Probability Of Single Strut Retaining Structure In Foundation Pit

In the foundation pit project, the traditional evaluating method is safety factor. It doesn't consider the variability of soil, regarding soil as a uniformity material with a certain "average nature" material. The method treats various kinds of design conditions, various kinds of indexes and parameters as fixed values, and the result from the method is defined, so it is easy to accept by people. But the very traditional method has neglected the uncertain parameters of the soil properties and others, which does not actually conform with reality.The reliability method is different from the method of traditional safety factor, which considers scattered parameters of soil and parametric dependence in soil. Uncertain factors actually existing have been considered by probability, so it objectively can reflect the real safety character of foundation pit.All work done is as follow:1.The JC method and the optimization method are used to calculate the reliability of anti-overturn of single strut retaining structure in foundation pit, analysing that ground load and other parameters' value and coefficient impact the reliability of anti-overturn and safety factor.2.Character of pile is analysed by bar system FEM, then analyses reliability of displacement and moment with Taylor stochastic finite element method and Monte-Carlo method. Taylor second-order series method analyses the reliability of pile's displacement and moment varying along with ground load and other parameters;Taylor first-order series and Taylor second-order series stochastic finite element method and Monte-Carlo method analyse reliability of the most unsafe place of pile about displacement and moment varying along with ground load and other parameters, which are compared with each other.3.Based on reliability of over-turn and displacement and moment of pile, the system reliability of retaining structure is analysed.4.According to the data of a real foundation pit, analyse reliability of-overturn and displacement and moment of pile, then analyse the system reliability by Ditlevsen narrow bound method. The results show that Taylor second-order series is not only brief but also accurate, so it can be widely applied in projects.