Gravity Dam Reliability And Sensitivity Studies Based On The Finite Element Calculation

Gravity dam is one of the most common type of dam in china. The concrete gravity dam produces anti-slide force mainly by its own weight, one of the most common failure mode is sliding failure and the gravity dam sliding failure process is complicated. It will bear down hard and cause great harm and economic loss once the dam is instability. The safety and stability of gravity dam is an important content in the design of gravity dam, it is accounting for the anti-sliding stability analysis of gravity dam.The traditional safety coefficient method is an important method to calculate the anti-sliding stability calculation, but the design structure of the traditional safety coefficient method has its limitations and is not scientific. It reflects some of the same type of stress state under the safety degree of the structure. But to the same structure of different types or different stress state of the same section, even with the same safety factor, can't have the same degree of safety. The reason is that the factor of safety method ignores the various design variables and objective existence of uncertainty. The method of coefficient of safety is the uncertain value cover it with a general K. The application of reliability theory are inadequate structural design and verification can overcome the disadvantages of traditional methods. Reliability theory is that almost all the variables are random variables. It takes the structure safety and reliability to design or check the value of the structure, has good application prospects.Based on the gravity dam stability to carry out the reliability and reliability sensitivity analysis in this paper. Firstly introduces the basic theory of structural reliability, and set up limit equation of adapted to anti-sliding stability of gravity dams, along with get the calculation formula of sensitivity. Then, establish the finite element model of a typical cross section of a gravity dam of a hydropower station by using the finite element software. It was calculated under the three different conditions of dam displacement, reliability, the effective distribution of the stress and the equivalent stress of the gravity dam, the final evaluation of global safety degree. Then the main influence factors on the sensitivity of reliability of the sensitivity analysis, the influence of different factors on the effect evaluation of reliability. Finally, this paper summarized and prospected.