Abstract: Tension piles are widely used for resisting uplift loads of underground structures such as deep basement and underground transformer substation,and foundations for tall buildings subjected to high bending moments.According to the principle of the minimum potential energy,the deformation of single tension pile and pile groups was analyzed using a modified variational approach.Based on the conventional variational approach,a simple approach was presented so that the deformation of tension pile groups could be solved by calculating a 2×2 array.Compared with the results of model experiment,the present method could not only save a large amount of computing time but also give reasonable results.