Joint Inverse Calculation of Pile Integrity Testing with Multi-Objective Genetic Algorithm

• Main Authors: Liang, Yu-Hsiang, 梁煜祥
• Other Authors: Tsai, Pei-Hsun
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/nvr8j4

碩士 === 朝陽科技大學 === 營建工程系 === 107 === ABSTRACT Some methods to analyze the pile integrity test have been developed. The results of analysis can only evaluate the length of the pile or the location of the defects. However, it is still impossible to accurately confirm the size or status of the defect of pile. If the signal from the defect pile integrity test can be further identified, the correct decision can be made as to whether the pile is retained or discarded. In order to further identify the signal of the defect pile in pile integrity test, this study used FLAC3D to perform the parametric analysis for a defect piles in the pile integrity test. The influence parameters discussed are the length and the defect-area-ratio of the defect of pile. The results obtained from the test are the acceleration history record and the acceleration spectrum diagram on the top of pile. The results show that when the defect length and the defect-area-ratio increases, the receive time of reflection waves from the pile bottom and the pile defect will be delayed. The resonant frequencies of the pile also decreases as the length and the defect-area-ratio of the defect of pile increases. In this study, a pile integrity test was performed in the campus of Chaoyang University of Technology, and the acceleration history record at pile top was obtained. Then, the multi-objective genetic algorithm was used to obtain the best eclectic solution of status of the defect pile. After six generations of back-calculation, the best eclectic solution obtained is close to the geometric dimensions of the defect pile on site.