Variational Analysis Of Lateral Or Vertically Loaded Barrette Group

Recently, barrettes have been used widely all over the world. A lot of researches carried out on their vertically-loaded behaviour, especially in influence of their non-axisymmetrical cross-section on it. But all these methods are implicit methods, which needs a lot of computing time. So in order to improve the understanding the vertically-loaded or lateral-loaded behaviour of barrette behaviour further, preliminary researches on barrettes are carried out in this paper. This method is variational method, which will be much faster and more efficiency than other method.Firstly we use gauss integral method to disperse the least potential energy of barrette pile group, with the help of vertical settlement finite series and Mindlin's equation, we derived vertical load-settlement solution of barrette pile group. This method is a approximate three-dimensional method and also can consider its non-axisymmetrical cross-section. With the aid of the solution, the barrette behaviour is analyzed preliminarily. At the same time, the program corresponding to the proposed method is compiled in FORTRAN90, which is used to analyze the influence of several factors on the behaviour of barrettes, including ratio of length to width, ratio of depth to equivalent diameter, ratio of modulus of pile to soil, Poisson's ratio, pile soacing etc. Many useful conclusions are obtained from the above analyse. In addition, some comparisons have been made between variational method and elastic theory method in this paper, proved the former to be a faster and efficiency method.Then we use the same method to derived lateral load-settlement solution of barrette pile group. With the aid of the solution we study the influence on lateral loaded barrette pile group and characteristic of lateral loaded barrette pile group.In order to study the behaviour of barrette pile group interaction and barrette pile group-soil-cap interaction, the proposed approximate three dimensional method of vertical and lateral loaded is extended in this paper. Variational method are used to analyze the influence of several factors on behaviour of barrette pile group and barrette pile group-soil-cap interaction, including collocation of pile, ratio of length to width, pile spacing, ratio of depth to equivalent diameter, ratio of modulus of pile to soil, Poisson's ratio, the finite layer, the number of piles etc.Lastly we made a comparison between variational method and finite element method on the lateral loaded behaviour of barrette pile group, and also proved variational method is a feasible and efficiency method.