Reliability Analysis Of Transverse Bent Structure On Overhead Vertical Wharf Located In Backwater Change Area Of Three Gorges Reservoir

Since the impoundment of the Three Gorges has been done, the structure of theoverhead vertical pier in the backwater change area of the reservoir has changed becauseof the complex hydrological conditions that the water depth is over30meters in thestorage period and the waterhead is over30meters and the flow velocity is3~5metresper second in the flood season. With the support of the second phase of the GuoYuanPartition of the Chong Qing port, this paper studies the stress state and the reliability inthe different load case combination type of the components which lies in the bent frameof the wharf. The research works are completed as follow:Firstly, the finite element model is created by the finite element software ANSYS.To get the most disadvantageous load case combination type and the combination valuein the next step, the mechanical response values of the components in the different loadcase are counted by the non-single load step solving.Secondly, the most disadvantageous load case combination value of the componentwhich lies in the primary bent frame is calculated by programming the ANSYS outputresults through the scientific calculation software MATLAB. And the correspondingcombination type is set as the calculation condition in the reliability analysis.Thirdly, the force calculation of the overhead vertical pier is usually completed bythe finite element analysis software. That causes the main difficulty that in the course ofreliability analysis the analytical expressions of the limit state equation is difficult tobuild. Therefore, the conventional algorithm of counting the reliability index (such as JCmethod) can’t be used directly. Considering of this, this study obtains the responsesurface function which can replace the limit state equation near the design check pointsaccording to the response surface method. The reliability index is calculated through theJC method which can be programming according to its iterative process.Fourthly, the Monte-Carlo sampling analysis based on the response surface methodis executed by the probability design system of ANSYS. So as to achieve the sensitivityof the random variables and its effect to the reliability of the structural components.