Reliability Analysis Of Three Dimensional Abutment Stability Against Sliding Of Arch Dam

The traditional construction of structure and verification of intensity is based on fixed value analysis, in another words, the geometrical size, physical performance and the load of structure are all fixed values. In fact, the factors are all have randomicity. The reliability theory of engineering structure is a method in which design of structure, verification of intensity and calculation of reliability index are all carried though with probability way. In the paper, based on random block theory, a mathematical model is developed for reliability analysis of 3-dimensional abutment stability against sliding. Calculative formulas of reliability analysis are given. Give an example, for a built arch dam, the paper worked out calculational programme based on the calculational model and calculate the reliability index of abutment with simple and double quadrature method. According to the instance of the arch dam built, take the discount quotiety , the verification flood water level , the frictional quotiety and , the agglomerate force and as stochastic variable quotiety, calculate the reliability index of the abutment with the calculational programme after the average value and variable quotiety is known. The results are coincident with the primary design, and the results are also verified the feasibility and practicability of the method.By contrast, the paper calculated the reliability index of the abutment after changing variable quotiety of the stochastic variable. Thereby drew a conclusion that variability of stochastic variable has remarkable effect on the reliability. And the different stochastic variable has different effect on the reliability while the variable quotiety increasing.The obtained results shown that the calculating method presented in the paper can be widely used in reliability analysis of abutment stability against sliding.