Reliability Analysis Of High Pile Mooring Pile Cap Based On Response Surface Method

High pile mooring pile cap is a common structure in the port project. With the development of harbor construction, more and more high pile mooring pile cap have been built. To insure high pile mooring pile cap can meet all the operational requirements during the design reference period, the reliability of high pile mooring pile cap should be guaranteed. In this thesis, a reliability simulation analysis has been done to the two high pile structures by response surface method. Combined with the powerful finite element software ANSYS's structural computing design system and its own Probabilistic Design System (PDS), and the numerical computing software Matlab.Usually, method of calculating the reliability contains First-Order Reliability Method, such as mean value method and the design point method (JC method), Monte Carlo method, response surface method, and so on. First-Order Reliability Method can solve the reliability problem only when the structure limit state function was given. Monte Carlo method can keep away from the difficulty of solving limit state function, but when the failure probability is less than 10-3, the number of loops will be too huge which means inefficiency. Choosing the sample points reasonably, fitting the response surface function to replace the real structure limit state function approximately, and combined the optimization toolbox of MATLAB software, response surface method can obtain a reliability index which can meet the engineering requirements by several times iterative computations.Because the Extreme value typeâ… probability distribution function, which is a common distribution function in the engineering, is not contained in the Probabilistic Design System of ANSYS, a new Equivalent normal method based on the principle of choosing the sample point in the ANSYS has been brought up to overcome this shortcoming in this thesis. The new method has been proofed to be feasible and accurate after comparison.Reliability analysis has been done to high-pile pier and high-pile slab-beam pier under static loads, with the new method proposed in this thesis. The reliability index, the coordinates of checking point and the response surface functions relevant to three failure modes were obtained. The sensitive factors of high pile mooring pile cap were obtained by the sensitivity analysis, which are significant to the design, construction and maintenance of the high pile mooring pile cap.