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Fuzzy Probability Analysis On Pre-Stressed Concrete Tube Piles

Posted on:2007-03-23Degree:MasterType:Thesis
Country:ChinaCandidate:B T LaiFull Text:PDF
GTID:2132360182992543Subject:Geotechnical engineering
Abstract/Summary:PDF Full Text Request
Probabilistic models and fuzzy set models describe different aspects of uncertainty. Probabilistic models primarily describe random variability. In Geotechnical engineering system safety of pre-stressed concrete tube piles, ultimate bearing capacity of piles is variability with soil layers and parameters of soil layers, material properties, geometrical dimensions, and loads. In other hand, fuzzy set models of uncertainty primarily describe vagueness, such as vagueness in the definition of safety.Firstly, reviewing the codes we use nowadays to calculate the ultimate bearing capacity of pre-stressed tube pile, though relative simple and convenient, many flaws are included and the results calculated by the codes are so rough compared to the load test results. The major object of this paper is to analyze the influence impacting the ultimate bearing capacity by analyzing the data collected from experiments of high strain dynamic testing of piles. Another main object is to establish formulations, which discribe the ultimate bearing capacity of pre-stressed tube piles more accurate and accessible on practical conditions than the code used nowadays.Secondly, a typical practical project in which a large number of pre-stressed concrete tube piles were use as a main foundation is introduced in detail. Furthermore, specific data collected from the project is analyzed to deduce the reliability index and fuzzy reliability index which are used to calculate the partial index in an ultimate bearing capacity formulation. Furthermore, a set of partial index depended on the probability theory and a set of partial index depended on the fuzzy probability theory are successfully deduced. Therefore, two formulations based on the two new sets of partial index are established in this thesis.Finally, in order to evaluate the two new established formulations, three typical piles are chosen to justify them. The results is that the formulation established by the fuzzy probability is the most accessible to the result of the load test of the three, and the formulation established by the probability takes the second place, the three place isthe method recommended by the code.These two formulations referred above will enable the significance of calculating the ultimate bearing capacity of pre-stressed concrete tube piles, which will lead to economical merits and offer reference to the establishment of new codes.
Keywords/Search Tags:pre-stressed concrete tube pile, bearing capacity, reliability index, fuzzy reliability, comparation analysis
PDF Full Text Request
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