نوع مقاله : پژوهشی
نویسندگان
دانشکده مهندسی عمران - دانشگاه تهران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Among advanced methods which determine pile bearing capacity, a relatively new method of dynamic pile testing is employed in practice by the use of Pile Driving Analyzer (PDA). To find the bearing capacity of a pile by PDA, the fitting of the calculated force-time signals with measured ones is undertaken, based on the selection of soil resistance parameters and resistance elements, using CAPWAP software. This is an empirical procedure. Considering the iterative nature of the procedure, a variety of soil parameters and a different number of soil segments can be used to fit the calculated force-time signals with the measured ones. Therefore, CAPWAP may come up with the same curve fitting result, referred to as the same match quality parameter, with different bearing capacities in different analyses. In the presented paper, the level of variation in the soil parameters and their effects on the overall bearing capacity of a pile, have been studied, when the same match quality number is derived. Further to the above mentioned analysis, a statistical reliability analysis has been carried out, considering pile bearing capacities derived from both conventional static formulas and pile dynamic testing results. The undertaken statistical reliability analysis is based on the "Load and Resistance Factor Design'' (LRFD) method using two approaches: 1. The determination of reliability index utilizing PDA test results, which lead to the evaluation of the probability of failure for the design, according to a specific conventional static formula, 2. The calibration of resistance factors in static pile capacity analyses with an LRFD method, utilizing PDA test results, considering a target reliability index.The paper concludes the reliability of PDA as a testing procedure to determine the bearing capacity of piles. It also presents a reliability analysis, which could be used to evaluate a specific conventional static formula by the use of dynamic testing results, based on the LRFD method.
کلیدواژهها [English]
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