverse filtering method to make the appropriate improvement in the pile testing and using the single pile structure to confirm its feasibility. Respectively established the high pile wharf complete pile and all kinds of defects of pile defect models in different depth. Respectively, using three ways for the detection: hammering on the pile and receive signal on the pile, hammering on the panel and receive signal on the pile,hammering on the panel and receive signal on the panel, using the inverse filtering method to measure pile signal analysis and processing, it can effectively enlarge the defect signal jamming to some extent signal. At the same time, pointing out the inadequacies of inverse filtering method on the adaptation and specify the next direction for improvement.3. Comparative analysis of the distinction of detection signal between single pile foundation and high-pile wharf when pile foundation exists shallow defects. Attempting to explore the applicability of the conventional shallow defect detection method in high-pile wharf pile foundation, finding that high-pile wharf pile foundation shallow defects affect a broader range and a more difficult detection, longitudinal wave was proved to be difficult to identify the defect signal. Deep study of the theoretical basis for torsional wave propagation, and speculated its role in the shallow defect detection theoretically. Selected appropriate vibration mode and applied torsional wave in the positioning of high pile the pier pile foundation shallow defects, compared to the longitudinal wave detection, it is concluded that torsional wave of advantages and disadvantages, as well as high-pile wharf pile testing applicability.4. According to the different scope of application for the detection of longitudinal wave and torsional wave detection, comprehensive using of the processing of inverse filtering and torsional wave detection technology, effectively locate the defection of high-pile wharf at different depths, try to take advantage of the S-wave detection technology to full range of positioning defects of high-pile wharf at different depths. |
