Research On Reliability Analysis Methods Of Composite Foundation With Long-short-pile

With the rapid developmente of society and economy, there are many new types of foundation have been put into design and construction, the composite foundation with long-short-pile is one of them, it si largely used in deep-thick soft soil areas. In this thesis, on the ground of the theoretical of composite foundation with long-short-pile, a theoretical framework for reliability analysis of it has been established.Firstly, the developing history and basic theory of composite foundation with long-short-pile are summarized in this pape. The research production of structures is introduced, included: research on reliability theory of structures engineering, research on reliability theory of geotechnical engineering, research on reliability theory of pile foundation engineering, and developing situation of reliability theory in abroad. The general theory and concept of reliability analysis is introduced. The methods will be used in this paper is also presented.Based on the above investigations, the JC method: which was usually used for reliability analysis of geotechnical engineering, was put forward in reliability analysis of bearing ability of composite foundation with long-short-pile. It included:1. The reliability analysis of ultimate bearing ability of adjacent soil in composite foundation with long-short-pile.2. The reliability analysis of ultimate bearing ability of single short-pile.3. The reliability analysis of ultimate bearing ability of composite foundation with short-pile.On the basis of above analysis, it is the new model and calculation method for ultimate bearing ability of composite foundation with long-short-pile that have been proposed.4. The reliability analysis of ultimate bearing ability of composite foundation with long-short-pile.Both of ultimate bearing ability calculation formulas have been analyzed with reliability theory. In all the reliability analysis mentioned above, sensing factors of bearing capacity reliability index have been studied in detail. It gives some useful conclusions for the practical engineering and design of the composite foundation with long-short-pile.In the finality, the problems requiring further studies are discussed.